MI Paste Effect on Longitudinal Sensitivity & Shade with Bleaching

OBJECTIVE: The purpose of this randomized controlled, split mouth clinical trial was to evaluate the effectiveness of MI paste in reducing sensitivity associated vital bleaching.

METHODS: 45 subjects were recruited for the study following IRB approval. Subjects were randomly divided into two groups, based upon which arch received MI paste. Subjects bleached the first arch for two weeks and were then provided with two bleaching trays for the second arch. Subjects were instructed to use MI paste (GC America) in the non-scalloped tray for 5 minutes, wait for 1 hour and then bleach using the second scalloped tray. Sensitivity was measured by VAS daily log scale at baseline and daily for the two weeks of each bleaching period. Shade was taken with colorimeter Shade Vision at baseline and post-bleaching.

RESULTS: Longitudinal sensitivity experience over the 14 day period of bleaching was summarized using trapezoidal area. The Wilcoxon Signed Rank test was used to compare summary measures between the arch allocations. Results indicated that there was a significant reduction in sensitivity scores the arch using the MI paste versus the arch using the standard protocol (p=0.005). The mean trapezoidal area for the 14-day period treated without MI paste was 38.1 and for the arch treated with MI Paste were 27.8. No evidence of interaction between treatment and arch allocation was found (p=0.78), nor was their any indication of a baseline difference in VAS scores between arches. Both arches with or with out the use of MI Paste showed significant shade change relative to baseline regardless of arch allocation group (p<0.0001).

CONCLUSION: From the results of this study it is concluded that MI paste significantly reduced the sensitivity associated with bleaching and did not interfere with shade change. “This study was supported by GC America GCRC Program, NIH.”