dental caries

DENTAL CARIES

Prepared by: Dr. karam Ahmed MSc. in Operative dentistry


Dental caries: is defined as a microbiological disease of the hard structure of teeth, which results in localized demineralization of the inorganic portion and destruction of the organic substances of the tooth.
Dental Caries

1. Tooth (Host) a. Variation in morphology b. Composition c. Position

LOCAL FACTORS AFFECTING THEINCIDENCE OF CARIES


2. Environmental factor A- Saliva i. Composition ii. Quantity iii. pH iv. Viscosity v. Antibacterial factors


B- DIET i.Physical factorsii. Local factors• Carbohydrate content—presence of refined cariogenic carbohydrate particles on the tooth surface• Fluoride content Etiolog of Dental Caries


C- Microorganisms Most commonly seen microorganisms associated with caries are Streptococcus mutans and Lactobacillus. These bacteria are called acidogenic because they produce acid from carbohydrates. The acids diffuse in to enamel or dentin and dissolve them Enamel and dentin are made of million tiny crystals which are break down inside the tooth by these acid.( Demineralization ). 3.TIME PERIOD

Etiology of Dental Caries

Diet
Caries
Bacteria
Time
Susceptible Surface (Host)

Possible interventions Reduce intake of cariogenic sugars Particularly sucrose

Possible interventions Avoid frequent sucrose intake (snacking) Stimulate salivary flow + sugar clearance
Possible interventions Reduce Strep. mutans numbers by: Reduction in sugar intake Active or passive immunization

Possible interventions Water + other types of Fluoridation Prevention during post-eruptive maturation Fissure sealing Properly contured restorations

New Theories of dental caries (1) Acidogenic Theory (2) Proteolytic Theory (3) Proteolysis-chelation Theory
Etiology of Dental Caries


(1) Acidogenic/Chemoparasitic Theory 1890 WD Miller dental decay is a chemoparasitic process consisting of 2 stages decalcification of enamel results in total destruction


Old Theories
New Theories (Exogenous Theory)

(1) Acidogenic/Chemoparasitic Theory decalcification of dentin as a preliminary stage followed by dissolution of softened residue
Old Theories
New Theories (Exogenous Theory)

(1) Acidogenic/Chemoparasitic Theory following factors cause decay: (1) Role of carbohydrates (2) Role of microorganisms (3) Role of acids (4) Role of dental plaque

Old Theories

New Theories (Exogenous Theory)

(1) Role of carbohydrates food substances act as substrate for microorganisms of dental plaque various carbohydrates have been examined for cariogenic potential

Old Theories

Acidogenic/ Chemoparasitic Theory


(1) Role of carbohydrates cariogenicity of carbohydrate varies with: (1) frequency of ingestion (2) physical form (3) chemical composition (4) route of administration (5) presence of other food constituents

Old Theories

Acidogenic/ Chemoparasitic Theory



(1) Role of carbohydrates (1) frequency of ingestion taken repeatedly in between two major meals provides constant supply of carbohydrate to plaque bacteria for fermentation + production of acids

Old Theories

Acidogenic/ Chemoparasitic Theory

(1) Role of carbohydrates (2) physical form sticky solid carbohydrates

Old Theories
Acidogenic/ Chemoparasitic Theory


(1) Role of carbohydrates (3) chemical composition in the form of glucose, sucrose + fructose due to low molecular weight rapidly diffuse into plaque make themselves easily available for fermentation by plaque bacteria

Old Theories

Acidogenic/ Chemoparasitic Theory

(1) Role of carbohydrates (4) Route of administration oral intake of sticky food

Acidogenic/ Chemoparasitic Theory



(1) Role of carbohydrates (5) Presence of other food constituents refined pure carbohydrates more caries producing
Acidogenic/ Chemoparasitic Theory


(2) Role of microorganisms caused by acid resulting from action of microorganisms on carbohydrates
Acidogenic/ Chemoparasitic Theory

(2) Role of microorganisms

Initiation of Dental Caries
Progression of Dental Caries
Streptococci S. mutans S. milleri S. mitior S. sanguis S. salivaris
Streptococcal species: Streptoccal species in deep dentinal caries and root caries
Lactobacilli L. acidophillus L. casei
Lactobacilli in dentin L. acidophillus L. casei
Actinomycoses A. viscosus A. naeslundii
Actinomycoses A. Israeli A. odontolyticus
Acidogenic/ Chemoparasitic Theory



(2) Role of microorganisms S. mutans has been proved for the initiation of caries
Acidogenic/ Chemoparasitic Theory


(3) Role of acids play most important role in pathogenesis of dental caries pH 5.5 is called critical pH below this pH demineralization of tooth substance begins
Acidogenic/ Chemoparasitic Theory


(4) Role of Dental Plaque found on uncleaned tooth surfaces appear as tenacious, thin film may accumulate within 24-48 hours
Acidogenic/ Chemoparasitic Theory


(2) Proteolytic Theory proteolysis of the organic components of tooth as an initial process than actual demineralization + dissolution of inorganic substances
Old Theories
New Theories (Exogenous Theory)

(2) Proteolytic Theory proposed that enamel lamellae or rod sheath (proteins) may be lysed which means proteolysis as first event in further progression of bacterial invasion + demineralization carious lesions
Old Theories
New Theories (Exogenous Theory)

(3) Proteolysis Chelation Theory suggests that caries is caused by simultaneous events of proteolysis + chelation proteolysis destruction of organic portion of tooth by proteolytic microorganisms
Old Theories
New Theories (Exogenous Theory)


(3) Proteolysis Chelation Theory chelation removal of calcium by forming soluble chelates oral bacteria attack organic component of enamel (proteolysis) breakdown products have chelating ability and this dissolves tooth minerals
Old Theories
New Theories (Exogenous Theory)

(1) Depending on nature of attack (2) Depending on progression of caries (3) Depending on surfaces involved (4) Based on direction of attack (5) Based on number of surfaces involved
Old Theories
Classification


(6) GV Black Classification based on treatment and restoration design (7) Based on location of lesion (8) Based on tissue involved
Old Theories
Classification


Primary Caries incipient; initial first attack on tooth surface Secondary Caries recurrent occurs on margins or walls of existing restorations
Old Theories
Nature of Attack


Acute rapidly invading process involves several teeth lesions are soft + light colored


Old Theories
(2) Progression of Caries


Acute usually pulp is involved at early stage Rampant caries Nursing bottle caries Radiation caries

Old Theories

(2) Progression of Caries

Chronic lesions are long standing fewer in number

Old Theories
(2) Progression of Caries

Pit and fissure Smooth surface caries

Old Theories
(3) Surfaces involved



Forward Caries proceeds from enamel to dentin lesion is triangle in shaped with base of triangle at enamel surface + apex towards dentin in pits + fissures base is at DEJ + apex is in the pit

Old Theories

(4) Direction of caries attack


Backward Caries proceeds from DEJ towards enamel surface also triangle shaped with base at DEJ + apex towards enamel surface

Old Theories

(4) Direction of caries attack


Simple only one surface is involved by caries Compound 2 surfaces are involved Complex more than 3 surfaces involved

Old Theories

(5) Number of Surfaces involved


Class I begin in pits, fissures + defective grooves seen in occlusal surface occlusal two-thirds of molars lingual pits of incisors
Old Theories
(6) GV Black Classification

Class II lesions seen on proximal aspects of molars + premolars

Old Theories
(6) GV Black Classification


Class III lesions involving proximal aspects of incisors do not involve or necessitate removal of incisal edge
Old Theories
(6) GV Black Classification


Class IV lesions involving proximal aspects of incisors involve or require removal of incisal edge
Old Theories
(6) GV Black Classification

Class V lesions present on gingival third of all teeth

Old Theories
(6) GV Black Classification



Class VI lesions found on incisal edges + cusp tips
Old Theories
(6) GV Black Classification


Pit and Fissure caries Occlusal Buccal or lingual pit Smooth surface caries Proximal Buccal or Lingual surface Root caries
Old Theories
(7) Location of the lesion

Enamel Caries Dentinal Caries Cemental Caries

Old Theories
(8) Tissue involved


Senile Caries caries associated with aging almost exclusively seen on root surface Residual Caries not removed during restorative procedure
Classification


Interproximal Caries opaque chalky region (white spot) some cases yellow or brown pigment area spots are generally located on outer surface of enamel between contact point + height of free gingival margin
Clinical Features: Smooth Surface Caries


Interproximal Caries as caries penetrates enamel, enamel surrounding the lesion assumes bluish white appearance usally apparent as laterally spreading caries at DEJ
Clinical Features: Smooth Surface Caries

Interproximal Caries common for proximal caries to extend both bucally + lingually
Clinical Features: Smooth Surface Caries

Clinical Features: usually extends from area opposite gingival crest occlusally to convexity of tooth surface extends laterally towards proximal surfaces
Cervical, Buccal, Lingual or Palatal Caries


Clinical Features: usually occurs on cervical area typical cervical lesion is a crescent shaped cavity beginning as slightly roughened chalky area gradually becomes excavated
Cervical, Buccal, Lingual or Palatal Caries


Clinical Features: appears brown or black feel slightly soft catch a fine explorer point
Pit and Fissure Caries


Clinical Features: enamel bordering the pit and fissure may appear opaque as it becomes bluish white undermined
Pit and Fissure Caries



Clinical Features: lateral spread of caries at DEJ as well as penetration into dentin along dentinal tubules may be extensive without fracturing away overhanging enamel there may be large carious lesion with only a tiny point of opening

Pit and Fissure Caries

also known as cemental caries involves both dentin + cementum in number of people exhibiting gingival recession with clinical exposure of cemental surface
Root Caries


Clinical Features: slowly progressing chronic lesion usually found in mandibular molar area + premolar region gingival recession is associated with root surface caries
Root Caries

occurs immediately adjacent to restoration may be caused by inadequate extension of restoration was not able to excavate or removed well original carious lesion

Recurrent Caries

Clinical Features: restoration with poor margins permitted leakage + entrance of both bacteria + substrate
Recurrent Caries



Etiology: due to nursing bottle containing milk or milk formula, fruit juice or sweetened water sometimes it occurs due to sugar or honey-sweetened pacifier
Nursing Bottle Caries


Pathogenesis: child is put on bed at afternoon nap time or at night with nursing bottle containing milk or a sugar containing beverage milk or sweetened liquid becomes pooled around maxillary anterior teeth
Nursing Bottle Caries


Pathogenesis: carbohydrate containing liquid provide an excellent culture medium for acidogenic microorganisms
Nursing Bottle Caries


Clinical Feature: prolonged feeding beyond usual time may result in early + rampant caries early carious involvement of maxillary anterior, maxillary + mandibular 1st permanent molars, mandibular canines
Nursing Bottle Caries


Clinical Feature: carious process is so severe that only root stumps remain
Nursing Bottle Caries


Prevention: parent should start brushing the child teeth as soon as they erupt in oral cavity discontinue bottle feeding as soon as child can drink from a cup, at approximately 12-15 months of age
Nursing Bottle Caries

suddenly appearing widespread resulting in early involvement of pulp

Rampant Caries


Etiology: may be due to nutritional deficiency malnutrition emotional disturbances

Rampant Caries

Clinical Features: occurs in children with poor dietary habits extensive inter-proximal + smooth surface caries
Rampant Caries

Management: extensive dental care parent education

Rampant Caries


Clinical Features: both deciduous + permanent are affected large open cavities brown-stained polished appearance + hard
Arrested Caries



Restorative Treatment Tooth Brushing Mouth Rinsing Dental Floss Topical Fluoride Application (Pedo Patients) Pit and Fissure Sealants
Prevention/Management of Dental Caries

Zones in Enamel Caries

Different zones are seen before complete disintegration of enamel. Early enamel lesion seen under polarized light reveals four distinct zones of mineralization.These zones begin from the dentinal side of the lesion.


Zone 1: Translucent zone– Represent the advancing front of the lesion– Ten times more porous than sound enamel– Not always present.Zone 2: Dark zone– It lies adjacent and superficial to the translucent zone– Usually present and thus referred as positive zone– Called dark zone because it does not transmit polarized light– Formed due to demineralization.

Zone 3: Body of the lesion– Largest portion of the incipient caries– Found between the surface and the dark zone– It is the area of greatest demineralization making it more porous.Zone 4: Surface zone– This zone is not or least affected by caries– Greater resistance probably due to greater degree of mineralization and greater fluoride concentration– It is less than 5 percent porous– Its radiopacity is comparable to adjacent enamel.

2-Dentinal Caries

Although caries of enamel is clearly a dynamic process, it is not a vital process because it does not defend itself from trauma. But since pulp and dentin are vital tissues, they are capable of defending. When enamel caries reaches the DEJ it spreads rapidly laterally because it is least resistant to caries.

Zones of Dentinal Caries

Five zones have been described in dentinal caries. These zones are clearly distinguished in chronic caries than in acute caries. These zones begin from the pulpal side:



Zone 1: Normal dentin– Zone of fatty degeneration of Tome’s fibers – Formed by degeneration of the odontoblastic process – Otherwise dentin is normal and produces sharp pain on stimulation. Zone 2: Zone of dentinal sclerosis – Intertubular dentin is demineralized – Dentinal sclerosis, i.e. deposition of calcium salts in dentinal tubules takes place – Damage to the odontoblastic zone process is apparent – There are no bacteria in this zone. Hence, this zone is capable of remineralization.

Zone 3: Zone of decalcification of dentin – Further demineralization of intertubular dentin lead to softer dentin.Zone 4: Zone of bacterial invasion – Widening and distortion of the dentinal tubules which are filled with bacteria – Dentin is not self-repairable, because of less mineral content and irreversibly denatured collagen –This zone should be removed during tooth preparation.

Zone 5: Zone of decomposed dentin due to acids and enzymes – Outermost zone – Consists of decomposed dentin filled with bacteria – It must be removed during tooth preparation.

The End