[Bitewing radiographs in dentistry: how frequently are they indicated?]

Bitewing radiographs should be taken on an individual indication. The individual's caries risk is an important factor in determining the frequency of bitewing radiographs and, therefore, a dentist should estimate the individual's caries risk. Given two serial bitewing radiographs, the dentist should be able to distinguish freshly developed caries lesions, which require preventive or restorative treatment, from old remineralized lesions, which do not require any treatment at all. Assessment of caries progression from serial bitewing radiographs should also provide the dentist with information to determine the moment of subsequent bitewing radiographs. Because in many western countries the caries prevalence is quite low, this is a complicated task, since the dentist is expected to carry out the diagnostic and decision making process without errors. The true probability of caries progression was derived and plotted as a function of the time span between two bitewing radiographs. The results indicated that the interval between standardized serial bitewing radiographs should be approximately three years for individuals which run a high risk of developing caries, and four years for individuals with a low caries risk.