All Free Oral Pathology and Medicine MCQs with Answers

• A. Infectious and transmissible
• B. Not due to microorganisms
• C. Can develop in the absence of sucrose
• D. Microorganisms play the most essential role

Explanation: Dental caries is a biofilm-mediated infectious disease in which microorganisms metabolize fermentable carbohydrates to produce acids.

• A. Virulant
• B. Saprophytic
• C. Sacchrolytic
• D. Avirulant

Explanation: Saccharolytic organisms split or ferment carbohydrates, producing acids that contribute to enamel demineralization and caries.

• A. Hyaluronic acid
• B. Dextran
• C. Amlyopecting
• D. Levan

Explanation: Levan is a soluble fructan formed from the fructose portion of sucrose by plaque bacteria.

• A. Lateral surface of the pit and fissure
• B. Wide and of the pit and fissure
• C. Apex of the pit and fissure
• D. Bottom of the pit and fissure

Explanation: Pit-and-fissure caries begins along the lateral walls of the fissure and advances toward the underlying enamel and dentine.

• A. Selenium
• B. Molybdenum
• C. Cadmium
• D. Magnesium

Explanation: Molybdenum is considered cariostatic because it can reduce enamel solubility and inhibit caries development.

• A. Cemental caries
• B. Early enamel caries
• C. Advanced dentinal caries
• D. Advanced enamel caries

Explanation: Liquefaction foci of Miller are characteristic microscopic areas of degeneration in advanced dentinal caries, where bacterial enzymes…

• A. Levans
• B. Lectins
• C. Polyfructans
• D. Glucans

Explanation: Streptococcus mutans converts sucrose into extracellular glucans, especially the adhesive polymer that helps bacteria attach and form…

• A. Plaque
• B. Materia alba
• C. Calculus
• D. All of the above

Explanation: Dental plaque is a gelatinous, structured bacterial deposit that adheres firmly to tooth surfaces.

• A. Translucent zone
• B. Body of lession
• C. Dark zone
• D. Surface zone

Explanation: The body of the lesion is the largest and most heavily demineralised zone of an enamel caries lesion.

• A. Mac conkey medium
• B. Nutrient agar
• C. Mitus salivarius bacitracin agar
• D. Tellurite medium

Explanation: Mitis salivarius bacitracin agar is the classic selective medium for isolating and counting Streptococcus mutans from plaque or saliva.

• A. Incremental lines of retzius
• B. Perikymata
• C. Imbrication lines of pickerill
• D. Wickham's striae

Explanation: Enamel caries can make the incremental lines of Retzius more prominent because these growth lines represent areas of differing…

• A. Malignancy
• B. Xerostomia
• C. Hairy tongue
• D. Watery saliva

Explanation: Xerostomia increases caries risk because reduced saliva removes less plaque acid, provides less buffering and reduces remineralisation.

• A. enamel hypoplasia due to hypocalcemia
• B. enamel hypoplasia due to birth injuries
• C. enamel hypoplasia due to local infection or local trauma
• D. enamel hypoplasia due to congenital syphilis

Explanation: Turner tooth is a hypoplastic or hypomineralized permanent tooth caused by infection or trauma affecting its primary predecessor during…

• A. Vitamin A deficiency
• B. Teratogens
• C. Vitamin D deficiency
• D. Excess of fluoride

Explanation: Mottled enamel is dental fluorosis, caused by excessive fluoride intake during enamel formation.

• A. Mand. Second premolar
• B. Max. lateral incisor
• C. Mand. Central incisor
• D. Mand. first premolar

Explanation: Microdontia most commonly affects the maxillary lateral incisor, often appearing as a small, peg-shaped tooth.

• A. Dilaceration
• B. Concrescence
• C. Fusion
• D. Gemination

Explanation: Fusion is the union of two tooth germs and commonly produces a reduced tooth count, with separate or partially joined canals.

• A. None of the above
• B. Permanent dentition
• C. Mixed dentition
• D. Primary dentition

Explanation: Fusion is more frequent in the primary dentition, particularly in the anterior teeth.

• A. More common in mandible
• B. Disto molars doesn't resemble any other tooth
• C. Mesiodens is the most common supernumerary tooth
• D. May have resemblance to normal teeth

Explanation: Supernumerary teeth occur more often in the maxilla, especially as mesiodens, so the statement that they are more common in the mandible…

• A. May involve both the deciduous and the permanent dentition
• B. In false anodontia tooth doesn't undergo full development
• C. May involve a single tooth
• D. In total anodontia all teeth are missing

Explanation: In false anodontia, teeth are formed but fail to erupt, such as because of impaction, so they have not simply failed to develop.

• A. Defective enamel and dentine
• B. Increased rate of caries
• C. Defective dentine and obliterated pulp chamber
• D. Oligodontia

Explanation: Dentinogenesis imperfecta primarily produces defective, opalescent dentine with early pulp obliteration, giving very small or absent pulp…