Caries Process and Prevention Strategies: Diagnosis
Diagnostic Criteria

The most commonly used criteria for assessing the depth of caries lesions are as follows:

Timing of Bitewing Radiography

For populations with low caries prevalence, or in individuals who are at low risk for caries based on their medical and dental history, yearly bitewing radiographs are no longer justified.²⁴ Instead, the decision to use radiography should depend on the benefit to the individual patient as it relates to the risk and cost of low-dose radiation exposure. Studies have confirmed that in low-risk populations, intervals of up to 3 years between bitewing radiographs do not jeopardise dental health.²⁵ Based on epidemiological data, four key ages have been identified when bitewing examinations are beneficial.²⁶ These are at:

• Age 5, when it gives a considerable diagnostic yield of otherwise undetected approximal lesions in primary molars.²
• Age 8–9, when the first permanent molar has been in contact with the second primary molar for about 2 years, and these surfaces are, therefore, at risk of approximal caries.²
• Age 12–14, when even in low caries-prevalence populations, one in five children has at least one approximal lesion that has been overlooked without bitewing radiography.²
• Age 15–16, when it is the first 3 to 4 years after tooth eruption and the establishment of approximal contacts create the risk of new approximal lesions.²

In adults, the caries process is slow compared to children and adolescents, but rapid behaviour and lifestyle changes can quickly increase caries risk and progression. Keeping an eye out for these changes by taking a patient’s medical and dental history can help a dentist decide when it might be useful to do a bitewing examination. Special attention should be paid to the third molar and distal surface of the second molar because the location is usually associated with plaque removal difficulty.²