Dental Caries

Question 1

Caries:

Answer 1

Pathological condition involving demineralization of tooth tissue.

Dental caries is caused by dietary carbohydrates being fermented by plaque bacteria to acid.

Question 2

Classification

Answer 2

• Enamel caries – limited to just enamel
• Root caries – on the exposed cementum and dentin
• Primary caries – unrestored surfaces
• Secondary caries – secondary caries, on restored surfaces
• Residual caries – demineralised
• Active caries – involves progressing demineralization
• Arrested caries – lesion in which demineralization ceased (no treatment needed)
• Initial/incipient caries or White spot lesion – lesion visible upon inspection (white)
• Rampant caries – multiple active lesions
• Can also classify according to anatomical location, ie:
– Free surface, pit and fissure, cervical, root, enamel, dentinal, etc.

Question 3

Acidogenic theory of caries aetiology

Answer 3

• Also known as Chemoparasitic theory as proposed by W.D. Miller in 1890.

1. fermentation of dietary carbohydrates by microorganisms in plaque to organic acids on the tooth surface;
2. rapid lowering of the pH at the enamel surface to below the critical pH (5.5) at which enamel will dissolve;
3. following plaque microbial metabolism the pH within plaque will rise due to the outward diffusion of acids and buffering so that remineralisation of enamel occurs;
4. demineralisation and remineralisation is an equilibrium so that dental caries progresses only when demineralisation is greater than remineralisation.

Question 4

Role of saliva

Answer 4

1. ion reservoir – supersaturated with calcium and phosphate ions which promotes remineralisation;
2. buffer – neutralises plaque pH after eating to minimise time for demineralisation;
3. fluid/lubricant – protects mucosa against mechanical, chemical and thermal irritation;
4. cleansing – clears food;
5. excretion – secretion of substances;
6. antimicrobial – IgA, lysozyme, lactoferrin and sialoperoxidase;
7. agglutination – aggregation of bacterial cells;
8. pellicle formation – a protective diffusion barrier of salivary proteins formed on enamel;
9. taste – acts as a solvent with foodstuff to interact with taste buds;
10. digestion – breakdown of starch by salivary amylase.

Question 5

Caries detection

Answer 5

1. Visual and tactile inspection (ball-ended or blunt probe only)
2. ICDAS-II(The International Caries Detection and Assessment
   System)- shown to be more accurate than other traditional methods)
3. Radiography.
   – Bitewings
   – orthopantomograms (OPTs)
   – bimolars
   – periapicals.
4. Transillumination
5. Tooth separation
6. Fluorescence.
   – Laser light fluorescence Electronic caries monitor (ECM)
7. Electronic caries monitor (ECM)

Question 6

Caries‐Risk Assessment:

Answer 6

• Socio-demographic:
1. Socio-economic status: low economic levels are associated with high caries risk.
2. Educational level: low education levels are associated with high caries risk.
3. Ethnicity: first-generation immigrants are at increased caries risk.

• Behavioural:
1. Diet: high-frequency intakes of cariogenic foods and drinks are associated with high caries risk.
2. Fizzy drinks and juices: increased frequency of intake and sipping are associated with high caries risk.
3. Habits: swishing and/or holding habits for fizzy drinks and juices are associated with high caries risk.
4. Baby bottle: night-time and on demand drinking of cariogenic drinks in a baby bottle are associated with high caries risk.
5. Fluoride exposue: irregular or no exposure to daily fluoride is associated with high caries risk.
6. Toothbrushing: irregular non-supervised brushing is associated withhigh caries risk.

• Clinical:
1. Caries prevalence: past caries is strongly associated with high caries risk.
2. Oral hygiene level: plaque index scores >50% are associated with high caries risk.
3. Gingival inspection: bleeding on probing is associated with high
4. caries risk.

• Radiographic:
1. Bitewing radiographs: interproximal as well as new or progression of lesions are associated with high caries risk.

• Supplementary tests:
1. Salivary flow: low (<0.5â•›ml/min) salivary flow is associated with high caries risk.
2. Salivary buffering capacity: low salivary pH and poor buffering
3. capacity are associated with high caries risk.
4. Bacterial: high mutans streptococci or lactobacilli counts are associated with high caries risk.

Question 7

4 Pillars of prevention

Answer 7

• plaque control;
• diet;
• fluoride;
• fissure sealants

Question 8

Dietary advice for prevention of dental caries

Answer 8

• Do not use sweetened drinks in a bottle or feeder cup

• Discourage prolonged on demand breast feeding (hig
lactose)

• Recommend safer drinks (water, plain milk and tea) without added sugar

• Recommend safer snacks (fruit, cheese, plain crisps, bread)

• Restrict sugary snacks to mealtimes or one day per week.
5&2 rule

• Avoid chewy, sticky and boiled sweets

• Be aware of hidden sugars (dried fruits like raisins, yoghurts, flavoured crisps and ketchup)

Question 9

Two main types of pits and fissures

Answer 9

1. V shaped: tends to be self cleansing and caries resistant
2. I shaped: caries susceptible as they provide a niche for plaque accumulation

Question 10

Assessing the need for fissure sealants

Answer 10

Indications

1. Deep, retentive pits and fissures that cause catching of an explorer
2. Stained pits and fissures with minimal decalcification
3. Pit and fissure caries (superficial)
4. No radiographic or clinical evidence of interproximal caries
5. Possibility of adequate isolation (use of rubber dam)
6. Tooth erupted in less than four years

Contraindications

1. Well‐coalesced, self cleansing pits and fissures
2. Radiographic or clinical evidence of occlusal or interproiximal caries
3. Presence of many interproixmal lesion or restoration
4. Partially erupted tooth
5. Pit and fissure caries that remained caries free for four years