Influência da associação entre biomateriais poliméricos e LED violeta sobre a eficácia estética, cinética de degradação e citotoxicidade de géis clareadores
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Data
2022-04-01
Autores
Martins, Beatriz Voss
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Universidade Estadual Paulista (Unesp)
Resumo
A catálise do peróxido de hidrogênio (H2O2) presente nos géis clareadores pode favorecer o resultado estético e reduzir a citotoxicidade causada pelo clareamento dental de consultório. Assim, o objetivo do presente estudo foi avaliar a influência da aplicação em esmalte, de um scaffold nanofibrilar (SN) e um primer polimérico contendo 10 mg/mL da enzima peroxidase hêmica (PPC), sobre a eficácia estética, cinética de degradação e citotoxicidade trans-amelodentinária de géis clareadores com 10%, 20% e 35% de H2O2, irradiados ou não com LED violeta (LED). Para isso, os seguintes grupos foram estabelecidos: G1- Nenhum tratamento (controle negativo); G2- SN+PPC; G3- LED; G4- SN+PPC+LED; G5- 35%H2O2comercial (controle positivo); G6- SN+PPC+35%H2O2comercial; G7- SN+PPC+35%H2O2comercial+LED; G8- 35%H2O2; G9- SN+PPC+35%H2O2; G10- SN+PPC+35%H2O2+LED; G11- 20%H2O2; G12- SN+PPC+20%H2O2; G13- SN+PPC+20%H2O2+LED; G14- 10%H2O2; G15- SN+PPC+10%H2O2; G16- SN+PPC+10%H2O2+LED. Discos de esmalte/dentina (n=8) foram manchados e então submetidos ou não a aplicação dos protocolos de clareamento por 45 min. Para determinar a eficácia estética, os discos foram analisados em espectrofotômetro de reflexão-UV (sistema CIE L*a*b*, ΔE00 e ΔWI). A geração de radicais hidroxila (OH• ) a partir da decomposição do H2O2 também foi determinada (sonda fluorescente HORAC). Para avaliar a citotoxicidade transamelodentinária, os mesmos procedimentos descritos anteriormente foram realizados sobre discos de esmalte/dentina adaptados em câmaras pulpares artificiais. Os extratos (meio de cultura + componentes dos géis que se difundiram pelos discos) foram recolhidos e imediatamente aplicados sobre células odontoblastóides MDPC23, as quais foram analisadas quanto a viabilidade (alamarBlue), estresse oxidativo (sonda carboxy-H2DCFDA) e morfologia (microscopia eletrônica de varredura, MEV). A quantidade de H2O2 presente nos extratos também foi determinada (violeta leucocristal/peroxidase). Os dados coletados foram submetidos aos testes Three-Way ANOVA e Tukey (p<0,05), sendo a Análise de Variância para medidas repetidas usada para avaliar a geração de OH• . Aumento nos valores de ΔE00 e ΔWI, bem como da geração de OH• ocorreu nos grupos G6, G7, G9, G10, G12, G13, G15 e G16 em comparação a G1 e G2 (p<0,05). G16 (SN+PPC+10%H2O2+LED) apresentou eficácia estética semelhante ao clareamento de consultório (G5; p>0,05). A citotoxicidade foi reduzida em todos os grupos onde SN+PPC foram aplicados sobre o esmalte antes do gel clareador (G6, G9, G12 e G15). Porém, os menores valores de citotoxicidade ocorreram nos grupos onde foi usado SN+PPC+LED (G7, G10, G13 e G16), nos quais também foi observado o menor estresse oxidativo celular em comparação aos grupos que receberam apenas o gel clareador (p<0,05). Assim, foi possível concluir que a fotocatálise do gel clareador com 10% de H2O2, aplicado sobre esmalte previamente recoberto com SN e tratado com PPC, aumenta a eficácia estética e reduz a citotoxicidade em comparação ao clareamento convencional de consultório.
The catalysis of hydrogen peroxide (H2O2) present in bleaching gels may improve the aesthetic result and reduce the cytotoxicity caused by in-office dental bleaching. Thus, the aim of the present study was to assess the influence of covering the enamel with a nanofibril scaffold (NS) and a polymeric primer containing 10 mg/mL of hemic peroxidase (PPC) on the aesthetic efficacy, degradation kinetics and transamelodentinal cytotoxicity of bleaching gels with 10%, 20% and 35% H2O2, irradiated or not with violet LED (LED). Using commercial or laboratory-made bleaching gels, which were associated or not to SN, PPC and violet LED, the following groups were established: G1- No treatment (negative control); G2- SN+PPC; G3- LED; G4- SN+PPC+LED; G5- 35%H2O2commercial (positive control); G6- SN+PPC+35%H2O2commercial; G7- SN+PPC+35%H2O2commercial+LED; G8- 35%H2O2; G9- SN+PPC+35%H2O2; G10- SN+PPC+35%H2O2+LED; G11- 20%H2O2; G12- SN+PPC+20%H2O2; G13- SN+PPC+20%H2O2+LED; G14- 10%H2O2; G15- SN+PPC+10%H2O2; G16-SN+PPC+ 10%H2O2+LED. Enamel/dentin discs (n=8) were stained and then submitted or not to the experimental bleaching protocols for 45 min. To determine the esthetic efficacy, the discs were analyzed under a UV-reflection spectrophotometer (CIE L*a*b*, ΔE00 and ΔWI system). To evaluate the amount of hydroxyl radicals (OH•) generated by H2O2 degradation, a fluorescent probe (HORAC) was used. The in vitro model of artificial pulp chamber was used to assess the transamelodentinal cytotoxic effects caused by the treatments to the odontoblast-like MDPC-23 cells. For this purpose, the extracts (culture medium + gel components that diffused through the discs) were collected and immediately applied to the cultured cells, which were assessed concerning their viability (alamarBlue), oxidative stress (carboxyH2DCFDA probe) and morphology (scanning electron microscopy, SEM). The amount of H2O2 present in the extracts was also determined (leuko-crystal violet/peroxidase). Data were submitted to the Three-Way ANOVA test complemented by Tukey post-test (p<0.05). Analysis of variance for repeated measures was used to analyze the OH• generation. Significant increase in ΔE00 and ΔWI values, as well as in OH• generation occurred in groups G6, G7, G9, G10, G12, G13, G15 and G16 in comparison with G1 and G2 (p<0.05). G16 group (SN+PPC+10%H2O2+LED) presented similar aesthetic efficacy to conventional in-office dental bleaching protocol (G5) (p>0.05). Reduced trans-amelodentinal cytotoxicity was observed in all groups in which SN+PPC were used to cover the enamel before the bleaching gel application (G6, G9, G12 and G15). However, the lowest cytotoxicity occurred in G7, G10, G13 and G16, in which SN, PPC, and LED were used to perform the bleaching therapies. Cells of these groups exhibited lower oxidative stress when compared with groups in which bleaching gels were applied directly on enamel (p<0.05). Thus, it was possible to conclude that the approach of photocatalyzing a bleaching gel with 10% H2O2, applied on enamel previously covered with SN and PPC, increases the degradation kinetics of H2O2, that, in turn, improves the aesthetic efficacy and reduces the cytotoxicity in comparison with the conventional in-office dental bleaching therapy.
The catalysis of hydrogen peroxide (H2O2) present in bleaching gels may improve the aesthetic result and reduce the cytotoxicity caused by in-office dental bleaching. Thus, the aim of the present study was to assess the influence of covering the enamel with a nanofibril scaffold (NS) and a polymeric primer containing 10 mg/mL of hemic peroxidase (PPC) on the aesthetic efficacy, degradation kinetics and transamelodentinal cytotoxicity of bleaching gels with 10%, 20% and 35% H2O2, irradiated or not with violet LED (LED). Using commercial or laboratory-made bleaching gels, which were associated or not to SN, PPC and violet LED, the following groups were established: G1- No treatment (negative control); G2- SN+PPC; G3- LED; G4- SN+PPC+LED; G5- 35%H2O2commercial (positive control); G6- SN+PPC+35%H2O2commercial; G7- SN+PPC+35%H2O2commercial+LED; G8- 35%H2O2; G9- SN+PPC+35%H2O2; G10- SN+PPC+35%H2O2+LED; G11- 20%H2O2; G12- SN+PPC+20%H2O2; G13- SN+PPC+20%H2O2+LED; G14- 10%H2O2; G15- SN+PPC+10%H2O2; G16-SN+PPC+ 10%H2O2+LED. Enamel/dentin discs (n=8) were stained and then submitted or not to the experimental bleaching protocols for 45 min. To determine the esthetic efficacy, the discs were analyzed under a UV-reflection spectrophotometer (CIE L*a*b*, ΔE00 and ΔWI system). To evaluate the amount of hydroxyl radicals (OH•) generated by H2O2 degradation, a fluorescent probe (HORAC) was used. The in vitro model of artificial pulp chamber was used to assess the transamelodentinal cytotoxic effects caused by the treatments to the odontoblast-like MDPC-23 cells. For this purpose, the extracts (culture medium + gel components that diffused through the discs) were collected and immediately applied to the cultured cells, which were assessed concerning their viability (alamarBlue), oxidative stress (carboxyH2DCFDA probe) and morphology (scanning electron microscopy, SEM). The amount of H2O2 present in the extracts was also determined (leuko-crystal violet/peroxidase). Data were submitted to the Three-Way ANOVA test complemented by Tukey post-test (p<0.05). Analysis of variance for repeated measures was used to analyze the OH• generation. Significant increase in ΔE00 and ΔWI values, as well as in OH• generation occurred in groups G6, G7, G9, G10, G12, G13, G15 and G16 in comparison with G1 and G2 (p<0.05). G16 group (SN+PPC+10%H2O2+LED) presented similar aesthetic efficacy to conventional in-office dental bleaching protocol (G5) (p>0.05). Reduced trans-amelodentinal cytotoxicity was observed in all groups in which SN+PPC were used to cover the enamel before the bleaching gel application (G6, G9, G12 and G15). However, the lowest cytotoxicity occurred in G7, G10, G13 and G16, in which SN, PPC, and LED were used to perform the bleaching therapies. Cells of these groups exhibited lower oxidative stress when compared with groups in which bleaching gels were applied directly on enamel (p<0.05). Thus, it was possible to conclude that the approach of photocatalyzing a bleaching gel with 10% H2O2, applied on enamel previously covered with SN and PPC, increases the degradation kinetics of H2O2, that, in turn, improves the aesthetic efficacy and reduces the cytotoxicity in comparison with the conventional in-office dental bleaching therapy.
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Palavras-chave
Clareamento dental, Toxicidade, Odontoblastos, Técnicas de cultura de células