Dental Caries: Causes, Progression, and Management (PDF)

Dental Caries BY Assoc. Prof. MONA MOHSEN ABDO Associate professor in the Oral Pathology Department Faculty of Dentistry Mansoura National University 1-Dental caries Definition: Bacterial disease of the calcified tissue of teeth characterized by progressive-irreversible deminer...

Dental Caries BY Assoc. Prof. MONA MOHSEN ABDO Associate professor in the Oral Pathology Department Faculty of Dentistry Mansoura National University 1-Dental caries Definition: Bacterial disease of the calcified tissue of teeth characterized by progressive-irreversible demineralization of inorganic and destruction of organic substance of the tooth.  The acidogenic theory (Miller’s chemico-parasitic theory) Etiology of dental caries: Is the most accepted etiologic theory that requires : A: Essential factors: 1. Dental plaque 2. Cariogenic (acidogenic) bacteria 3. Susceptible tooth surfaces 4. Fermentable bacterial substrate (sugar) B: Contributing factors: 1:internsic factors (tooth related) -composition, morphology, and position 2:extrinsic factors: A-Diet related : -physical factors: unrefined(natural) food less caries. -local factor: diet content of carbohydrates, calcium, fluoride, and vitamins. B-Saliva related:- composition  increases ammonia decreases caries -Ph: normal (6.2-7.6) or alkaline Ph is better -Quantity: Xerostomia increases caries -Viscosity: increases caries.  Role of saliva in caries production Formation of Buffering pellicle from Washing action: via salivary effect bicarbonates glycoproteins. & phosphates. Other Antibodies antibacterial content: substances : IgA(immunoglubilin lysozyme ,peroxid A) ase and lactorferrin.  Role of Dental plaque: Def: is a biofilm of bacteria embedded in an extracellular polysaccharide matrix. Clinically: 1-adherent deposit on the teeth 2-visible, on the labial surfaces of the incisors, when no tooth brushing for 12–24 hours. Function: concentration of acid and bacteria over tooth surface especially smooth surfaces.  Role of bacteria Functions: utilizes carbohydrates in the formation of acid that decalcifies tooth structure and polymerizes monosaccharides to form the dense plaque matrix. Types: many types of bacteria got isolated but -Strept.coccus mutans is the most important in initiation of early enamel caries specially in smooth surface caries that requires plaque. -Lactobacilli in progression. -Strep.sanguis ,salivaries and mitis in pit and fissures.  Clinical presentation 1- according to site of the attack: A-pit and fissure caries: Early caries brown and probe sticks Undermined enamel : at borders are bluish white fractures under stress due to the lateral spread of caries along the amelodentinal junction.(hidden or occult caries) 2-Smooth surface caries: In the early stages chalky white spots do not catch a probe. then got yellowish pigment with progression. 3-root surface caries: Saucer shape with ill-defined borders. 2-According to rate of attack: a-slowly progressive(chronic caries): b- Rampant (acute caries): -rapidly progressive -involve many or all of the teeth with early pulp involvement.  Nursing bottle caries: Def : rampant caries affecting deciduous teeth in babies due to prolonged use of milk after eruption. Mostly affect maxillary incisors followed by molars. Nursing bottle caries Rampant caries c-Arrested caries(static): -Caries that is no more progressive. FORMS: 1-Arrested white spotted lesion: (mainly on labial or lingual surfaces): 1-has shiny hard surface. 2-may be brown in color. 3–is more resistant to attack by acid than sound enamel. 4–regarded as scar tissue  thus should not be attacked with a dental drill Management of arrested white spots 1.Topical Remineralization Products: Products like fluoride varnishes, can help reduce the visibility of white spots by promoting deeper remineralization and blending the lesion with the surrounding enamel. 2.Resin Infiltration (Icon): This minimally invasive procedure involves applying a clear resin material that infiltrates and fill the porous enamel of the white spot lesion without drilling. 3.Microabrasion: gently removes a very thin layer of enamel, helping to reduce the visibility of the white spots. This is combined with polishing and sometimes followed by fluoride treatment. 4.Bleaching (Whitening): However, this approach may temporarily make the white spots more visible 2-Arrested caries in Dentin: Usually in large cavities in occlusal surfaces lack food retention and receive the washing effect of saliva  eburnated dentine. N.B eburnated dentine=hard brown polished surface of dentine that does not catch the probe. 3-According to onset: a-1ry caries b-Recurrent of 2ry caries: under defective restoration c-Residual caries: Which is not removed during a restorative procedure.  Histopathology of dental caries 1- Enamel caries : demineralization results in A: VIA GROUND increasing the enamel SECTIONS porosity. Which changes its UNDER LIGHT color , hardness and resistance to bacterial attacks. MICROSCOPE The caries progression follows the direction of the enamel rods. Pit & fissure caries  Dentine caries role: progression of caries follows the direction of the dentinal tubules.  Zones of early dentine caries: 1)Zone of fatty degeneration of tomes fibers (odontoblastic processes): due to irritation by acid Dead tracts. Dead tracts: are the empty dentinal tubules resulting from degeneration of the odontoblasts and their processes by bacterial acid irritation which appear opaque in ground sections examined by 2) Zone of dentinal sclerosis: Translucent zone beneath carious areas. 3) Zone of demineralization: Decalcification of dentinal tubules allow the packing of bacteria inside. Dentine caries 4) Zone of bacterial invasion: Pioneer bacteria: is the 1st generation of bacteria that invades the dentinal tubules. Each dentinal tubule is invaded by single isolated type of bacteria. Acidogeneic bacteria is found first then proteolytic bacteria predominate in deep caries. In this zone softening of D.tubule occurs with the intense packing of bacteria &the bending and compression of adjacent tubules occur Early dentine caries Late dentine caries started with the formation of two structures: 1) Liquefaction foci: are ovoid foci filled with necrotic debris that result from the local coalescence and breakdown of dentinal tubules. They are parallel to the course of D.tubule. 2) Transverse clefts: they are formed at right angles to the D.tubules due to the extension of caries along the lateral branches. Late dentine caries ( liquefaction foci ) Late dentine caries ( transverse cleft ) THANK YOU