Impact of caries on tooth structure

Question 1

what do you need to develop caries?

Answer 1

dental plaque

substrate

tooth surface

time

oral bacteria/biofilm

Question 2

what is a white spot lesion?

Answer 2

the white area of dental plaque typically near the gingival margin

demineralised enamel but has not been infiltrated

Question 3

what is an enamel lesion?

Answer 3

demineralisation of enamel

• acid / H+ ions react with phosphate in mouth to form phosphoric acid
• acidic environment erodes / demineralises enamel

Question 4

how does caries spread along the edj? clinically how will this impact?

Answer 4

enamel rod length is preserved but caries infiltrates and enlargens gaps between enamel rods

inverse triangle shape

if the patient can clean the tooth surface, do not restore.

Question 5

how does demineralisation of enamel affect dentine?

Answer 5

dentine tubules lose diameter, forming a gap between tubules

caries infiltrates in gap and dentine begins to demineralise

Question 6

what are inactive lesions? typically gingivally located ones.

Answer 6

slight cavitation under a microscope but no evidence of caries now

appears shiny white and is very superficial

the lesion is said to have arrested

Question 7

how may you gain access to an interproximal carious lesion?

Answer 7

use a small piece of rubber to widen the gap temporarily.

Question 8

what would your thought process be if a patient presented with white spot lesion on lower 6, you cannot tell if it is cavitated?

Answer 8

promote oral hygiene as you cannot investigate with a probe

no evident grey discolouration so not evident it is a cavity

Question 9

why are pits and fissures a trap for caries?

Answer 9

saliva can only buffer superficially

substrate and bacteria can penetrate deep into fissures and cause caries development

Question 10

what does grey areas around pit and fissures show?

Answer 10

there is a large cavity below the fissures

enamel is undermined by a pit

Question 11

what is a plaque biofilm and how does it develop?

Answer 11

saliva acts as a primer allowing bacteria to bond to enamel and form a biofilm

selective attachment of bacteria through receptors

bacteria that join create new niches for more bacteria

after brushing, biofilm cannot produce acid early enough as lacks infrastructure