Importance of design, control, & quantitative data in dental clinical research

The ultimate test of a restorative dental biomaterial is its performance in vivo. Often laboratory test data does not correlate directly with clinical performance, so clinical research with human patients is essential. Clinical research that obtains maximum information from a minimum number of patients must be well designed and controlled. Pilot studies are necessary to establish experimental conditions and to determine the sample size. Previous clinical studies with various restorative materials have shown that careful screening and comprehensive oral examinations of patients are necessary to insure maximum recall for evaluation. Controlled placement procedures and randomized alloy placement are extremely important. Restorations are evaluated both by the response of patients to the restorations and by trained and calibrated dental examiners using established ranking criteria. Quantitative data measured in vivo such as that obtained from stereophotogrammetry reduced the need for large patient populations. The interfacing of a computer to record patient, placement, and evaluation data assisted greatly in project management.