DESCRIPTION: (From applicant abstract) Caries and its sequelae remain the major reasons for dental treatment and tooth loss in the USA. Caries is not uniformly distributed; 80% of the total caries burden in children is found in 25% of the population. This skewed distribution of disease calls for methods to identify those at greatest risk and apply appropriate interventions. Recent advances have led to the introduction of diagnostic, preventive and therapeutic technologies which hold the promise of enduring cure of the disease. The overall objective of this study is to provide clinical evidence that the use of scientifically based caries risk assessment in conjunction with aggressive preventive and therapeutic measures to restore the balance between pathological and protective factors, and conservative restorations will result in little or no further caries increment compared to conventional treatment. The specific aims are: (1) To conduct a 2.5 year randomized, controlled clinical trial, to compare an "intervention" group (148 patients), whose caries will be managed based upon their low or high caries risk status (assessed by salivary microbiological and chemical assays) to a control group (148 patients) that receives "conventional" restorative treatment without knowledge of risk status The hypothesis to be tested is that caries management (primarily chlorhexidine fluorides, sealants) and conservative restorative treatment based on caries-risk status will significantly reduce the need for caries restorative treatment over two (plus) years compared to usual dental treatment. Study participants will be adult patients with at least one frank carious lesion who enter the comprehensive care clinic at UCSF. (2) To determine caries increment proportion and number of new restorations due to caries, changes in mutans streptococci (MS), lactobacilli (LB), and fluoride (F) in whole saliva, and dichotomized caries risk category in both the test (intervention) and control group patients. If successful this study will markedly change the teaching and practice of caries management.