16 - Composition, Physiology + Functions of dental cementum

Question 1

Composition of cementum

Answer 1

Cementum ⇢ hard avascular CT that covers root of teeth

Composition

Cementum is not a uniform CT ⇢ differences in chemical constituents exist

General cementum composition:

• 12% water
• 27% organic matrix
• 61% inorganic matrix ⇢ hydroxyapatite crystals

Question 2

Mineral composition

Answer 2

• Cementum < mineralised < Root dentin
• Contains mainly: Hydroxyapatite, calcium phosphate, sulphur, Zn²⁺, Na²⁺, Cu²⁺
• AEF element highly mineralised compared to CIF element

Question 3

Organic composition

Answer 3

• Mainly collagen I + II
• Also 2 major non-collagenous proteins:
• Sialoprotein + Osteoprotein ⇢ cell attachment properties
• These proteins more expressed in AEF cement + AAF cement

Question 4

Cement repair

Answer 4

• Protective function of cementoblasts after resorption of root’s dentin cementum
• Cementoblasts are programmed to keep root’s surface smooth ⇢ by deposition of repair cementum in defects

Question 5

Cement repair

Answer 5

• Protective function of cementoblasts after resorption of root’s dentin cementum
• Cementoblasts are programmed to keep root’s surface smooth ⇢ by deposition of repair cementum in defects

Question 6

Functions of cementum

Answer 6

• Roofing function
• Function to attach periodontal ligaments ⇢ AEFC anchors tooth to ligament
• Protective function ⇢ Keeps root surface smooth by deposition of repair cementum in defects
• Adaptive function