Dental Caries: Aetiology and Risk

Question 1

7 properties of enamel?

Answer 1

• highly mineralized.
• acellular tissue.
• calcium phosphate crystals (make up 99% of dry weight).
• resemble the mineral hydroxyapatite.
• very hard and brittle.
• not innervated.
• forms white spot lesions when affected by caries.

Question 2

What is the normal oral cavity pH?

Answer 2

ABOUT pH 7.0.

• Oral fluids supersaturated with hydroxyapatitie and fluoroapatitite.
• Hence these form.

Question 3

What happens to the oral cavity pH once sugars are metabolized?

Answer 3

pH decreases <4.5<pH<5.5.

• saliva & biofilm become undersaturated with respect to HAp while still supersaturated with respect to FHAp.
• HAp dissolves from subsurface and FHAp forms in surface layers

Question 4

7 properties of dentine

Answer 4

• 70% inorganic materials
• 20% organic material (90% of which is collagen type 1)
• 10% water
• Due to its elastic properties it is a good support for enamel. Its flexibility prevents brittle enamel fracturing.
• Dentinogenesis begins prior to the formation of enamel
• Initiated by the odontoblasts of the pulp.
• Dentine continues to form throughout life and can be initiated in response to stimuli

Question 5

What is pulp

Answer 5

An unmineralised tissue composed of soft connective tissue, vascular,lymphatic and nervous tissue.

Question 6

What are the components of the pulp (3)?

Answer 6

• Cells: fibroblasts and undifferentiated mesenchymal cells (macrophages, lymphocytes, etc.) required for the maintenance and defense of the tissue. Odontoblasts immediately adjacent to the dentin component of the tooth.
• Fibrous matrix: collagen fibers, type I and II
• Ground substance: rich in proteoglycans, glycoproteins and large amounts of water.

Question 7

2 key organisms for dental caries

Answer 7

• Strep mutans.
• Lactobacilli.

Question 8

What is Marsh’s ecological plaque hypothesis?

Answer 8

Cariogenic bacteria are ubiquitous in plaque, but usually in concentrations too low to cause problems unless there is a shift in the balance driven by local environmental change.

Question 9

Success rate of hall technique compared to traditional restorations?

Answer 9

Hall Technique:
- 2 years: 98%
- 5 years: 92%

Composite:
- 2 years: 71%
- 5 years: less than 50%.

GI:
- 2 years: 0%.
- 2 weeks: 20%.

Question 10

What is the important clinical event in the caries process? Why?

Answer 10

Cavitation is the important event clinically.

The breakdown of the outer enamel makes it difficult to remove the biofilm out of the cavity

Question 11

What is needed for an effective caries treatment plan?

Answer 11

you need a reliable diagnosis of caries for an effective treatment plan

Achieved via CLEAN, DRY TEETH, WELL LIT, MAGNIFICATION.

Question 12

What are 2 benefits of early caries diagnosis?

Answer 12

• More management options.
• better outcomes for the patient.

Question 13

2 disadvantages of using a probe in pits and fissures for checking for caries?

Answer 13

• Poor diagnostic accuracy.
• causes irreversible traumatic defects.

Question 14

What should be used to check for caries in pits and fissures?

Answer 14

BALL ENDED PROBES.

Question 15

What is the color of healthy enamel?

Answer 15

Largely transparent (takes on the color of the dentine underneath it).

Question 16

What does it mean when you etch and the surface looks glossy?

Answer 16

The pores are filled with water and the bone will FAIL!

Question 17

What is NOT a good indicator of caries progression in dentine?

Answer 17

COLOR.

(unless it is green in which case it is well established and likely active).

Question 18

3 ways in which caries can be classified?

Answer 18

Site, extent, activity

Question 19

Dental biofilm in health?

Answer 19

In health, the dental biofilm is constituted of a balanced population of microorganisms of low virulence and cariogenicity

Question 20

Dental biofilm in disease

Answer 20

With frequent access to fermentable dietary carbohydrates, a dysbiotic microbiological population of high cariogenicity capable of increased production of organic acids promoting dental hard tissue mineral loss forms.

Question 21

3 most important factors for determining caries risk (predict future caries development)?

Answer 21

• Current/ past disease
• Socioeconomic status
• Intuition

Question 22

2 advantages of determining a child’s caries risk?

Answer 22

• Allow caries preventive interventions to be targeted at those who need them most.
• Aid selection of the optimum caries management technique for existing carious lesion.

Question 23

What is used to determine a family’s/ child’s disadvantages level?

Answer 23

Scottish Index of Multiple Deprivation (SIMD).

Question 24

when should kids see the dentist for the first time?

Answer 24

6 months

Question 25

What quantiles in SIMD indicate disadvantages area?

Answer 25

Quantiles 1 -3.

Question 26

Family has SIMD 1. How does this affect your treatment plan?

Answer 26

Increase prevention, frequency of radiographs and recall.