Effect of rubber dam isolation on restoration deterioration

The consequence of using either rubber dam or cotton roll isolation on the subsequent clinical deterioration of 546 polished amalgam and 148 anterior enamel-bonded resin composite restorations was evaluated over periods of up to 15 and 10 years, respectively. Double-blind assessments for several clinical factors or parameters of the restorations were made using both direct and indirect observation methods. The transformed rating scores obtained were evaluated using a mixed model analysis of variance. With very few exceptions, all restoration placements were of high quality, and there were relatively few unsatisfactory rating scores given for any of the clinical factors assessed over the study. The low mean deterioration scores for most of the clinical factors assessed were also fairly similar, irrespective of the isolation method used. Therefore, although a statistically significant difference was found between the two isolation methods for marginal fracture of the composites, the clinical relevance of this difference is questionable.