Influência de um primer catalisador sobre a eficácia estética, cinética de degradação e toxicidade de géis clareadores
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Data
2022-03-24
Autores
Dias, Marlon Ferreira
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Universidade Estadual Paulista (Unesp)
Resumo
Alguns agentes catalisadores atuam diretamente na degradação do peróxido de hidrogênio (H2O2), o que pode favorecer o resultado estético e reduzir a citotoxicidade causada pelo clareamento dental de consultório (CDC). Assim, o objetivo deste estudo foi avaliar a eficácia clareadora (EC), cinética de degradação (CD) e citotoxicidade trans-amelodentinária (CT) de géis clareadores com diferentes concentrações de H2O2, aplicados sobre esmalte previamente revestido ou não com um primer polimérico contendo 10 mg/mL de óxido de manganês (PPC). Para isso, os seguintes grupos foram estabelecidos: G1: Sem tratamento (controle negativo); G2: PPC; G3: 10%H2O2; G4: PPC+10%H2O2; G5: 20%H2O2; G6: PPC+20%H2O2; G7: 35%H2O2; G8: PPC+35%H2O2; G9: 35%H2O2comercial (clareamento convencional de consultório, controle positivo); G10: PPC+35%H2O2comercial. Para determinar a EE (espectrofotômetro de reflexão-UV, sistema CIE L*a*b*, ΔE00 e ΔWI), discos padronizados de esmalte/dentina (DE/D) foram manchados e as terapias clareadoras realizadas por 1 sessão de 45 minutos. Após esta etapa, foi avaliada a produção de radicais hidroxila (OH•, sonda fluorescente HORAC). DE/D manchados também foram adaptados em câmaras pulpares artificiais e submetidos aos mesmos procedimentos clareadores. Então, os extratos (meio de cultura + componentes dos géis que se difundiram pelos DE/D) foram coletados e aplicados sobre células odontoblastóides MDPC-23, as quais foram avaliadas quanto a viabilidade (alamarBlue), estresse oxidativo (EOx, sonda carboxy-H2DCFDA) e morfologia (MEV). O total de H2O2 difundido pelos discos também foi quantificado (violeta leuco-cristal/peroxidase). Os dados coletados foram submetidos aos testes Two-Way ANOVA, Tukey e t-student pareado, com nível de significância de 5%. Os maiores valores de ΔE00 e ΔWI foram observados em todos os grupos onde o PPC foi usado quando comparados aos grupos sem PPC (p<0,05). Porém, a EC foi estatisticamente semelhante entre G4, G6, G7 e G9 (p>0,05). A maior produção de radicais OH• ocorreu em todos os grupos onde géis clareadores foram associados ao PPC (G4, G6, G8 e G10), em comparação aos seus respectivos grupos (G3, G5, G7 e G9; p<0,05). PPC aplicado isoladamente sobre o esmalte (G2) não causou qualquer CT. Os maiores valores de viabilidade celular e menores índices de EOx ocorreram nos grupos G4, G6 e G8. Desse modo, conclui-se que a aplicação do gel clareador com 10% de H2O2 (G4) por 45 minutos sobre o esmalte recoberto com PPC, além de promover excelente resultado estético, tal como aquele alcançado com o CDC, também minimiza os efeitos citotóxicos causados por esta terapia profissional.
Some catalytic agents act directly on the degradation of hydrogen peroxide (H2O2), that may improve the aesthetic result and reduce the cytotoxicity caused by in-office tooth bleaching therapy (I-OTBT). Thus, the aim of this study was to assess the bleaching efficacy (BE), degradation kinetics (DK) and trans-amelodentinal cytotoxicity (TC) of bleaching gels with different concentrations of H2O2, applied on enamel previously covered or not with a polymeric primer containing 10 mg/mL of manganese oxide (PPC). For this purpose, the following groups were set: G1: no treatment (negative control); G2: PPC; G3: 10%H2O2; G4: PPC+10%H2O2; G5: 20%H2O2; G6: PPC+20%H2O2; G7: 35%H2O; G8: PPC+35%H2O2; G9: 35%H2O2commercial (in-office tooth bleaching, positive control); G10: PPC+35%H2O2commercial. To determine the AE (UV reflection spectrophotometer, CIE L * a * b * system, ΔE00 and ΔWI), standardized enamel/dentin discs (ED/D) were stained and then bleached for a session of 45 minutes. After this stage, the production of hydroxyl radicals (OH•, HORAC fluorescent probe) was evaluated. Stained ED/D were also adapted to artificial pulp chambers and the enamel treated or not according to the established groups. The extracts (culture medium + components of the gels that diffused through the ED/D) were collected and applied to odontoblast-like MDPC-23 cells, which were evaluated concerning their viability (alamarBlue), oxidative stress (EOx, carboxy-H2DCFDA probe) and morphology (SEM). The quantity of H2O2 diffused through the ED/D was also determined (leuco-crystal violet/peroxidase). The data were submitted to two-way ANOVA, Tukey test and t-student paired at a significance level of 5%. Groups in which enamel was covered with PPC before application of the bleaching gels exhibited higher ΔE00 and ΔWI in comparison with those groups in which PPC was not used (p<0.05). However, G4, G6, G7, and G9 presented similar BE (p>0.05). G4, G6, G8 and G10 showed the highest production of OH• in comparison with those groups in which PPC was not employed (G3, G5, G7, and G9; p<0.05). PPC applied solely on enamel (G2) did not cause TC. The highest cell viability and lowest EOx occurred in G4, G6, and G8. Therefore, one can conclude that the application of a bleaching gel with 10% H2O2 for 45 minutes on enamel recovered with PPC (G4) achieves the BE similar to the I- OTBT, as well as reduces the cytotoxic effects caused by this professional therapy.
Some catalytic agents act directly on the degradation of hydrogen peroxide (H2O2), that may improve the aesthetic result and reduce the cytotoxicity caused by in-office tooth bleaching therapy (I-OTBT). Thus, the aim of this study was to assess the bleaching efficacy (BE), degradation kinetics (DK) and trans-amelodentinal cytotoxicity (TC) of bleaching gels with different concentrations of H2O2, applied on enamel previously covered or not with a polymeric primer containing 10 mg/mL of manganese oxide (PPC). For this purpose, the following groups were set: G1: no treatment (negative control); G2: PPC; G3: 10%H2O2; G4: PPC+10%H2O2; G5: 20%H2O2; G6: PPC+20%H2O2; G7: 35%H2O; G8: PPC+35%H2O2; G9: 35%H2O2commercial (in-office tooth bleaching, positive control); G10: PPC+35%H2O2commercial. To determine the AE (UV reflection spectrophotometer, CIE L * a * b * system, ΔE00 and ΔWI), standardized enamel/dentin discs (ED/D) were stained and then bleached for a session of 45 minutes. After this stage, the production of hydroxyl radicals (OH•, HORAC fluorescent probe) was evaluated. Stained ED/D were also adapted to artificial pulp chambers and the enamel treated or not according to the established groups. The extracts (culture medium + components of the gels that diffused through the ED/D) were collected and applied to odontoblast-like MDPC-23 cells, which were evaluated concerning their viability (alamarBlue), oxidative stress (EOx, carboxy-H2DCFDA probe) and morphology (SEM). The quantity of H2O2 diffused through the ED/D was also determined (leuco-crystal violet/peroxidase). The data were submitted to two-way ANOVA, Tukey test and t-student paired at a significance level of 5%. Groups in which enamel was covered with PPC before application of the bleaching gels exhibited higher ΔE00 and ΔWI in comparison with those groups in which PPC was not used (p<0.05). However, G4, G6, G7, and G9 presented similar BE (p>0.05). G4, G6, G8 and G10 showed the highest production of OH• in comparison with those groups in which PPC was not employed (G3, G5, G7, and G9; p<0.05). PPC applied solely on enamel (G2) did not cause TC. The highest cell viability and lowest EOx occurred in G4, G6, and G8. Therefore, one can conclude that the application of a bleaching gel with 10% H2O2 for 45 minutes on enamel recovered with PPC (G4) achieves the BE similar to the I- OTBT, as well as reduces the cytotoxic effects caused by this professional therapy.
Descrição
Palavras-chave
Clareamento Dental, Toxicidade, Odontoblastos, Tooth bleaching, Toxicity, Odontoblasts