Methods of projecting long-term relative efficacy of products exhibiting small short-term efficacy.

There is ample evidence that caries can develop well into the middle-aged years, and for many subjects, for most of their adult lives. The kinds of benefits to expect for adults in the longer term for improved fluoride products, especially dentifrices, based upon small observed relative improvements in short-term efficacy is a topic currently of considerable interest. For example, what longer-term benefits can be expected by the continued use of an improved fluoride dentifrice, corresponding to an observed 5% or 10% short-term improved efficacy relative to a positive control product? In this study, three models are presented and discussed for projecting longer-term relative benefits of fluoride products for which valid short-term efficacy estimates are available: the compound growth model (CGM), which is a derivative of the compound interest model; the demineralization square root model (DSR), used in demineralization-remineralization studies, and the stabilization model (STA), which is based on the assumption of constant caries attack rates. Published results from long-term studies of fluoride dentifrices and other topical fluoride products (rinses and tablets) suggest that anticaries benefits for topical fluorides do propagate over time, providing increased relative benefits to patients in the longer-term, as compared with the benefit estimates from short-term clinical experiences.(ABSTRACT TRUNCATED AT 250 WORDS)