THE EFFECTS OF SIMPLE INTERVENTIONS ON TOOTH MORTALITY - FINDINGS IN ONE-TRIAL AND IMPLICATIONS FOR FUTURE STUDIES

The purpose of this report was to use a particular clinical trial, the Preventive Geriatric Trial (PGT), as a starting point to discuss whet her treatment efficacy can be evaluated by means of tooth mortality. I n the PGT, 296 subjects were recruited and randomly assigned to five t reatment groups: (1) usual procedures (UP); (2) UP + a cognitive-behav ioral intervention (CB); (3) UP + CB + weekly chlorhexidine rinse (CHX ); (4) UP + CB + CHX + semi-annual fluoride varnish (F); and (5) UP CB + CHX + F + semi-annual prophylaxis, including scaling (P). Explora tory analyses revealed that tooth mortality after the 1st year was low er in treatment groups 3, 4, and 5 than in groups 1 and 2. A one-year exposure resulted in a 45% reduction in tooth mortality (p < 0.05); a two-year exposure resulted in a 59% reduction (p-value < 0.04). The PG T findings suggested that it is possible to design trials based on cli nically relevant endpoints, such as tooth mortality. For the detection of moderate treatment effects, such trials could take the form of Lar ge, Simple Trials (LST), where many subjects are recruited with minima lly restrictive entry criteria, and data are collected only on essenti al baseline characteristics and tooth mortality. LSTs have provided '' reliable answers to important clinical questions'' for other chronic d iseases, and several arguments suggest that they could play a similar critical role in dental research: (1) Periodontitis and caries are amo ng the most common and costly chronic diseases affecting humans, and t he identification of even moderately effective treatments by LSTs can have a large socio-economic impact; (2) the identification of low-cost widely practicable treatments that lend themselves to be investigated in LSTs is likely to benefit more people than the identification of h igh-cost complex treatments; and (3) tooth mortality is simple to asse ss and more relevant than the unvalidated surrogate endpoints that hav e largely failed for more than 20 years to provide reliable answers to certain controversial issues regarding treatment efficacy. The cost o f not reliably establishing the safety and the efficacy of treatments may be far greater than the cost of conducting LSTs.