Initial and pulp chamber concentration of hydrogen peroxide using different bleaching products

Abstract

Objective: This study’s aim was to quantify the hydrogen peroxide (HP) penetration into the pulp chamber of teeth submitted to different protocols of bleaching. Material and Methods: Ninety premolars were randomly divided into nine groups according to the bleaching agent protocol (n = 10): control (no bleaching), carbamide peroxide 10% [10% CP], carbamide peroxide 16% [16% CP], carbamide peroxide 22% [22% CP], hydrogen peroxide 4% [4% HP], hydrogen peroxide 6% [6% HP], hydrogen peroxide 7.5% [7.5% HP], hydrogen peroxide 10% [10% HP] and hydrogen peroxide 35% [35% HP]. The penetration of HP was measured via spectrophotometric analysis of the acetate buffer solution from the pulp chamber. The absorbance of the resulting solution was determined in a spectrophotometer and converted into equivalent concentration of HP (μg/ mL). To analyze the concentration of HP, the titration of bleaching agents with potassium permanganate was used. Data were subjected to ANOVA and Tukey’s test for pairwise comparison (α = 0.05). Results: Higher concentration of HP in the pulp chamber was found in the HP 35% group (p < 0.0001). No significant difference between at-home protocols were observed (p = 0.64). Titration values showed that the concentration of the products was similar to that claimed by the manufacturer. Conclusion: It follows that the amount of HP that reaches the pulp chamber is not proportional to the concentration of whitening gels, but depends on the application time recommended by the manufacturers.KEYWORDSAt-home bleaching; Dental enamel permeability; Inoffice bleaching; Tooth bleaching.

Effects of microabrasion association to at‐home bleaching on hydrogen peroxide penetration and color change

“…The access to the pulp cavity was slightly expanded using a #1014 spherical drill (KG Sorensen, Cotia, SP, Brazil), taking care not to touch the inner vestibular region of the pulp cavity. This was done with the objective that 25 μl of solution could be introduced inside the pulp cavity using a micropipette (LABMATE Soft, HTL Lab Solutions, Warsaw, Poland) 17,18 . After specimen preparation, to standardize the buccal thickness of the specimens and to prevent influencing the penetration of HP, X‐ray radiographs were performed after specimen preparation (Timex 70C, Gnatus, Ribeirão Preto, SP, Brazil).…”

“…The central X‐ray beam was focused at a 90° angle to the tooth's buccal surface. After exposure, the images were digitally obtained and the corresponding buccal tooth thickness was measured with New IDA software (Dabi Atlante, Ribeirao Preto, SP, Brazil) 17,18 …”

“…This solution was diluted in an acetate buffer solution (pH = 4) and titrated using traditional methods. The solution was titrated with a potassium permanganate solution to determine the analytical grade and the actual concentration of the solution 16–18,20 . Based on this initial concentration, serial volumetric dilutions of 0.000–0.403 μg/ml were performed to draw the analytical curve.…”

A novel carbamide peroxide polymeric nanoparticle bleaching gel: Color change and hydrogen peroxide penetration inside the pulp cavity

“…This study's primary outcome involved the quantify of hydrogen peroxide inside the pulp cavity. Based on previous literature, 21 teeth submitted to the control group had 0.001 ± 0.001 μg/mL of hydrogen peroxide inside the pulp cavity. Using a bilateral test with an alpha of 0.05 and a power of 80%, the result should involve at least six teeth in each group to detect a difference of 0.001 μg/mL.…”

“…The control group was subjected to ultra‐purified water without the bleaching agents (Table 1). As a quality test, both gels were titrated before the bleaching procedure with a standard potassium permanganate solution to determine their initial concentrations inside the tube 21 . Their pH was measured using a pH meter 25 (Extech pH 100: ExStik pH Meter; Extech instruments, Nashua, New Hampshire) (Table 1).…”