[Strips versus gel: a clinical comparison of two over-the-counter bleaching systems]

The objective of this clinical, randomized, examiner-blinded split-mouth study was to compare the efficacy, the side effects and patients acceptance of two over-the-counter bleaching systems (strips versus gel) with respect to the bleaching times required to achieve six grades of whitening in human teeth. Tooth shades were documented by matching with the VITA shade guide, or dered according to value and assigned a numeric ranking from 1 to 16, lightest to darkest. Twenty-six adults participated in the study. Both treatments were applied twice daily according to the manufacturer's instructions. Efficacy and the PBI were measured by a dental examiner. Tooth hypersensitivity, gingival irritations as well as patients acceptance were recorded by a visual analog scale ranging from 0 to 10. In order to detect changes in the enamel surface due to treatment epoxy casts of the study teeth were analysed by SEM. A total of 20 volunteers completed the study. The subjects teeth treated with the strips-system exhibited a 6.0 +/- 0.0 mean shade scores improvement compared to baseline (53.7 cycles; 1610.3 min), and the subjects teeth treated with the gel-system exhibited a 3.3 +/- 1.4 mean shade scores improvement (64.6 cycles; 969.0 min). However, both treatments were able to whiten teeth statistically significantly compared to baseline. Side effects caused by the two systems were minimal and reversible. None of the teeth studied showed detectible enamel surface changes in the subsequent SEM analysis. Both methods were well accepted.