Abstract
Objective The role of toothpaste used during aesthetic treatments is rarely investigated. The objective was to evaluate the effects of a bioactive glass-based toothpaste (BGT) used before or after the dental bleaching with 35% hydrogen peroxide (HP).
Materials and Methods Bovine enamel blocks (4 × 4 mm; n = 12) were submitted to tooth bleaching and different treatments/storage, before or after HP, based on: (1) no toothpaste and immersion in artificial saliva (AS) after HP for 24 hours, 7 days, or 14 days (control); (2) daily BGT use and AS storage for 7 or 14 days (after HP); and (3) daily BGT use and AS storage for 7 or 14 days (prior to HP). Surface and in-depth color were determined using the CIE L*a*b* system (ΔL*, Δa*, Δb*, and ΔE) on enamel surface and underlying dentin. The surface microhardness (SMH) was evaluated using a Knoop microhardness tester.
Statistical Analysis Data were submitted to analysis of variance (ANOVA) (color variables), repeated measures ANOVA (SMH), and Tukey’s test (α = 0.05).
Results The color changes on the enamel or underlying dentin were not statistically different among the groups (p > 0.05). Twenty-four hours after HP presented a decrease in SMH differing from baseline (p < 0.01). This decrease did not occur in the groups previously exposed to BGT (p > 0.05). BGT use after HP for 7 days differed from group with exclusive AS storage (p < 0.05).
Conclusion In-office tooth bleaching can decrease the microhardness of enamel surface; however, the use of BGT promotes the protection or enables the mineral recovery of tooth without the influence the bleaching efficacy.
Keywords
hydrogen peroxide - surface properties - tooth bleaching - tooth bleaching agents
