Novel in-office peroxide-free tooth-whitening gels: bleaching effectiveness, enamel surface alterations, and cell viability

Juliana Silva Ribeiro,Andressa Da Silva Barboza,Adriana Fernandes Da Silva,Rafael Guerra Lund,Evandro Piva,Carlos Enrique Cuevas-Suárez

doi:10.1038/s41598-020-66733-z

Abstract

To evaluate the bleaching ability, the effect on enamel surface and cytotoxicity of novel tooth-whitening formulations containing papain, ficin, or bromelain. Forty bovine dental discs (6 cm ×4 cm) were pigmentated and randomly allocated into the following groups (n = 10): Group 1, 20 wt% carbamide peroxide (control); group 2, 1% papain-based whitening; group 3, 1% ficin-based whitening; and group 4, 1% bromelain-based whitening. The whitening gels were prepared and applied on the enamel three times per day once a week, for 4 weeks. Color measurement was obtained by CIEDE2000. Enamel Knoop microhardness and roughness were evaluated. The WST-1 assay was used to evaluate the cell viability of mouse fibroblast cells (L929). Data were statistically analyzed by one-way analysis of variance (ANOVA) and Student Newman Keuls’s post hoc test at α = 0.05 significance level. Bromelain, ficin-based, and carbamide peroxide bleaching gels showed a similar color change (p < 0.001). Higher enamel hardness decrease and higher enamel roughness were caused by the carbamide peroxide (p < 0.05). The experimental whitening gels did not affect cell viability. Tooth bleaching gels containing bromelain, papain, or ficin have substantial clinical potential to be used in the development of peroxide-free tooth whitening gels.

Highlights

To evaluate the bleaching ability, the effect on enamel surface and cytotoxicity of novel toothwhitening formulations containing papain, ficin, or bromelain
It was hypothesized that tooth sensitivity after dental bleaching is related to the degradation of the hydrogen peroxide into reactive oxygen species (ROS) which can diffuse to the pulp chamber through the dentinal tubules, inducing the release of inflammatory mediators, like IL-1β and RANK-L9,10
Bromelain and ficin-based bleaching gels resulted in a similar color change than the carbamide peroxide gel (p < 0.05)

Summary

Introduction

To evaluate the bleaching ability, the effect on enamel surface and cytotoxicity of novel toothwhitening formulations containing papain, ficin, or bromelain. Ficin-based, and carbamide peroxide bleaching gels showed a similar color change (p < 0.001). The two whitening techniques traditionally used are the at-home and the in-office whitening techniques Both techniques involve the use of different concentrations of carbamide or hydrogen peroxide as active agents[3]. We hypothesized that the development of new whitening agents based on natural products could provide similar aesthetic results and minor side effects[12] Up to now, it seems that despite some papers relate the use of natural compounds as dental bleaching agents, these were not more effective than the traditional techniques[14]

Objectives

Methods

Conclusion