Comparison in vitro of 3 Tooth Bleaching Systems

Objective: To compare various power bleaching systems using a model in vitro. Methods: Nineteen groups of 5 internally stained tooth specimens were allocated to treatments using 3 commercial bleaching products all based on 35% hydrogen peroxide with and without 4 different light sources. Assessments of shade change were Shade Guide (SG), Shade Vision System (SVS) and chromometer. Results: For SG all but the light only treatment resulted in measurable improvement in shade ranging from 4.6 to 14.6 shade guide units. Similar findings were apparent with SVS and chromometer. No change was seen in the light only treatments by SVS and SG with very small changes by chromometer. For the 3 gels least change was recorded when there was no light used. For SG, SVS and chromometer data analysis over all treatment groups, excluding light only treatments, revealed highly significant differences. Within bleach product treatment differences were only significant with one gel both with and without light activation. Differences between gels with the same light and no light revealed some significant differences in SG and chromometer data but not SVS. In mean terms the order of efficacy of gels with each light and no light was the same for the majority of data sets. Conclusions: There were some significant differences within one and between all the bleaching systems. The stain model could be used to plan manageable clinical studies.