Quality assessment of randomized control trials in dental research II. Results: Periodontal research.

Twenty-one reports of 14 randomized control trials (RCTs) published between 1968 and 1984 comparing methods of periodontal treatment were evaluated using a system to assess the quality of RCTs based an published reports. The quality assessment system evaluates the design, implementation, and analytic methods used. An index of quality is calculated with a maximum score attainable of 1.00. The mean quality score for these 14 RCTs was 0.35±0.07 (ISD). There was no evidence of improvement in scores over lime. Ninety-five percent of the trials used the `split-mouth' protocol. Although the results of 17 reports claimed no statistically significant differences between treatments, in no case was a type II error calculated to ensure that a sample size sufficient to detect a difference of clinical interest had been used. It is recommended that future RCTs of periodontal treatment utilize and report a standard design protocol so that results may be better compared and combined, [ABSTRACT FROM AUTHOR]