Cariology

Question 1

Define Decay + difference between active vs arrested decay:

Answer 1

Rot/ destruction of tooth surface caused by bacteria or poor oral hygiene.

• Active lesion: progressing decay
• Arrested lesion: decay successfully in remission (white spot scar appearance)

Question 2

Explain how caries develop:

Answer 2

Causes: poor OH and sugar diet

1. plaque (contains Cario/acidogenic bacteria) + sugar (sucrose) –> ferments to ACID which then
2. breaks down enamel and can get into dentine
3. first sign of decay: white spot lesion/ radiolucency in enamel image

Question 3

Identify the 4 factors that can affect the development or prevention of caries:

Answer 3

1. saliva: rich in calcium phosphate (helps remineralise teeth), alkaline, removes plaque.
2. Fluoride: remineralises teeth, can join with Apatite to form fluoroapatite = makes stronger teeth (1.0ppm is good amt of fluoride in water)
3. Plaque: poor oral hygiene-> plaque buildup (around gum margins, interproximal areas, grooves, on over hangs of poor fillings)
4. lifestyle: oral hygiene, diet

Question 4

How can we prevent/control caries?

Answer 4

decrease sugar
remove plaque biofilm
increase fluoride and saliva

Question 5

How can caries be treated?

Answer 5

non invasive: fluoride, promote remineralisation

invasive: drill and fill

Question 6

An acquired pellicle is which of the following?

a) Acellular, homogenous organic film, coats enamel/ other hard surfaces by selectively absorbing salivary proteins

b) cellular, homogenous organic film, coats enamel/ other hard surfaces by selectively absorbing salivary proteins

c) acellular, homogenous organic film, coats dentin/ other hard surfaces by selectively absorbing salivary carbohydrates

Answer 6

a) Acellular, homogenous organic film, coats enamel/ other hard surfaces by selectively absorbing salivary proteins

further notes: Acquired salivary pellicle acts as a natural barrier to prevent a tooth’s surface from making direct contact with acids and to protect it from erosive demineralization. It contributes to the control of dental erosion by modulating calcium and phosphate concentrations on the tooth surface. (Chawhuaveang et al., 2021)

Question 7

which layer of bacteria/bacterial deposit on the teeth is mineralised: dental plaque (biofilm) or calculus?

Answer 7

answer: calculus

notes: plaque= soft bacterial deposit on teeth/hard structure, not yet hardened/mineralised, normally white, can be brushed off. if plaque not properly cleaned over time it will become calculus
calculus= layer of bacteria and matrix that is hardened/calcified, hard to brush off.

Question 8

dental caries requires:

a) cariogenic/acidogenic bacteria and biofilm, stagnation areas, fermentable bacterial substrate (sugars), susceptible tooth surfaces, time

b)cariogenic/acidogenic bacteria and biofilm, high salivary rate, fermentable bacterial substrate (sugars), susceptible tooth surfaces, time

c)cariogenic/acidogenic bacteria and biofilm, high salivary rate, calcium and phosphate ions, susceptible tooth surfaces, time

d) cariogenic/acidogenic bacteria and biofilm, high salivary rate, hydroxyapatite breakdown, susceptible tooth surfaces, time

Answer 8

a) cariogenic/acidogenic bacteria and biofilm, stagnation areas, fermentable bacterial substrate (sugars), susceptible tooth surfaces, time

Question 9

Use the acronym BAD to list the 3 factors that can cause decay:

Answer 9

Bad bacteria: acid producing bacteria (present due to poor oral hygiene = diet)

Absence of saliva: no healthy salivary function

Dietary habits (poor): frequent sugars/ acids → low ph allowing bacteria to survive → demineralisation → decay

BAD factors + time + stagnation areas= leads to caries

Question 10

why is saliva important?

Answer 10

we need saliva for buffering (neutralise acid), sugar clearance, mineralisation of teeth (saliva has minerals in it e.g. calcium and phosphate ions which enamel structure needs)

Question 11

A biofilm on tooth is also called?

Answer 11

dental plaque

Question 12

the presence of dental plaque is sufficient to cause decay. true or false?

Answer 12

false.

DECAY IS NOT CAUSED BY ONLY DENTAL PLAQUE:
1. Plaque/ bacteria AND high frequency of sugar is required →
2. sugars upsets bacteria ecology balance in mouth (i.e promotes bad cariogenic bacteria, which feed off the sugars from food then produce acid) →
3. acid enter into tooth structure and breaks it down= decay

Answer 13

Specific plaque
Non- specific plaque
Ecological plaque
Only few bacteria in plaque causing decay
ALL bacteria in plaque causes decay
Bacteria can exist in sound state but can go whack causing decay when sugar is present (i.e. change of local environment by sugar presence will shift bacteria to be cariogenic)