Tooth Structure

Question 1

Dentine

Answer 1

70% HA, 20% organic matter, 10% H2O
Harder than bone but softer than enamel
Yellow shows when enamel is lost
Tubules extend from external surface to the pulp (30,000 to 40,000 per nm 2)
Tubules shouldn’t be exposed as they transmit pain to pulp if dentine is exposed so sensitive
Dentine contains osteoblasts so continues to develop over time

Question 2

Crown

Answer 2

Dentine covered with enamel
Inside is pulp center
Roots are held in dentine by periodontal ligament

Question 3

Enamel

Answer 3

Hydroxyapatite
5mdhs on mineral hardness so hardest body tissue from precise arrangement of HA in rod pattern
Less protein and highly mineralised prone to caries
Acellular so cant regenerate

Question 4

Cementum

Answer 4

Covers root surface giving anchorage to the periodontal ligament providing chewing flexibility
Attaches tooth to socket
50% HA, 50% organic matter
Cementoblasts sit on tooth surface and secrete cementum for remodeling and repair

Question 5

Alveolar bone

Answer 5

Normal bone in between teeth to support and protect
Compact bone lines tooth socket allowing attachment of fibers from the periodontal ligament
Bone contains osteoblasts/clasts/cytes, good never and blood supply

Question 6

Periodontal ligament

Answer 6

Specialised soft connective tissue enveloping tooth root and providing attachment to the alveolar bone anchoring the tooth in place
0.2 nm wide composed of highly organised tissue architecture and specialised biochemical composition
Blood vessels and nerves
Main constituent is collagen fiber orientated to allow movement of tooth in socket
Highly cellular with 55% fibroblasts to make collagen

Question 7

Dental pulp

Answer 7

Tooth center with many cells
Provides nutrition for surrounding mineral tissue
Sensory role in detecting temp extremes, pressure or trauma perceived as pain
Forms reparative dentine to mend/protect dental pulp
Pulpitis when inflammation (constricted space)

Question 8

Gingiva

Answer 8

Level gums and oral mucous protecting peritoneum from bacteria and food preventing infection if food meets root
Attached to underlying bone
Retract with age

Question 9

Saliva

Answer 9

Fights germs, prevents bad breath and prepares food for swallowing
Contains antimicrobial peptides called lysozymes and enzymes
Buffering capacity and balances de/remineralisation as it contains minerals that prevent acid softening