Effect of Assisted Whitening on Tooth Whitening Outcome and Sensitivity

Objective: There is little clinical data on the practice of combining home-whitening with 16% carbamide peroxide with a course of assisted whitening. This randomised clinical study was undertaken to see if the use of 9% or 27% hydrogen peroxide gels had any effect on the efficacy of tooth whitening or the production of sensitivity produced by that of home whitening alone. Methods: 36 volunteers were randomly allocated to one of three groups: (A) home whitening with 16% carbamide peroxide (B) as group A but supplemented with assisted whitening with 9% hydrogen peroxide; (C) as group A but supplemented with assisted whitening with 27% hydrogen peroxide. Whitening effect was assessed with a value-ordered shade guide by two independent examiners. Sensitivity was self-assessed using a visual analogue scale. Results: Home whitening alone (Group A) effected mean changes in lightness of the order of 8 shade-tabs immediately after cessation of the home whitening procedure. Groups B and C experienced a further significant change in shade immediately following their respective in-surgery treatments. This significance, however, was lost within one week. The shade change produced by the groups which received both home- and in-surgery whitening was not significantly different (p=0.63 and p=0.75) to that produced by the group which received home-whitening alone. Similarly, there were no significant differences in the degree of sensitivity recorded. Conclusion: Home whitening with 16% carbamide peroxide produces significant changes in mean tooth shade of approximately 8 shade-tabs. The in-surgery element of combined whitening produced no significant change in tooth colour or sensitivity when compared to that of home whitening alone.