Influence of Tooth Pigmentation on H2O2 Diffusion and Its Cytotoxicity After In-office Tooth Bleaching

Abstract

Clinical Relevance Pigments in tooth structures affect the diffusion of H2O2 through enamel and dentin. The bleaching methodology can be impacted.

Polymeric biomaterials maintained the esthetic efficacy and reduced the cytotoxicity of in‐office dental bleaching

“…Thus, the discs were incubated in distilled water at 37 C for 24 h to eliminate extrinsic pigments that remained on the dentin surface. 6 To keep the discs hydrated, they were individually stored in an environment with 100% humidity, at a temperature of 37 C, for 72 h (dentin in contact with cotton imbibed in deionized water, and enamel covered with cotton imbibed in a saliva type solution). 9…”

“…to the extracts of each group (n = 8). 6,13 When 4 h had elapsed after incubation at 37 C and 5% CO 2 , the formazan crystals deposited by the cells were dissolved in 100 μl of isopropanol solution (Sigma-Aldrich Corp.) acidified in HCl 0.04 M, and the absorbance was measured at 0 nm (Synergy H1; Biotek). Considering that the control group G1 (no treatment of discs) represented 100% viability of cells, this parameter was used for calculating the cell viability in the other groups established in this study.…”

“…With the purpose of standardizing the initial color of the discs, the protocol of staining with black tea was performed. 6 For this, 3.2 g of black tea (Leão Jr S. A., Fazenda Rio Grande, PR, Brazil) was filtered in 100 ml of boiling water for 5 min, and the discs were immersed in this solution (37 C) for 24 h. After this time interval, the superficial pigments on the enamel were mechanically removed with pumice stone paste (S.S. White). Thus, the discs were incubated in distilled water at 37 C for 24 h to eliminate extrinsic pigments that remained on the dentin surface.…”

“…During this procedure, the teeth remained immersed in distilled water at a temperature of 4 C. 6 Discs with cracks in enamel or dentin were excluded from the study. The thickness of the discs was established at 2.3 mm by means of dentin surface wear using 400 and 600 grit water abrasive papers (P-1200; 3 M, Sumaré, SP, Brazil) and circular manual movements.…”

“…5,6,[8][9][10][12][13][14] Analysis of the color change and cytotoxic potential of these new products in association with the bleaching gel was determined. In this study, it was interesting to observe that the highest color change values occurred in the groups in which the polymeric biomaterials coated the enamel discs.…”