A cross-over Randomised Controlled Trial of selective pressure impressions for lower complete dentures.

OBJECTIVES The objective of the research was to assess patient preference for a selective pressure impression technique for complete dentures by means of a Randomised Controlled Clinical Trial (RCT). METHODS A literature review revealed no reported RCT's of selective pressure impressions for complete dentures. A cross-over, randomised, controlled, clinical trial was performed comparing selective pressure impressions with a placebo and an alternative method of re-distributing pressure. A sample size calculation yielded 65 patients. Sixty-nine patients, who had a superficial mental foramen on the lower denture bearing area, were recruited for the study. The primary outcome was the patients' preference of the dentures provided. The hypothesis under investigation was that one of the dentures would be preferred by the patients. RESULTS Sixty-six participants completed the trial, 33 (50%) preferred the denture from the selective pressure impression, 19 (29%) the denture with traditional pressure relief, and 14 (21%) the placebo control. 95% confidence intervals showed that the preference for the selective pressure impression was greater than that of the other two techniques. The null hypothesis was rejected. CONCLUSIONS The participants in this trial showed a preference for the denture constructed from the selective pressure impression technique, providing dentists with useful evidence for a clinical impression technique.