Free Cementum and Periodontium MCQs with Answers

• A. Cervical third of the root
• B. Apical third of the root
• C. Middle third of the root
• D. No secondary cementum forms

Explanation: Secondary cementum is deposited after the tooth reaches functional occlusion and is found mainly in the apical third and furcation areas.

• A. Sharpehy's fibres and elastic fibres
• B. Collagen fibres and blood vessels
• C. Canaliculi and incremental lines
• D. Lacunae and elastic fibres

Explanation: Cellular cementum and compact bone both contain lacunae with canaliculi, and their layers may show incremental lines.

• A. First formed cementum
• B. Less irregular
• C. More calcified than acellular type
• D. Less calcified than acellular type

Explanation: Cellular cementum is generally less mineralized and more irregular than acellular cementum because it is formed more rapidly and contains…

• A. Alveolar bone
• B. Periodontal ligament
• C. Cementum
• D. Longbones

Explanation: Bundle bone is the part of alveolar bone into which the principal fibres of the periodontal ligament insert.

• A. More than dentin
• B. Less than dentin
• C. Equal dentin
• D. None of the above

Explanation: Even when fully mineralized, cementum is softer than dentin. This relative softness permits cementum deposition and periodontal fibre…

• A. Forms during root formation
• B. Formation is a slow process
• C. Seen at the coronal portion of the tooth
• D. Forms after the eruption of the tooth

Explanation: Cellular cementum is secondary cementum, deposited mainly after root formation and often after eruption, particularly in the apical and…

• A. Pulp chamber
• B. Curved
• C. Twisted
• D. Lateral canal

Explanation: At the cervical region near the CEJ, the narrow root canal transitions coronally into the wider pulp chamber.

• A. Highly defined cellular zone near cemento - dentinal junction (CDJ)
• B. Poorly defined zone near cemento-dentinal junction
• C. Highly defined fibrillar zone near CDJ
• D. Both a and B

Explanation: Intermediate cementum is a poorly defined, often amorphous zone located near the cemento-dentinal junction.

• A. 55 to 60%
• B. 50 to 55%
• C. 45 to 50%
• D. 60 to 65%

Explanation: Cementum contains about 45% to 50% inorganic material by weight, with the remainder mainly organic matrix and water.

• A. Hyperplasia
• B. Functional repair
• C. Physiological repair
• D. Anatomic repair

Explanation: Anatomic repair restores the original outline and form of the root surface.

• A. Exforliation of teeth occur
• B. Ankylosis may occur
• C. Delayed eruption
• D. No change occurs

Explanation: Without cementum, periodontal ligament fibres cannot attach properly to the root surface, so the tooth may eventually loosen and…

• A. Apex of root
• B. Apical half of root
• C. Coronal half of root
• D. Entire root

Explanation: Acellular cementum is mainly deposited on the cervical and middle, or coronal, portion of the root.

• A. Cementum meets enamel
• B. Cementum overlaps enamel
• C. Cementum does not meet enamel
• D. All of the above

Explanation: At the cemento-enamel junction, cementum may overlap enamel, meet it edge-to-edge, or fail to meet it and leave exposed dentin.

• A. 10%
• B. 30%
• C. 60%
• D. 90%

Explanation: At the cemento-enamel junction, a butt-joint relationship is found in approximately 30% of teeth.

• A. Often overlaps the enamel
• B. Is acellular in the apical third of the tooth
• C. Is derived from the sheath of hertwig
• D. Does not contain collagen fibres

Explanation: Cementum often extends coronally to overlap enamel at the cemento-enamel junction.

• A. Before dentin formation
• B. After dentin formation
• C. Both are formed at same time
• D. None of the above

Explanation: Cementum formation follows dentin formation because Hertwig's epithelial root sheath induces peripheral dental papilla cells to become…

• A. Cementoblasts
• B. Odontoblasts
• C. Fibro blast
• D. Merkel cells

Explanation: Fibroblasts are the predominant cells in gingival connective tissue and produce and maintain its collagenous extracellular matrix.

• A. Impaction
• B. Gingivitis
• C. Occlusal wear
• D. Gingival recession

Explanation: Gingival recession exposes part of the root, making the clinically visible crown longer than the anatomic crown.

• A. II
• B. I
• C. III
• D. IV

Explanation: Type I collagen forms the great majority of the gingival connective tissue and provides tensile strength.

• A. Dentin
• B. Epithelial rest cells
• C. Cementum
• D. The Epithelial diaphragmExplore Anatomy Models

Explanation: At the apical end of a fully formed tooth, cementum extends toward and usually lines the apical foramen.