Effect of carbodiimide and chlorhexidine on the bond strength longevity of resin cement to root dentine after radiation therapy

Abstract

Aim To evaluate the effect of carbodiimide (EDC) and chlorhexidine (CHX) on the bond strength (BS) of resin cement to root dentine of teeth submitted to radiotherapy. Methodology One hundred and twenty extracted maxillary canines were selected and assigned to 2 groups (n = 60): nonirradiated and irradiated (30 cycles of 2 Gy, total 60 Gy). Roots lengths were standardized, and canals were prepared and filled. Post spaces were then prepared, and the samples were redistributed according to dentine treatment (n = 20): saline solution (SF); CHX 2%; or EDC 0.5M. After drying the post space, fibreglass posts were cemented. Cross‐sectioned slices were obtained, and in half of the specimens of each subgroup (n = 10), the analysis was performed immediately; the others (n = 10) were stored for 10 months before analyses. The most cervical slice of each third was subjected to a push‐out test and failure pattern analysis (n = 10), and the most apical slice submitted to the analysis of the adhesive interface by SEM (n = 5). The bond strength data were submitted to anova and Tukey tests, the adhesive interface adaptation was submitted to Kruskal–Wallis and Dunn's tests, and the Chi‐square test was used to evaluate the type of failure. Results The irradiated specimens had significantly lower bond strength (13.8 ± 4.3) than the nonirradiated (18.1 ± 3.1; P < 0.001). For the irradiated teeth, the bond strengths were significantly lower in the SF and CHX groups (P < 0.001). Also, the bond strengths reduced significantly after 10 months in the SF and CHX groups (P < 0.001). Cohesive failures occurred in dentine for irradiated specimens. Poorer interface adaptation, dentine fractures and microfractures were observed in irradiated specimens, and better adaptation was observed for specimens after EDC treatment. Conclusions Radiotherapy was associated with lower bond strength and worse interface adaptation. Dentine treatment with EDC contributed to adhesive interface longevity during the cementation of glass fibre posts in nonirradiated and irradiated teeth.

Effects of carbodiimide combined with ethanol–wet bonding pretreatment on dentin bonding properties: an in vitro study

“…( Breschi et al, 2018 ; Ryou et al., 2015 ). Recent studies have shown that Carbodiimide (EDC), as a zero-length chemical cross-linker, directly conjugates carboxylates to primary amines in the collagen polypeptide chain without becoming part of the final crosslink ( Comba et al, 2019 ; Maravic et al, 2021 ), and it enhances the mechanical properties of collagen through intermolecular and intramolecular crosslinking ( Hebling et al, 2015 ; Lopes et al, 2020 ). In addition, EDC can cross-link matrix Metalloproteinases (MMPs) and inactivate the catalytic sites on MMPs by altering the three-dimensional conformation of MMP molecules, which inhibits MMPs and prevents the enzymatic hydrolysis of collagen fibrils ( Comba et al, 2019 ).…”

Avaliação da resistência de união do sistema de pino de fibra de vidro ajustável em conduto radicular oval tratado endodonticamente

“…Após a seleção das amostras, os canais radiculares foram irrigados com 2,5 mL de hipoclorito de sódio (NaOCl) a 2,5% com seringa plástica descartável (Ultradent Products Inc., South Jordan, UT, EUA) e explorados com o instrumento tipo K#15 (Dentsply Maillefer, Ballaigues, Suiça) até que a extremidade livre do instrumento surgisse no forame apical. Dessa medida, subtraiu-se 1,0 mm para o estabelecimento do comprimento de trabalho (CT) (LOPES et al, 2020).…”

“…Dentes tratados endodonticamente são frequentemente restaurados com pinos intrarradiculares devido à perda excessiva de estrutura coronária causada por lesões de cárie, restaurações prévias ou fratura (SARKIS-ONOFRE et al, 2017;FERNANDES et al;. A retenção dos pinos de fibra de vidro no interior do canal radicular depende do comprimento, diâmetro e tipo de superfície (cilíndrico serrilhado, cilíndrico liso, cônico e dupla conicidade), bem como do tipo de material de cimentação (SOARES et al, 2021), da técnica utilizada para a inserção do material cimentante no interior do conduto radicular (PEDREIRA et al, 2016;BALDION et al, 2020) e da integridade da interface adesiva (GORACCI et al, 2007;MONTICELLI et al, 2008;PEDREIRA et al, 2016;PAIOLA et al, 2018;YAMIN et al, 2018;ASSIS et al, 2020;LOPES et al, 2020;SOUZA et al, 2021).…”

“…O desempenho mecânico do conjunto pino de fibra de vidro e cimento resinoso tem sido avaliado por meio do teste de resistência de união ao cisalhamento por extrusão (push-out) (PAIOLA et al, 2018;YAMIN et al, 2018;ASSIS et al, 2020;LOPES et al, 2020), uma vez que esse se apresenta como um método rápido, de fácil execução, que permite a determinação da resistência de união nos diferentes terços do canal radicular (CASTELLAN et al, 2010;MANICARDI et al, 2011;CARNEIRO et al, 2012). Esse teste tem sido associado à análise do padrão de falhas por meio da estereomicroscopia e avaliação da interface adesiva por meio de microscopia confocal de varredura a laser ou microscopia eletrônica de varredura (MEV), possibilitando a visualização da camada de cimento resinoso (ROPERTO et al, 2016;SOUZA-GABRIEL et al, 2016;YAMIN et al, 2018;ASSIS et al, 2020;LOPES et al, 2020).…”

Efeito do uso da bromelina na resistência de união de pinos de fibra de vidro utilizando diferentes cimentos resinosos

“…A utilização de substâncias que apresentem potencial para inibir enzimas que degradam fibrilas colágenas, pode contribuir para a manutenção da durabilidade da interface adesiva. 42 Além disso, o efeito cross-linking aumenta a resistência do tecido dentinário, contribuindo para a estabilidade da camada híbrida e consequentemente para a durabilidade do conjunto dentina/cimento/pino. 8, 94,95 Ademais, as ligações cruzadas nos sítios catalíticos das MMPs e a inibição de outras proteínas não colágenas que ativam as MMPs são também uma hipótese.…”