Hydrogen Peroxide Release Kinetics of Four Tooth Whitening Products—In Vitro Study

Tooth whitening efficacy can be influenced by several factors, of which concentration and application time are two of the most important. This in vitro study aimed to evaluate the initial content and release kinetics of the hydrogen peroxide (HP) content, or the carbamide peroxide (CP) content as converted to its HP equivalent, of four tooth whitening products with different concentrations (6% HP, 16% CP, 10% CP, and 5% CP). Titrations with Cerium Sulphate IV were performed to determine HP concentration. HP release kinetics were evaluated by a spectrophotometric technique. The results were expressed as the mean values and 95% confidence interval of the percentage of hydrogen peroxide content during release kinetics. One sample t-test, one-way ANOVA, Tukey post hoc testing, and Pearson correlation testing were used, as appropriate, with a significance level of α = 0.05. The concentration of titrated HP was higher than that indicated by the manufacturers in all tested products (p < 0.01). At the minimum application times indicated by the manufacturers, all products released at least 85% of HP content; the gel containing 10% CP registered the lowest release at 85.49 (81.52–89.46). There was a significant HP release in all products during the application times indicated by the manufacturers. Further studies are needed to assess in vitro release kinetics.

Whitening effect of brushing with activated charcoal-based products on enamel: integrative review

Objective: The purpose in this study was to analyze in the literature whether toothbrushing with charcoal-based products promotes a whitening effect. Methodology: An integrative literature review was carried out in the PubMed/MEDLINE database, which had as its guiding question: Does brushing with activated charcoal-based products have a whitening effect on the tooth? The search strategy was performed through the use of terms (charcoal AND “dentifrice OR toothpaste OR toothbrushing” AND “bleaching OR whitening” AND tooth), and only articles published in English in any period were included. Result: From a total of 34 scientific articles identified, 6 articles were included in the study, between the years 2019 and 2021. According to the evidence, three articles did not observe an advantage in performing brushing with activated charcoal-based products and another three observed a slight whitening effect, generally inferior when compared to other whitening agents. In addition, most articles recommend attention to the use of these products for oral hygiene containing charcoal, since many of these studies observed an increase on the roughness of tooth enamel, which is directly related to the inherent abrasiveness of each product and which depends on the source and the methods used to prepare and mill charcoal. Conclusion: From the studies analyzed so far, it is observed that brushing products based on activated charcoal have few effectiveness of tooth whitening, often lower when compared to other abrasive agents present in whitening dentifrices.

Invasive cervical resorption: case report

Invasive cervical resorption (ICR) is an insidious, aggressive, and asymptomatic form that can lead to destruction and even loss of the dental unit. ICR is somewhat uncommon, but it can affect any tooth, with the maxillary central incisors being the most affected. Even after numerous studies, the etiology is still unclear. There are some predisposing factors, including orthodontic treatment, trauma, and internal tooth whitening, which may occur in isolation or in conjunction with each other. This article reports a clinical case of ICR class 3 with a rosy discoloration at the cervical margin and the presence of a fistula associated with a history of trauma. This suspicion was raised after radiographic examination and confirmed by cone-beam computed tomography (CBCT), with treatment via an internal approach and endodontic treatment involving debridement of the resorptive areas and filling with a bioceramic repair material and suturing. After treatment, the patient remained asymptomatic, but the fistula was no longer present. Prospective observation at 10 months showed bone formation in the middle third and well-adapted material in the cervical region, with no resorptive tissue present.

Minimally Invasive Multidisciplinary Restorative Approach to the Esthetic Zone Including a Single Discolored Tooth

SUMMARY Objectives: The case report describes a minimally invasive, multidisciplinary approach to a single discolored anterior tooth, with internal bleaching using traditional Japanese paper (Washi), a gingivoplasty with a three-dimensional (3D) printed surgical guide, and ultrathin feldspathic porcelain veneers. Clinical consideration: The patient’s primary concern was improving her smile. After clinical evaluation, internal tooth bleaching for the discolored tooth and gingivoplasty with restoration of the maxillary anterior six teeth and first premolars was recommended. The internal tooth whitening was accomplished with sodium perborate mixed with 30% hydrogen peroxide impregnated in Washi and sealed in the root canal with glass ionomer. Once the tooth bleaching was completed, the 3D printed surgical guide was placed in the patient’s maxillary anterior region and used to guide soft tissue recontouring. After 6 months, ultrathin feldspathic porcelain veneers were placed. Conclusion: Well-planned restorative procedures combining internal tooth bleaching using Washi, gingivoplasty performed with electrosurgery using a 3D printed surgical guide, and ultrathin feldspathic porcelain veneers can achieve the desired results in the esthetic zone and remain successful for 4 years.