The Impact of Pre-Treatment with Desensitizing Agents on the Effectiveness of In-Office Bleaching: An In Vitro Study

In-office teeth bleaching is an esthetic dental procedure performed to whiten teeth. A desensitizing procedure often requires prior in-office bleaching to relieve tooth hypersensitivity. The objective of this study was to evaluate the bleaching efficiency of teeth specimens pre-treated with different desensitizing agents by analyzing the color parameters. A total of 25 bovine specimens were stained and divided into five groups (<i>n</i> = 5). The specimens were pre-treated with GLUMA, ICON, bonding, or fluoride varnish according to the manufacturer's instructions. Subsequently, the samples underwent three consecutive 20 min bleaching sessions using an in-office bleaching product. Color values in the CIE L*, a*, and b* color space were initially recorded, both before any treatment and after each bleaching session. The color difference (ΔE) was then computed. The data were analyzed using SPSS 24.0 software. The color alteration after pre-treatment was analyzed using a one-way ANOVA test, and the color alteration in each bleaching session was compared using a repeated-measure ANOVA test. A one-way ANOVA analysis showed a statistically significant difference in the bleaching efficiency of teeth specimens pre-treated with different desensitizers (<i>p</i> < 0.001). The repeated-measure ANOVA analysis showed no statistically significant difference in additional bleaching sessions (<i>p</i> = 0.133). The ICON and bonding pre-treatment showed the color alteration of teeth specimens before the bleaching procedure. Although the different desensitizer pre-treatments showed significant differences in bleaching efficiency, the differences in color parameters of the teeth specimens at the end of three bleaching sessions were statistically insignificant. Desensitizer pre-treatment influenced the degree of color change during multiple bleaching sessions; however, the outcome of bleaching was not affected by desensitizer pre-treatment.