A multitude of clinical approaches have been taken to study the mechanism of how caries lesions progress and regress, and to evaluate various intervention strategies directed at the prevention of dental caries. Model systems can be broadly classified as demineralization (caries) models and remineralization models. A demineralization model is one in which there is a net loss of mineral over the course of a study period. The focus of this review is on the clinical approaches that can be considered as remineralization models where there is net gain of mineral as an experimental endpoint, usually as a result of a therapeutic intervention. The remineralization models are presented in two major categories: namely, in vivo models and in situ models. The in vivo models involve the use of natural dental tissues as the experimental substrate, while the in situ models use pieces of extracted teeth as the hard tissue substrate. The in vivo models are further subdivided into short-term clinical trials, and studies with experimentally induced caries. The outcome measures used, in conventional clinical trials studying remineralization use subjective criteria; namely, caries reversals based on visual/ tactile assessment for occlusal and smooth surfaces, visual assessment of bite-wing radiographs for interproximal surfaces, and tactile changes in hardness for dentinal lesions. These relatively insensitive methods cannot be easily adapted for remineralization studies and are subject to examiner error. The use of visual criteria to classify the caries activity status of non-cavitated lesions has been proposed, but remains to be validated. The limitations of conventional caries detection methods has led to increasing interest in developing objective, quantitative approaches for assisting in caries diagnosis, and for monitoring changes in caries status (mineral loss/mineral gain) over time. Quantitative light-induced fluorescence, infrared laser fluorescence, electrical conductivity, and digital imaging fiber-optic transillumination are among the most promising techniques currently available. The greater sensitivity of these quantitative methods permits the detection of lesions at an earlier stage than conventional methods. There is now the potential that short-term clinical trials may replace conventional caries trials for some research applications, once these new approaches have been properly validated. In addition to studies evaluating the repair of naturally occurring caries, it is possible to experimentally induce incipient caries on natural teeth by restricting oral hygiene practice, or by using artificial means to eliminate mechanical forces on the tooth surface (banding or placing brackets on teeth). In situ models continue to be useful approaches to evaluate innovative remineralization technology. They have been applied in a wide range of remineralization studies, including topical fluoride products, remineralizing solutions, dairy products, and chewing gum. Whatever the approach used to study remineralization, the ultimate goal of clinical intervention strategies is the preservation of tooth structure and the prevention of lesion progression to the point where restorative intervention would be required. Therefore, the arrestment of caries lesions, as well as the reversal of the caries process, can be considered clinically successful outcomes.
|Original language||English (US)|
|Number of pages||12|
|Journal||Journal of Clinical Dentistry|
|State||Published - Jan 1 1999|
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