Effects of Home-Use Bleaching Gels on Enamel Gloss and Roughness

Purpose:  To examine effects of two professional home-use bleaching gels on enamel surface gloss and roughness in a clinical trial.  Material and Methods: With the IRB approval, 60 adult subjects were randomly assigned to two groups (30/group): of either Night White ACP 16% CP or Opalescence PF 15% CP, which were used once daily for 14-day following manufacturers' instructions.  Vitapan Classical shade, L*a*b* and visual enamel surface gloss of maxillary anterior teeth, Ra of maxillary central incisor replicas, tooth sensitivity, and oral tissues examinations were evaluated at the baseline, 14-Day and 3- and 6-month.  The within-treatment effects were analyzed using the one-way ANOVA or Kruskal-Wallis one-way ANOVA on ranks.  Wilcoxon signed rank test was used to determine the before and after treatment effect; the between-treatment effects were examined using the Student t-test or Mann-Whitney rank sum test.  Results: Fifty-two subjects (26/group) completed the study.  Shade reductions were 8.05 and 7.98 at 14-day and 7.47 and 6.96 at 6-month for the Night White ACP and Opalescence PF groups, respectively.  The L*a*b* data were supportive of the shade results.  The gloss values for the Night White ACP group increased 0.22 (p<0.001), 0.20 (p=0.002) and 0.16 (p=0.007) at 14-Day, and 3- and 6-month, respectively; the differences at the 14-Day and 3-month were significantly higher (p<0.05) than those of the Opalescence PF group. The Ra data showed a similar trend to the gloss findings, although the within- and between-treatment effects were not significant.  No clinical adverse effect other than transient mild to moderate tooth sensitivity and/or gingival irritation was detected in any subjects.  Conclusion: Both bleaching systems are highly effective in whitening teeth.  Night White ACP appears to improve the perception of enamel surface gloss after the 14-day bleaching treatment; such improvement is stable for up to 6 month. Sponsored by Discus Dental, Inc.