Improving clinical visual detection--potential for caries clinical trials.

It has been the norm in caries clinical trials to measure caries increment by several different caries-recording systems, including the crude DMF-S/T index. However, there is a reserved attitude as to whether to subdivide the non-cavitated lesions and use arrested lesions in clinical trials. This has been due to the belief that it is not possible to achieve reliable data of the early stages of the disease (Radike, 1972). However, recently, Ekstrand et al.(1997, 1998) showed that it was possible: (1) to differentiate between different stages of non-cavitated occlusal lesions, (2) to differentiate between active and inactive occlusal lesions, and (3) to predict the depth of the lesion. In at least 4 other clinical studies, the reproducibility of recording initial active lesions, cavitated active lesions, and arrested lesions was found to be adequate (Carvalho et al., 1989; Nyvad et al, 1999; Ekstrand et al., 2000; Machiulskiene et al., 2001). Since caries today is a more slowly developing disease in many countries in the world, this will result in prolongation of the duration of the clinical trial, which will increase the costs. As indicated above, there is now sufficient evidence that caries can be clinically diagnosed accurately and reliably in earlier stages as well as in an arrested stage. If such stages of caries are used as outcome variables in caries clinical trials, they may have a positive influence on the trials' duration and costs.