Objectives: To investigate the physical-chemical properties of home bleaching gels based on Carbamide Peroxide (CP) and Hydrogen Peroxide (HP) after accelerated stability (AS) and its effects on enamel.
Materials And Methods: A total of 360 bovine teeth blocks were divided (n = 12): Control, CP10%-Whiteness Perfect, CP10%-Pola Night, HP7.5%-Pola Day, and HP7.5%-White Class Calcium. Microhardness (KHN), roughness (Ra), color (ΔE and ΔE), hardness, compressibility, elasticity, cohesiveness, adhesiveness, weight, pH, and calcium (Ca) quantification in enamel were analyzed without storage of the bleaching gels and after AS at 1 and 3 months. Data of Ca, KHN, and Ra were analyzed through mixed models for repeated measurements and the Tukey-Kramer test. Values of weight, hardness, compressibility, and elasticity were analyzed with two-way ANOVA and Tukey's test. ΔE/ΔE data, cohesiveness, and adhesiveness were analyzed with Kruskal-Wallis and Dunn tests (α = 0.05).
Results: Groups subject to AS had lower ΔE and ΔE compared to those without storage. Lower KHN and higher Ra values were found after bleaching treatment in all groups compared to controls. Higher amounts of Ca were found on the first day of evaluation in the gels subject to AS for 3 months, regardless of the bleaching agent used.
Conclusions: Incorrectly stored bleaching gel accentuates adverse effects on enamel. Temperature and humidity interfere directly with the chemical stability of bleaching agents, reducing their properties.
Clinical Relevance: HP is an unstable oxidizing agent when stored at high temperatures. Therefore, pH becomes more acidic and potentiates the demineralizing effect on enamel.
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http://dx.doi.org/10.1007/s00784-022-04683-8 | DOI Listing |
Dent J (Basel)
December 2024
Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO), University of Modena and Reggio Emilia, 41124 Modena, Italy.
: Potential adverse effects and pH-related effectiveness of bleaching agents have raised some concerns. The aim of this study was to compare three bleaching agents containing hydrogen peroxide (HP) and carbamide peroxide (CP) in terms of whitening effectiveness, pH variation, and changes in enamel surface roughness. : After controlled staining with a black tea solution, 42 human enamel specimens underwent bleaching treatment using the following agents: HP 40%; HP 35%; CP 16%.
View Article and Find Full Text PDFClin Oral Investig
December 2024
Department of Restorative Dentistry, Piracicaba Dental School, University of Campinas, 901 Limeira Avenue, Areião, Piracicaba, SP, 13414-903, Brazil.
Objective: To investigate the effect of reducing exposure time to at-home bleaching gel on color change and tooth sensitivity.
Materials And Methods: The search was carried out using PubMed, Scopus, Web of Science, EMBASE, LILACS, Cochrane. Randomized clinical trials (RCTs) were included involving adult patients who have never undergone bleaching treatment before (P), subjected to bleaching with a reduced exposure time to the at-home bleaching agent (I) compared to those who used it for the time indicated by the manufacturer (C), to evaluate the effects on color change and tooth sensitivity (O).
Photodiagnosis Photodyn Ther
December 2024
Department of Restorative Dentistry, CEUMA University, Maranhão, Brazil.
Objective: This randomized controlled trial aimed to evaluate the bleaching efficacy and tooth sensitivity (TS) of participants submitted to different application protocols of in-office bleaching with violet light using 6 % hydrogen peroxide (HP) nanoparticulate photocatalyst gel.
Materials And Methods: Sixty-six participants were randomized and bleached using either a 6 % HP (Nano White, DMC), and/or violet light (Bright Max Whitening, MMOptics), according to the following protocols: 1) only violet light (VIOL); 2) only bleaching gel application (BG) and; 3) combined bleaching gel application + violet light (BG+VIOL). The bleaching efficacy was evaluated with the Vita Easyshade spectrophotometer, Vita Classical and Vita Bleachedguide scales.
Odontology
November 2024
Department of Pharmaceutical Sciences, School of Pharmacy, State University of Ponta Grossa, Uvaranas, PR, Brazil.
This study assessed the hydrogen peroxide (HP) diffusion into the pulp chamber, bleaching efficacy (BE), surface roughness (Ra), and Knoop microhardness (KHN) of an experimental bleaching gel containing a hydroxyapatite-capsaicin composite (HAp-CAP). Human premolars were randomly assigned to three groups (n = 9) based on the dental bleaching gel used (50 min; one session): only 35% HP, 35% HP + HAp-CAP, and not exposed to bleaching (negative control; NC). HP diffusion (µg/mL) into the pulp chamber was assessed using UV-Vis spectrophotometry, and BE (ΔE, ΔE, and WI) was evaluated using a digital spectrophotometer.
View Article and Find Full Text PDFInt J Biol Macromol
December 2024
Commonwealth Scientific and Industrial Research Organisation (CSIRO), Agriculture and Food, Canberra, ACT 2601, Australia.
Transforming oil palm empty fruit bunches (OPEFB) waste into value-added cellulose as a reinforcement agent for eco-friendly slow-release fertilizer (SRF) composites is a strategy to achieve clean and sustainable production. OPEFB cellulose was isolated by alkalization (10 % w/v NaOH) for 1 h and bleaching (30 % v/v HO) for 1.5 h.
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