Influência de um scaffold polimérico de nanofibras e de um primer polimérico catalisador sobre a alteração de cor e citotoxicidade do clareamento dental de consultório
Carregando...
Data
2021-06-01
Autores
Ortecho Zuta, Uxua
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
O objetivo deste estudo foi desenvolver produtos poliméricos capazes de atuar como coadjuvantes no clareamento dental de consultório, acelerando a alteração de cor e reduzindo a citotoxicidade deste tipo de terapia profissional. Para isso, foi desenvolvido um scaffold polimérico de nanofibras (ScP) e um primer polimérico contendo a enzima horseradish peroxidase (PrP). Após avaliar os produtos poliméricos quanto sua caracterização, temperatura, pH e seus efeitos na cinética de degradação do H2O2, a influência do uso individual ou associado do ScP e o PrP sobre a alteração de cor promovido pelo clareamento dental de consultório foi determinado em espectrofotômetro UV-Vis (∆E). Para este teste, um gel com 35% de H2O2 foi aplicado por 3x15 min sobre discos de esmalte/dentina manchados artificialmente (n=8), sendo o esmalte previamente recoberto ou não com ScP e/ou PrP. Discos submetidos apenas ao clareamento de consultório ou não tratados foram usados como controles. Para o teste de citotoxicidade, esses mesmos procedimentos foram realizados sobre discos de esmalte/dentina adaptados em câmaras pulpares artificiais (CPAs). Os extratos (meio de cultura + componentes do gel que se difundiram pelos discos) foi recolhido e imediatamente aplicado por 60 minutos sobre células odontoblastóides MDPC-23. Então, a viabilidade (teste de MTT), morfologia (MEV) e estresse oxidativo (carboxy-H2DCFDA) celular foram avaliados, sendo a difusão trans-amelodentinária de H2O2 quantificada (ensaio violeta leuco-cristal). Os dados obtidos foram submetidos ao teste ANOVA, complementado por Tukey, com nível de significância de 5%. O uso individual ou associado dos ScP e PrP aumentou a formação de radicais livres e radical hidroxila (HO•), esses efeitos favoreceram a alteração de cor e diminuição da citotoxicidade dos tratamentos em comparação ao controle, onde apenas o gel clareador foi aplicado sobre o esmalte (p0,05), reduziu a difusão de H2O2, bem como diminuiu o estresse oxidativo celular. Apesar dos melhores resultados gerais terem sido obtidos quando do uso integrado entre ScP e PrP, o procedimento clareador usando os produtos poliméricos ainda reduziu em cerca de 34% a viabilidade das células MDPC-23. Assim, essa mesma estratégia de clareamento passou a ser avaliada em tempos mais curtos (30 e 15 minutos), porém com 3 sessões consecutivas de aplicação. Dentro desta condição, o gel clareador aplicado por 15 minutos sobre o esmalte revestido com ScP e PrP determinou alteração de cor semelhante ao clareamento convencional de consultório e citotoxicidade estatisticamente igual ao grupo onde nenhum tratamento foi realizado sobre os discos de esmalte/dentina (100% de viabilidade celular) (p0,05). Assim, foi possível concluir que o revestimento do esmalte com o scaffold polimérico de nanofibras e o primer polimérico catalisador previamente a aplicação por 15 minutos do gel clareador com 35% de H2O2, além de ter proporcionado alteração de cor semelhante ao clareamento convencional de consultório, também reduziu significativamente a citotoxicidade trans-amelodentinária causada pela técnica profissional.
The aim of this study was to develop polymeric products capable of acting as coadjutant on the in-office tooth bleaching, fastening the esthetic outcome and reducing the cytotoxic effects caused by this professional therapy. For this purpose, a nanofibers polymeric scaffold (ScP) and a polymeric primer containing the horseadish peroxidase enzyme (PrP) were developed. After assessing the polymeric products concerning their characterization, temperature, pH, and effects on the kinetics of H2O2 degradation, the influence of using the ScP in association or not with the PrP on the esthetic outcome promoted by the in-office tooth bleaching therapy was evaluated using spectrophotometer UV-Vis (∆E). Then, a bleaching gel with 35% H2O2 was applied for 3x15 minutes on enamel of stained enamel/dentin discs (n=8) previously covered or not with ScP and/or PrP. Non treated discs and discs submitted to the conventional in-office tooth bleaching therapy were used as controls. To assess the cytotoxic effects, the same procedures were performed on stained enamel/dentin discs adapted to artificial pulp chambers (APCs). The extracts (culture medium + bleaching gel components that diffused through the discs) were collected and immediately applied for 60 minutes on cultured MDPC-23 pulp cells. Thus, the cells were analyzed concerning their viability (MTT assay), morphology (MEV) and oxidative stress (carboxy-H2DCFDA assay), and the transenamel/transdentinal diffusion of H2O2 was quantified (violet-leuco-crystal assay). The data obtained were submitted to the analysis of variance for 1 fixed criterion and the Tukey post-test (p0.05). The application of the ScP associated or not with the PrP on enamel increased the formation of free-radicals and hydroxyl ion (HO•), these positive effects enhanced the esthetic outcome and decreased the cytotoxicity of this innovative bleaching strategy in comparison with the control group in which only the bleaching gel was applied on enamel (p0.05), reduced the H2O2 diffusion as well as the oxidative cells stress. Despite the exciting data found when both ScP and PrP were used together to cover the enamel before the bleaching gel application, this experimental therapy still reduced by 34% the pulp cell viability. Therefore, the assessment of this innovative esthetic therapy was carried out after applying the bleaching gel for shorter periods (30 and 15 minutes) on the polymeric products (3 consecutive sessions). Overall, the bleaching gel applied for 15 minutes on enamel previously covered with ScP and PrP determined an esthetic outcome like that obtained for the conventional in-office bleaching therapy (p0.05). In addition, this shorter bleaching treatment caused a very low cytotoxicity that was not different of the control group in which no treatment was performed (100% cell viability) (p0.05). It was concluded that covering the enamel with the ScP associated with the catalytic PrP before applying the bleaching gel with 35% H2O2 for 15 minutes, besides promoting an esthetic outcome similar to the conventional in-office therapy, also reduces the cytotoxicity commonly triggered by the professional therapy.
The aim of this study was to develop polymeric products capable of acting as coadjutant on the in-office tooth bleaching, fastening the esthetic outcome and reducing the cytotoxic effects caused by this professional therapy. For this purpose, a nanofibers polymeric scaffold (ScP) and a polymeric primer containing the horseadish peroxidase enzyme (PrP) were developed. After assessing the polymeric products concerning their characterization, temperature, pH, and effects on the kinetics of H2O2 degradation, the influence of using the ScP in association or not with the PrP on the esthetic outcome promoted by the in-office tooth bleaching therapy was evaluated using spectrophotometer UV-Vis (∆E). Then, a bleaching gel with 35% H2O2 was applied for 3x15 minutes on enamel of stained enamel/dentin discs (n=8) previously covered or not with ScP and/or PrP. Non treated discs and discs submitted to the conventional in-office tooth bleaching therapy were used as controls. To assess the cytotoxic effects, the same procedures were performed on stained enamel/dentin discs adapted to artificial pulp chambers (APCs). The extracts (culture medium + bleaching gel components that diffused through the discs) were collected and immediately applied for 60 minutes on cultured MDPC-23 pulp cells. Thus, the cells were analyzed concerning their viability (MTT assay), morphology (MEV) and oxidative stress (carboxy-H2DCFDA assay), and the transenamel/transdentinal diffusion of H2O2 was quantified (violet-leuco-crystal assay). The data obtained were submitted to the analysis of variance for 1 fixed criterion and the Tukey post-test (p0.05). The application of the ScP associated or not with the PrP on enamel increased the formation of free-radicals and hydroxyl ion (HO•), these positive effects enhanced the esthetic outcome and decreased the cytotoxicity of this innovative bleaching strategy in comparison with the control group in which only the bleaching gel was applied on enamel (p0.05), reduced the H2O2 diffusion as well as the oxidative cells stress. Despite the exciting data found when both ScP and PrP were used together to cover the enamel before the bleaching gel application, this experimental therapy still reduced by 34% the pulp cell viability. Therefore, the assessment of this innovative esthetic therapy was carried out after applying the bleaching gel for shorter periods (30 and 15 minutes) on the polymeric products (3 consecutive sessions). Overall, the bleaching gel applied for 15 minutes on enamel previously covered with ScP and PrP determined an esthetic outcome like that obtained for the conventional in-office bleaching therapy (p0.05). In addition, this shorter bleaching treatment caused a very low cytotoxicity that was not different of the control group in which no treatment was performed (100% cell viability) (p0.05). It was concluded that covering the enamel with the ScP associated with the catalytic PrP before applying the bleaching gel with 35% H2O2 for 15 minutes, besides promoting an esthetic outcome similar to the conventional in-office therapy, also reduces the cytotoxicity commonly triggered by the professional therapy.
Descrição
Palavras-chave
Clareamento dental, Peróxido de hidrogênio – Toxicidade, Odontoblastos, Tooth whitening, Hydrogen peroxide - Toxicity, Odontoblasts