Basics of Dentistry

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Basics of Dentistry

Dr. Md. Arifur RahmanBDS, MPH

Assistant Professor & HeadNorth East Medical College Dental Unit

[email protected]

Dr. Md. Arifur Rahman , NEMC

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Introduction• This document has been created to run

the MBBS students through the basics of dental health, diseases, dental treatments and Oral Manifestations of Systemic Diseases.


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DENTAL ANATOMY AND PHYSIOLOGY

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Primary (deciduous)

•Consist of 20 teeth•Begin to form during the first trimester of pregnancy

•Typically begin erupting around 6 months

•Most children have a complete primary dentition by 3 years of age

Dental Anatomy and PhysiologyDentition (teeth): There are two dentitions


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Dental Anatomy and Physiology

Secondary (permanent)

•Consist of 32 teeth in most cases

•Begin to erupt around 6 years of age

•Most permanent teeth have erupted by age 12

•Third molars (wisdom teeth) are the exception; often do not appear until late teens or early 20s

Dentition (teeth): There are two dentitions

Mandible

Maxilla IncisorsCanine (Cuspid)

Premolars

Molars


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Classification of Teeth:

•Incisors (central and lateral)

•Canines (cuspids)•Premolars (bicuspids)•Molars

Dental Anatomy and PhysiologyIdentifying Teeth

Incisor Canine Premolar Molar


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Dental Anatomy and PhysiologyIdentifying Teeth2

Incisor Canine Premolar Molar

•Incisors function as cutting or shearing instruments for food.

•Canines possess the longest roots of all teeth and are located at the corners of the dental arch. Function as tearing of food.

•Premolars act like the canines in the tearing of food and are similar to molars in the grinding of food.

•Molars are located nearest the temporomandibular joint (TMJ), These teeth have a major role in the crushing, grinding, and chewing of food.


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•Apical•Labial•Lingual•Distal•Mesial•Incisal

Teeth: IdentificationTooth Surfaces

Labial

Apical

Lingual

Distal

Apical

Mesial

Incisal Incisal


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Dental Anatomy and Physiology•Apical: Pertaining to the apex or root of the tooth

•Labial: Pertaining to the lip; describes the front surface of anterior teeth

•Lingual: Pertaining to the tongue; describes the back (interior) surface of all teeth

•Distal: The surface of the tooth that is away from the median line

•Mesial: The surface of the tooth that is toward the median line

Labial

Apical

Lingual

Distal

Apical

Mesial


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Enamel

Alveolar Bone

PulpChamber


•Enamel (hard tissue)•Dentin (hard tissue)•Odontoblast Layer•Pulp Chamber (soft tissue)

•Gingiva (soft tissue)•Periodontal Ligament (soft tissue)

•Cementum (hard tissue)•Alveolar Bone (hard tissue)

•Pulp Canals•Apical Foramen

The Dental Tissues:

Dentin

Odontoblast Layer Gingiva

Periodontal Ligament

Cementum

Pulp Canals

Apical Foramen


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•Anatomic Crown•Anatomic Root•Pulp Chamber

The 3 parts of a tooth:Anatomic Crown

Anatomic Root

PulpChamber



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Anatomic Crown

Anatomic Root

PulpChamber

Dental Anatomy and Physiology•The anatomic crown is the portion of the tooth covered by enamel.

•The anatomic root is the lower two thirds of a tooth.

•The pulp chamber houses the dental pulp, an organ of myelinated and unmyelinated nerves, arteries, veins, lymph channels, connective tissue cells, and various other cells.


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•Enamel•Dentin•Cementum•Dental Pulp

The 4 main dental tissues:

Dental Anatomy and PhysiologyEnamel

Dentin

Cementum

Dental Pulp


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•Structure•Highly calcified and hardest tissue in the body

•Crystalline in nature•Enamel rods

• Insensitive—no nerves•Acid-soluble—will demineralize at a pH of 5.5 and lower

•Cannot be renewed•Darkens with age as enamel is lost

•Fluoride and saliva can help with remineralization.


Dental Tissues—Enamel


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Dental Tissues—EnamelDental Anatomy and Physiology

• Enamel can be lost by:– Physical mechanism

• Abrasion (mechanical wear)• Attrition (tooth-to-tooth contact)

– Chemical dissolution • Erosion by extrinsic acids (from diet)• Erosion by intrinsic acids (from the oral cavity/digestive tract)

• Multifactorial etiology–Combination of physical and chemical factors


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•Softer than enamel•Susceptible to tooth wear (physical or chemical)

•Does not have a nerve supply but can be sensitive

•Is produced throughout life

•Three classifications •Primary•Secondary•Tertiary

•Will demineralize at a pH of 6.5 and lower

Dental Tissues—Dentin



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Three classifications:•Primary dentin forms the initial shape of the tooth.

•Secondary dentin is deposited after the formation of the primary dentin on all internal aspects of the pulp cavity.

•Tertiary dentin, or “reparative dentin” is formed by replacement odontoblasts in response to moderate-level irritants such as attrition, abrasion, erosion, trauma, moderate-rate dental caries, and some operative procedures.

Dental Tissues—Dentin



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DentinPulp

Tubule

Fluid Nerve Fibers

Odontoblast Cell

Dental Anatomy and PhysiologyDental Tissues—Dentin

(Tubules)•Dentinal tubules connect the dentin and the pulp (innermost part of the tooth, circumscribed by the dentin and lined with a layer of odontoblast cells)

•The tubules run parallel to each other in an S-shape course

•Tubules contain fluid and nerve fibers

•External stimuli cause movement of the dentinal fluid, a hydrodynamic movement, which can result in short, sharp pain episodes


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Association between erosion and dentin hypersensitivity• Open/patent tubules

– Greater in number– Larger in

diameter• Removal of smear layer• Erosion/tooth wear

Enamel

ExposedDentin

RecedingGingiva

Tubules

Odontoblast

Dental Anatomy and

PhysiologyDental Tissues—Dentin

(Tubules)


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•Thin layer of mineralized tissue covering the dentin

•Softer than enamel and dentin

•Anchors the tooth to the alveolar bone along with the periodontal ligament

•Not sensitive

Dental Tissue—Cementum


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•Innermost part of the tooth

•A soft tissue rich with blood vessels and nerves

•Responsible for nourishing the tooth

•The pulp in the crown of the tooth is known as the coronal pulp

•Typically sensitive to extreme thermal stimulation (hot or cold)

Dental Tissue—Dental Pulp



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• Pulpitis is inflammation or infection of the dental pulp, causing extreme sensitivity and/or pain.

• Pain is derived as a result of the hydrodynamic stimuli activating mechanoreceptors in the nerve fibers of the superficial pulp (A-beta, A-delta, C-fibers).

• Hydrodynamic stimuli include: thermal (hot and cold); tactile; evaporative; and osmotic

• These stimuli generate inward or outward movement of the fluid in the tubules and activate the nerve fibers.

• A-beta and A-delta fibers are responsible for sharp pain of short duration• C-fibers are responsible for dull, throbbing pain of long duration• Pulpitis may be reversible (treated with restorative procedures) or irreversible (necessitating root canal).

• Untreated pulpitis can lead to pulpal necrosis necessitating root canal or extraction.

Dental Tissue—Dental Pulp



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•Gingiva•Alveolar Bone•Periodontal Ligament

•Cementum

Periodontal Tissues


Gingiva

Alveolar bone

Cementum



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•Gingiva: The part of the oral mucosa overlying the crowns of unerupted teeth and encircling the necks of erupted teeth, serving as support structure for subadjacent tissues.

Dental Tissue—Dental Tissue


Gingiva


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•Alveolar Bone: Also called the “alveolar process”; the thickened ridge of bone containing the tooth sockets in the mandible and maxilla.



Alveolar bone


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•Periodontal Ligament: Connects the cementum of the tooth root to the alveolar bone of the socket.





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•Cementum: Bonelike, rigid connective tissue covering the root of a tooth from the cementoenamel junction to the apex and lining the apex of the root canal. It also serves as an attachment structure for the periodontal ligament, thus assisting in tooth support.



Cementum


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•Plaque•Saliva •pH Values•Demineralization•Remineralization

Oral Cavity/Environment



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Dental Anatomy and

PhysiologyPlaque:•is a biofilm •contains more than 600 different identified species of bacteria

•there is harmless and harmful plaque

•salivary pellicle allows the bacteria to adhere to the tooth surface, which begins the formation of plaque

Oral Cavity


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Dental Anatomy and

PhysiologySaliva:•complex mixture of fluids•performs protective functions:– lubrication—aids

swallowing– mastication– key role in

remineralization of enamel and dentin

– buffering

Oral Cavity


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Dental Anatomy and

PhysiologypH values:•measure of acidity or alkalinity of a solution

•measured on a scale of 1-14 •pH of 7 indicated that the solution is neutral

•pH of the mouth is close to neutral until other factors are introduced

•pH is a factor in demineralization and remineralization

Oral Cavity

3. Strassler HE, Drisko CL, Alexander DC. Dr. Md. Arifur Rahman , NEMC

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Demineralization:•mineral salts dissolve into the surrounding salivary fluid: –enamel at approximate pH of 5.5 or lower

–dentin at approximate pH of 6.5 or lower

•erosion or caries can occur

Oral Cavity


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Remineralization:•pH comes back to neutral (7)

•saliva-rich calcium and phosphates

•minerals penetrate the damaged dentine surface and repair it:– dentin pH is above

6.5

Oral Cavity



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Maxillary bones Every structure in the

oral cavity (gum, teeth and muscles) is supported by two bones:

• Upper jaw: the maxillary bone or maxilla;

• Lower jaw: the mandibular bone or mandible.


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Mandible


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Maxilla


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Blood Supply of teeth


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Nerve Supply of Teeth


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Temporomandibular Joints

The temporomandibular joints connect the upper jaws to the mandible.

The part of the mandible which mates to the under-surface of the disc is the condyle and the part of the temporal bone which mates to the upper surface of the disk is the glenoid (or mandibular) fossa.


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DIAGNOSIS ID , TOOLS


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Four Quadrants ID


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Four Quadrants ID• Upper Right 1st Molar

• Lower Left Canine

• Upper Deciduous Rt. 1st Molar

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3

D


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Deciduous Dentition ID


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Permanent Dentition ID


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RADIOGRAPHIC EXAMS• orthopantomograp

hy /OPG• Periapical X-ray• Bite wing x-ray• Occulsal view • CT scan


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Major Dental Specialties1)Conservative/Operative/ Endodontics2) Periodontics3) Orthodontics4) Pediatric Dentistry or Paedodontics7) Prosthodontics8) Oral and Maxillofacial Surgery


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Conservative/Operative/ Endodontics

Endodontics (from the Greek endo "inside"; and odons "tooth") is the dental specialty concerned with the study and treatment of the dental pulp. Endodontists perform a variety of procedures including filling, endodontic therapy (commonly known as "root canal therapy"), treating cracked teeth, and treating dental trauma.).

Root canal therapy is one of the most common procedures. If the pulp becomes diseased or injured, endodontic treatment is required to save the tooth.


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How Caries Occurs?


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treatment options in caries

• Filling (if cavity doesn’t reach pulp chamber)


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treatment options in caries • Root Canal Treatment (RCT)


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Root Canal Treatment (RCT)


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treatment options in caries

• Dental Extraction – If the infection is out of control, teeth become 3rd degree mobile or Patient doesn’t have time/money for RCT.


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PeriodonticsPeriodontology or Periodontics is the specialty of dentistry that

studies supporting structures of teeth, diseases and conditions that affect them. The supporting tissues are known as the periodontium, which includes the gingiva (gums), alveolar bone, cementum, and the periodontal ligament. Periodontal diseases take on many different forms but are usually a result of a coalescence of bacterial plaque of the gingiva and the teeth. They are usually called:

GINGIVITIS: inflammation of the gum tissue, characterized by swelling, reddening, gums that are tender and painful to the touch, bleeding gums;

PERIODONTITIS: involves progressive loss of the alveolar bone around the teeth, and if left untreated, can lead to the loosening and subsequent loss of teeth.


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GINGIVITIS & PERIODONTITIS


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Treatment options • Scaling – Ultrasonic/

Air/Hand Scaling• Root Planning• Gingivectomy


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OrthodonticsOrthodontics is the branch of dentistry that

corrects teeth and jaws that are positioned improperly.

Its aim is to diagnose, prevent and treat irregularities of the teeth and face, in order to:

- Get a good teeth alignment;- Obtain an efficient chewing function;- Achieve a good aesthetic of the smile;- Reach and/or improve the health of the teeth and

periodontium;


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Orthodontics


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Orthodontics

darsheel safary


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Orthodontics


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OrthodonticsNicholas Cage


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OrthodonticsMorgan freeman


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OrthodonticsTom Cruise


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Orthodontic appliancesOrthodontic treatment uses

appliances to correct the position of the teeth. The two main types are:

fixed braces – a non-removable brace made up of brackets that are glued to each tooth and linked with wires

removable braces – usually plastic plates that cover the roof /floor of the mouth and clip on to some teeth; they can only carry out very limited tooth movements


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Pediatric Dentistry or Paedodontics

• training the child to accept dentistry;

• restoring and maintaining the primary, mixed, and permanent dentitions;

• applying preventive measures for dental caries and periodontal disease;

• preventing, intercepting, and correcting various problems of occlusion.

Paedodontics is the branch of dentistry that includes the following:


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ProsthodonticsProsthodontics is the dental specialty

pertaining to the diagnosis, treatment planning, rehabilitation and maintenance of the oral function, comfort, appearance and health of patients with clinical conditions associated with missing or deficient teeth and/or oral and maxillofacial tissues using biocompatible substitutes.


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Dental Prosthesis • Dental Crown / Cap • Dental Bridge• Partial Denture• Complete Denture • Dental Implant


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Dental Crown / Cap


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Dental Bridge


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Partial Denture


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Complete Denture


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Dental Implant


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Oral and Maxillofacial Surgery

Oral & Maxillofacial surgery (OMS) specializes in treating many diseases, injuries and defects in the head, neck, face, jaws and the hard and soft tissues of the Oral (mouth) and Maxillofacial (jaws and face) region.


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OMS Deals with Diagnosis and treatment of:

-benign pathology (cysts, tumors etc.)-malignant pathology (oral & head and neck cancer) with

(ablative and reconstructive surgery, microsurgery)-cutaneous malignancy (skin cancer), lip reconstruction-congenital craniofacial malformations such as cleft

lip and palate.-temporomandibular joint (TMJ) disorders-soft and hard tissue trauma of the oral and maxillofacial

region (jaw fractures, cheek bone fractures, nasal fractures, LeFort fracture, skull fractures and eye socket fractures).

ORAL MANIFESTATION OF SYSTEMIC DISEASES

Systemic diseases manifesting oral ulcers are:

Microbial disease-Herpetic stomatitisChicken poxHand ,foot and mouth diseaseInfectious mononucleosisHIVANUGTBSyphilis

Contd.. Blood disorders• Disorders of Red Blood

Cells and Hemoglobin

• Disorders of White Blood Cells

• Bleeding Disorders

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Anemia (cont.)• Clinical features

– Pallor of skin and oral mucosa

– Angular cheilitis

– Erythema and atrophy of oral mucosa

– Loss of filiform and fungiform papillae on the dorsum of the tongue

.ThrombocytopeniaO/M: petechia , purpura, ecchymosis, hemorhagic bullae, hematomas

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Oral Manifestations of Aplastic Anemia

• Infection, • spontaneous bleeding • purpuric spots

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Oral Manifestations of Acute Leukemias

• Gingival enlargement

• Oral infection

• Bleeding gums, petechiae and ecchymosis


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Mucocutaneous diseaseLichen planusPemphigus vulgarisErythema multiformeDermatitis herpetiformisLinear IgA diseaseulcerative stomatitis

Vitamin deficiency disordersVitamin B complex deficiency

Reddening of oral mucosa, tongue with or without ulceration, swelling and burning

Scurvy (vitamin C deficiency)

Petechiae in oral mucosa and swollen bleeding gums

Pernicious anaemia, Iron deficiency Pellagra

Bald tongue (atrophic glossitis )

Contd…• Gastrointestinal disease

– Coeliac disease– Crohns disease– Ulcerative colitis

• Rheumatic diseases– Lupus erythematosus– Sweet syndrome– Reiter syndrome

• Endocrine disorders– Diabetes

. Oral lesions1.Lichen planus-O/M : Erosive – diffuse erythema and painful

ulceration with peripheral radiating striae Reticular – white lacy striae, especially on

bilateral buccal mucosa

Management• In symptomatic patients, oral lesions

may be treated with a topicalcorticosteroid gel or rinse

Candidiasis (oral thrush)• CONDITIONS ASSOCIATED WITH INCREASED

VULNERABILITY :Poor oral hygiene, xerostomiaRecent antibiotic treatmentDental applianceEarly infancyGenetic immune deficiency, aidsCorticosteroid therapyPancytopenia, anaemia, malnutrition,

malabsorbtionDiabetes , advanced systemic disease

Candidiasis (oral thrush)

Systemic factors causing periodontal disease

Neutropenia Immunodficiency state Downs syndrome Diabetes melitus Pregnancy Oral contraceptives Drug induced-Dilantin sodium, phenytoin,

nifedipine Idiopathic hereditory familial fibrosis

Periodontal bleeding and inflammation

• Diabetes melitusO/M: gingivitis ,

periodontitis, candidiasis, generalized atrophy of the tongue papillae,taste dysfunction, salivary dysfunction, burning mouth syndrome, delayed wound healing

HIV – associated periodontal disease

O/M: linear gingival erythema necrotising ulcerative gingivitis necrotising ulcerative

periodontitis

ALTERATION IN TEETH IN SYSTEMIC DISORDERS

Morphological change

Teeth involved Disease/condition

Enamel hypoplasia Primary & permanent teeth

Rickets , Osteomalacia, Malabsorption, Coeliac disease, Hypoparathyroidism

Enamel hypoplasia with discoloration

Primary & permanent teeth

Tetracyclines given during pregnancy,infancy and childhood upto 8years of age

Enamel discolouration(mottling)

Primary & permanent teeth

Dental fluorosis

Loss of deciduos dentition

Primary Downs syndrome,Juvenile hypophosphataemia

Syndromes associated with cleft lip and palate

• Most common is Pierre Robin syndrome (micrognathia, cleft palate and glossptosis, airway distress )

• Other syndromes includes Goldenhar syndrome, median cleft face syndrome, orofacial digital syndrome, Perts syndrome , Nagar syndrome, Oto palato digital syndrome, Down syndrome and Marfan syndrome

Sjogren syndrome• Oral signs and symptoms• -dry mouth• -cracker sign• -burning• -salivary swelling• -caries• -candidiasis

Management : • Follow up regularly• Salivary substitutes• Eye drops• Caries control• Soft diet• Control of secondary infections

Somebody asked: "You're a Doctor? How much do you make?“

I replied: "HOW MUCH DO I MAKE?" ...I can make holding your hand seem like the most important thing in the world when you're scared...

I can make your child breathe when they stop..I can help your father survive a heart attack... I can make myself get up at 4AM to make sure

your mother has the medicine she needs tolive...and I will work straight

through until 4am to keep her alive and start theday all over again!

I work all day to save the lives of strangers...


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I will drop everything and run a code blue forhours trying to keep you alive!!!

I make my family wait for dinner until I know your

family member is taken care of...

I make myself skip lunch so that I can make sure that everything I did for your wife

today was correct...

I work weekends and holidays and all through thenight because people don't just get sick Monday

though Saturday and during normal workinghours.


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Today, I might save your life. How much do I make?

All I know is, I make a difference.


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THANK YOU

Health & Medicine

Basics of Dentistry