Introduction into operative dentistry.pdf mazen doumani

Mazen Deeb Doumani

History

Operative Dentistry was considered to be the entirety of the clinical practice of dentistry, from which most other aspects do dentistry evolved.

History In USA, Dentistry originated in 17th century, when several barbers were sent from England.

Dental practice was limited to tooth extraction without scientific-basis.

History

In 1840, First evidence for dental education at Baltimore college of dental surgery,

followed by starting dental programs in Harvard University in 1867.

History G. V. Black became the founder of the dental professions,

(Why?)

• Related the clinical practice of dentistry to a scientific basis.

• Standardized both; cavity preparation & manufacturing process of silver fillings.

The scientific foundation for operative dentistry was further expanded by black's son, Arthur Black.

Definition: It is the art & science concerned with all procedures by which defects in hard structures are diagnosed, treated, eliminated, prevented & the lost teeth structures are restored.

Factors affecting operative treatment

I. Indications:

The three main categories that primary needs restorative treatment:

1) caries

2) malformed, discolored , non-esthetic, or fractured teeth

3) restoration replacement or repair.

Factors affecting operative treatment:

II. Considerations:

1. An understanding of and appreciation for infection control measurments.

2. A thorough examination of not only the affected tooth.

3. A diagnosis of the dental problem.

4. A treatment plan to enhance the overall health and well-being of the patient

Factors affecting operative treatment: II. Considerations: 5. An understanding of the material to be used to restore the

affected area.

6. An understanding of the microbial nature of oral environment

7. The necessary biologic knowledge of the various tooth components and supporting tissues.

8. The effect of the operative procedure on other dental treatments.


III. Conservative Approach: The rule “Extension

for Prevention” is not followed any more, (Why ?) Caries

Prevention Methods

Improved Restorative Materials

Advanced Clinical

Techniques


III. Conservative Approach: More conservative approaches are now available for:

1) Many typical restorative procedures (classes I, II, III, IV, and V).

2) Diastema closure procedure.

3) Esthetic and/or functional correction of malformed, discolored, or fractured teeth.

4) Actual replacement of teeth.


IV: Dynamics Of Operative Dentistry:

Advances in treatment techniques, philosophies, and materials almost certainly will be made, just as in the past several decades, technological and scientific advances have dramatically affected the need for restorative services.

Projected Need For Operative Dentistry: 1) Restorations for teeth with carious lesions.

New caries:

• Caries incidence in children

(ages 5 to 17) is 45% .

• By age 17, 3:4 adolescents

have experienced caries.

• caries percent may be

higher in people over 55

years old .

Less than 6% of people

ages 18 to 64 have no caries.

Root caries:

increased of Root caries

incidence is due to:

• periodontal diseases.

• systemic problems

¼ of all dentate adults have

evidence of root caries.

Projected Need For Operative Dentistry: 2) restorations to replace existing, faulty restorations.

75% of all operative treatment is due to replacement of existing restorations, specially for patients older than 40.

Projected Need For Operative Dentistry: 3) Restorations to enhance the esthetic appearance of patients.

The incidence of Esthetic Restorations is increased due to:

• the publicity in the form of magazine articles, television shows, and special news programs.

• With more teeth being retained, more people are likely to seek appearance enhancement.

10% of a dentist's gross income was derived from esthetic treatment on non-carious teeth.

Public's Perception Of Dentistry: The public considers dentists and dentistry very positively.

• The public ranks a dentist as one of the most respected members of the community.

• Dentistry has the highest satisfaction rating when the public assesses the services they receive.

• The public appreciates the benefits of good dental health.

All of this suggests a continuing demand for operative services.

Lesions Affecting The Calcified Tooth Structures:

1) Dental Caries.

2) Erosion.

3) Abrasion.

4) Attrition.

5) Fracture.

6) Nonhereditary Enamel Hypoplasia.

7) Amelogenesis Imperfecta.

8) Dentinognesis Imperfecta.

2) Erosion: Definition:

It is the irreversible loss of tooth structure due to chemical dissolution by acids not of bacterial origin.

Causes:

Extrinsic acidic sources

• Acidic drinks and foods of low pH include; fruit juices, sports drinks, and carbonated drinks.

Intrinsic acidic sources

• Gastric acid from the stomach comes into contact with the teeth, associated with diseases such as anorexia nervosa, bulimia, and gastroesophageal reflux disease often suffer from this.

http://en.wikipedia.org/wiki/Gastric_acid

http://en.wikipedia.org/wiki/Anorexia_nervosa

http://en.wikipedia.org/wiki/Bulimia

http://en.wikipedia.org/wiki/Gastroesophageal_reflux_disease



3) Abrasion: Definition:

It is the abnormal loss of the tooth structure due to frictional forces from a foreign element

Causes:

Possible sources of this wearing of tooth are toothbrushes, toothpicks, floss, and any dental appliance frequently set in and removed from the mouth.

http://en.wikipedia.org/wiki/Toothbrush

http://en.wikipedia.org/wiki/Toothpick

http://en.wikipedia.org/wiki/Dental_floss

• The appearance is commonly described as V-shaped .

• The teeth most commonly affected are premolars and canines.

http://en.wikipedia.org/wiki/V-shaped



http://en.wikipedia.org/wiki/Premolar

http://en.wikipedia.org/wiki/Canine_tooth

4) Attrition: Definition:

• It is the mechanical wear of the incisal or occlusal surfaces as a result of functional or para functional habits (Bruxism, Clenching).

N.B:

It includes proximal surfaces at the contact area due to the physiological tooth movement.

4) Attrition: Characteristic Features:

Development of a facet (flat surface with circumscribed and well defined border).

5) Fracture Classification:

I. Incomplete Fracture Not Involving The Pulp (Cracks)

• Not painful, or pain is associated with mastication.

• Patient can't identify the offended tooth.

• Difficult to be diagnosed or treated.

5) Fracture Classification:

II. Complete fracture

• Not involving the pulp

If Limited to enamel not sensitive.

If Limited to dentin sensitive (due to exposed dentin / irritation of PDL).

• Involving the pulp

Sever pain, increases with infection

6)Nonhereditary Enamel Hypoplasia: Definition:

It is defective enamel formation with whitish to light brown area due to the injury of ameloblasts during enamel deposition,

Most common site:

• Anterior teeth, 1st molars

7) Amelogenesis Imperfecta: The enamel is defective either in form or calcification as a result of heredity and has an appearance ranging from essentially normal to extremely unsightly

8) Dentinognesis Imperfecta: It is a hereditary condition in which only the dentin is defective. Normal enamel is weakly attached and lost early.

The Lesion, Etiology, Prevention, and Control

Introduction & Definitions Dental plaque:

It is a gelatinous mass of bacteria adhering to the tooth surface. • The plaque bacteria metabolize refined

carbohydrates (sucrose) for energy and produce organic acids as a by-product. These acids may cause a carious lesion by dissolution of the tooth's crystalline structure.

Introduction & Definitions Dental caries:

• It is an infectious microbiologic disease of the teeth that results in localized dissolution and destruction of the calcified tissues.

Etiology of Caries • Oral bacterial flora composed of a complex

community of many species, represented as a mass of tightly packed cells held together by the sticky matrix of polymerized glucose.

• The most common cariogenic bacteria is Streptococcus mutans (MS) & lactobacilli that produce great amounts of acids (acidogenic), are tolerant of acidic environments (aciduric), are vigorously stimulated by sucrose.

Etiology of Caries • Exacerbations of caries activity are

characterized by periods of high bacterial metabolic activity and low pH in the plaque near the tooth surface.

• The pH rises (above 5.5) during intervening episodes, aiding in remineralization of the damaged tooth structure using calcium and phosphate ions in Saliva.

Epidemiology of Caries • The number of individuals in a population

having a disease at a specific point in time is known as the prevalence of the disease.

The number of individuals developing new cases of disease in a population over a specific period of time, usually 1 year, is the incidence of the disease.

Epidemiology of Caries The most common epidemiologic measure of caries is an evaluation of the number of permanent teeth that are diseased, missing, or filled DMF, (Measures of primary teeth are reported as dmf).

based on teeth DMFT, dmft

based on surfaces affected DMFS, dmfs

Classification of Caries 1) according to the attack

• primary caries:

it is the first attack of caries in the previously sound healthy tooth.

• Secondary (recurrent) caries:

it occurs with a restored tooth, at the borders of a restoration then under it.

Classification of Caries 2) According to the onset Acute (Rampant) Caries: It is when caries rapidly damage the tooth structure (painful, soft & light in color).

Chronic Caries It Is When caries occurs over time and demands regular dental intervention, (Brown in color).

Arrested Caries It Is when caries progress paused without actual damage to tooth structure, (Black in color).

Theories of Caries

1) Acidogenic Theory

2) Proteolytic Theory

3) Proteolysis Chelation Theory

Theories of Caries 1) Acidogenic Theory

caries is a chemo-parasitic process consisting of:

1st stage:

• fermentation of the food materials by micro-organisms → liberation of lactic acids → demineralization of the inorganic substance → softening of the tooth.

2nd stage:

• dissolution of the soft part of the tooth, due to the proteolytic enzymes of the micro-organisms.

Theories of Caries 2) Proteolytic theory

• It was found that caries can develop when the pH of the dental plaque is 6-8

• It also can occur without the presence of of food debris, as in:

Caries of impacted / uneruptrd tooth.

Caries under perfectly sealed restoration.

Theories of Caries 3) Proteolysis chelation theory

the release of a variety of complexing agents, as aminoacids, poly phosphates and organic acids which then dissolve the crystalline apatite.

Clinical Sites For Caries Initiation:

1. Developmental pits and fissures.

2. Smooth enamel surfaces.

3. Root surface.

The pits and fissures of newly erupted teeth are rapidly colonized by bacteria.

Clinical Sites For Caries Initiation: (1) Pits and Fissures:

There is considerable morphologic variation of the pits and fissures that contributes to higher susceptibility to caries. a) shallow groove. b) complete penetration. c) end blindly. d) open into an irregular chamber.


Pit & fissure caries expands as it penetrates into the enamel. Thus, the entry site may appear much smaller than the actual lesion, making clinical diagnosis difficult.


Common sites:

1. Proximal surfaces that are gingival to the contact.

2. Non-contacting proximal surfaces because of tooth surface contour or position.

3. Areas gingival to the height of contour of the facial and lingual surfaces.

Clinical Sites For Caries Initiation: (2) Smooth Enamel Surfaces:

Lesions starting on smooth enamel surfaces have a broad area of origin and a conical, or pointed, extension toward the DEJ. The path of ingress of the lesion is roughly parallel to the long axes of the enamel rods in the region

Clinical Sites For Caries Initiation: (2) Smooth Enamel Surfaces:

• The root surface is rougher than enamel → allowing plaque formation in the absence of good oral hygiene.

• The cementum covering the root surface is extremely thin and provides little resistance to caries attack, and so progress more rapidly.

• Root caries lesions have less well defined margins, tend to be U-shaped in cross-section.

Clinical Sites For Caries Initiation:

(3) Root Surfaces:

Histopathology of Caries Enamel Caries

Histological Characteristics:

In cross-section, the gross appearance of a carious lesion at:

• Pit & fissure lesion shows an inverted V with a narrow entrance and a progressively wider area of involvement closer to the DEJ.

• Smooth surface lesion shows a V shape with a wide area of origin and the apex of the V directed toward the DEJ.

Zones of Incipient Lesion:

1) The translucent zone.

2) The dark zone.

3) The body of the lesion.

4) The surface zone.


Zone 1: Translucent Zone

• The deepest zone is the translucent.

• It has a structureless translucent appearance,

• The pore volume of the translucent zone of enamel caries is 1%, 10 times greater than normal enamel.


Zone 2: Dark Zone,

• It does not transmit polarized light.

• It has a structureless dark appearance,.

• The total pore volume is 2% to 4%.

• The size of the dark zone is probably an indication of the amount of remineralization that has recently occurred.


Zone 3: Body of the Lesion,

• It represents the largest portion of the lesion & has the largest pore volume, varying from 5% at the periphery to 25% at the center.

• The striae of Retzius are well marked, indicating preferential mineral dissolution.

• Bacteria may be present in this zone if the pore size is large enough to permit their entry.


Zone 4: Surface Zone,

• It appears as unaffected enamel & has a lower pore volume than the body of the lesion (less than 5%)

• Layer radiopacity is comparable to unaffected adjacent enamel.


Zones of Dentinal Caries

• Zone 1: Normal Dentin

• Zone 2: Subtransparent Dentin

• Zone 3: Transparent Dentin

• Zone 4: Turbid Dentin

• Zone 5: Infected Dentin

Histopathology of Caries Dentin Caries

• In managing caries, the objective is to focus on the diagnosis, preventive measures, and treatment modalities.

• It is imperative to understand that restorative treatment does not cure the carious process. Instead, identifying and eliminating the causative factors.

Management of Caries

Dr Mazen D Doumani

Caries Diagnosis The primary objectives of caries diagnosis are to identify:

Lesions require surgical (restorative) treatment.

Lesions require nonsurgical treatment.

Preventive strategies for persons who are at high risk for developing carious lesions.

Caries Diagnosis: assessment tools

1) Patient history. 2) clinical examination. 3) Nutritional Analyses. 4) Salivary Analyses. 5) Radiographic Assessment

• Factors include: age (children and elderly), gender, decreased fluoride exposure, increased smoking habits, increased alcohol intake, medications, high sucrose intake, lower economic, lower educational status, and poor general health result in increased risks for caries development.

past caries experience is the best predictor of future caries activity.

Caries Diagnosis Assessment Tools

1) Patient history

• General information regarding inadequate salivary functioning, plaque accumulation, inflammation of soft tissues, poor oral hygiene, and also are instructive in determining potential risk to caries development.

• The tooth surface is examined visually and tactilely.


2) Clinical Examination

• Visual evidence of caries includes detection of cavitation, surface roughness, faulty existing restorations, opacification, and discoloration.



• Drill & fill Approach means penetration and resistance to removal of an explorer tip (a "catch") have been interpreted as evidence of demineralization and weakening of tooth structure.



• Frequent exposure to sucrose increases the likelihood of plaque development by the more cariogenic MS organisms


3) Nutritional Analyses

• It may provide important information about secretion rates, buffering capacity, and numbers of both MS and lactobacilli.

Caries Diagnosis Assessment Tools 4) Salivary Analyses

• Dental radiographs may show caries that is not visible clinically.

• Despite of this, many proximal lesions evident radiographically are not cavitated (60%) and should be remineralized rather than restored.


5) Radiographic Assessment.

New techniques are available for earlier detection, including digital radiography, and quantitative light-induced fluorescence

• Discoloration of pits and grooves, limited to the depth of the fissure or pit, is almost a universal finding in normal healthy teeth of adults.

Caries Diagnosis For Pits And Fissures:

Cavitation at the base of a pit or fissure sometimes can be detected tactilely or visually.

additional criteria have been developed by the U.S. Public Health Service for pit-and-fissure caries diagnosis. These factors are:

1. Softening at the base of the pit or fissure.

2. Opacity surrounding the pit or fissure.

3. Softened enamel may be flaked away by extensive explorer penetration.

4. On bitewing radiographs, evidence of dentinal caries.

Caries Diagnosis For Pits And Fissures:

• Bitewing radiographs are the most typical method for evaluation of the proximal smooth surfaces.

• A common diagnostic error; noncavitated caries appear as well-defined radiolucent area,

Caries Diagnosis For Smooth Surfaces:

Many incipient proximal lesions in healthy patients end up as arrested lesions.

• Root caries may become more common in the population.

• Visual examination: shallow initially, spreads laterally, discoloration associated with remineralization.

• No patient symptoms.

Caries Diagnosis For Root Surfaces:

• The lesion development may be rapid

The goal is Limitation of tooth demineralization by cariogenic bacteria, in order to:

• Control the already existed carious lesion .

• Prevent the initiation of new lesions.

Through:

(1) Limiting pathogen growth and metabolism.

(2) Increasing the resistance of the tooth surface to demineralization.

Caries Prevention:

• A caries prevention program is a complex process involving multiple interrelated factors, such as:

1) General health

2) Fluoride exposure

3) Immunization

4) Salivary functioning

5) Antimicrobial agents

Which factor the patient usually is capable to control?

Caries Prevention:

6) Diet

7) Oral hygiene

8) Xylitol gums

9) Pit & fissure sealants

10)Restorations

Declining health signals the need for increased preventive measures, (Why?)

• Patients undergoing radio/chemotherapy have significantly decreased immune-competence and are at risk for increased caries.

Caries Prevention 1) General Health:

Fluoride in trace amounts increases the resistance of tooth structure to demineralization.

Sources of fluoride: fluoridated community water systems, diet, toothpastes, mouth rinses, & professional topical applications.

• Excessive fluoride exposure (10 ppm or more) results in fluorosis, a brownish discoloration of enamel, termed mottled enamel.

Caries Prevention 2) Fluoride Exposure

Bacteria passing through the mouth into the stomach and intestines → come into contact with specialized lymphoid tissue (Peyer's patches) → sensitizing certain T and B cells → migrate through bloodstream → settle in the salivary glands → produce IgA → secreted in the saliva → agglutination of oral bacteria → prevents adherence to the teeth.

Caries Prevention 3) Immunization

Xerostomia may occur because of aging, or medication.

Consultation with the physician may be necessary to identify alternate treatments, if possible, with less salivary impact.

Saliva stimulants (gums paraffin waxes, or saliva substitutes) .

also may be prescribed for patients with impaired salivary functioning.

Caries Prevention 4) Salivary Functioning

Chlorhexidine

• It interacts with MS organisms while adhering to oral structures.

• It was first available in the United States as a rinse.

• Prescription: as a 0.12% rinse or varnish for high-risk patients for short-term use.

Caries Prevention 5) Antimicrobial Agents

Caries activity is most strongly stimulated by the frequency rather than the quantity of sucrose ingested.

Caries Prevention 6) Diet

Daily removal of plaque by dental flossing, tooth brushing, and rinsing is the single best measure for preventing both caries and periodontal disease.

Caries Prevention 7) Oral Hygiene

• Supragingival plaque → etiologic agent of long-standing gingivitis → damage of the epithelial attachment → progression to a more serious periodontal disease.

• Oral hygiene measures → Effective plaque control → resolution of the gingival inflammation and remineralization of the enamel surface.

Caries Prevention 7) Oral Hygiene

Indications:

• Prevent caries in newly erupted teeth,

• Arrest incipient caries, by cutting off the nutrient supply to the pathogenic plaque trapped under the sealant.

• Prevent odontopathogenic bacterial growth in sealed fissures,

• Prevent infection of other sites.

Caries Prevention

9) Pit & Fissure Sealants:

The treatment regimen is dictated by the patient's caries status.

• Patient with high risk for caries development, treatment should consist of both restorative procedures and many of the preventive measures described previously.

Caries Treatment

Patients with acute carious lesions, caries control restorative treatment may be indicated first.

Technique:

(1) removing the infected tooth structure.

(2) medicating the pulp, if necessary.

(3) restoring the defects with temporary / permanent.

(4) application of other preventive measures.

Caries Treatment

Dr. Mazen D Doumani

introduction Rotary instruments are the most universally used

instruments for gross removal of tooth structure.

Rotary instruments are tools or attachment that are fitted in the handpiece and work by energy delivered from a source of power.

Handpiece

Rotary instrument

introduction They are chiefly used for the removal of tooth

structure and restorative materials.

The ideal preparation is done by a combination of rotary and hand cutting instruments.

Rotating instruments in operative dentistry are either:

1- Dental handpieces

2- Dental burs

3- Dental abrading tools

Each one is designed for a specific range of functions

1- dental handpieces

a) straight handpieces.

b) Contra-angle handpieces:

i. Low speed contra-angle

ii. high speed contra-angle

a) straight handpieces The long axis of the bur is the same of the long axis of

the handpiece.

It is mainly used in laboratory work .

b- contra-angle handpieces i- low speed contra-angle Its speed range is (500-35000 rpm). It is used for : Removal of deep carious dentine Finishing and polishing procedures

Speed ranges in dentistry

low or slow speeds: <12000 r.p.m

medium or intermediate speeds:12000-200000r.p.m

high or ultra high speeds : >200000

b- contra-angle handpieces ii – high speed contra-angle Its speed range is (160,000-500,000 rpm). It is used for : It is very efficient in cutting both enamel and

dentin. We should use coolant to avoid heat

generation from high speed.

Handpieces will retain the cutting tools by:

a. screwing

b. latch

c. friction grip

Types of Attachment:

2- dental burs The rotary tools used in removing tooth structures

may be classified into burs and abrasives depending on whether they work by an actual cutting or an abrading process.

The bur is considered a form of drills or milling

cutters specially manufactured to suit dental purposes.

Parts of dental burs 1. shank

It is the part that fit into the handpiece . It has different lengths and shapes: • Long straight shank for straight handpieces. • Latch and tapered short burs for regular and

medium –speed handpieces. • Friction-grip bur (contra –angle bur)for ultra

speed air turbine.

Parts of dental burs 2. neck

It connects the head of the bur to the shank.

the straight bur has longer neck .

The contra –angle bur has a shorter neck to permit its use in posterior area.

Parts of dental burs 3. head

It is the working part of the bur.

according to the shape of the head rotary instruments are classified into :

1) bladed cutting instruments(burs).

2) abrasive instruments(stones).

Types and classifications of burs They may be classified according to their :

composition.

Shape of the shank.

Length of the neck.

Shape of the head.

Classification of burs according to their composition

Two kinds of burs are available that differ in hardness and composition:

steel burs: they were the early materials of burs but they became dull rapidly wich cause increased heat and vibrations.so they are now used for finishing procedures.

carbide bur: they are harder , stiffer and stronger than steel burs , but they are more brittle. They are used at different speed ranges.

Classification of burs according to the shape of the shank

(A): long straight shank: for straight handpiece.

(B): latch and tapered short burs: for regular and medium – speed handpiece .

(C): friction-grip bur(contra – angle bur): for ultra-speed air turbine.

Classification of burs according to the length of the neck

(A): short neck : in contra angle burs.

(B): long neck: in straight burs.

Classification of burs according to the shape of the head

(A): Round or rose head burs

This shape is used for:

1) Initial entry into the tooth.

2) Extension of the preparation.

3) Caries removal.

4) Preparation of retentive features into the cavity.


(B): inverted cone burs

This design is used for:

1) Extension of the preparation.

2) Producing undercuts in the preparation.

3) Adding retentive features in the cavity.


(C): Regular plane fissure bur

It is elongated and cylindrical in shape, it is used for:

1) Extension of the cavity.

2) Preparation of the resistance and retention form.


(D): tapered fissure burs

it is used for:

1) Preparing inclination walls for cast gold restoration.

2) Preparing undercut grooves for retention of proximal amalgam restorations .


(E): finishing burs

1) They have great number of blades (more than 8 blades, usually 12 blades).

2) They are used with low-speed for finishing and polishing metallic restorations.

Cutting efficiency of dental burs

Definition:

It is the ability of a bur to remove a maximum amount of tooth tissues with a minimum of effort and time involved

Factors affecting the cutting efficiency

1) Bur design.

2) Technique and manner of use.

3) Bur composition.

4) Rotational speed.

5) The tissue to be cut.


1) Bur design.

I. Number of blades

The more the number of blades, the greater the cutting efficiency. However, this is within limits, the best number of blades is (6-8) beyond which:

Weakening of blades occur.

Increased clogging tendency.

Increased heat generation.


1) Bur design.

II. Surface area of the blade:

the lesser the surface area, the greater the cutting efficiency

(e.g. since the surface area of a fissure bur is about 3 times that of a corresponding size inverted cone, the latter is to be 15 times more efficient).


2) Bur design

The operating pressure should be kept to a minimum by exerting minimum load of force on the bur as more pressure on the bur leads to:

Increases heat generation.

Increases dulling tendency of the bur.

Decreasing the cutting efficiency of the bur.

N.B. Based on this, it can be concluded that the round bur is the most efficient end-cutting bur. While, the inverted cone and fissure burs are effective as lateral cutting tools and must never be used for end cutting.


3) Bur composition

Carbide burs are much more efficient than steel burs for reasons of greater hardness, strength and better manufacturing treatment and design.

Carbide burs cut enamel and dentine and their cutting efficiency increases with increasing the rotational speed of the bur.

While steel burs cut only dentine at low speed ranges.


4) Rotational speed :

Cutting efficiency increases with increasing the rotational speed.

5) Tissue to be cut:

Enamel is harder than dentine and cementum, so cutting in enamel makes the bur less efficient than cutting in dentine and cementum

3- dental abrading tools Types of abrading tools

There are different types of abrading tools varying according to the abrasive material and form of the head.

3- dental abrading tools Types of abrading tools:

A- diamond abrasives:

They are the hardest and most efficient abrasives

stones for removing tooth enamel.

The head may be in the form of cylinders, wheels,

tapering point or disks.

They are more efficient with medium speed ranges.

3- dental abrading tools Types of abrading tools:

B- Sand paper and carborundum discs

They are useful in smoothening tooth structures and

metallic restorations.

3- dental abrading tools

Types of abrading tools:

C- Rubber wheels:

They are used for metal polishing. Softer types are

preferred as they bend into the contours of the

restoration.

How to control heat generation by rotary tools?

1) Correct use of sharp tools of proper size as dull large

tools increase heat generation.

2) Avoid application of pressure on the rotary tools

while operating.

3) Selection of proper speed.

4) Use of coolant.

Instruments and equipment for tooth preparation

Dr. Mazen D Doumani

Hand instruments

General classification of instruments

Cutting hand instruments excavators, chisels

Non-cutting hand instruments amalgam condensers, mirrors, explorers, probes

A) Diagnostic instruments B) Restoring instruments

Instruments that are used by the hands.

Parts of the hand instruments Composed of 3 parts:Handle , shank , and blade(nib). Noncutting instruments:the part corresponding to blade

is termed Nib Blade on both ends of the handle are known double-

ended instruments

I. Hand instruments

Blade

Handle (shaft)

Shank

The handle is used to hold the instrument. Different sizes and shapes . It may be smooth or serrated. The number , series , manfacturer’s name are written

on the handle.

Handle(shaft)

It connects handle with the working point\nib , blade\ of the instrument.

It tapers from the shaft down to the blade and is normally smooth , round or taperd

It may be straight or bent for better control of the working point when force is applied.

The working point should be within 3mm to the center of the long axis of the handle.

shank

According to the numbers of angles , the instruments are classified as:

- Straight :no angle

- Mon-angle: one angle

- Bin-angle: two angles

- Triple-angle: three angles

If the shank has more than one angle ,it is termed (contra-angled).

it is connected to the handle by the shank.

For cutting instrument, the working point is called blade.

For non cutting instrument, the working point is called nib.

If the blade is only in one end it is called single ended instrument.

If the blade is only in two ends it is called double ended instrument.

Working point :Blade(nib)

Most blades have three bevels :

- one on the end of the blade forming the primary cutting edge.

- two along the side of the blade forming the secondary cutting edge .

- the instrument is called bi-beveled instrument .

Working point :Blade(nib)

1- function (scaler , excavator).

2- manner of use (hand condenser).

3- design of the working end (spoon excavator , sickle scaler).

4- shape of the shank (mon-angle,bin-angle).

5- these names were combined to form the complete description of the instrument:bin-angle spoon excavator

Black’s classification system by instrument name categorized instruments by

Dr. G. V. Black classified instruments according to order names, suborder names, class names, and subclass names. Order names :denote the purpose for which the instrument is to be used, such as mallet or clamps. Suborder names :define the manner or position of use of the instrument, such as hand mallet or molar clamps. Class names: describe the working point of the instrument, such as spoon excavator or inverted cone bur. Subclass names: indicate the angle of the shank, such as bin-angle.

Black’s instrument formula

Black’s formula describes :

the dimensions of an instrument.

the angulation of the instrument.

Hand - cutting instruments (cut hard or soft tissues)

A- Excavators Hatchet,hoes,spoons,

angle former

B- Chisels Straight ,curved, bin –angle,

enamel hatchet

C- Others Knives,files,carvers,gingival

marginal trimmer

Ordinary hatchet excavator:

The cutting edge of the blade directed in the same plane of the long axis of the handle and is bi-beveled.

we use it primarily on anterior teeth to prepare retantative areas and sharpening internal line angles

A- Excavators

Hoe excavators:

has the primary cutting edge of the blade perpendicular to the axis of the handle.

we use it for: planning tooth preparation walls and forming line angles.

used in class III and V for direct golden restorations.and intended for use on enamel of posterior teeth.

A- Excavators

angle former:

• it is used for sharpening line angles and creating retentive feauters in dentin in preparation for gold restorations .

• It also may be used in placing a bevel on enamel margins.

• It is mon-angled and has the primary cutting edge at an angle (other than 90 degrees) to the blade.

• It may be described as a combination of a chisel and gingival margin trimmer.

• It is available in pairs (right and left).

A- Excavators

Spoon excavators:

they are used for removing caries and carving amalgam or direct wax patterns.

The blades are slightly curved and the cutting edges are either circular or clawlike.

The circular edge is known as a discoid, whereas the clawlike blade is termed a cleoid.

The shanks may be bin-angled or triple-angled to facilitate accessibility.

A- Excavators

Straight Chisel: The straight chisel has a straight shank and blade, with the

bevel on only one side.

Its primary edge is perpendicular to the axis of the handle.

B- Chisels

The bin-angle and Wedelstaedt chisels:

the primary cutting edges is in a plane perpendicular to the axis of the handle.

may have either a distal bevel or a mesial (reverse) bevel.

The blade with a distal bevel is designed to plane a wall that faces the blade's inside surface.

B- Chisels

Enamel hatchet:

it is similar in design to the ordinary hatchet except that the

blade is larger, heavier, and is beveled on only one side.

It has its cutting edges in a plane that is parallel with the axis of the handle. It is used for cutting enamel and comes as right or left types for use on opposite sides of the preparation.

B- Chisels

Gingival margin trimmer:

is designed to produce a proper bevel on gingival enamel margins

of proximoocclusal preparations.

It is similar in design to the enamel hatchet, except the blade is curved.

the primary cutting edge is at an angle (other than perpendicular) to the axis of the blade.

It is made as right and left types

B- Chisels

Other hand cutting instruments, such as the knife, file, and discoid-cleoid instrument, are used for :

trimming restorative material rather than for cutting tooth structure.

C- Other cutting instruments

1- knives: known as finishing knives, amalgam knives,or gold

knives, are designed with a thin, knifelike blade that is made in various sizes and shapes.

Knives are used for trimming excess restorative

material on the gingival, facial, or lingual margins of a

proximal restoration or trimming and contouring the

surface of a Class V restoration.


File: They used to:

trim excess restorative material.

They are particularly useful at gingival margins.

Blades of files are very thin, and teeth on the cutting surfaces are short.


Dr. Mazen D Doumani

A-Diagnostic instruments These instruments are used in: the assessment of tooth lesions . differentiation between normal and affected tooth structure. It can be helpful in the determination of the periodontal

condition of the tooth. These instruments include: Mirrors Probes explorers

Diagnostic instruments Mirrors : • Dental mirror is a tool specially designed for the purpose of

clear and distinct vision. • It is available in a variety of sizes with flat or convex

magnifying surfaces. They are used for : To reflect light Retract soft tissues Indirect vision Tissue protection

Diagnostic instruments Explorers It is used for:

1) Exploring caries.

2) Exploring presence or absence of calculus.

3) Restoration examination.

Diagnostic instruments Probes:

They are similar to explorers but with blunt tip.

It is usually graduated to evaluate the periodontal condition of the tooth .

cotton pliers (tweezers) It is used to carry small objects

It could be locking or non locking

Examination kit (instruments): Mirror.

Tweezers or plier.

Explorer.

B- restoring instrument They are similar in appearance to cutting instruments but their working end is a nib (non cutting).

They are divided into : 1) Amalgam application instruments (for amalgam).

2) Plastic instruments (for composite and glass ionomer).

3) Others:

• Spatulas.

• Cavity liners applicators.

1-Amalgam application instruments Amalgam carriers: Amalgam restoration is placed into the preparation with an instrument with a hollow cylinder that is filled with amalgam.

A plunger operated with finger pushes the amalgam out of the carrier into the preparation.

1-Amalgam application instruments Dippen dish :

1-Amalgam application instruments Amalgam condenser :

They are used to compress amalgam and push resin composite or glass ionomer material into prepared tooth .

The working end is usually round in section,with flat smooth or serrated end.

It is supplied with different sizes and shapes of the nib

1-Amalgam application instruments Carvers:

They are used to: shape amalgam, resin composite and tooth colored restorative materials .

They are also used to: remove excess amalgam as discoid and cleoid carvers wich are used mainly for the occlusal surface.

They have different nib shapes.

Hollenback carvers

They used for carving occlusal anatomy in unset amalgam restorations

1-Amalgam application instruments Burnishers:

Used to produce smooth and shiny surface .

They have many shapes like ,ball shape and egg-shaped.

Burnishers:

Burnishers:

Pk thomas burnisher anatomic burnisher

1-Amalgam application instruments Matrices

instruments wich give form to any thing .

it acts as a temporary wall in class II or III to enable the condensation of the restorative material until it hardens .

it prevents the marginal overhangs and keeps the gingival tissues away from the cavity during the whole procedure.

1-Amalgam application instruments Types of the matrices

Ivory matrix holder no. 1:

It provides one proximal wall only in class II cases


Ivory matrix holder no.8:

It can encircle the entire crown of the tooth and can be used in all compound cavities particularly those with three surfaces (MOD cavities).


universal or tofflemire matrix band retainer:

It is the best one in its stability , anatomic adaptation and easy construction and removal.

Tofflemire ( Universal ) Retainer

Head

Slots Retaining

screw

Adjustable

nut

Locking nut

Vise

Straight and contra-angled retainers OCCLUSAL

2- plastic instruments They are called plastic because they were originally

used with plastic restorative materials.

They are used for: carving and shaping of composite and glass ionomer restorative materials.

They are supplied with different shapes and sizes .

They are made either from plastic or metals.

Alluminum coated Plastic disposable

3- Others Spatulas

Many restorative materials in the operative dentistry need mixing , either on glass slab or paper pad so we use spatula in this step.

It is supplied with different sizes and thickness : - smaller spatula are used for mixing small amounts of materials . - thinner spatulas are mor flexible while thicker spatulas are more rigid . - the choice between them depends on the desired vicosity of the restorative material.

3- Others Cavity liners applicator

it is a small instrument wich helps in applying cavity liners in thin layers in the cavity.

It is very small ball in diameter.

Sharpening of the hand instrument Instruments with dull cutting edges cause more pain,

prolong operating time, are more difficult to control, and reduce quality and precision in tooth preparation.

Many types of sharpening equipment exist, including stationary sharpening stones, mechanical sharpeners, and stones that are used in the handpiece.

To make proper manual sharpening , the cutting part should be placed facing the stone and instrument should pushed and pulled 2-3 times with apropriate force

Importance of sharpening Increase the cutting efficiency of the instrument.

Produce smoother surface for the cavity .

Reduce pain coming from heavy force on a dull instrument .

Rotary sharpening

Isolation of the Operating Field

Goals of Isolation 1. Moisture Control

Excluding sulcular fluid, saliva, and gingival bleeding from the operating field.

2. Retraction and Access

It provides maximal exposure of the operating site and usually involves maintaining an open mouth.

3. Harm Prevention

It prevents the patient from being injuried during the operative procedure

Small instruments and debris can be aspirated or swallowed.

Materials Used for Moisture Control:

I. Rubber Dam Isolation

I. Cotton Roll Isolation & Cellulose Wafers

II. Other Isolation Techniques

Isolation of the Operating Field


It ensures appropriate dryness of the teeth & improves the quality of clinical dental procedures, by defining the operating field.

Advantages:

Dry, Clean Operating Field

Improved Access and Visibility

Improved Properties of Dental Materials

Protection of the Patient and Operator

Disadvantages

Time consumption and patient objection are the most frequently quoted disadvantages of the rubber dam.

Certain oral conditions may preclude the use of the rubber dam;

1. Some third molars,

2. psychologic reasons

3. Partially erupted teeth

4. Patients suffering from asthma

5. Extremely malpositioned teeth.

6. Latex allergy


II. Cotton Roll Isolation & Cellulose Wafers

Absorbents (cotton rolls, cellulose wafers, gauze sponges).

Using a saliva ejector in conjunction with absorbents may further abate salivary flow.

The assistant has the responsibility of keeping dry cotton rolls in the mouth.

Position: Placed in the facial vestibule for maxillary teeth & in the lingual vestibule (between the teeth) and the tongue for mandibular teeth.

II. Cotton Roll Isolation & Cellulose Wafers

Many commercial devices for holding cotton rolls in position are available.

III. Other Isolation Techniques 1) High-Volume Evacuators & Saliva Ejectors

2) Mirror and Evacuator Tip Retraction

3) Throat Shields

4) Retraction Cord

5) Mouth Props

6) Drugs

Rubber Dam Application Materials &Instruments

1) Rubber dam Sheet

2) Retainer Forceps

3) Retainer

4) Holder

5) Punch

6) Lubricant

7) Napkin

8) Anchor


1) Rubber dam Sheet

Sterile Rubber dam is also available packaged as individual sheets in different:

Sizes: 5X5 inch or 6X6 inch

Colour: light and dark dam material

shiny and a dull side.

Thickness: thinner material → passing through the contacts easier.

thicker dam → retracting tissue & resistant to tearing.


1) Rubber dam Sheet

2) Retainer Forceps

It is used both for placement and removal of the retainer from the tooth


1) Rubber dam Sheet

2) Retainer Forceps

3) Retainer (Clamp)

It is used to anchor the dam to the tooth and retract gingival tissue. It consists of four prongs and two jaws connected by a bow, with the presence of wings some times.

Special consideration: Stability and retention test.

Stretching the retainer for long periods should be avoided.

Dental floss should be tied to the bow of the retainer or both holes of the jaws


1) Rubber dam Sheet

2) Retainer Forceps

3) Retainer

4) Holder

It is a U-shaped metal / plastic frame with small projections.

Position → outside the dam

Curvature → concentric & parallel to the patient's face.

An optional adjustable neck strap.


1) Rubber dam Sheet

2) Retainer Forceps

3) Retainer

4) Holder

5) Punch

It is a precision instrument having a rotating metal table (disk) with six holes of varying sizes and a tapered, sharp-pointed plunger.

The plunger should be centered in the cutting hole so the edges of the holes are not at risk of being chipped by the plunger tip when the plunger is closed.


1) Rubber dam Sheet

2) Retainer Forceps

3) Retainer

4) Holder

5) Punch

6) Lubricant

A water-soluble lubricant applied in the area of the punched holes facilitates the passing of the dam septa through the proximal contacts.

If commercial products are unavailable, other lubricants, such as shaving cream or soap slurry, are also satisfactory.

Cocoa butter or petroleum jelly may be applied at the corners of the patient's mouth to prevent irritation.


1) Rubber dam Sheet

2) Retainer Forceps

3) Retainer

4) Holder

5) Punch

6) Lubricant

7) Napkin

It is placed between the rubber dam and the patient's skin, particularly for long appointments, due to the following advantages:

It prevents skin contact with rubber.

It absorbs any saliva seeping at the corners of the mouth.

It provides a convenient method of wiping the patient's lips on removal of the dam.


1) Rubber dam Sheet

2) Retainer Forceps

3) Retainer

4) Holder

5) Punch

6) Lubricant

7) Napkin

8) Anchore

The proximal contact

Waxed dental tape (or floss) or a small piece of rubber dam material (cut from a sheet of dam).

The material used should be trimmed to approximately 0.5 inch in total length to prevent interference with the operating site.

Isolation is either: Single isolation Multiple isolation

The distance between holes is equal to the distance from the center of one tooth to the center of the adjacent tooth, measured at the level of the gingival tissue. Generally, this is approximately 1/4inch (6.3 mm). Holes size: use the smaller holes for the incisors, canines, and premolars and the larger holes for the molars. The largest hole is generally reserved for the posterior anchor tooth.

Rubber Dam Application Hole Number, Size &Position

Holes position: should follow the arch form, making adjustments for malpositioned or missing teeth.

For maxillary teeth, the holes are positioned approximately 1 inch (25 mm) from the superior border of the dam,

For mandibular teeth, mentally divide the rubber dam into three vertical sections: left, middle, and right.

For first premolar.

For first molar.

For second or third molar.


Consideration:

For Class V lesion, the tooth hole should be punched slightly facial to the arch form.


A rubber stamp is available that imprints both permanent and primary arch forms on the rubber dam.

A plastic template can also be used to mark hole position.

I. Applying the Retainer Before the Dam

II. Applying the Dam Before the Retainer

III. Applying the Dam and Retainer Simultaneously

Rubber Dam Application Techniques:

(1) (2) (3)

(4) (5) (6)

Rubber Dam Application I. Applying the Retainer Before the Dam

(7) (8) (9)

(10) (11) (12)

Rubber Dam Application Applying the Retainer Before the Dam

Advantage:

To reduce the risk of the retainer being swallowed or aspirated before the dam is placed.

To solves the occasional difficulty of trying to pass the dam over a previously placed retainer.

Rubber Dam Application II. Applying the Dam Before theRetainer

Advantage:

There is no need to manipulate the dam over the retainer.

Disadvantage:

Reduction in visibility of underlying gingival tissue.

Rubber Dam Application III. Applying the Dam &the Retainer Simultaneously

(1) (2) (3)

(4) (5) (6)

Removal of Rubber Dam

Errors in Application and Removal Off-center arch form:

Inappropriate distance between the holes:

Too little

too much

Incorrect hole size:

Inappropriate retainer:

The general fundamentals of cavity preparations

Dr . Mazen Deib Doumani

Definition of tooth preparation Mechanical alteration of defective, injured, or diseased

tooth to best receive restorative material that will reestablish healthy state, including esthetic corrections, along with normal form and function.

Objective of tooth preparation 1) Remove all defects and provide necessary protection to the

pulp

2) Extend the restoration as conservatively as possible.

3) Form the tooth preparation so under force of mastication, Tooth or Restoration will not fracture and not be displaced.

4) Allow for esthetic and functional placement of a restorative material.

Stages and steps of tooth preparation May facilitate better adherence to preparation principles

and pulpal protection for all operators,

It is particularly beneficial in an academic setting.

Divided into two stages :

1) Initial tooth preparation stage.

2) Final tooth preparation stage .

Stages and steps of tooth preparation 1) The Initial tooth preparation stage:

Mechanical alterations of tooth are extended to sound tooth structure in all directions (facially, lingually, gingivally, incisally or occlusally, mesially, and distally) .

Stages and steps of tooth preparation 2) The final tooth preparation stage:

Excavating any remaining, infected carious dentin.

Removing old restorative material if indicated.

Protecting the pulp.

Incorporating additional preparation design features

that minimize tooth or restoration fracture against

oblique forces .

Factors influencing cavity preparation 1 – Diagnosis :

Caries.

Fracture.

Esthetic needs.

Pulp & periodontal condition.

Occlusal relationship.

Needs for function.

Factors influencing cavity preparation

2- knowledge of dental anatomy :

Direction of enamel rods.

Thickness of enamel.

Dentin body.

Size & position of the pulp.


3- patient factors:

Economic status.

Age.

4- Restorative material factors:

The patient's input into the decision is important.

Economic and esthetic values are primary patient

decisions.

The ability to isolate the operating area.


3- patient factors:

Economic status.

Age.

4- Restorative material factors:

The patient's input into the decision is important.

Economic and esthetic values are primary patient

decisions.

The ability to isolate the operating area.


5) Conservation of tooth structure

Minimal extensions of the tooth preparations .

Supragingival margins .

Rounded internal line angles.

Factors to consider befor tooth preparation

Tooth preparation terminology Internal Wall:

internal wall is a prepared (cut) surface that does not extend to the external tooth surface

External Wall:

An external wall is a prepared (cut) surface that extends to the external tooth surface, and such a wall takes the name of the tooth surface (or aspect) that the wall is toward.

Tooth preparation terminology

Axial wall

An axial wall is an internal wall parallel with the long axis of the tooth.

Pulpal wall

A pulpal wall is an internal wall that is both perpendicular to the long axis of the tooth and occlusal of the pulp.


Floor (or Seat)

A floor (or seat) is a prepared (cut) wall that is reasonably flat and perpendicular to those occlusal forces that are directed occlusogingivally (generally parallel to the long axis of the tooth).

Examples are the pulpal and gingival walls. Such floors may be purposefully prepared to provide stabilizing seats for the restoration, thus distributing the stresses in the tooth structure, rather than concentrating them. This increases the resistance form of the restored tooth against post-restorative fracture.


Enamel Wall

The enamel wall is that portion of a prepared external wall consisting of enamel.

Dentinal Wall

The dentinal wall is that portion of a prepared external wall consisting of dentin, in which mechanical retention features may be located

Tooth preparation angles Line Angle A line angle is the junction of two planal surfaces of different orientation along a line.

An internal line angle

is a line angle whose apex points into the tooth.

An external line angle

is a line angle whose apex points away from the tooth.

Point Angle A point angle is the junction of three planal surfaces of different orientation.

Cavosurface Angle and Cavosurface Margin

The cavosurface angle is the angle of tooth structure formed by the junction of a prepared (cut) wall and the external surface of the tooth. The actual junction is referred to as the cavosurface margin

Tooth preparation terminology Simple Tooth Preparations.

If only one tooth surface is involved .

compound Tooth Preparations.

If two surfaces are involved .

Complex Tooth Preparations.

For a preparation involving three (or more) surfaces

Tooth preparations design Conventional design preparation.

Beveled conventional designs.

Modified preparation designs

Tooth preparations design

1- Conventional design preparation.

Typical for amalgam restoration and includes the

following :

Uniform pulpal and/or axial wall depths.

Cavosurface margin design that results in 90°

restoration margin.

Primary retention form derived from occlusally

converging vertical walls.


1- Conventional design preparation.

Typical for amalgam restoration and includes the

following :

Uniform pulpal and/or axial wall depths.

Cavosurface margin design that results in 90°

restoration margin.

Primary retention form derived from occlusally

converging vertical walls.


2- Beveled Conventional designs.

are characterized as conventional preparations with

beveling of some accessible enamel margins.


3- Modified preparation designs :

may not have uniform axial or pulpal depths or

occlusally converging vertical walls.

Amalgam tooth preparations only use conventional

designs, whereas composite preparations may be any

of the three designs.

Classification of tooth preparations Class I Caries : pit and fissure, on occlusal, buccal,

and lingual surfaces of posterior teeth, and Lingual of

anterior teeth.

Class II Caries: affecting proximal surfaces of molars

and premolars.

Class III Caries : proximal surfaces of centrals,

laterals, and cuspids.

Classification of tooth preparations Class IV Caries : proximal including incisal edges of

anterior teeth.

Class V Caries : gingival 1/3 of facial or lingual surfaces

of anterior or posterior teeth.

Class VI :(never described by Black, added later by

others) Caries : cusp tips of molars, premolars, and

cuspids

Stages of tooth preparation Initial Tooth Preparation Stage

Step 1: Outline form and initial depth.

Step 2: Primary resistance form.

Step 3: Primary retention form.

Step 4: Convenience form.

Stages of tooth preparation

Final Tooth Preparation Stage

Step 5: Removal of any remaining infected dentin

and/or old restorative material, if indicated .

Step 6: Pulp protection, if indicated.

Step 7: Secondary resistance and retention forms.

Step 8: Procedures for finishing external walls.

Step 9: Final procedures: cleaning, inspecting,

sealing.

Initial Tooth Preparation Stage

Step 1: Outline form and initial depth.

1) Placing Prep. margins in the positions they will occupy

in the final preparation .

2) Preparing initial depth of 0.2 to 0.8 mm pulpally of DEJ

position.


Principles of establishing the outline form :

1) all friable and/or weakened enamel should be removed .

2) all faults should be included.

3) all margins should be placed in a position to afford good

finishing of the margins of the restoration.


Step 2: Primary Resistance Form.

1) Is that shape and placement of the preparation

walls that best enable both restoration and tooth to

withstand, without fracture, masticatory forces

delivered principally in the long axis of the tooth.

2) The relatively flat pulpal and gingival walls

prepared perpendicular to the tooth's long axis help

resist forces in the long axis of the tooth and

prevent tooth fracture from wedging effects .


Step 2: Primary Resistance Form.

1) Is that shape and placement of the preparation

walls that best enable both restoration and tooth to

withstand, without fracture, masticatory forces

delivered principally in the long axis of the tooth.

2) The relatively flat pulpal and gingival walls

prepared perpendicular to the tooth's long axis help

resist forces in the long axis of the tooth and

prevent tooth fracture from wedging effects .

Obtaining Primary Resistance Form.

1) Use the box shape with relatively flat floor .

2) to restrict the extension of the external walls as small

as possible to allow strong cusp and ridge areas .

3) to have a slight rounding of internal line angles to

reduce stress concentrations .

Obtaining Primary Resistance Form.

4) in extensive tooth preparations, to cap weak cusps and

envelope or include enough of a weakened tooth within

the restoration.

5) to provide enough thickness of restorative material to

prevent its fracture under load.

6) to bond the material to tooth structure when

appropriate.

Step 3: Primary Retention Form

1) Is that shape or form of the conventional preparation

that resists displacement or removal of the restoration

from tipping or lifting forces.

2) Retention form and resistance form are accomplished in

the same cutting procedure .

3) For amalgam restorations in most Class I and all Class

II the external tooth walls converge occlusally .

Step 4: Convenience Form

is that shape or form of the preparation that provides for

adequate observation, accessibility, and ease of operation

in preparing and restoring the tooth.

FINAL TOOTH PREPARATION STAGE

Step 5: Removal of Any Remaining Enamel Pit or Fissure,

Infected Dentin, and/or Old Restorative Material, if

Indicated.

Step 6: Pulp Protection, if Indicated (Placement of liners

and bases).

is not a step in tooth preparation in the strict sense of the

word, it is a step in adapting the preparation for receiving

the final restorative material.

Step 7: Secondary Resistance and Retention Forms.

FINAL TOOTH PREPARATION STAGE

Step 8: Finishing the External Walls of the Tooth

Preparation.

Step 9: Final Procedures: Cleaning, Inspecting, and

Sealing

Health & Medicine

Introduction into operative dentistry.pdf mazen doumani