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INTERNATIONAL ISLAMIC UNIVERSITY MALAYSIA

KULLIYYAH OF DENTISTRY

PHASE 1 YEAR 1 Operative Dentistry 2007/2008 Session

Prepared by Dr.Shawfekar

(BDS,Bed, MSc, MDSc) Lecturer

Kulliyyah of Dentistry

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Contents DEMONSTRATION/SEMINAR and PRACTICAL SESSIONS: 20 hours Students are divided into 4 groups.

1. The function of a dental unit. 6 • The Dental Chair 6 • Dental Stools 8 • Dental Unit 10 • Operating Light 15 • Cabinetry 16 • Sink 16 • Dental X-Ray Unit 16 • Small equipment 17 • Dental Air Compressor 19

2. Classification of cavity preparation and the various filling materials available. 19

• Classification of carious lesions 19 • Cavity design 20 • GV Black’s Classification 20 • Abbreviation for simples, compound and complex cavities 21 • Available of various filling materials 24

3. Charting: Ministry of Health “Kad Rawatan Pesakit”( Patient treatment card), Palmer’s notation, International notation, history taking etc. 29

• Dental Charting 30 • Numbering System 30 • History Taking 35 • Present Complaint 36

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• The Dental History 36 • Medical History 38

4. Measuring of vital signs: pulse, respiratory rate, blood

pressure and cardio-pulmonary resuscitation. 39

• Introduction 40 • Vital Signs 40 • Body Temperature 40 • Taking Oral Temperature 42 • Taking Pulse 43 • Respiration 47 • Blood Pressure 48

5. Instrumentation for Operative Dentistry such as burs (stainless steel, tungsten carbide and diamond) for high speed and low speed), various other instrument such as mouth mirror, dental probe, polishing disc etc. 55

• Introduction 56 • Hand Instruments 56 • Hand instrument design 56 • Instrument griping 63 • Rotary Instruments. 65 • High-speed handpiece 65 • Low-speed handpiece 66 • Burs and stones 69

6. Practicing of prophylaxis and four handed assisting and polishing of amalgam restoration. 73

• Basic tenets of four-handed dentistry 73 • Work simplification 75 • Principles of motion economy 77 • Zones of activity 81 • Treatment room design 84 • Ergonomic practice facts 89

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• Equipment selection 90 • Seating the patient and operating team 91 • Instrument transfer and grasps 94 • Small items 104 • Oral evacuation 107 • Restoration of amalgam and polishing 109

7. Pulp Protection: theory and practical. 114

• Introduction 114 • Cavity preparation / pulp protection theory 114 • Treatment of the ideal cavity preparation 115 • Treatment of the beyond-ideal cavity preparation 116 • Treatment of the near-exposure cavity preparation 116 • Treatment of the exposed-pulp cavity preparation 116 • Cavity liners 116 • Cavity varnish 117 • Cement base lining 118

8. Impression taking on manikin and casting of impression as a laboratory work. 119

• Objectives 119 • Learning outline 119 • Introduction 120 • Hydrocolloid impression materials 120 • Tray used for alginate impression 123 • Taking alginate impression for diagnostic casts ( Study model ) 124 • Disinfecting the impression 129 • Accuracy of an alginate impression 129 • Wax bite registration 129 • Elastomeric impression materials 133 • Equipment and supplies for polysulfide impression 133 • Gypsum materials 138 • Dental wax 151 • Custom tray 153

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• Constructing the custom tray 153 • Types of temporary restoration 160 • Custom temporary restoration 163 • Cementing the temporary restoration 167

9. Isolation of the working field: placement of rubber dam. 168

• Objectives 168 • Learning outline 168 • Introduction 168 • The procedure of mouth rinsing 168 • The oral evacuation method 169 • The isolation technique 173 • The placement of rubber dam 176

ASSIGNMENT AS A GROUP PROJECT (STUDENT DIRECTED LEARNING) 184 Topics are related to the above demonstration. This will be followed by a 30 minutes presentation by the groups in the 5th and 10th week.

1. Tooth filling materials 2. Causes and the treatment of shock 3. Types of rotary instruments 4. Types of impression materials in dentistry.

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Function of dental unit Objectives:

1. To identify the special need of dental equipments. 2. To define and demonstrate how to maintain the oral cavity and the equipment utilized in

treatment of the oral cavity.

Outline: 1. The Dental Chair 2. Dental Stools 3. Dental Unit 4. Operating Light 5. Cabinetry 6. Sink 7. Dental X-Ray Unit 8. Small equipment 9. Dental Air Compressor

Dental Chairs The dental is the centre of all clinical activity (Fig-1.1A,B, C, D). The chair is designed for the operator and the assistant to work on the patient in the comfortable and efficient manner. The dental chair supports the patient’s entire body, in either an upright, supine position (nose and knees on the same plane) or sub supine position (the head lower than the feet). The dental chair is designed to accommodate both children and adults. It is also control to move the chair up and dawn, recline the back rest, and raise the seat and a combination button that automatically recline and raise the patient. The controls are either side o of the chair back or on the floor.

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Fig-1.1A. 2 Operatories.

Fig-1.1B. Dental Chair with foot controls for adjusting chair.

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Fig-1.1C. Dental chair with side controls for adjusting the chair.

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Fig-1.1D. Dental chair with foot control. Dental Stools The dental stools are required by the operator and the assistant during most procedures. Ergonomic studies have resulted in the improved design dental stools to provide comfort and prevent fatigue during dental procedures. The operator’s and assistant’s stools have some similarities but also have several differences (Fig-1.2A, Fig-1.2B) A. Operator’s Stool

The operator’s stool has the following characteristics: • Adjustable height • Adjustable back rest • Comfortable seat • Mobility • Broad base

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Figure-1.2A Dental Operator’s Stool with back support. B. Dental Assistant’ stool The dental assistant’s stool has the following characteristics.

• Adjustable height • Adjustable back rest • Comfortable seat • Mobility • Broad base • Foot rest • Easy to adjust

Fig-1.2B, Assistant’s stool with front arm support.

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Dental Unit

Fig-1.3A. 2 Operatories. Fig-1.3B The Dental Unit including handpieces, saliva ejector, and HVE

The dental unit (Fig-1.3A, Fig-1.3B) consists of handpieces, an air-water syringe, a saliva ejector, an oral evacuator (HIVE), ultrasonic scaling unit and numerous other options. The dental unit may be fixed to the wall, the cabinets, or on mobile charts. The unit is position according to the preference of the dentist, whether dentist is left-handed or right-handed, if he or she routinely works within assistant, and according to the design of the treatment room. The dental unit is available in three basic modes of delivery (Fig-1.4A, Fig-1.4B, Fig-1.4C).

1. The rear delivery system is designed with the equipment located behind the patient’s head.

2. The side delivery system is designed with the equipment located on the dentist’s side. The unit is mounted to a moveable arm or a mobile cart.

3. The front delivery system is designed so that is can be pulled over the patient’s chest and is located between the dentist and the assistant.

Fig-1.4A Rear delivery system.

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Fig-1.4B Side delivery system. Fig-1.4C Front delivery system.

Mobile carts: Sometimes, mobile carts (Fih-1.5A, Fig-1.5B) are used to hold delivery systems, including the air-water syringe, oral evacuator, handpieces, and saliva ejector. One cart may be used by both the operator and the dental assistant with the instrumentation on the appropriate side. Two charts, one on each side of the dental chair, may be equipped and used. The operator’s cart is usually set up for two or three dental handpieces plus an air-water syringe. The assistant’s charts is usually set up with the air-water syringe, saliva ejector, and HVE. Carts are designed to be moved easily, provide a work space and some storage, and hold basic instruments.

Fig-5A. Operator’s chart with dental handpiece and air-water syringe.

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Fig-1.5B. Assistant’s chart with saliva ejector, HVE, air-water syringe Air-Water syringe: The air water syringe (Fig-1.6A, Fig-1.6B) provides air, water, or a combination spray of air and water. The tip of the syringe is removable and made of either disposable plastic or autoclavable metal. New barriers are placed on the syringe handle and the tubing for each patient. The controls for the syringe are on the handle and should be easy to operate with the thumb of one hand. Air, water, and the combination spray help keep the oral cavity clean and dry and protect tooth from the heat produced by the handpiece. For easier use, the syringe tips come in several lengths and are slightly angled. To reduce the risk of retaining oral fluid, flush the air-water syringe with water between patients at beginning and end of the day.

Fig-1.6A Air-water syringe. (A) handle, (B) air-water control, (C) removable and disposable tip.

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Fig-1.6B Air-water syringe.

Dental handpieces: There are usually two dental handpiece; low and high speed. The handpieces are attached to hoses that are part of the dental unit. It is important that these hoses are not bent or tangled. Each handpiece has two controls. First, the hose attachment has on/off switch to prevent more than one handpiece from running at once. Second, the speed of handpiece is controlled by a foot pedal called a rheostat. The dental handpieces are removed after each patient’s treatment and are sterilized. at the beginning and end of the day, the handpiece should be run for several minutes. Between patients, run the handpiece for at least one minute to flush the system (Fig-1.7A, 7B, 7C, 7D, 7E).

Fig-1.7A.Dental unit. (a) Dental handpieces, (b) Saliva ejector, (c) HVE.

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Fig-1.7B Contra-angle low Fig-1.7C Straight handpieces. speed handpieces.

Fig-1.7D High speed handpieces Fig-1.7E High speed with diamond burs. contra-angle handpieces Ultrasonic Scalar: The ultrasonic scalar is attached to the dental unit. The scalar is used during prophylaxis and periodontal procedures. Small tips attach to the ultrasonic scalar. The scalar has a vibrating action that remove hard deposits, such as calculus, and other debris from the teeth (Fig-1.8).

Fig-1.8 Ultrasonic scalar with polishing brushes.

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Saliva Ejector: The saliva ejector is used to remove saliva and fluid from the patient’s mouth slowly. It has a low volume suction that is used during certain procedures, such as fluoride treatments and under rubber dams. The saliva ejector tip is a thin, flexible, plastic tube that is disposable of after each patient’s treatment. This plastic tip slides into the opening of the saliva ejector hose that part of the dental unit. There is a small trap located in the saliva ejector that needs to be cleaned routinely (Fig-1.9 A, 1.9B).

Fig-1.9A Disposable saliva ejectors. Fig-1.9B Saliva ejectors. High Volume Evacuation (HVE): The high volume evacuation (HVE) is also called the oral evacuator. It is used by the assistant to remove fluids from the patient’s mouth. Evacuation tips are wider tubes that are often bevelled at both ends. Some of the tips are metal and can be sterilized, but most offices use plastic tips that can be sterilized or disposed of. The evacuation tips fit into the handle of the hose, which is covered with a protective barrier during procedures. The on/off control for the HVE is on the handle. Each unit has a trap that collects debris from the evacuator. This trap must be changed or cleaned weekly or as needed. There are cleaning systems available to flush the HVE at the end of the day and week. Operating Light The operating light is attached to the dental chair or mounted to the ceiling. Both the operator and the assistant should be able to adjust the position of the light. Operating lights have improved in many ways. They are easier to move, more flexible, and direct less heat on the patient. The light has a control switch for high and low intensities, an on/off switch, and handles on both sides. The light is attached to extension arms for positioning over the patient’s face in order to view either the maxillary or mandibular arch. The handles and on/off switch are covered with barriers during procedures. The barriers are changed between each patient. Maintenance includes changing the light bulb occasionally and keeping the heat shield clean. It is important to follow the manufacturer’s instructions for both of these procedures (Fig-1.10).

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Fig-1.10 Operating light Cabinetry Most treatment rooms have some type of cabinetry for storage of supplies and materials used during treatment. Some dental units are designed in fixed cabinets that surround the patient, operator, and assistant. These units include cupboards that open from the front and the back for treatment trays, drawers for materials frequently used, and sinks for both the operator and the assistant. The amount of cabinetry depends on the size of the room and the dentist’s preference. Mobile cabinets are also used in the treatment room. These cabinets come in a variety of designs and are used for storage and as work space. The mobile cabinet is stored against the wall and then pulled into position after the patient is seated. Sink The treatment room should be designed with sinks in convenient locations for the dentist and the assistants. Some treatment rooms have to sinks, one on each side of the dental chair. Other treatment rooms have one sink that is located centrally behind the dental unit for both the dentist and assistant to use. The water controls on the sink should be operated by wrist, foot, or knee control. There are light and motion sensor devices that turn the water on and off automatically when standing in front of the sink the sinks should be easy to clean and have an area nearby for soap and towel dispensers. Dental X-Ray Unit A dental x-ray unit used to expose intraoral radiograph is part of most treatment rooms. Sometimes the x-ray tube head is housed between two rooms with doors on both sides for x-ray tube head to slight out into either room. The controls are found out side the room, so that the dental assistant is not exposed to radiation. The panoramic machine for exposing extra oral radiograph is usually located in a separate area out side the treatment room.

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Small equipment There may be variety of equipments in the treatment room depending on the primary use of the room. Most rooms have an x-ray view box, curing light, amalgamator, communication system, computerized intra oral dental camera, and satellite computer. X-ray View box: The x-ray view box is used to read and diagnosed radiograph. It consists of bright light source covered with a frosted surface. X-rays are placed on the frosted surface for clear viewing (Fig-11).

Fig-1.11 X-ray view box Dental Curing Light: A dental curing light is used to “cure” or “set” light-cured materials. Many dental products are light cured. The curing light has a small motor that produces the high intensity light, a wand, a protective shield, a handle, and trigger to turn the light on and off. The curing light used halogen bulbs. Follow the manufacture’s instructions when changing the bulb (Fig-1.12A, B, C, D, and E).

Fig-1.12A Light Cure unit. Fig-1.12B Light cure unit.

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Fig-1.12C Light cure unit. Fig-1.12C Light Cure set.

Fig-1.12D Dental curing light. Fig-1.12E Laser curing light. Amalgamator: The amalgamator is a small machine that mixes dental amalgam and some dental cement. It is placed near the assistant either on the counter or in a drawer (Fig-1.13A, 13B).

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Fig-13A. Amalgamator. Fig-13B. Amalgamator Dental Air Compressor and Central Vacuum System The air compressor provides compressed air for the handpiece and air for the air-water syringe. The size of air compressor depends on the number of dental units utilized by the office. Usually, the compressor is stored away from the main office because of it size and noise level. The dental vacuum system provides suction for saliva ejector and oral evacuators at each dental unit. The filters or traps must be cleaned regularly to keep this system working to capacity. This system is also stored away from the main office. Dental office staffs and dental service companies must follow the manufacturer’s instructions for maintenance and repairs on the air compressor and the vacuum system. Both units may be set up on time clocks to run only when the office is open and operating.

2. Classification of cavity preparation and the various filling materials available. Classification of cavity preparation: Objective: : To understand the principles of the cavity design To define G.V. Black’S six classification of cavity preparation

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Out Line: : Able to determine the cavity classification Able to prepare the cavity Abbreviation of tooth surface

Classification of carious lesions Class I. Caries affecting pit and fissures. Class II. Caries affecting the approximal surfaces of posterior teeth. Class III. Caries affecting the approximal surfaces of anterior teeth Class IV. Caries affecting the approximal surfaces of anterior teeth and involving the

incisal angle. Class V. Caries affecting the cervical surfaces

Cavity Design The general principles of cavity design are related to the following.

The structure and the properties of the dental tissues The disease (e.g. caries, pathological tooth wear, periodontal disease) The properties of restorative materials.

G.V Black developed five standard cavity classification and sixth class was added later. Class I: :Class I caries are developmental cavities in the pit and fissure of teeth

(following Figure-2.1) They are located in: : The occlusal surface of the posterior teeth (premolar and molar) The buccal or lingual pit of molar The lingual pit near the cingulum of the maxillary incisors. Class I cavity (Fig-2.1) up to down, Occlusal surface of Premolar and molar, Buccal

surface of Molar, Lingual surface of Maxillary incisors.

Fig-2.1 Class I cavity on the surface of the tooth.

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Abbreviations for simple, compound, and complex cavities: MOD: :Mesio-occlusal-distal DO: :Disto-occlsal MO: :Mesio-occlusal MI: :Mesio-incisal DI: :Disto-incisal LI: :Linguo-incisal DL: :Disto-lingual MODBL: :Mesio-occluso-disto-bucco-lingual I=incisal, M=Mesial, D=Distal, B=Baccal, O=Occlusal

Class II Cavity: Class II caries are on the proximal (mesial or distal ) surface of the posterior teeth

(permolars and molars) The following figure-2.2 shown on the proximal surfaces of (A) premolar and molar,

(B) placed prior to an MO or MOD restoration on the surface of premolar and molar The bottom part of the following figure-2.2 is Class III cavity

Fig-2.2 Class II and III cavities on proximal surfaces of the tooth.

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Class III cavity: Class III caries are on the interproximal surface (mesial or distal) of the anterior teeth

(canines, lateral incisors and central incisors. The lowerst part of above figure-2.2 shown the class III cavity (M and D on the

interproximal surface of central incisor and lateral incisor. Class IV Cavity: Class IV caries are on the interproximal surface (mesial or distal) of anterior teeth

include the incisal edge. This figure-2.3 shown that, Class IV cavity.

Fig-2.3 Class IV cavity on surface of anterior tooth.

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Class V cavity: Class V: Caries affecting on the cervical surfaces. This figure-2.4 shown, as class V cavity.

Fig-2.4 Class V cavities on lingual/buccal surface of the teeth. Root surface caries: As gingival recession

Fig-2.5 Root surface cavity on the buccal/lingual surface of the teeth. Principles of tooth preparation Why restore? To restore function. To prevent further spread of an active lesion which is not amenable to preventive

measures. To prevent pulp vitality. To restore aesthetics.

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General principles of tooth preparation: Gain access to caries. Remove all caries. Cut away all significantly unsupported enamel. Extended margins so that they are accessible for instrumentation and cleaning. Shape preparation so that remaining tooth tissue and restorative material will be able

to withstand functional forces. Shape preparation so that restoration will be retained, i.e. undercut for amalgam, none

required for resin composite or bonded amalgams. Check preparation margins are appropriate for restorative materials. Small areas of

unsupported enamel may be left if a resin composite restoration is being placed Remove remaining caries unless indirect pulp cap to be carried out. Wash and dry preparation.

Helpful Hints: While care must be exercised not to over cut a preparation, do not skimp on access so

that the caries removal is compromised by poor visibility. Mark centric stop with articulating paper prior to tooth preparation and dry to

preserve if possible, or place the preparation margins past the occlusal contact areas. Avoid crossing marginal ridges. In removing caries, a tactile appreciation of the hardness of dentine is important, so

use slow-speed instruments or excavators. The base of the preparation should not be flattened as this runs the risk of pulp

exposure. Unless caries dictates, margins should be supragingival. All internal line angles should be rounded to internal stresses. Removing caries with a

large diameter round bur automatically produces the desired shape. In a proximal box, the margin should extend below the contact point. Available of various filling materials Amalgam Resin composite Glass ionomer Gold Glass ionomer cement Compomer Giomers Cements

Amalgam materials and instruments. Alloys for dental amalgam consist principally of silver and tin, with smaller amount of copper, often zinc, and sometimes mercury or other metals, which may alter substantially the physical properties of the material and require different manipulative techniques. When mixed in a manner to wet the surfaces of the alloy particles with mercury, a plastic mass is

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formed that can be condensed into a prepared cavity to form a dental restoration. Dental amalgam is used in all classes of restoration, class I through V, with very limited use for classes III and IV, in both the primary and permanent dentitions. It is also used to build a core, usually in conjunction with some form of pin retention, upon which preparation for a gold casting is made. In endodontics, amalgam is used as a retrograde filling material for the apical end of a treated tooth. The ratio of alloy / mercury are 1/1 or 1/ 1.2, and so forth. The setting characteristics of various dental amalgams are regular set, fast set, and low set are available.

Fig-2.6 Amalgam filling materials and instruments. Resin Composite: The modern resin composite is a mixture of resin and particulate filler, the handling

characteristics of which are determined largely by the size of the particles and method of cure.

Most composites are of the hybrid type. There are two types of composites, (1) Chemically cured (self-cure), and (2) Light

cured.

Fig-2.7 Composite self-cure and light cured materials.

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Class Ionomer: Type I:: luting cements for crowns, bridges, and orthodontic bands. Type II:: restorative cement used as a fissure sealant, for the restoration of deciduous

teeth, for repairing defective restoration. Type III: fast-setting lining materials. Defer placement of amalgam for at least 15 min

and composite for 4 min. Type IV: light cure and dual cure GI.Light-cured, which have higher bond strengths

than self-cure GI. Gold: Relies on minimally divergent walls and cement lute for retention. Give good marginal fit to restoration and to allow burnishing. Melting point <950 degree centigrade.

Class Ionomer Cement (GIC): These are similar to GI, except that the ion-leachable glass is fused with fine silver

power. Mixing with polymeric acid gives, cement consisting of unreacted glass particles to with silver is fused, held together by a metal-salt matrix.

Used for Low –stress bearing restorations, restoration of deciduous teeth.

Fig-2.8 Class Ionomer Cement material.

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Resin Modified Class Ionomer Cement Compomer: Recently introduced hybrid material. It combines the adhesive and

fluoride-releasing properties of GI with the abrasion resistance of resin composite. It was composed of a single hydrophobic resin filled with acid-leachable glass particles.

Giomers: Materials with active filler particles, fully reacted GI filler particles. Cements: Used for a variety of purposes, including temporary dressings, preparation liners, and

as luting agents. With the exception of calcium hydroxide, the materials available are based on combinations of powder and liquid.

Setting occurs by an acid-base reaction. The set cement comprises core of unreacted powder in a matrix of reaction products.

Various Type of Cements: Zinc oxide eugenol (ZOE) Zinc phosphate Zinc polycarboxylate Calcium hydroxide GI cements

Fig-2.9 Dycal lining cement materials.

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Fig-2.10 Temporary dressing, Zinc oxide Euginol Cement. Choice of Cement: Temporary cement: :ZOE, GI Luting cement: :Zincphosphate,GI,polycarboxylate Lining cement: :calcium hydroxide Amalgam cement: :direct or indirect pulp capping Resin composite: :dircet or indirect pulp capping Pulp capping: : hard-setting calcium hydroxide Sedative dressing: :ZOE & / or calcium hydroxide Bacteriostatic dressing: : calcium hydroxide plus GI

Reference: Mictchell DA, Mitchell L, 2005 Oxford handbook of clinical dentistry, 4th. Edn,

Oxford university press. Kidd EAM, Smith BGN,and Watson TF, 2006 Pickard’s Manual of Operative

Dentistry, 8th.edn,Oxford. Robinson DS, and Bird DL, 2007 Essentials of Dental Assisting, 4th.edn, Saunders. Phinney DJ and Halstead, 2000 Delmar’s Dental Assisting, Delmar Thomson

Learning. Denttist’s Desk Reference: Materials: Instruments and Equipment 1981, First

Edition, American Dental Association.

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3. Charting: Ministry of Health “Kad Rawatan Pesakit”, Palmer’s notation, International notation, history taking etc.

INTRODUCTION

•• RReeccoorrddiinngg tthhee ccoonnddiittiioonnss pprreesseenntt iinn tthhee ppaattiieenntt’’ss oorraall ccaavviittyy.. •• DDeennttaall cchhaarrtt uussiinngg ssyymmbboollss,, nnuummbbeerrss,, aanndd ccoolloorr.. •• CChhaarrttiinngg iiss uusseedd iinn mmoosstt ddeennttaall ooffffiicceess.. •• CChhaarrttiinngg iiss ppaarrtt ooff ppaattiieenntt’’ss lleeggaall rreeccoorrdd.. •• EEaacchh ppaattiieenntt’’ss cchhaarrtt sshhoouulldd bbee ccoorrrreecctt.. •• TThhee iinniittiiaall cchhaarrttiinngg iiss nnoorrmmaallllyy aaccccoommpplliisshheedd dduurriinngg ffiirrsstt

eexxaammiinnaattiioonn.. •• TThhee ddeennttaall cchhaarrtt iiss uusseedd ffoorr bbiilllliinngg ppuurrppoossee,, ddiiaaggnnoossiiss,,

ccoonnssuullttaattiioonn,, aanndd ffoorreennssiicc ddeennttiissttrryy ttoo pprroovviiddee tthhee iinnffoorrmmaattiioonn..

DDeennttaall CChhaarrttiinngg

• Objectives

• Explain why charting is used in most dental practices.

• Identify charts that used symbols to represent conditions present in the oral cavity.

• List and explain the system used for charting the permanent and deciduous dentations.

• Describe basic terminology used in dental charting.

• Explain color indicators and identify charting symbols.

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DDeennttaall CChhaarrttiinngg

•• TThheerree aarree sseevveerraall ttyyppeess ooff ddeennttaall cchhaarrttss.. •• EEaacchh cchhaarrtt hhaass aann aarreeaa ddeessiiggnneedd ttoo rreeccoorrdd.. •• TThhee mmoosstt ccoommmmoonn uusseedd cchhaarrtt iiss wwiitthh ddiiaaggrraamm.. •• TThhee tteeeetthh mmaayy sshhooww aann aannaattoommiicc oorr ggeeoommeettrriicc rreepprreesseennttaattiioonn

ooff tthhee tteeeetthh.. •• TThhee aannaattoommiicc cchhaarrtt sshhooww tthhee ccrroowwnn,, tthhee ccrroowwnn aanndd ssmmaallll

ppoorrttiioonn ooff rroooott,, aanndd tthhee ccrroowwnn aanndd ccoommpplleettee rroooott.. •• TThhee ggeeoommeettrriicc sshhooww tthhee tteeeetthh aass aa cciirrcclleess.. •• EEaacchh cciirrccllee rreepprreesseennttss tthhee ttooootthh aanndd ffiivvee ssuurrffaacceess ooff tthhee ttooootthh..

NNuummbbeerriinngg SSyysstteemmss

•• UUnniivveerrssaall // nnaattiioonnaall ssyysstteemm ffoorr NNuummbbeerriinngg •• FFeeddeerraattiioonn DDeennttaaiirree IInntteerrnnaattiioonnaallee ((FFDDII)) SSyysstteemm ffoorr NNuummbbeerriinngg •• PPaallmmeerr SSyysstteemm ffoorr NNuummbbeerriinngg

UUnniivveerrssaall // NNaattiioonnaall SSyysstteemm ffoorr NNuummbbeerriinngg::

•• IInn 11996688,, tthhee ((AADDAA)) aaddoopptteedd tthhee uunniivveerrssaall // nnaattiioonnaall ssyysstteemm ffoorr nnuummbbeerriinngg..

•• EEaacchh ppeerrmmaanneenntt ttooootthh hhaass oowwnn nnuummbbeerr.. •• SSttaarrttiinngg ffrroomm tthhee mmaaxxiillllaarryy rriigghhtt tthhiirrdd mmoollaarr aass ##11 aanndd mmoovviinngg

iinn aa cclloocckkwwiissee ttoo lleefftt mmoollaarr aass ##1166 aanndd ##1177 mmaannddiibbuullaarr lleefftt mmoollaarr aanndd ##3322 aass mmaannddiibbuullaarr rriigghhtt mmoollaarr..

TThhee ffoolllloowwiinngg ffiigguurree--33..11 iiss cchhaarrtt ooff PPeerrmmaanneenntt tteeeetthh ((NNuummbbeerriinngg SSyysstteemm))..

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FFiigg--33..11 UUnniivveerrssaall // NNaattiioonnaall SSyysstteemm ffoorr NNuummbbeerriinngg TThhee pprriimmaarryy tteeeetthh aarree ggiivveenn aa lleetttteerr oorr ““dd”” wwiitthh aa nnuummbbeerr::

•• TThhee mmaaxxiillllaarryy rriigghhtt sseeccoonndd mmoollaarr iiss AA oorr ““dd--11”” mmoovviinngg cclloocckkwwiissee ddiirreeccttiioonn ttoo JJ oorr ““dd--1100”” aass lleefftt mmaaxxiillllaarryy mmoollaarr ttoo KK oorr ““dd--1111 aass mmaannddiibbuullaarr lleefftt sseeccoonndd mmoollaarr aanndd mmoovvee ttoo mmaannddiibbuullaarr rriigghhtt mmoollaarr aass TT oorr ““dd--2200””..

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FFiigg--33..22 PPrriimmaarryy DDeennttiittiioonn,, SShhoowwiinngg tthhee LLeetttteerriinngg aanndd NNuummbbeerriinngg SSyysstteemm.. FFeeddeerraattiioonn ddeennttaaiirree iinntteerrnnaattiioonnaallee ((FFDDII)) ssyysstteemm ffoorr nnuummbbeerriinngg::

•• TThhee ppeerrmmaanneenntt ddeennttaattiioonn iiss ggiivveenn ffoouurr qquuaaddrraanntt 11 aass uuppppeerr rriigghhtt aanndd 22 aass uuppppeerr lleefftt,, 33 aass lloowweerr lleefftt aanndd 44 aass lloowweerr rriigghhtt..

•• EEaacchh qquuaaddrraanntt iiss nnuummbbeerreedd ffrroomm 11 ttoo 88 •• 1122 iiss uuppppeerr lleefftt,, 1111 iiss uuppppeerr rriigghhtt,, 3311 iiss lloowweerr lleefftt,, aanndd 4411 iiss

lloowweerr rriigghhtt cceennttrraall iinntteerriioorr.. •• EExxaammppllee:: :: uuppppeerr rriigghhtt sseeccoonndd mmoollaarr iiss 1177,, lloowweerr rriigghhtt ffiirrsstt

mmoollaarr iiss 4466.. •• EEaacchh qquuaaddeerraanntt iiss NNuummbbeerreedd ffrroomm 11 ttoo 88,, ssttaarrttiinngg wwiitthh

CCeennttrraallss aanndd eennddiinngg WWiitthh mmoollaarrss..

34

FFiigg--33..33 TThhee ddiiaaggrraamm ooff ppeerrmmaanneenntt tteeeetthh.. PPrriimmaarryy DDeennttaattiioonn

•• PPrriimmaarryy tteeeetthh hhaass ffoouurr qquuaaddrraannttss •• UUppppeerr rriigghhtt iiss 55 •• UUppppeerr lleefftt iiss 66 •• LLoowweerr lleefftt iiss 77 •• LLoowweerr rriigghhtt iiss 88 •• EExxaammppllee:: ::UUppppeerr lleefftt llaatteerraall aanntteerriioorr iiss 6622,, lloowweerr rriigghhtt ffiirrsstt

mmoollaarr iiss 8844.. PPrriimmaarryy ddeennttiittiioonn sshhoowwiinngg ((FFiigg--33..44)) IISSOO ssyysstteemm ffoorr nnuummbbeerriinngg:: EEaacchh qquuaaddeerraanntt iiss11 ttoo 55 tteeeetthh ssttaarrttiinngg ffrroomm cceennttrraallss aanndd eennddiinngg mmoollaarr..

35

FFiigg--33..44 TThhee ddiiaaggrraamm ooff pprriimmaarryy tteeeetthh.. PPaallmmeerr’’ss SSyysstteemm ffoorr NNuummbbeerriinngg

•• TThhee ppeerrmmaanneenntt tteeeetthh aarree nnuummbbeerreedd 11 tthhrroouugghh 88 iinn eeaacchh qquuaaddrraanntt.. 11 iiss uuppppeerr lleefftt,, uuppppeerr rriigghhtt,, lloowweerr lleefftt,, aanndd lloowweerr rriigghhtt ooff cceennttrraall aanntteerriioorr..

•• TThhee ddeecciidduuoouuss tteeeetthh aarree lleetttteerreedd AA tthhrroouugghh EE iinn eeaacchh qquuaaddrraanntt.. CC iiss uuppppeerr rriigghhtt,, uuppppeerr lleefftt,, lloowweerr rriigghhtt,, aanndd lloowweerr lleefftt ooff ccaanniinnee..

36

FFiigg--33..55 DDiiaaggrraamm ffoorr PPaallmmeerr’’ss nnuummbbeerriinngg ssyysstteemm

FFiigg--33..66 DDiiaaggrraamm ffoorr PPaallmmeerr’’ss lleetttteerriinngg ssyysstteemm HHiissttoorryy ttaakkiinngg::

•• HHiissttoorryy ttaakkiinngg iiss tthhee ffiirrsstt sstteeppss iinn tthhee ccaarree ooff aannyy ppaattiieenntt.. •• HHiissttoorryy ttaakkiinngg sshhoouulldd bbee ccoonndduucctteedd wwiitthh ppaattiieenntt ssiittttiinngg ccoommffoorrttaabbllyy.. •• AAllwwaayyss iinnttrroodduuccee yyoouurrsseellff ttoo tthhee ppaattiieenntt aanndd aannyy aaccccoommppaannyyiinngg ppeerrssoonn aanndd

eexxppllaaiinn..

37

•• RReemmeemmbbeerr tthhaatt ppaattiieennttss aarree nneeiitthheerr mmeeddiiccaallllyy nnoorr ddeennttaallllyy ttrraaiinneedd,, ssoo uussee ppllaaiinn ssppeeeecchh wwiitthhoouutt ssppeeaakkiinngg ddoowwnn ttoo tthheemm..

•• QQuueessttiioonnss aarree aa kkeeyy ppaarrtt ooff hhiissttoorryy ttaakkiinngg aanndd iinn wwhhiicchh ccaann lleeaadd ttoo aa qquuiicckk ddiiaaggnnoossiiss,, aasskk qquueessttiioonn wwhhiicchh ttoo eelliicciitt rreelleevvaanntt iinnffoorrmmaattiioonn..

PPrreesseennttiinngg ccoommppllaaiinntt::

•• TThhee aaiimm ooff tthhiiss ppaarrtt iiss ttoo hhaavvee aa pprroovviissiioonnaall ddiiffffeerreennttiiaall ddiiaaggnnoossiiss.. •• SSuuggggeessttiioonn oouuttlliinnee rreeqquuiirree.. •• WWhhyy ddiidd yyoouu ccoommee ttoo sseeee uuss ttooddaayy?? •• WWhhaatt iiss tthhee pprroobblleemm??

IIff ssyymmppttoommss aarree pprreesseenntt;;

•• OOnnsseett aanndd ppaatttteerrnn:: ::WWhheenn ddiidd tthhee pprroobblleemm ssttaarrtt?? IIss iitt ggeettttiinngg bbeetttteerr,, wwoorrssee oorr ssttaayyiinngg tthhee ssaammee??

•• FFrreeqquueennccyy:: ::HHooww oofftteenn,, hhooww lloonngg ddoossee iitt llaasstt?? DDoossee iitt ooccccuurr aatt aannyy ppaarrttiiccuullaarr ttiimmee ooff ddaayy oorr nniigghhtt..

•• EExxaacceerrbbaattiinngg aanndd rreelliieevviinngg ffaaccttoorrss:: ::WWhhaatt mmaakkeess iitt bbeetttteerr,, wwhhaatt mmaakkeess iitt wwoorrssee?? WWhhaatt ssttaarrtteedd iitt??

IIff ppaaiinn iiss mmaaiinn ssyymmppttoomm;;

•• OOrriiggiinnaall:: ::WWhheerree iiss tthhee ppaaiinn aanndd ddoossee iitt sspprreeaadd?? •• CChhaarraacctteerr:: ::HHooww wwoouulldd yyoouu ddeessccrriibbee tthhee ppaaiinn,, sshhaarrpp,, sshhoooottiinngg,, dduullll,, aacchhiinngg,,

eettcc.. •• AAssssoocciiaattiioonn:: ::iiss tthheerree aannyytthhiinngg,, iinn yyoouurr oowwnn mmiinndd,, wwhhiicchh yyoouu aassssoocciiaattee wwiitthh

tthhee pprroobblleemm.. TThhee ddeennttaall hhiissttoorryy

•• HHooww oofftteenn ddoo yyoouu ggoo ttoo tthhee ddeennttiisstt?? •• WWhheenn ddiidd yyoouu llaasstt sseeee aa ddeennttiisstt aanndd wwhhaatt ddiidd hhee ddoo?? •• HHooww oofftteenn ddoo yyoouu bbrruusshh yyoouurr tteeeetthh aanndd hhooww lloonngg ffoorr?? •• HHaavvee yyoouu eevveerr hhaadd aannyy ppaaiinn oorr cclliicckkiinngg ffrroomm yyoouurr jjaaww jjooiinnttss?? •• DDoo yyoouu ggrriinndd yyoouurr tteeeetthh oorr bbiittee yyoouurr nnaaiillss?? •• HHooww ddoo yyoouu ffeeeell aabboouutt ddeennttaall ttrreeaattmmeenntt?? •• WWhhaatt ddoo yyoouu tthhiinnkk aabboouutt tthhee aappppeeaarraannccee ooff yyoouurr tteeeetthh?? •• WWhhaatt iiss yyoouurr jjoobb?? •• WWhheerree ddoo yyoouu lliivvee?? •• WWhhaatt ttyyppeess ooff ddeennttaall ttrreeaattmmeenntt hhaavvee yyoouu hhaadd pprreevviioouussllyy?? •• WWhhaatt aarree yyoouurr ffaavvoouurriittee ddrriinnkkss // ffooooddss??

38

FFiigg--33..77 AA ssaammppllee ooff ddeennttaall rreeccoorrdd ffoorr uuppppeerr aarrcchh..

39

FFiigg--33..88 AA ssaammppllee ooff ddeennttaall rreeccoorrdd ffoorr lloowweerr aarrcchh.. MMeeddiiccaall hhiissttoorryy::

•• AArree yyoouu ffiitt aanndd wweellll?? •• HHaavvee yyoouu eevveerr aaddmmiitttteedd ttoo hhoossppiittaall?? IIff yyeess,, pplleeaassee ggiivvee aa bbrriieeff ddeettaaiillss.. •• HHaavvee yyoouu eevveerr hhaadd aann ooppeerraattiioonn?? IIff ssoo wweerree tthheerree aannyy pprroobblleemm?? •• HHaavvee yyoouu eevveerr hhaadd aannyy hheeaarrtt ttrroouubbllee oorr hhiigghh bblloooodd pprreessssuurree?? •• HHaavvee yyoouu eevveerr hhaadd aannyy cchheesstt ttrroouubbllee?? •• HHaavvee yyoouu eevveerr hhaadd aannyy pprroobblleemm wwiitthh bblleeeeddiinngg?? •• HHaavvee yyoouu eevveerr hhaadd aasstthhmmaa,, eecczzeemmaa,, hhaayy ffeevveerr?? •• AArree yyoouu aalllleerrggiicc ttoo ppeenniicciilllliinn?? •• AArree yyoouu aalllleerrggiicc ttoo aannyy ootthheerr ddrruugg oorr ssuubbssttaannccee??

40

HHaavvee yyoouu eevveerr hhaadd:: •• RRhheeuummaattiicc ffeevveerr?? •• DDiiaabbeetteess?? •• EEppiilleeppssyy?? •• TTuubbeerrccuulloossiiss?? •• JJaauunnddiiccee?? •• HHeeppaattiittiiss?? •• OOtthheerr iinnffeeccttiioouuss ddiisseeaasseess •• AArree yyoouu pprreeggnnaanntt?? •• AArree yyoouu ttaakkiinngg aannyy ddrruuggss,, mmeeddiiccaattiioonn,, oorr ppiillllss?? IIff yyeess,, pplleeaassee ggiivvee ddeettaaiillss:: •• WWhhoo iiss yyoouurr ddooccttoorr?? •• CChheecckk tthhee mmeeddiiccaall hhiissttoorryy aatt eeaacchh rreeccaallll.. •• IIff iinn aannyy ddoouubbtt,, ccoonnttaacctt tthhee ppaattiieenntt’’ss GGMMPP,, oorr tthhee ssppeecciiaalliisstt tthheeyy aarree aatttteennddiinngg

bbeeffoorree pprroocceeeeddiinngg.. •• NNAA:: :: aa ccoommpplleettee mmeeddiiccaall hhiissttoorryy ((aass rreeqquuiirreedd wwhheenn cclleerrkkiinngg iinn--ppaattiieennttss)) wwoouulldd

iinncclluuddee ddeettaaiillss ooff ffaammiillyy hhiissttoorryy aanndd ssoocciiaall hhiissttoorryy.. AA ssyysstteemmaattiicc eennqquuiirryy

•• CCaarrddiioovvaassccuullaarr:: ::cchheesstt ppaaiinn,, ppaallppiittaattiioonnss,, bbrreeaatthhlleessssnneessss.. •• RReessppiirraattoorryy:: :: bbrreeaatthhlleessssnneessss,, wwhheeeezzee,, ccoouugghh——pprroodduuccttiivvee oorr nnoott.. •• GGaassttrrooiinntteessttiinnaall:: ::aappppeettiittee aanndd eeaattiinngg,, ppaaiinn,, ddiisstteennssiioonn,, aanndd bboowweell hhaabbiitt.. •• GGeenniittoouurriinnaarryy:: ::ppaaiinn,, ffrreeqquueennccyy ((ddaayy aanndd nniigghhtt)),, iinnccoonnttiinneenncceess,, ssttrraaiinniinngg,, oorr

ddrriibbbblliinngg.. •• CCeennttrraall nneerrvvoouuss ssyysstteemm:: :: ffiitt,, ffaaiinnttss,, aanndd hheeaaddaacchheess..

RReeffeerreenncceess::

•• MMiittcchheellll DDAA,, MMiittcchheellll LL,, 22000055 OOxxffoorrdd HHaannddbbooookk ooff CClliinniiccaall DDeennttiissttrryy,, 44tthh..eeddnn,, OOxxffoorrdd..

4. Measuring of vital signs: pulse, respiratory rate,

blood pressure and cardio-pulmonary resuscitation

Measuring-of-vital-signs: 1.Pulse 2.Respiratory-Rate 3.Blood-Pressure 4.Cardio-pulmonary-resuscitation.

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Objective of study: Define vital signs and four signs commonly taken in the dental office Describe the procedure for taking a patient’s temperature, pulse, respiration, and

blood pressure. Learning outline: Introduction To recognize the Vital signs Able to take body temperature To understandard the pulse To recognize the respiratory rate To get knowledge of blood pressure

Introduction: Preparation for patient care is an important part of providing quality dental service to

each patient. This clinical evaluation includes obtaining vital signs and performing both an internal

and external evaluation. Vital signs: The measuring and recording of vital signs is an important part of health evaluation

and it should do every patient before starting any dental treatment. Vital signs aid in the planning of the patient’s dental treatment and are essential

during emergency treatment. Vital signs are the basic signs of life. They are including body temperature, pulse,

blood pressure, and respiratory rate. Body temperature: Body temperature is compared to the normal body temperature range. Normal range in Fahrenheit:99.5 degree F

:98.6 degree F (Average) :96.0 degree F Normal range in Celsius: :37.5 degree C

:37.0 degree C (Average) :35.5 degree C

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Fig-4.1 Indicating Fahrenheit and Celsius thermometers.

Fig-4.2 Fahrenheit Thermometer.

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Taking an oral temperature using a digital thermometer: This procedure is performed by dental assistant in order to obtain the patient’s body

temperature. Equipment and supplies

1. Digital thermometer 2. Probe covers 3. Biohazard waste container Procedure steps: Wash hands. Assemble the thermometer and probe cover. Seat patient in the dental treatment room and position him or her comfortably in an

upright position. Verify that the patient has not had a hot or cold drink or smoked within the last half

hour. (This may give a false temperature reading). Explain the procedure to the patient. Position the new probe cover on the digital thermometer (Fig-4.3). Insert the probe under the tongue to either side of the patient’s mouth. Instruct the patient to carefully close his or her lips around the probe without biting

down on it. (Fig-4.4) Leave the probe in position until the digital thermometer beeps. Remove the probe from the patient’s mouth. Read and results from the digital thermometer display window. Dispose of the probe cover in a hazardous waste container. Wash hands. Document the procedure and record the results on the patient’s chart.

Fig-4.3 Slide the probe into the disposable adjusting.

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Fig-4.4 Insert thermometer under the tongue to enter side of mouth. (For example, Temperature is 99 degree F). Taking Pulse: The pulse is the intermittent beating sensation felt when the fingers are pressed

against an artery. A pulse rate is determined by palpation (feeling with the fingers or hand). Dental assistant most commonly uses the radial artery.

Fig-4.5 Location of pulse

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Radial Pulse Site; The radial pulse site is located on the radial artery, on the thumb side of the wrist

(Fig-4.6) It can be found approximately one inch above the base of the thumb. This is the most common site used for obtaining pulses in dental office.

Fig-4.6A Radial pulse site location

Fig-4.6B Radial pulse site location

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Carotid pulse Site; The carotid pulse site is located on the carotid artery in the neck just below the angle

of the mandible (Fig-4.7). It is normally large and therefore easy to locate.

Fig-4.7 Carotid pulse site location.

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Temporal Pulse site; The temporal pulse site is over the smaller temporal artery located in the temporal

fossa, which is a slight depression the level of the eyebrow just in front of the ear . (Fig-4.8)

The temporal pulse is more difficult to locate than the radial and carotid.

Fig-4.8 Temporal pulse site location

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Fig-4.9 Taking patient’s brachial pulse. The pulse rate: After the locating the pulse site, the dental assistant determines the number of

best per minute. This is varies depending on the patient’s age, sex, and physical and mental

condition. Normal pulse rates are as follows:

1. For adults : :60 - 90 beats / min 2. For Children: :90 - 120 beats / min Respiration: Respiration is one breath taken in (inhalation) and one breath let out

(exhalation). Tachypnea is rapid and bradypnea is slow respiration rate. Normal respiration rates are as follows:

1. For adults: :12 – 18 / min 2. For children: : 12 – 40 / min

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Fig-4.10Taking patient’s radial pulse and respiration. Blood Pressure: Blood pressure is the most complex vital sign to obtain. Blood pressure is an important indicator of the health of a patient’s cardiovascular

system. Taking and recording a patient’s blood pressure is very important. Blood pressure is measured by placing a sphygmomanometer, a “blood pressure

apparatus,” around the brachial artery. (fig-4.9) Blood pressures reading are recorded as the systolic pressure (the higher number) over

the diastolic pressure (the lower number). For example, 129/78 indicates systolic pressure of 129 and diastolic pressure of 78.

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Fig-4.11 Aneroid sphygmomanometer.

Fig-4.12 Sphygmomanometer.

Fig-4.13 Sphygmomanometer

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Fig-4.15 Automated electronic blood pressure device. An electronic blood pressure: This is used in many practices to simplify and speed the process. It is important to read the directions carefully Using the device until to obtain an accurate reading, while maintaining patient’s

comfort. An alternative is the use of a stethoscope and sphygmomanometer. The stethoscope is used to amplify the sounds of the blood pumped within the artery

(Fig-4.16, Fig-4.17). The sphygmomanometer is used to measure blood pressure (Fig-4.11 to Fig-4.15). This device consists of a gauge attached to an inflatable rubber bladder enclosed in a

cloth cuff.

Fig-4.16 Stethoscope.

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Fig-4.17 Stethoscope.

Fig-4.18 Position of Dental Team (Operator, Assistant, Patient). Taking a Patient’s Blood Pressure: Equipment and Supplies Stethoscope Sphygmomanometer

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Patient’s record to document the finding Procedural Steps: Seat the patient with the arm extended at heart level and either supported on the chair

arm or on a table. Purpose: :The patient’s arm should be at the same level as the heart.

If possible, roll up the patient’s sleeve. Purpose: :Tight clothing can interfere with an accurate measurement and reading. If you are taking the patient’s blood pressure for the first time and you do not have a previous blood pressure reading to use for reference, you will need to establish a basis to determine how high to inflate the cuff. To do this, first palpate the brachial artery to feel for the patient’s pulse.

Take the patient’s brachial pulse for 30 seconds; then double the number fr a 1-minute reading. Add 40 mm Hg to the reading to provide your inflation level. For example, if the reading was 85, you would add 40, arriving at an inflation level of 125 mm Hg.

Expel any air from the cuff by opening the valve and pressing gently on the cuff. Place the blood pressure cuff around the patient’s arm approximately 1 inch above the

antecubital space, marking sure to center the arrow over the brachial artery. Purpose: : pressure must be applied directly over the artery for a correct reading.

Fig-4.19 Placing the blood pressure cuff around the arm.

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Tighten the cuff, using the Velcro closure to hold it in place. Note : : Make sure that

the cuff is tight enough so that you can squeeze only a finger between the cuff and arm.

Place the earpieces of the stethoscope into your ears so that they are facing toward the front. Purpose : :This position of the earpieces is more comfortable and blocks out distracting noises while you are taking blood pressure.

Place the stethoscope disk over the side of the brachial artery, using slight pressure with the fingers.

Grasp the rubber bulb with the other hand, locking the valve. Inflate the cuff to the noted reading. Note : :you need to inflate the bulb quickly. Slowly release the valve and listen through the stethoscope.

Note the first distinct thumping sound as the cuff deflated. This is the systolic pressure reading.

Slowly continue to release the air from the cuff until you hear the last sound. This is the diastolic pressure reading.

Record the reading, indicating which arm was used.

Fig-4.20 Tighten the cuff.

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Fig-4.21 Placing the disk of stethoscope.

Fig-4.22 Slowly releasing the valve. Date BP 117/68 R

Signature

Disinfect the stethoscope earpieces and diaphragm as recommended by manufacturer. Return the setup to its proper place.

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Reference: Robinson DS, Bird DL, 2007 Essentials of Dental Assisting, 4th.edn, Saunders. Phinney DJ, Halstead JH, 2000 Delmar’s Dental Assisting, Delmar Thomson

Learning. Roberson TM, Heymann HO, and Swift EJ, 2006 Tturdevant’s Art and Science of

operative dentistry, 5th. edn, Mosby.

5. Instrumentation for Operative Dentistry such as burs (stainless steel, tungsten carbide and diamond) for high speed and low speed), various other instrument such as mouth mirror, dental probe, polishing disc etc.

Instruments Objective: :To recognize the instruments which are used in operative dentistry

Outline: : 1.Introduction

2. Hand instruments 3. Rotary instruments

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1. Introduction Instruments are used to examine, clean, cut, and restore teeth. Instrumentation for Operative Dentistry such as burs (stainless steel, tungsten carbide and diamond) for high speed and low speed), various other instrument such as mouth mirror, dental probe, polishing disc etc. Two main types of Instruments are

Hand instruments

Rotary instruments

2. Hand Instruments

Instruments used for Examining the mouth and teeth. Instruments used for removing caries and cutting teeth. Instruments used for placing and condensing restorative materials

Hand Instrument design:

Using Hand Instrument

Maintaining Hand Instruments 1. Sharpening Hand Instruments 2. Decontaminating and sterilizing hand instruments Hand Instrument: Instruments used for examining the mouth and teeth

Mouth mirrors Tweezers Probes Excavators Chisels, Hatchets, and Hoes Plastic Instruments Condensers or pluggers Carving and finishing instruments

Mouth mirrors: Are used; For general purpose For retracting tongue and cheeks Reserving the front surface mirror for detailed examination

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Fig-5.1 Various types of Disposable Mouth Mirrors.

Fig-5.2 Disposable Mouth Mirrors.

Tweezers: To examine the mouth and teeth, used tweezers, probes and mouth mirrors

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Fig-5.3 Tweezers.

Probes: To examine the mouth and teeth used tweezers, probes and mouth mirrors. Probe are used To diagnose the enamel surface

To check the margins of restoration To examine caries during cavity preparation To detect the sub gingival calculus. To measure the depth of periodontal pockets To measure the width of the tooth.

Fig-5.4 Probes.

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Fig-5.5Various Types of probes, from left: Straight, Briault, Graduated Periodontal, Furcation and CPTIN Periodontal probe. Hand Scalar:

For removing supra- and sub gingival calculus and other deposits. For removing temporary crowns. For periodontal purpose, use more details.

Fig-5.6 Various Kinds of Hand Scalars.

Excavators:

Instruments used for removing caries and cutting teeth. (1)Exactors (2) Chisels, hatchets, and hoes. Excavators: :Have a discoid or ovoid blade, the margin of which is beveled to a sharp cutting edge as shown in Figure.

Used for remove softened dentine Used for temporary fillings Placing lining Carving amalgam.

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Fig-5.7 Various types of Excavators.

Chisels,Hatchets,&Hoes: These Instruments used for removing caries and cutting teeth. The Chisels, hatchets, and hoes

Splitting off unsupported enamel. To trim the gingival margin. To trim the margins of small cavities

Fig-5.8 A selection of chisels, hatchets, and hoes (From left straight and angle chisels, straight hatchets and A pair of hoes).

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Plastic Instruments: Instruments used for placing and condensing restorative materials. Plastic Instruments are:

Used for shaping and conveying materials Used for placing materials Used for pushing the materials into the cavities. Used for burnishing the materials. Used for heating, according to some materials (e.g. wax ) necessary to heat.

Fig-5.9 A set of four titanium nitride instruments (From left, Flat-plastic, Carving instruments, burnisher, and plugger).

Fig-5.10 From left: : Amalgam Condenser, burnisher, curving instrument, and flat-plastic.

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Condensers or pluggers: Instruments used for placing and condensing restorative materials,

Used for compressing and forming filling materials Used for condensing amalgam materials. Used for heavy pressure

Fig-5.11 Various types of Pluggers.

Carving and finishing instruments: Instruments used for placing and

condensing restorative materials. Carving and finishing instruments which, have sharp or semi-sharp blade of various shape and used to curve the materials by cutting or scraping.

Used for carving materials Used for carving amalgam Used for caving wax.

Hand-instrument-design: Most instruments are made of stainless steel or carbon steel;

The majority of hand instruments have three parts The blade The shank The handle

The design of handle: The design of handle is related to the purpose of the instrument. Purpose of used for tactile and exploratory;

The probes have small-diameter and lightweight handle. Scalars have larger-diameter and heavier handles.

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Using Hand Instruments:

A hand instrument may be grasped in one of two ways The pen grip and the palm grip The pen grip is self-descriptive and frequently used The palm grip is held the instrument the thumb and forefinger. The finger grip is modification of palm grip.

The Instrument griping:

Fig-5.12 Pen Grip.

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Fig-5-13 Finger grip.

Fig-5.14 Palm Grip.

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Maintaining Hand Instruments:

Sharpening hand instruments Decontaminating and sterilizing hand instruments

Sharpening Hand Instrument;

A chisels can be sharpened on sharpening stone or A chisels can be sharpened with a disc in a straight hand pieces. An excavators can be sharpened with a mounted stone in a straight hand pieces.

Decontaminating and sterilizing hand instruments;

All instruments must be cleaned before being sterilized. Stainless steel, tungsten carbide, and Teflon-coated instruments can be autoclaved. Carbon steel instruments will corrode if autoclaved then left in a wet condition.

3. Rotary Instruments

Rotary instruments, consisting of burs, stones and discs are small instruments held in a handpiece.

The instruments are rotated in the handpiece by power from an external compressed air or an electric motor.

There are two type of equipment used to provide the rotary power.

The Air turbine (High speed Hand pieces)

The air turbine or airoto (high speed handpiece) give the highest speeds. The speed range are 250,000 – 500,000 rev / minute. High speed achieved by contra-angle handpiece The shank of bur is inserted into the handpiece. Handpiece always contains water spray and a fibre-optic light at the head of bur. High speed handpiece can be rotated only clockwise.

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Fig-5.15 Air-turbine handpiece, the water spray and fibre-optic light system.

Low speed hand pieces

Contra-angle handpiece, used almost exclusively in the mouth. Straight hanpiece, used for trimming temporary crowns, denture and other similar

procedure outside the mouth. The speed of these handpiece s lower than air turbine Most handpieces are equiped water spray. The drive come from a small electric motor attached handpiece. The speed controlled by foot control or a control on electric motor or on the dental

unit. Low-speed handpiece can be rotated clockwise or anti-clockwise. Following figure, from left : 1:1 ratio contra-angle handpiece used for most procedure. Latch-grip burs are used.

Speed range 400-40,000 rev /minute, a blue dot on the head. 1:4 ratio increasing, speed range 16,000 – 160,000. Identified with a red band. 7:1 ratio reducing, speed range 500-5500 rev / minute. Identified with green band. 1:1 ratio straight handpiece, identified with green band.

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Fig-5.16 Slow speed Contra-angle Handpieces.

Fig-5.17 Electric Motor for Slow-speed both Cotra-angle and straight handpieces.

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Fig-5.18 Slow speed straight hand pieces with bur.

Fig-5.19 Contra-angle and straight handpieces.

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Maintaining and sterilizating handpieces.

Modern handpieces are autoclavable and must be autoclaved between patients Most handpieces should be lubricated Aerosol are available for lubricating.

Burs and stones.

Burs, and Stones Friction- with a separate bur changer A latch grip – in the contra-angle low-speed handpiece A quick-release clam pig chuck – in the straight handpiece, contra-angle, low-speed handpiece and turbines.

Air turbine burs Low-speed burs Stones

Fig-5.20 From left: :Three tungsten carbide burs, three diamond burs, and three metal-cutting burs.

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Fig-5.21 from left: : Three round burs, three straight cross-cut

fissure burs, a tapered cross-cut fissure bur, and an inverted cone burs.

Fig-5.22 Tungsten carbide bur (right) Steel shank bur (left)

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Fig-5.23 Four stone mounted latch-grip shank and three straight shank

Finishing instruments

Burs and points: : Steel for amalgam And tungsten carbide for composite. Discs:Rigid and flexible discs are available with abrasive materials. Abrasive strips: :Hands-held flexible strips of metal, plastic, or linen with abrasive on

one side.

Fig-5.24 From left: Five steel burs, two stone burs, three abrasive rubber point burs, and one abrasive rubber cup burs.

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Finishing Instruments for composite;

From left: : A mounted fine white stone bur Two medium grit diamond burs Two fine grit diamond burs A rubber disc A mandrel Two flexible discs Four plastic stubs discs with a mandrel (Fig-5.25).

Matiaining and Sterilizing handpieces burs and stones; all hndpiece’s burs must be

sterilized after used.

Fig-5.25 Finisging Instruments for Composite. Reference:

Phinney DJ, Halstead JH, 2000 Delmer’s Dental Assisting, Delmer Thomson Learning.

Kidd EAM, Smith BGN, and Walson TF,2006 Pickard’s Manual of Operative Dentistry,8th.edn, Oxford.

Aesculap Dental Catalouge

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6. Practicing of prophylaxis and four handed assisting and polishing of amalgam restoration.

Objectives:

Able to perform an ergonomic chairside by a well-trained dental team. Able to make significant changes in dental practices. To under standard the polishing of amalgam restoration.

Learning Outline:

Basic tenets of four-handed-dentistry. Principles of motion economy. Treatment room design. Types of delivery systems. Ergonomic practice facts. Equipments selection. Seating the patient and operating team. Instrument transfer. Polishing amalgam restoration.

Basic tenets of four-Handed-Dentistry

Work simplification Elimination Combination Rearrangement Simplification Equipment must be designed to minimize unnecessary motion. The operating team and patient are seated comfortably in ergonomically designed

equipment (Figure-6.1)

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Fig-6.1 The operating team and patient are seated comfortably to practice four-handed dentistry.

The dentist assigns all legally delegable duties to qualified auxiliaries based on the state’s guidelines.

Patient treatment is planned in advance in a logical sequence. The patient is placed in supine position (Figure-6.2).

Fig-6.2 The patient is placed in supine position with the head and toes in the same plane.

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Motion economy is practiced. Preset trays are utilized (Figure-6.3). Participatory ergonomic are practiced.

Fig-6.3 Preset Trays.

Work Simplification

The concept of work simplification requires the dental team to take a look at the work environment and apply four principles:

The concept of work simplification requires the dental team to take a look at the work environment and apply four principles:

Elimination Combination Rearrangement Simplification

Elimination:

Can save time and motion if eliminate items of equipment or instrument. Bracket tray is position in view of the patient. Fixed cabinetry that holds instrument and material. Extra instruments that are seldom used seldom used take up on the preset

tray.

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Combination:

50% of time can be save if you combine the functions of two instruments into one, or two steps in a procedure can be one.

Use a double-ended instrument instead of a single-ended instrument; use a condenser for more than one task.

Rearrangement:

Consider rearranging instruments on the tray setup to improve efficiency. Relocate equipment that causes excess reaching close to the transfer zone. Review the sequence of a procedure or the scheduling of patients to improve

time and motion. Delegate more duties to auxiliaries so that they are productive during a

procedure. Fig-6.5 Back up instruments and supplies can be retrieved easily by the

assistant from the mobile cabinets. What to rearrange? Locate the high-velocity evacuator (HVE) tip (Fig-6.4),

air / water syringe, and handpieces on a transthorax dental unit nearest the assistant. Place backup instruments and supplies at the assistant’s fingertips in a mobile cabinet instead of the fixed cabinetry (Fig-6.5).

Fig-6.4 (upper one), Fig-6.5 (down one) Fig-4 The high velocity evacuator (HVE) tip, air/water syringe and handpieces are placed nearest the assistant.

Simplification:

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Make an effort to simplify equipment and procedure in order to function more effectively.

Changing the step to eliminate repetition in instrument transfer. Select multipurpose dental materials. Delegate bur changes to the assistant.

Principles of Motion Economy

Minimize the number of instruments used for a procedure (Figure-6). Position the instruments on a preset tray/cassette in the sequence that they

will be used. Position instruments, materials, and equipment in advance, whenever

possible (Figure-6.6).

Fig-6.6 A minimal number of instruments are placed on the preset tray / cassette.

Place the armamentarium on a mobile cabinet as close to the patient as possible (Figure-6.7).

Place the patient in a supine position (Figure-6.8) Seat the operating team as close to the patient as possible (Figure-6.9). Use operating stools are that promote good posture, and provide back,

abdominal support that adjusts vertically, and horizontally (Figure-6.10). Provide work areas that are 1 to 2 inches below the elbow (Figure-6.11). Minimize the number of eye movements. Reduce the length and number of motions. Use smooth continuous motions and avoid distracting zigzag movement.

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Fig-6.7 In advance, the instruments are placed on the preset tray / cassette in sequence of use and positioned as closed to the patients as possible.

Fig-6.8 The patient is placed in supine position.

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Fig-6.9 The operator and assistant are seated as close to the patient as possible.

Fig-6.10A The operator’s stool promotes good posture and provides back support.

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Fig-6.10B The abdominal support on the assistant’s stool adjusts vertically and horizontally and can be positioned to provide back support.

Fig-6.10C The abdominal support on the assistant’s stool adjusts vertically and horizontally and can be positioned to provide back support

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Fig-6.11 The assistant’s work area should be 1 to 2 inches below the elbow. The classifications of motions are;

• Class I : Movement of the fingers only, as when picking up a cotton roll. • Class II: Fingers and wrist motion, as used when transferring an instrument to the

operator. • Class III: Fingers, wrist, and elbow motion, as when reaching for a handpiece. • Class IV: Movement of entire arm and shoulder, as when reaching into a supply tub or

container. • Class V: Movement of the entire torso, as when turning around to reach for equipment

from a side or split delivery unit. Zones of activity

• All treatment revolves around the patient’s mouth. • Area around the mouth is divided into four zones of activity; operator's zones,

assistant’s zone, transfer’s zone, and static zone. • These zones of activity are best illustrated by using the patient’s head as the face of a

clock, as shown in Figure-12.

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Fig-6.12A Zones of activity for a right-handed operator.

Fig-6.12B Zones of activity for a left-handed operator.

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Team responsibilities during treatment procedures.

• Team • General guidelines • Be aware of each other’s needs. • Develop a standardized routine for basic dental procedures. • Recognize the need to reposition the patient and operating team. • Make changes in positioning as necessary to reduce strain. • Observe patient movement, especially during syringe or sharp instrument transfer;

avoid contacting the patient with an instrument. • Transfer instruments only within the transfer zone.

Dentists / Operators:

• General guidelines • Develop a nonverbal signal denoting a need to exchange an instrument. • When necessary, give advance distinct verbal direction to communicate a need for a

different instrument or material. • Positional guidelines. • Maintain a working position within the opera’s zone; avoid legs interfering with the

static or assistant’s zone. Transfer guidelines:

• Confine eye focus to the field of operation. • Confine hand and arm movement to the transfer zone. • Avoid twisting and turning to reach instruments. • Exchange instruments only in the transfer zone. • Avoid removing instruments from the preset tray / cassette. • Return instruments to the assistant to return to the tray / cassette. • Rely on the assistant to change burns and transfer needed instruments.

Clinical assistant:

• General guidelines • Recognize any change in procedure. • Develop a thorough understanding of the procedure. • Positioning guideline (Figure-6.13). • Be seated as close to the patient as possible; align legs parallel to the long axis of the

patient’s body. • Position feet on the stool rim instead of the floor to avoid leaning forward. • Position the mobile cabinet top over the legs and as close to the chair as possible.

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Fig-13 The assistant is seated as close to the patient as possible; legs parallel to the long axis of the patient’s body, with the mobile cabinet extending over the top of the legs, and positioned as close to the patient chair as possible. Transfer guidelines:

• Anticipate the operator’s need. • When transferring an instrument, position the working end for the for the proper arch;

up for the maxilla and down for the mandible. • Follow a safe standardized exchange procedure. • Change burs and maintain handpiece positioning. • Exchange instruments only in the transfer zone. • Remove debris from instruments before returning to the tray. • Maintain instruments and materials in sequence of use. • Keep the preset tray / cassette and work area free of debris.

Treatment Room Design

• Treatment areas • Provide a treatment room size that conforms to the guidelines of the Americans with

disabilities act. • Create traffic patterns. • Select a transthorax delivery systems (Fig-6.14). • Provide mobile cabinet (Figure-6.15). • Locate all instruments within a 20-inch radius. • Position handpiece on the dental unit by frequency of use (Figure-6.17). • Provide separate sink areas for the assistant and the operator, and include hands-free

controls.

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• Use minimal fixed cabinetry. • Provide adequate light to avoid shadows.

• Treatment areas • Provide a treatment room size that conforms to the guidelines of the Americans with

disabilities act. • Create traffic patterns. • Select a transthorax delivery systems (Fig-6.14). • Provide mobile cabinet (Figure-6.15). • Locate all instruments within a 20-inch radius. • Position handpiece on the dental unit by frequency of use (Figure-6.17). • Provide separate sink areas for the assistant and the operator, and include hands-free

controls. • Use minimal fixed cabinetry. • Provide adequate light to avoid shadows.

Fig-6.14 The transthorax unit promotes safe practice and ergonomic concepts.

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Fig-6.15 The mobile cabinet houses major equipment and back up supplies and is free of umbilical attachments. The extended arm rest is provided for the operator to support the non-dominant arm.

Fig-6.15B Schematic of internal components of a mobile cabinet.

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Fig-6.16 Instruments on the unit are placed within a 20-inch radius of the assistant’s hand for efficient transfer.

Fig-6.17 Handpieces are located on the dental unit by frequency of use.

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Access:

• Provide easy access to and exit from treatment room for the patient. • Provide a convenient traffic pattern to the treatment support areas such as

sterilization, radiography, supply storage, and business office. • When possible, create a pass-through area that separates clean from nonclean

equipment and materials. General Guide Line:

• Provide a location for the patient clinical record area that is free from potential aerosol contamination.

• Provide adequate ventilation. • Create a warm, corner when possible. • Evaluate the cleanliness of the facility constantly.

Type of delivery System:

• Transthorax delivery system • Split-unit / cabinet delivery system • Side delivery system • Rear delivery system

Fig-6.18 Type of delivery system (Figure-18 A, B, C, and D).

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Ergonomic practice facts:

• Instruments should be easy to use in an ergonomically efficient posture. • Instruments should be well maintained to ensure that moving parts are well lubricated. • The force needed to operate and instrument should be minimized. • A handpiece should be used instead of a manual hand instrument. • Hoses on handpieces and evacuators should be position that maintain an

ergonomically sound posture. • Hose should be locked into position to prevent pullback on the operator (Figure-6.19). • The patient chair must provide support for the patient’s entire body in every position

(Figure-6.20). • The chair back and headrest must combine strength with thinness (Figure-6.20). • The patient chair should move automatically. • Handpiece should rotate and turn. • Retentive mechanism for holding a bur to remove and replace easily (Figure-6.21). • The diameter of a handpiece should be relatively larger at the base (Figure-6.22A). • Switches on handpiece and HVE system must move with minimal effort (Figure-

6.22B). • Knurled or cross-hatched surfaces require less force to grasp. • Syringe, such as air/water, impression, and even anesthetic syringes must be reduced

stress on the thumb and fingers. • Lighting is critical to dentistry, used personal protective eyewear. • Personal protective equipment used to reduce the spread of infection must also

influence ergonomics.

Fig-6.19 Hoses should be locked into position prior to transferring to the operator to prevent pullback.

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Fig-6-20 Upper and Fig-6.22A (Upper), Fig-6.21 Lower. Fig-6.22B (Lower). Equipment Selection: • Does the design of the product make intuitive sense given the goal of the design? • Does the product feel comfortable to use? • Does the product put the user into a more neutral posture? • Can the manufacturer / designer clearly articulate what the ergonomic objectives are

specific design elements? • Does the manufacturer have any research evidence to demonstrate that their product

works? • Can the manufacturer give contacts for other already using the product? • If you are still in doubt and if it is appropriate, is the manufacturer willing to let you

have a 30-days trial period using the equipment?* • See the following equipment selection criteria. • Patient chair • Dental unit • Dental unit components including air/water syringe, handpieces, HVE system • Dental stools • Mobile cabinet • Fixed cabinetry • Food control • Operating light • Room light • Sinks

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Seating the patient and operating team: • Room preparation and initial patient seating • Patient positioning • Operator positioning • Assistant positioning Room preparation and initial patient seating: • Offer to store personal items in a safe location nearby, out of the way of treatment. • Raise the chair for case of entry. • Signal the area of the chair in which the patient should be seated by pointing with a

hand or providing verbal directions. • Lower the chair arm. • Place the patient napkin. • Offer protective eye wear. Patient positioning: • Encourage the patient to move the uppermost portion of the chair nearest the operator. • Avoid sudden jerky motions; explain changes in chair positioning to the patient as

they occur. • Raise the chair base about 10 to 12 inches. • Initially tilt the chair back until the patient’s calves are parallel to the floor. • Place the patient in a supine position, which the knees and nose on the same plane. • Lower the operating light to a position the assistant can reach when seated. • Place the unit and mobile cabinet in position. Operator positioning: • The stool is adjusted to allow the operator’s feet to rest firmly on the floor and to

provide adequate back support. • Use an arm rest attached to the mobile cabinet to reduce arm strain. • The patient’s head is positioned so that the mouth is as close as possible to the

operator’s elbow. • Elbows should be close to the side of the body. • Shoulders should not be raised. • The back should be straight. • Keep the neck neutral (straight). • The distance from the operator’s eyes to the patient’s mouth should be approximately

14 inches. • The eyes should remain focused on the treatment site. • Whenever possible, try to keep the wrist straight. • Limit exposure to hand-held instruments or handpieces that vibrate • Avoid awkward reaching.

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Fig-6.23 The operator is positioned with feet resting firmly on the floor, back supported, elbows close to the side of body, shoulders not raised, back straight, and the neck in a neutral position. Assistant positioning: • The stool is positioned as close to the patient’s chair as possible. • The front edge of the stool, or the assistant’s knees, are nearly even with the patient’s

mouth. • Te torso is centered on the stool. • The feet rest on the rim of the stool and are parallel to the floor. • The body support is positioned to come around the left side and to support the

assistant’s torso when learning forward. • When seated, the assistant’s eye level is 4-6 inches than operator’s eye level. • Position the mobile cabinet directly in front of the assistant’s knees. • Extend the working area over the knees or lap. • Maintain a relatively straight back and neck. • Avoid forcefully grasping an instrument while flexing the wrist. • Avoid forceful holding of instruments and hoses. • Avoid reaching or twisting the torso; position equipment within a 20-inch radius.

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Fig-6.24 The assistant is positioned with the torso centered on the stool, close to the patient, the edge of the stool or assistant’s knees are even with the patient’s mouth; the thighs are parallel to the side of the patient chair and are parallel to the long axis of the patient’s body, eye level is 4-6 inches higher than the operator’s eye level.

Diagram-1 Suggested guidelines for patient and dental team positioning regarding specific treatment sites.

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Instrument transfer and grasps:

• Instrument transfer • Instrument grasps

Instrument transfer:

• The operator can maintain vision on the field of operation. • The operating team saves time and motion. • Stress and strain on the operating team are reduced. • When instrument transfer is used in conjunction with the oral evacuator and the

air/water syringes, the operative site will always be clean and the next instrument will always be ready for use.

Instrument grasps:

• The pen grasp resembles the position commonly used to hold a pen or pencil and is widely used for most operative instruments (Fig-6.25).

• The modified pen grasp is similar to the grasp, except the operator uses the pad of the middle finger on the handle of the instrument.

• The palm grasp is used for bulky instruments. It is commonly used for surgical forceps, rubber damp clamp forceps, and the air /water syringe (Fig-6.26).

• The assistant for holding the oral evacutor (Fig-6.27) uses the palm-thumb or thumb-to-nose grasp.

Fig-6.25 Pen Grasp (Holding Suction Evacuator).

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Fig-6.26 The Palam Grasp. Fig-6.27 A The Thumb Grasp Fig-6.27B Palm-Thumb Grasp

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Type of instrument transfer:

• Single –handed transfer procedure (for right-handed operator). • When working with a left-handed operator, all the positions are reversed. • The assistant’s transfer hand is divided into two parts, the pick up and the delivery

portion. • The fingers of the assistant’s transfer hand include the thumb, first, second, third and

fourth (the small finger).

Fig-6.28 When transferring instruments with a single handed transfer to a right-handed operator the assistant transfers with the left hand and holes the oral evacuator tip and air/water syringe in the right hand.

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Fig-6.29A (Upper), Fig-6.29B (Lower).

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Instrument Transfer Procedure Outline:

• Assemble instruments in sequence of use. • Place the instrument trays as close to the patient as possible. • Place auxiliary equipment such as anesthesia or rubber dams on the mobile

cabinet farthest from the patient. • Pick up the instrument with the thumb and first finger at the nonworking third

of the instrument. • At the beginning of the procedure, simultaneously pass the mirror with the right

hand and the explorer with the left hand. • Prior to instrument transfer the instruments are assembled in sequence of use on

the tray, the tray placed close to the patient, with auxiliary equipment placed nearby on the mobile cabinet (Fig-6.30A).

• The instrument is picked up with the thumb and first finger at the non-working third of the instrument (Fig-6.30B).

• Rest the instrument on the middle finger, making certain that the working end is positioned for the correct arch (Fig-6.30C).

• When the operator signals for an exchange, move the new instrument into

position (Fig-6.31A). • Parallel the new instrument with the operator’s instrument to be exchanged

(Fig-6.31B). • Grasp the used instrument and tuck it toward the wrist with the pick up portion

of the hand (Fig-6.31C). • Deliver the new instrument firmly into the operator’s hand with the delivery

portion of the hand (Fig-6.31D). • With the thumb roll the used instrument from the palm back into the delivery

portion of the hand (Fig-6.31E). • Retain the instrument in the delivery portion of the hand if it is to be used again.

If not, return it to the proper location on the tray (Fig-6.31F).

Fig-6.30A Fig-6.30B Fig-6.30C

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Fig-6.31A Fig-6.31B Fig-6.31C

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Fig-6.31D Fig-6.31E Fig-6.31F

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Hidden-syringe transfer:

• The hidden-syringe transfer requires the assistant and operator to plan in advance the technique.

• A 2 X 2 gauze is passed to dry the site (Fig-6.32A). • Topical anesthetic may be applied with a cotton-tipped applicator. • The protective cap on the needle is loosened slightly. • The syringe is placed in the assistant’s right hand. • The assistant stabilizes the operator’s hand. • A cotton tipped applicator for placing topical anesthetic may be exchanged for the 2 X

2 gauze (Fig-6.32B). • Stabilize the operator’s hand and place the syringe into the operator’s hand with the

thumb ring securely in place (Fig-6.32C). • Remove the protective cover and place the cover in the recapping device (Fig-6.32D). • The injection is made by the operator (Fig-32E). • When the syringe is returned to the assistant be certain to grasp it under the barrel,

and transfer a gauze sponge to the operator (Fig-32F). • The syringe is placed in a recapping device and then placed out of the way unless

needed again (Fig-32G).

Fig-6.32A. A2 X 2 gauze is passed to dry the site.

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D G Fig-6.33 (B,C,D) Up to down. Fig-6.32 (E,F,G) up to down Two handed transfer: • A right-handed operator place the used instrument in the assistant’s left hand (Fig-

6.33A). • The new instrument is delivered by the assistant with the right hand as the operator

uses a palm grasp (Fig-6.33B). • For aright-handed operator, the assistant picks up the mirror from the handle end and

the explorer is picked up with the left hand at the end nearest the assistant (Fig-6.34 A).

• The two instruments are transferred simultaneously at the beginning of the procedure (Fig-6.34B).

• When using non-locking forceps, the materials is placed into the forceps, with a firm grasp on the forceps, the for forceps are paralleled with the used instrument that is to be exchanged (Fig-6.35A).

• The used instrument is retrieved while still grasping the forceps (Fig-6.35B). • The used instrument is tucked into the palm of the hand (Fig-6.35C).

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• The forceps are delivered (Fig-6.35D). • When retrieved, the forceps are grasped by the working end and tucked into the palm,

and the new instrument is delivered (Fig-6.35E).

Fig-6.33A (Upper), Fig-6.34A (Upper), Fig-6.33B (Lower). Fig-6.34B (Lower).

Fig-6.35 (A) Upper, (B) Lower.

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Fig-6.35C,Fig-6.35D, Fig-6.35E (Up to down). Small items: • Small items such as medicaments can be placed in the transfer zone so the operator

can easily obtain them (Fig-6.36A). • Small items such as a gauze 2 X 2 is placed in the transfer zone (Fig-6.36B). • When transferring scissors, open the beaks and parallel with the instrument to be

exchanged (Fig-6.37A). • Grasp and tuck the used instrument (Fig-6.37B).

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• The operator adjusts the hand to easily place fingers into the handle opening (Fig-6.37C).

• The used instrument is returned to the delivery portion of the assistant’s hand and the operator prepares to use the new instrument (Fig-6.37D).

• A handpiece is picked up at the non-working third of the handle (Fig-6.38A). • Parallel the handpiece with the instrument to be exchanged (Fig-6.38B). • Deliver the handpice as any other hand instrument (Fig-6.38C). • When exchanging one handpiece for another, the handpices are made parallel just as

when exchanging small hand instruments (Fig-6.38D). • The used handpice is retrieved in the pick up portion of the hand and the new

handpiece is delivered (fig-6.38E). • The used handpiece is tucked into the palm of the hand and then returned to the

delivery portion of the hand if to be used again, or returned to the dental unit (Fig-6.38F).

• A reverse transfer is used when the operator wishes to return to the previous handpiece. The assistant picks up the new handpiece with the pickup portion of the hand and receives the used instrument with the delivery portion to avoid hose tangling (Fig-6.38G).

Fig-6.36(A) Up,(B) down. Fig-37 (A,B,C) Up to down.

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Fig-6.37D, Fig-6.38A, Fig-6.38B Fig-6.38 (C,D,E) up to down. ( Up to down).

Fig-6-38 (F,G) up to down.

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Oral Evacuation: • The HVE tip is placed into the hose for an anterior location. This is shown when the

bevel of the tip is not visible (Fig-6.39A). • The HVE tip is placed into the hose for a posterior location. This is shown when the

bevel of the tip is visible (Fig-6.39B). • The HVE hose is held in a thumb-to-nose position for the posterior area or when

stronger retraction is needed (Fig-6.39C). • The HVE hose is held with a pen grasp when in the anterior area or when retraction is

not difficult (Fig-6.39D). • Place the HVE tip before the handpiece is placed (Fig-6.39E). • Place the tip as close to the tooth as possible (Fig-6.39F). • Place the tip even or slightly above the occlusal surface or incisal edge (Fig-6.39G). • When working on the right side of the mouth, the tip is placed on the side of the tooth

nearest the assistant or the lingual for a right-handed operator (Fig-6.39H). • When working on the left side of the mouth, the tip is placed on the side of the tooth

nearest the assistant or the buccal for a right-handed operator (Fig-6.39 I); • When the handpiece is placed on the same side as the evacuator tip move the HVE tip

slightly distal (Fig-6.39 J). • When the air-water syringe and HVE are both being used during an instrument

exchange, transfer the A/W syringe to the right hand and grasp it simultaneously with the HVE hose during the instrument exchange (Fig-6.39-K).

Fig-6.39 (A) Upper, (B) Lower.

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Fig-6.39 (C, D, E) Fig-6.39 (F, G, H) Up to down. Up to down.

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Fig-6.39 ( I, J, K ) up to down. Restoration of Amalgam and Polishing: The restoration of amalgam in molar teeth as following procedure;

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Fig-6. 40 Amalgam in this heavily restored upper first molar is to be replaced, LA given and rubber dam placed.

Fig-6.41 The old restoration is removed.

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Fig-6.42 Removal of caries at the enamel-dentine junction distally.

Fig-6.43 Three pins are placed to aid retention of the amalgam.

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Fig-6.44 A badly placed matrix.

Fig-6.45 The matrix band is reapplied with the retainer lingually.

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Fig-6.46 The band is removed and the amalgam carved, rubber dam must be removed.

Fig-6.47 At a subsequent visit the amalgam is polished, articulating paper has used for occlusion.

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Reference:

• Betty LF, 2001 Four-Handed Dentistry, A Handbook of Clinical Application and Ergonomic Concepts, prentice Hall.

• Kidd EAM, Smith BGN, and Watson TF,2006 Pickard’s Manual of Operative Dentistry, 8th.edn, Oxford.

7. Pulp Protection: theory and practical.

Objectives: Cavity preparation is relationship with pulp. Explain the protecting the pulp with cavity. Describe the purpose of using cavity liners, list the type of materials that can be used

and explain the placement procedure. Describe the purpose of using cement base. List types of materials and placement

procedure. Course Outline: Introduction. Able to understand Pulp Protection Theory and Cavity preparation /Pulp protection. Describe the Practically in Treatment of Cavity Preparation. To recognize the Cavity Liners. To recognize the Cavity Varnish. To recognize the Cement Bases.

Introduction: Should be familiar preparation of the cavity with the amount of enamel and dentin

removed and how near the preparation is to the pulp. Should understand the pulp protection theory that the depth of cavity preparations and

pulpal relation. Cavity Preparation / Pulp Protection Theory: The cavity preparation for a restoration depends on the amount of decay, the location

of the decay, and the type of materials used to restore the tooth. Should examine the cavity preparation to assess pulpal involvement and then place

the liners, base, or varnish.

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Treatment of Cavity Preparation: Treatment of the ideal cavity preparation. Treatment of the beyond-ideal cavity preparation Treatment of the near-exposure cavity preparation

Table-7.1 Pulp Relation ( Cavity preparation Pulp Protection). Treatment of the ideal cavity preparation: A base is not required because only a minimal amount of enamel and dentin has been

removed. Some dentists place only the restoration, while other prefer to place a fluoride-

releasing liner If an amalgam restoration is going to be placed, two thin layers of cavity varnish are

often placed over the dentin. If a composite restoration is going to be used, a glass ionomer liner or calcium

hydroxide is placed over the exposed dentin.

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Treatment of the beyond-ideal cavity preparation: With a beyond-ideal preparation, the level of the dentin is restored with a cement

base. With an amalgam restoration, there are several options. One option is to place two

thin layers of varnish to seal the dentin tubules and then place a layer of a cement base, such as zinc phosphate.

Another option is a reinforced ZOE base, which has a soothing effect on the pulp. Varnish is not used with this material.

Other options include polycarboxylate or glass ionomer base, which also do not require varnish.

Under composite restorative materials, use a glass ionmer base or calcium hydroxide. Treatment of the near-exposure cavity preparation: The closer the cavity preparation comes to the pulp, the more precautions are needed.

There are also several options of treatment of the near-exposure preparation. Cavity which going to restore with amalgam, a liner of calcium hydroxide, glass

ionomer, or ZOE is placed first, then a layer of cement base such as Zinc phosphate, polycarboxylate, or glass ionomer cements.

Another option for amalgam restoration is to place a liner, then a layer of reinforced ZOE, polycarboxylate, or glass ionomer cement. This is then sealed with cavity varnish, although some dentist do not place cavity varnish.

Restore with composite, a liner is placed first, then place a layer of either polycarboxylate or glass ionomer cement.

A cavity liner is placed on a near exposure, the procedure isoften referred to as an indirect pulp capping.

Treatment of the exposed-pulp cavity preparation: In an exposed pulp, should be decided whether endodontic treatment is indicated or

should save the vitality of the tooth. If the treatment of choice is to save the pulp, a procedure called a direct pulp capping is performed.

On this direct pulp capping treatment, place the calcium hydroxide or glass ionomer liner and then reinforced ZOE as a temporary restoration. This gives the dentist time to see whether the pulp is going to heal.

Another treatment involves the placement of a liner, a layer of ZOE cement, two thin layers of varnish, and cement base.

Some dentist prefer to place a liner and then a layer of polycarboxylate or glass ionomer cement base.

Cavity Liners: Cavity liners are placed in the deepest portion of the cavity preparation on the axial

walls or pulpal walls.

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When the liners are hardened, they form as a cement layer with minimum strength. Liners are protect the pulp from chemical irritations and also provide a therapeutic

effect to the tooth. Liners are calcium hydroxide, zinc oxide eugenol, and glass ionomer. Liners also called low-strength base.

Fig-7.1 Placing Liners. Cavity Varnish: Cavity varnish is used to seal the dentin tubules to prevent acids, saliva and debris

from the pulp. It is used under amalgam restorations to prevent microleakage and under zinc

phosphate cement to prevent penetration of acids to the pulp. If cavity liners or medicated based are used, varnish is placed after or on top of these

materials.

Fig-7.2 Placement of varnish.

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Cement Bases: Cement bases are mixed to a thick putty consistency and placed in the cavity to

protect the pulp and provide mechnical support for the restorstion These cement bases are placed on the floor of the cavity Cement bases are glass ionomesr, hybrid ionomers, reinforced zinc oxide.

Fig-7.3 Placing Cement base. Reference: Phinney DJ, Halstead JH, 2000 Delmar’s Dental Assisting, Delmar Thomson

Learing.

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8. Impression taking on manikin and casting of impression as a laboratory work.

Objectives: • Identify the materials used in the dental laboratory and perform the associated

procedures. • Demonstrate the knowledge and skills needed to prepare, take, and remove alginate

impressions and wax bites. • Demonstrate the knowledge and skills necessary to prepare reversible hydrocolloid

impression material for dentist. • Demonstrate the knowledge and skills necessary to prepare elastomeric impression

materials such as polysulfide, silicone (polysiloxane and polyvinyl siloxanes), and polyether for the dentist.

• Demonstrate the knowledge and skills necessary to use gypsum products such as Type I: Impression plaster; Type II: Laboratory or model plaster; Type III: Laboratory stone; Type IV: Die stone; and Type V: High-strength die stone.

• Demonstrate the knowledge and skills necessary to pour and trim a patient’s alginate impression (diagnostic cast).

• Identify the use of a dental articulator for dental cast or study models. • Identify the different classifications and uses of waxes used in dentistry. • Demonstrate the knowledge and skills necessary to fabricate acrylic tray resin self-

curing and light-curing custom trays, vacuum-formed, and ther-moplastic custom trays

• Demonstrate the knowledge and skills necessary to contour prefabricated temporary crowns and to fabricate and fit custom temporary restorations.

Learning Outline:

• Introduction • Able to know and able to prepare the Hydrocolloid Impression Materials. • To get knowledge of Elastomeric Impression Materials. • To recognize the Gypsum Materials and able to prepare it. • To understandard the Articulating Cast or Study Models • To get knowledge of dental Waxes. • Able to prepare the Custom Trays • Able to Construct a Custom Tray • To recognize the Vacuum-Formed Tray. • Able to prepare Temporary Restorations.

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Introduction:

• A numbers of materials are used by dental laboratory and dental treatment room. • Some materials are used initially in the treatment room and then taken to the

laboratory , where a second procedure is completed. • Many models are taken to dental laboratory, where the laboratory technician complete

the procedures or the models are sent out to a commercial dental laboratory for additional procedures to be completed.

• A number of basic functions in the dental laboratory are routinely performed by dental assistant, such as pouring and trimming study models, fabricating custom trays, and fabricating temporaries.

• The dental assistant must understand the materials that are used, the properties of each material, and the step in each procedure.

Hydrocolloid Impression Materials:

• Impressions are taken to produce an accurate three dimensional duplicate of an individual’s teeth and surrounding tissues.

• The impression makes a negative reproduction where gypsum material can be poured and therefore creates a completed positive model.

• Normally, the impression material used is irreversible hydrocolloid, whch is commonly called alginate.

Alginate Impression Materials:

• Alginate is used for making diagnostic casts or study models • Alginate is used for making opposing model of fixed and removable prosthetics,

orthodontic appliances, mouth guards, bleach trays, provisional restorations, and custom trays.

Ingredient of Alginate:

• Primary ingredient is potassium alginate, it extracted from seaweed and kelp, which is a marine growth and found from coastline of Japan.

• Added to this potassium alginate is a calcium sulfate then forms a gel (solid). • To control the setting time and allow for the material to be placed in a tray and into

the patient’s mouth, trisodium phosphate is added. • A small amount of potassium titanium fluoride id added to soften the surface of the

gypsum products, not allowing it to fully set on the surface. Advantages of Alginate:

• Ease of manipulation • Minimal equipment required • Economical

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• Meets the requirements for accuracy for a number of applications • Rapid setting • Comfort for the patient • Can be used for both teeth and tissue impressions • Withdraws over undercuts because of its elastic properties.

Disadvantages of Alginate:

• The loss of accuracy due to atmospheric conditions. • If the impression is stored prior to pouring, it is susceptible to dimensional change due

to loss or gain of water. • If the impression looses water content due to heat, dryness, or exposure to air, it

causes shrinkage. This condition is known as syneresis. • Impression takes on additional water and causes swelling, the impression will have a

dimensional enlargement, known as imbibition. • It can cause some tissue distortion due to its thickened consistency. • It is not as precise or accurate as some of the other materials on the market.

Setting Time for Alginate:

• The time of alginate powder mixed with water completely set is called the gelatin time.

• The gelatin time is different depending on the type of materials used. Working and setting time is 1-2 minutes.

• There are Type I is fast-set alginate and Type II is a regular-set alginate. Working and setting time is 2-4 minutes.

Alginate packing, storage, and self live:

• Alginate is packing in air-tight plastic canisters or sealed bags. Figure-1 • It is important to storage in cool, dry place. • The normal self life for alginate materials is not more than one year.

Fig-8.1 Alginate with measuring devices.

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Fig-8.2 Fast Set Alginate Materials.

Fig-8.3 Silicone Impression Material (Base + Catalyst). Alginate Powder and water ratio:

• All the alginate materials come with their own measuring devices for both powder and water.

• First, read the manufacturer’s direction. • The water measure is normally a plastic cylinder with lines on it to indicate the

amount of water for each scoop of powder.

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• Normally, it takes two scoops of powder to two increments of water for each mandibular impression. Three of each is normally needed for maxillary impression. (depending on the size of patient’s arches)

Bowls and Spatulas Used for Alginate Impression:

• Flexible rubber bowl and stiff spatula to mix alginate. • Disposable bowl with built-in water measuring lines. • The flexible rubber bowl allows easy mixing of alginate and must be sterilized or

disinfected after use. • Disposable bowl and spatula can be thrown away.

Fig-8.4 (B) Bowl with water measuring (A) Disposable bowl and spatula for alginate and plaster. line and disposable spatula. Tray used for alginate impression:

• Several trays are available for alginate impression (Figure-8.5 (a, B). • Most commonly used are the perforated trays that come in metal and plastic. Some

are rim lock tray. • The trays have holes in them for the materials to ooze through and lock the

impression material in the tray. • Make sure the tray fits correctly in the patient’s mouth. • Metal trays can cleaned and reused after sterilization.

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A

B Fig-8.5 (A, B ) Various types of Impression Trays. Taking alginate impression for diagnostic casts ( Study model):

• In some states, dental assistants are allowed to take the alginate impressions. • While in other states, the dental assistant can select the tray, mix the materials, load

the materials into the tray, and pass the tray for dentist to place in the patient’s mouth.

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Fig-8.6 Alginate tray with beading wax on the periphery to comfort the patient. Preparing for alginate impression:

• Equipment and supplies • Flexible spatula / broad blade or disposable. • Flexible rubber bowl or disposable bowl • Alginate material with water and powder measuring devices. • Water • Impression trays

Step by step procedure:

• Patient preparation • Health history is reviewed. • The patient is seated in an upright position with a patient napkin in place. • The patient’s mouth is rinsed with water or mouth wash/rinse to remove any food

debris and thick saliva. • The procedure is explained to the patient. • Select the fit impression trays with mouth. • Materials Preparation: • Wax is placed around the borders of the impression trays (Figure-8.6) • The water is place in the bowel first and place the powder is incorporated into the

mixture.

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• Mix the water and powder first with a stirring motion. Then, mix by holding the bowl in one hand, rotating the bowl occasionally, and using the flat side of the spatula to incorporate the material through pressure against the side of the bowl (Figure-8.7).

• The mixing time for type I first-set is thirty to forty-five seconds; Type II regular set is one minute,

• The mixture should be homogeneous and creamy, then load it into the tray (Figure-8.8)

• The material firmly condense into the tray, if necessary smooth the surface, take a gloved hand, moisten, and smooth the top (Figure-8.9 )

• The mixing time for type I first-set is thirty to forty-five seconds; Type II regular set is one minute,

• The mixture should be homogeneous and creamy, then load it into the tray (Figure-8) • The material firmly condense into the tray, if necessary smooth the surface, take a

gloved hand, moisten, and smooth the top (Figure-8.10)

Fig-8.7 Mixing the alginate materials.

Fig-8.9Loading the alginate in the mandibular tray.

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Taking impression:

• Facing the patient, retract the right cheek slightly. • Use the excess alginate material to rub onto the occlusal surfaces of the teeth in order

to obtain more accurate anatomy. • Invert the impression tray so that the material is toward the teeth. • Turn the tray passes through the lip opening with one side of tray entering first, the

other hand to retract the opposite corner of the mouth. • When the tray is completely in the patient’s mouth, center it above the teeth. • Placing the posterior area first then leaving the impression tray slightly anterior. • Have the patient’s tongue raise and move it side to side to ensure the lingual aspect of

the alveolar process is defined in the impression. • Pull out the lip from the centre with other hand and finish placing the impression tray

down. • Allow the lip to cover the tray and hold it in the patient’s mouth with two fingers until

set (Figure-9.9). • To determine the material is set, it should feel firm and not change shape when

pushed. • Maxillary impression is loaded and completely fill the tray without voids (Figure-9.10

A). Smooth the material (Figure-9.10 B). • Take a small amount of alginate from the plate to prevent the impression material

going down the patient’s throat after insertion the tray (Figure-9.10 C).

Fig-8.9Holding the mandibular tray in the patient’s mouth.

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Fig-8.10 Taking Maxillary Impression. Inserting maxillary tray • Place the tray in the patient’s mouth, using the hand to retract the opposite corner of

the mouth (Figure-9.10 D). • Raise the tray to the maxillary arch and hold out the lip prior to seating the tray in

place. Hold it in position until the material is set in the bowl (Figure-9.10 E). Removing the alginate:

• When the material is completely set, remove it from the mouth by loosening the tissue of the lips and cheek.

• Place finger of the opposing hand on the opposite arch to protect the adjacent arch as tray is being removed.

• Remove the tray in an upward or downward motion (depending on the arch) with a quick snap

• Turn it to the side to allow it to be removed from the oral cavity. • Remove any excess alginate material from the mouth with evacuator and have the

patient rinse. Check patient face and give the patient a tissue and mirror to remove the materials.

• Check the impression for accuracy (Figure-8.11) • Rinse the impression with water to remove saliva or blood. • Maximum of twenty minutes prior to pouring, wrap the impression an air-tight

container or a moist towel.

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Fig-8.11 Impression after removed from the patient’s mouth. Disinfecting the impression: • Rinse the impressions with water to remove any debris, blood, or saliva. • Spray the impressions with an approved disinfectant (alcohol, phenolics, sodium

hypochlorite, and etc). • If not pouring immediately, place the impressions in a covered container. • Label the container with the patient’s name.

Accuracy of an alginate impression:

• The tray covers all the necessary area. • The tray is centered on the central incisors • The tray is not pushed down or up too far, allowing the teeth to penetrate through the

material to the tray. • The impression is not torn. • The impression is free of bubbles and voids. • The impression shows sharp anatomic detail of all the teeth and tissues. • The impression has a good “peripheral roll” and includes all the vestibules areas. • The mandibular impression shows good detail on the retramolar area and shows

lingual frenum and the mylohyyoid ridge area. • The maxillary impression shows good detail in the tuberosities and palate areas.

Wax bite registration:

• A wax bite registration is taken to establish the relationship between the maxillary and mandibular teeth.

• It can be used to verify the occlusal when trimming study models.

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• Normally a horseshoe shape wax and flat sheets wax are used for taking bite. • Polysilloxane is used for occlusal registration, patient is asked to close in the normal

biting position and remain closed until the materials set. • The set material removed, disinfected, stored, and used to establish the patient’s

occlusal relationship.

Procedure for taking bite: • The wax is heated in warm water or with a torch to soften the wax. • The wax is placed on the mandibular occlusal surface of the patient. If using

polysiloxane, it is extruded from disposable tip directly onto the occlusal surface of the mandibular teeth (Fig-9.12).

• The wax will cool in one to two minutes while the patient keeps the teeth together in occlusion. If using polysiloxane, the patient gently occludes until the material set (Figure-9.13).

• The wax or polysiloxane bite is then removed gently without distortion. • The wax or polysiloxane bite is disinfected, labeled, and stored fir use during

trimming casts (Figure-9.14).

Fig-8.12 Bite registration material is extruded onto. the occlusal surface of mandibular teeth.

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Fig-9.13 Patient gently occludes until material sets.

Fig-9.14 Wax bite, or polysiloxane bite. Reversible Hydrocolloid Impression Material ( Agar-Agar): • One of the first impression material used for final impression. • Composition for this material is seaweed and kelp. • A hydrocolloid conditioner unit is used for prepare the material for use. • This material used for crown and bridge construction.

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Fig-8.15 Reversible hydrocolloid impression material Figure-15, (A) Tubes. (B) Syringe and cartridges. (C) Trays used with the hydrocolloid conditioning unit to obtain final impressions.

Fig-8.16 Hydrocolloid conditioning unit.

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Elastomeric Impression Materials: • This materials have rubber-like qualities and used for that require precise duplication. • This is not affected by atmospheric change. • There are three groups: polysulfide, silicone, and polyether. • All have a catalyst and base and self-curing process. • Many of the material are dispensed in an “extruder gun” with a mixing tip (Fig-8.17).

Fig-8.17 Extruder gun cartridge and tips used in mixing and dispensing material. Equipment and supplies for polysulfide impression:

• Two rigid, tapered, laboratory spatulas. • Paper pad, provide by the manufacturer. • Two pastes each (two syringes, two trays) from the same manufacturer). • Impression syringe with tip in place and plunger out of the cylinder. • Custom tray. • Dispense the catalyst and base onto the pad (Figure-18). • Mix the materials and loaded into an impression syringe (Figure-19). Mixing and

loading time is four minutes. • The impression must remain in the patient’s mouth for six minutes to set.

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Fig-8.18 The polysulfate material is dispensed and ready for mix. The lines are equal length, but amount of material is different.

Fig-8.19 Loading the mixed material into the syringe for placement directly around the prepared tooth.

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Fig-8.20 Showing that the polysulfide materials provides for easy cleanup.

Fig-8.21 Putty type Impression.

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Fig-8.22 Silicone ( Polysiloxane ) impressional material.

Fig-8.23 The syringe material is extruded from the extruding gun into the prepared tray.

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Fig-8.24 Polyether impression material is dispensed on the paper pad, ready to be mixed.

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Fig-8.25 Mixed polyether is loaded into a syringe. Gypsum Materials:

• Type I: Impression plaster • Type II: Model or laboratory plaster • Type III: Laboratory Stone • Orthodontic Stone: Type II + Type III • Type IV: Die Stone • Type V: High-strength, High-Expansion Die Stone

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Water –powder ratio:

Gypsum

Powder/gm

Water/mL

Type I 100 grams to 60 mL

Type II 100 grams to 50 mL

Type III 100 grams to 30 mL

Type IV 100 grams to 24 mL

Type V 100 grams to 18-22 mL

Fig-8.26 Equipment needed to pour plaster (Pouring plaster into the impression).

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Fig-8.27 Measure 50 mL of water into a flexible mixing bowl.

Fig-8.28 Measure 100 gram of plaster powder for pouring an impression.

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Fig-8.29 The vibrator bring the air bubbles to the surface of the plaster.

Fig-8.30 Consistency of plaster position ready to pour model.

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Fig-8.31 Mixed plaster is vibrated into impression.

Fig-8.32 Plaster is gathered to make a base.

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Fig-8.33 Smooth out the plaster sides of the base after the filled impression is inverted on it.

Fig-8.34 Removing plaster from impression.

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Fig-8.35 The cast after trimming model.

Fig-8.36 The base of model before proceeding to trim.

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Fig-8.37 The base of the model is trimmed with trimming wheel.

Fig-8.38 A pencil line is drawn from 2 mm distal from last molar.

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Fig-8.39 The posterior of the base of the model is cut.

Fig-8.40 The models are placed together to trim the back cut.

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Fig-8.41 the models are placed on their backs on a hard, flat surface in occlusion to verify whether the back cuts are correct.

Fig-8.42 The vestibule or side area is cut at the deepest area. A line can be drawn to establish a proper cut.

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Fig-8.43 A line is drown from the midline of the central incisors to the middle of the cuspid to establish a cut line for the anterior.

Fig-8.44 The maxillary area is cut in a point, bringing both cuspid cuts to the midline between the maxillary central incisors.

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Fig-8.45 A rounded line is drown on the mandibular from the cuspids to cuspids to indicate where the cut should be made.

Fig-8.46 The heel cuts are established on the models and cut.

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Fig-8.47 Trimmed study model. Trimmed Diagnostic Casts ( Study Model ) Evaluation Fig-8.47.

• Both maxillary and mandibular models are trimmed symmetrically following specific cut angles indicated.

• All the anatomic portion of the model are accurate. • The trimmed models sit on end and maintain occlusion. • Models exhibit a one-half inch base each and a one inch anatomic portion each. • Final finishing is accomplished and the models present a professional appearance.

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Fig-8.48 Articulator is used to duplicate the patient’s occlusion on models. Dental Wax:

• Groups of waxes • Pattern wax • Processing wax

Sticky wax Utility wax

• Impression or bite registration wax • Additional waxes

Fig-8.49 Pattern waxes. (A) Inlay wax. (B) Base plate wax.

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Fig-8.50 Processing waxes, (A) Boxing wax. (B) Utility wax. (C) Sticky wax

Fig-8.51 Study Wax Block.

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Custom trays:

• The custom tray are used get accurate impression. • A custom tray can be fabricated to meet the need of impression. • Several materials are available to make custom trays, it may constructed from self-

cure or light-cure acrylic resin, or a thermoplastic material. • All the materials must be rigid enough to provide substance. • The material adapts well during the construction.

Required Criteria For A Custom Trays:

• Stable enough to hold the material rigid during placement and removal. • Can be smooth and contoured to the arch. • Can be adapted to an edentulous, a partially edentulous, and a full dentition. • Can be adapted to allow uniform thick ness of impression materials in all area of the

arch. • Can be altered and contoured to any irregular area. • Can be designed so that stops are in the spacer, therefore holding material in a stable,

specifically determined area, providing a more accurate impression. Types of Available Custom Trays:

• Acrylic Tray Resin Self-Curing Custom Trays. • Acrylic Tray Resin Light-Curing Custom Trays. • Vacuum-Formed Custom Trays. • Thermoplastic Tray Material Custom trays.

Constructing a custom tray:

• The tray margin is outlined on the stone cast. The deepest area is marked in blue color and 1 to 2 mm up from that a red line indicating where the wax spacer is to be located and can be drown as shown in Figure-52.

• A wax spacer is trimmed to the indicated line on the working cast (fig-8.53). • Stops are cut into the wax spacer. These allow room for the impression material

(Figure-54). • The custom tray materials is kneaded for use (Figure-55). • (A). The custom tray material is adapted to the model over the wax spacer. (B). The

handle is attached to the adapted custom tray (Figure-56). • The custom tray is trimmed with acrylic bur (Figure-57). • The adhesive is applied in a thin coat to the custom tray and allowed to dry (Figure-

58). • Various types of vacuum-formed materials (Figure-59). • Constructing vacuum-formed acrylic custom tray. The resin sheets are secured in

placed and the cast is placed on the platform of the vacuum-forming unit (Figure-60).

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• The resin sheet is begins sagging as the material is heated (Figure-61). • When the resin material sagged one inch below the holding ring, it is ready to be

dropped into the position over the cast. The unit is held by the handles to ensure that the operator is not burned (Figure-62).

• The vacuum form can be trimmed with scissors (Figure-63).

Fig-8.52 Constructing Custom Tray.

Fig-8.53A wax spacer is trimmed to the indicated line on the working cast.

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Fig-8.54 Stops are cut into the wax spacer. These allow room for the impression material.

Figure-8.55The custom tray materials is kneaded for use.

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Figure-8.56 (A). The custom tray material is adapted to the model Over the wax spacer. (B). The handle is attached to the adapted custom tray.

Figure-8.57 The custom tray is trimmed with acrylic bur.

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Figure-8.58 The adhesive is applied in a thin coat to the custom tray and allowed to dry.

Figure-8.59 Various types of vacuum-formed materials.

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Figure-8.60 Constructing vacuum-formed acrylic custom tray. The resin sheets are secured in placed and the cast is placed on the platform of the vacuum-forming unit.

Figure-8.61 The resin sheet is begins sagging as the material is heated.

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Figure-8.62 When the resin material sagged one inch below the holding ring, it is ready to be dropped into the position over the cast. The unit is held by the handles to ensure that the operator is not burned.

Figure-8.63 The vacuum form can be trimmed with scissors.

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Types of temporary restoration:

• Performed aluminum temporary crown.

• Performed acrylic temporary crown.

• Custom temporary restoration. Preparation for temporary crown:

• Sizing, adapting, and seating an aluminum temporary crown. Selection of temporary

crown (Figure-64). • An explorer is used to establish the height of the temporary crown (Figure-65). • The aluminum crown is trimmed with crown and collar scissors (Figure-66). • Smooth the rough and jagged edges of the temporary crown (Figure-67). • Sizing, adapting, and seating a performed acrylic crown. Selection of acrylic

temporary crown (Figure-68). • The acrylic crown is tried over the prepared tooth, holding on to the incisal tab

(Figure-69). • Temporary materials (Figure-70).

Figure-8.64 Sizing, adapting, and seating an aluminum temporary crown. Selection of temporary crown.

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Figure-8.65 An explorer is used to establish the height of the temporary crown.

Figure-8.66 The aluminum crown is trimmed with crown and

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collar scissors.

Figure-8.67Smooth the rough and jagged edges of the temporary crown.

Figure-8.68 Sizing, adapting, and seating a performed acrylic crown. Selection of acrylic temporary crown.

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Figure-8.69 The acrylic crown is tried over the prepared tooth, holding on to the incisal tab.

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Figure-8.70 Temporary materials.

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Custom temporary restoration:

• Criteria for temporary restoration • (A ).Good proximal contacts • (B ). Good Acclusal contacts • (C ). Good food deflection • (D ). Good marginal contour

Fig-8.71 Criteria for custom acrylic or composite temporary restoration.

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Fig-8.72 Adapting, trimming, and seating a matrix and custom temporary restoration. The matrix is removed.

Fig-8.73 Removed the acrylic bridge from the matrix.

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Fig-8.74 Trimming the temporary. Cementing the temporary restoration:

• Equipment • Temporary luting cement • Paper pad • Mixing spatula plastic filling instrument • Dental floss • Procedure • Prepared tooth is rinse and dry • Cement is mixed and placed temporary restoration • Temporary restoration is placed on the prepared tooth and ask the patient to bite

occlusion or operator will hold the temporary restoration until cement is set. References:

• Phinney DJ and Halstead JH, 2000 Delmar’s Dental Assisting, Delmar Thomson Learing.

• Kidd EAM, Smith BGN, and Watson TF, 2006 pickard’s Manual of Operative Dentistry, 8th.edn,Oxford.

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9. Isolation of the working field: placement of rubber dam.

Objective of study: Discuss moisture control techniques used in dental procedures. Describe the two types oral evacuation systems. Describe the benefits for a procedure and a patient when using

dental dam. Learning outline:

Introduction To know the procedure of Mouth rinsing Able to understandard Oral evacuation method To recognize the Isolation techniques To get knowledge of the Placement of rubber dam.

Introduction: A clinical assistant should be maintain the clinical field. The tooth, the surrounding tissue, and oral cavity can become a “catch all” for water,

saliva, blood, and tooth fragments. The type of procedure will dictate the type of isolation method Fluids need for removed from the mouth for the patient’s comfort and to improve the

dentist’s vision. The procedure of Mouth rinsing:

Two basic types of rinsing procedures used in dentistry. Limited-area rinsing: :Performed frequently, quickly and efficiently without delay in

the procedure. The complete moth rinse: :Performed at the completion of dental procedure, to leave

the patient with a comfortable and fresh feeling.

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The Oral evacuation method: Saliva ejector High-volume oral evacuation Oral evacuation caution HVE Tip Holding the oral evacuator

Saliva ejector: This instrument used to remove small amounts of saliva and water from patient’s

mouth. This small straw like tube has flexibility to conform to many areas in the mouth. Placement of saliva ejector is simple and comfortable for the patient. Can bend the shape of a candy cane and place it under the tongue on the opposite side

from your working place.

Fig-9.1 Bend the Saliva Ejector.

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Fig-9.2 A Type of Saliva Ejectors.

High-volume oral evacuation:

The high-volume oral evacuator (HVE) is a stronger source of moisture control The HVE system is as a vacuum principle like a household vacuum cleaner. It was used for maintain the mouth free from saliva, blood, water, and debris. Also used for retract the tongue or cheek away from the procedure site.

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Fig-9.3 High-volume oral Evacuator. Oral evacuation caution:

HVE can cause sift tissue to be accidentally “sucked” into the tip and tissue damage

could result. If the soft tissue is accidentally “sucked” into the tip, rotate the angle of the tip to

break the suction or quickly turn the vacuum control off, to release the tissue.

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Fig-9.4 The HVE tip is placed on the opposite site. HVE Tip:

HVE tips are made by a semihard plastic which can sterilized after single use. Tips are also made by a stainless steel, which also can be sterilized before reuse. HVE tips are available either with straight or a slight angle in the middle.

Holding the oral evacuator:

The oral evacuator may held in two ways. Thumb-to-nose grasp Pen grasp To be most efficient in HVE placement, should position the HVE tip in the mouth

first and then position the handpice and mouth mirror.

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Fig-9.5 Method of holding oral evacuator tip. Top: :thumb-to-nose grasp. Bottom: :pen grasp.

The Isolation techniques:

Cotton Rolls: : During the placement of amalgam or composite or cement

restoration, a clean ,dry environment is necessary. On the method of ensuring dry condition is the used of cotton rolls. When a dental dam is not an option, cotton roll isolation is used as an alternative

method to control moisture in the operative area.

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Fig-9.6 Isolation With Cotton Roll.

Fig-9.7 Type of Cotton Roll.

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Cotton Roll Placement: Maxillary arch: :cotton rolls are placed on the cheek side of the teeth in the

mucobuccal fold. Mandibular arch: :cotton rolls are placed in the mucobuccal fold and on the lingual

side of the arch.

Fig-9.8 Cotton Roll Placement on Maxillary Arch.

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Fig-9.9 Cotton Roll Placement on Mandibular Arch. Cotton roll removal: At the completion of a procedure, remove the cotton roll before the full-mouth rinse.

If the cotton roll is dry, moisten it with water from air-water syringe. Using cotton pliers, retrieve the contaminated cotton roll from the site. If appropriate for the procedure, perform a limited rinse.

Related Aids: Dry Angles Some dentist use a triangle-shape absorbent pad To isolate posterior areas in both maxillary and mandibular arch. The pad is placed on the buccal mucosa. To remove it, used water and wet the pad and separate from tissue.

The Placement of rubber dam. The dental dam is a thin latex barrier used to isolate a specific tooth or several teeth. The dental dam is applied after the local anesthetic has been administered. Before the application of dental dam, the isolated tooth should be clean and free of

plaque or debris.

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Before the placing the dental dam, review the patient’s medical history for any indication of latex sensitivity.

The specialized equipment used for the rapid and efficient placement of the dental rubber dam is shown in following figure-9.10.

Fig-9.10 Dental dam and equipments.

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Fig-9.11 Placement and removal of rubber dam. Basic Setup: Precut 6-by-6 inch dental dam Dental dam stamp and inkpad or template and pen Dental punch Dental dam clamp or clamps with ligature attached Dental dam clamp forceps Young frame Dental dam napkin Dental tape or waxed floss Cotton rolls Lubricant for patient’s lip Lubricant for dam Black spoon Crown and bridge scissors

A set of rubber dam (fig-9.1): GW: Premolar clamp EW: small tooth AW: : Molar BW: :Molar JW: :Molar Ferrier: :Anterior tooth

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Fig-9.12 A set of Rubber Dam. Punching the dental dam Use a template or stamp to mark on the dam the teeth to be isolated. Correctly punch the marked dam according to the teeth to be isolated. Be sure to use

the correct size of punch hold for the specific tooth. If teeth have tight contacts, lightly lubricate the holes on the tooth surface of the dam.

Placing the clamp and frame Select the correct size of clamp. Secure the clamp by tying a ligature of dental tape on the bow of the clamp. Place the beaks of the rubber dam forceps into the holes of clamp. Grasp the handles

of the rubber dam forceps, and squeeze to open the clamp. Turn upward , and allow the locking bar to side down to keep the forceps open for placement.

Place yourself in the operator’s position, and adjust your patient for easier access. Retrieve the rubber dam forceps. Position the lingual jaws of the clamp first, then the

facial jaw. During the placement, keep index finger on the clamp, check the clamp for fit.

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Lingual jaw placement same as facial jaw. As shown the following figure-9.13.

Fig-9.13 Retrieve the dam. Transfer the dental dam: Transfer the dental dam as shown in following figure-9.14 to the site, stretch the

punched hole for the anchor tooth over the clamp. Using the cotton pliers, retrieve the ligature and pull it through and easy to grasp. Position the frame over the dam and slightly pull the dam, allowing it to hook onto the

projections of the frame. Ensures a smooth and stable fit.

Fig-9.12 Transfer the dental Dam.

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Position the frame: Fit the last hole of the dam over the last tooth to be exposed at the opposite end of the

anchor tooth. Using the index fingers of the both hands (fig-9.15), stretch the dam on the lingual

and facial surfaces of the teeth. With a piece of dental tape or waxed floss, floss through the contacts, pushing the

dam below the proximal contacts of each tooth to be isolated. A ligature is placed to stabilize the dam at the opposite end of the anchor tooth.

Fig-9.15 Position the frame. Inverting the dam: Invert, or reverse, the dam by gently stretching it near the cervix of the tooth. Inverting the dam creates a seat to prevent the leakage of saliva. Apply air from air-water syringe to the tooth being inverted to help in turning the dam

material under. A black spoon or burnisher can be used to invert in edges of the dam. When all punched holes are properly inverted, the dental dam application is complete. For patient comfort, a saliva ejector can place under the dam. If the patient is uncomfortable to breath, cut a small hold in the palatal area.

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Fig-9.16 Inverting the dam. Removing the dental dam: Remove the ligature first. If saliva ejector was used, remove it. Slide your finger under the dam parallel to the arch, pull outward so that you are

stretching the holes away from the isolated teeth. Working from posterior to anterior, use the crown and brides scissors to cut from hole to hole, creating on long cut.

When all septa are cut, the dam is pulled lingually to free the rubber from the interproximal space.

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Fig-9.17 Removing the dam and frame. Using the dental dam forceps Remove both the dam and the frame at one time. Use a tissue or the dam napkin to wipe the patient’s mouth, lips, and chin free of

moisture. Inspect the dam to ensure that the entire pattern of the torn septa of the dental dam has

been removed.

Fig-9.18 Removing the dam.

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Fig-9.19 Removed the dental frame. If a fragment of the dental dam is missing, use dental floss to check the corresponding

interproximal area of the oral cavity. Fragments of the dental dam left under the free gingiva can cause gingival irritation.

Reference: Robinson DS, Bird DL, 2007 Essentials of dental Assisting, 4th.edn, Saunders. Kidd EAM, Smith BGN, and Watson TF, 2006 Pickard’s Manual of Operative

Dentistry, 4th. edn, Oxford.

ASSIGNMENT AS A GROUP PROJECT (STUDENT DIRECTED LEARNING)

Topics are related to the above demonstration. This will be followed by a 30 minutes presentation by the groups in the 5th and 10th week.

1. Tooth filling materials 2. Causes and the treatment of shock 3. Types of rotary instruments 4. Types of impression materials in dentistry.

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