Caries Diagnosis & Detection

Question 1

Scope of practice laid out by GDC

Answer 1

Carry out a clinical examination within their competence
Diagnose and treatment plan within their competence
Prescribe radiographs, take, process, and interpret various film views used in general dental practice
Plan the delivery of care for patients

Question 2

Learning outcomes

Answer 2

Prepare students for clinical practice

Classify and describe clinical appearance of carious lesions

Understand and apply diagnostic methods of caries detection

Question 3

Any diagnostic test carried out need to be..

Answer 3

Valid and reliable

Question 4

Visual exam requirements

Answer 4

• requires good lightning
• dry clean tooth
• loupes if preferred
• investigation with a probe is not recommended and may cause cavitation if pressed into early lesion to see if its sticky
• wedges / separators for proximal surface
• take verbal history - sh, dh, mh + oral hygiene prior to carrying out any exam

Question 5

Apart from a visual exam, how else can we diagnose / detect caries?

Answer 5

Radiographic exam

Question 6

How is a radiographic exam carried out?

Answer 6

Radiographs are taken following clinical examination and need to be justified and taken in accordance with the current guidelines

Question 7

Which type of radiograph is used?

What are the limitations?

Answer 7

Bitewings are most commonly used to help confirm the presence of caries, however their use has limitations -

• occlusal and buccal caries is difficult to detect in radiographs unless more than 2-3mm deep into dentine or 1/3 of the bucco-lingual distance
• not as good for occlusal/buccal surfaces, parallel technique (contact points)
• a certain amount of demineralisation of the tooth tissue has to have occurred for the lesion to be detected on the radiographs - this becomes increasingly important if lesions appear close to the pulp chamber

Question 8

Radiographs of permanent dentition

Answer 8

• can clinically detect more enamel lesions than radiographically
• radiographs are more important in diagnosis of proximal carious lesions

Question 9

Less frequently used caries detection aids - Transillumination

Answer 9

Transillumination
- assists diagnosis of approximately caries
- technique consists of shinning light through contact points
- carious lesion has low index of light transmission and appears as dark shadow
- Anterior - light reflected though teeth using dental mirror
- Posterior - stronger light needed (ie, fibrotic)

Question 10

Transillumination disadvantages

Answer 10

Not so good for small lesions can only detect large lesions

Question 11

Less frequently used caries detection aids - Detector dyes

Answer 11

Detector dyes
- usually 0.5% basic fushsin or 1% acid red
- claimed to aid discrimination between infected and uninflected dentine

Question 12

Disadvantages of detector dyes

Answer 12

• unable to discriminate between infected and demineralised (but uninfected) dentine
• food debris in fissures may also be stained and may result in unnecessary removal of tooth substance

Question 13

Less frequently used caries detection aid - electrical resistance

Answer 13

Measures the electrical resistance between the tooth surface and the tissue
Resistance values are site specific and they undergo post eruptive changes in normal teeth
Values depend on the porosity of the tooth surface and the contact medium (wet or dry) and temperature

Question 14

Electrical resistance disadvantages

Answer 14

Calibration is difficult
The results need careful interpretation and can lead to false positive ratings

Question 15

What are the treatment options when caries is diagnosed?

Indices that can aid with caries management -

Answer 15

ICDAS - international caries detection and assessment system
- allows clinician to clinically examine the tooth surface and appreciate the underlying damage that has been caused

Iceberg of dental caries
- diagnostic threshold determines what is recorded as disease or sound

Question 16

ICDAS Code 0-6

Answer 16

0 - Sound tooth surface: no evidence of caries after 5 sec air drying
1 - Visual change in enamel: opacity / discolouration (white/brown) visible at entrance to pit/fissure after prolonged air drying
2 - Distinct visual change in enamel visible when wet, lesion must be visible when dry
3 - localised enamel breakdown (without clinical visual signs of dentinal involvement) seen wet and after prolonged drying
4 - Underlying dark shadow from dentine
5 - Distinct cavity with visible dentine
6 - Extensive (more than half the surface) distinct cavity with visible dentine

Question 17

The iceberg of dental caries - diagnostic thresholds in clinical trials and practice

What does diagnostic threshold determine?

Answer 17

What is recorded as ‘diseased’ or ‘sound’

Question 18

The iceberg of dental caries - diagnostic thresholds in clinical trials and practice

Answer 18

D1 - Clinically detectable enamel lesions with ‘intact’ surfaces
D2 - Clinically detectable ‘cavities’ in enamel
D3 - Threshold used in classical clinical trials and in survey examinations
D4 - lesions into pulp

Question 19

Classifying and recognising caries by…

Answer 19

Classify caries according to
1. the surface affected
2. stage of the lesion
3. along the cervical margins of the tooth - root caries
4. around existing restorations - can be classified as recurrent or secondary caries

Question 20

What is residual caries?

Answer 20

Demineralised tissue left before filling is placed

Question 21

Radiation caries as a result of..

Answer 21

Head and neck radiotherapy

Question 22

Rampant / Gross caries of the mouth

Answer 22

Arrested with some areas of activity

Question 23

Can also classify caries according to caries activity

Answer 23

Concept of activity is very important as it directly affects the management of a lesion as active lesions require active management

Active carious lesions are progressive / orange / brown / soft

Question 24

Arrested or inactive caries are…

Answer 24

Formed earlier and then stopped (arrested) / dark brown / black / hard / leathery

Due to..
- habits change
- pt stop eating / drinking sugary food
- cavity that has broken down and becomes more self cleansing