The clinical trial in multidisciplinary research

Dental research has developed along two separate paths. Epidemiological studies can only indicate a cause-disease relationship while laboratory experiments can only be applied to the human situation as a working hypothesis. The final solution can only be arrived at by setting up controlled studies in man, though there are limitations on the possibility of control of some variables in human studies. Experimental studies on the formation of pellicles and plaque are described as examples of the use of clinical trials to bridge the gap between basic research and epidemiological data. The ideal model for dental research would involve the identification of a clinical problem and its subdivision into small biological units which could be studied in the laboratory in order to develop working hypothesis. An in vivo model would then be devised to test the hypotheses and finally they would be applied in a well controlled trial.