Tooth enamel lesions related to whitening toothpaste

Abstract

Several studies have attributed the appearance of lesions in the enamel morphology after the use of tooth- whitening toothpaste. However, there is no consensus among researchers regarding the relevance of the severity of lesions detected on the tooth surface. Objectives: The present study had the aim of evaluating, in vitro, the effects of the hydrogen peroxide, carbamide peroxide and sodium bicarbonate contained in dentifrice formulations, on human tooth enamel. Method and materials: After darkening process in laboratory, human premolars were brushed using dentifrice containing the two whitening substances and the abrasive product. The degree of specimen staining before and after this procedure was determined using spectrophotometry. Scanning electron microscopy (SEM) was used to obtain images, which were analyzed to show the nature of the lesions that appeared on the enamel surface. Results: The effectiveness of the whitening caused by hydrogen peroxide and carbamide peroxide and the abrasion caused by bicarbonate were confirmed, given that the treated test pieces returned to their original coloration. Based on SEM, evaluation of the enamel surfaces subjected to the test products showed that different types of morphological lesions of varying severity appeared. Conclusions: Whitening dentifrice containing hydrogen peroxide and carbamide peroxide produced lesions on the enamel surface such that the greatest sequelae were associated with exposure to hydrogen peroxide.