In vitro evaluation of single application per session of two-bottle bleaching gels.
| Title: | In vitro evaluation of single application per session of two-bottle bleaching gels. |
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| Authors: | Condolo L; Department of Restorative Dentistry, State University of Ponta Grossa, Parana, Brazil. Electronic address: leticiaccondolo@gmail.com.; Teixeira MB; Department of Restorative Dentistry, Tuiuti University of Parana, Parana, Brazil. Electronic address: murilobelotx@gmail.com.; Barbosa LMM; Department of Restorative Dentistry, State University of Ponta Grossa, Parana, Brazil; IDIBO Research Group, Rey Juan Carlos University, Alcorcón, Madrid, Spain. Electronic address: laryssamylenna@hotmail.com.; Mayer-Santos E; Department of Restorative Dentistry, University of São Paulo, São Paulo, Brazil. Electronic address: eric.mayer.santos@usp.br.; Loguercio AD; Department of Restorative Dentistry, State University of Ponta Grossa, Parana, Brazil. Electronic address: aloguercio@hotmail.com.; Favoreto MW; Department of Restorative Dentistry, Tuiuti University of Parana, Parana, Brazil; IDIBO Research Group, Rey Juan Carlos University, Alcorcón, Madrid, Spain. Electronic address: michaelfavoreto@hotmail.com. |
| Source: | Journal of dentistry [J Dent] 2026 May; Vol. 168, pp. 106592. Date of Electronic Publication: 2026 Feb 27. |
| Publication Type: | Journal Article; Randomized Controlled Trial |
| Language: | English |
| Journal Info: | Publisher: Elsevier Country of Publication: England NLM ID: 0354422 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1879-176X (Electronic) Linking ISSN: 03005712 NLM ISO Abbreviation: J Dent Subsets: MEDLINE |
| Imprint Name(s): | Publication: Kidlington : Elsevier; Original Publication: Bristol, Eng., Wright. |
| MeSH Terms: | Tooth Bleaching Agents*/administration & dosage ; Tooth Bleaching Agents*/chemistry ; Tooth Bleaching Agents*/pharmacokinetics ; Hydrogen Peroxide*/administration & dosage ; Hydrogen Peroxide*/pharmacokinetics ; Hydrogen Peroxide*/chemistry ; Tooth Bleaching*/methods; Dental Enamel/drug effects ; Dental Enamel/ultrastructure ; Dental Pulp Cavity/drug effects ; Bicuspid/drug effects ; Molar/drug effects ; Dental Enamel Permeability/drug effects ; Humans ; Hydrogen-Ion Concentration ; Gels ; Microscopy, Electron, Scanning ; Surface Properties ; Hardness ; Time Factors ; Spectrophotometry ; Materials Testing |
| Abstract: | Objectives: To evaluate the hydrogen peroxide (HP) permeability into the pulp chamber, bleaching efficacy, physicochemical properties (pH and HP concentration), and enamel surface effects of two-bottle in-office bleaching gels applied in 30-minute sessions.; Materials and Methods: Sixty sound human premolars and thirty molars were randomly assigned into six groups according to the in-office bleaching protocol: DSP White Clinic 35 %, DSP [WC]; Pola Office, SDI [PO]; Potenza Bianco Pro 35 %, PHS [PB]; Total Blanc One Step Drop 35 %, DFL [TD]; Whiteness HP, FGM [WH]; and Whiteness HP Maxx, FGM [WM]. All gels were applied in three 30-min sessions, with seven-day intervals. HP permeability (μg mL-1) into the pulp chamber was determined using UV-Vis spectrophotometry. Bleaching efficacy was assessed by digital spectrophotometer (ΔE00, ΔWID, ΔL*, Δa*, and Δb*). pH and HP concentration were measured using a pH meter and titration, respectively. Enamel surface analysis was performed by scanning electron microscopy, and microhardness (VHN) and roughness (Ra) were measured. Statistical analysis was performed using two-way ANOVA and Tukey's post-hoc (α = 0.05).; Results: PO exhibited the highest diffusion of HP (p < 0.01), while TD showed the lowest (p < 0.01). All gels demonstrated progressive bleaching over the sessions (p < 0.0001), with no significant differences among groups (p > 0.05). Most gels exhibited initial acidic pH, whereas TD maintained neutral pH; after 30 minutes, all presented unstable pH. HP concentration decreased after 30 min but remained above 30 % active HP in all gels. All gels induced detectable enamel surface alterations, with PO exhibiting the most pronounced irregularities and TD the least morphological changes. Enamel microhardness decreased and surface roughness increased after bleaching, regardless of the gel used (p < 0.001).; Conclusions: A 30-min application per session was sufficient to promote bleaching efficacy and morphological changes in all groups. However, only the TD exhibited significantly lower HP diffusion into the pulp chamber, due to its more neutral initial pH.; Clinical Significance: The two-bottle gels should still be used according to the manufacturer's recommendations for renewal. Although they all have similar bleaching efficacy and morphological changes, only the TD gel had a lower amount of HP in the pulp, due to its more initial neutral pH, and may allow a single application per session.; (Copyright © 2026 Elsevier Ltd. All rights reserved.) |
| Competing Interests: | Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: ADL is an Editorial Board Member of the Journal of Dentistry. Given this role, ADL had no involvement in the peer review of this article and had no access to information regarding its peer review. |
| Contributed Indexing: | Keywords: Hydrogen peroxide; Pulp chamber; Tooth bleaching |
| Substance Nomenclature: | 0 (Tooth Bleaching Agents); BBX060AN9V (Hydrogen Peroxide); 0 (Gels) |
| Entry Date(s): | Date Created: 20260228 Date Completed: 20260327 Latest Revision: 20260327 |
| Update Code: | 20260328 |
| DOI: | 10.1016/j.jdent.2026.106592 |
| PMID: | 41763523 |
| Database: | MEDLINE |
Journal Article; Randomized Controlled Trial