Characteristics of adhesive bonding with enamel deproteinization

Abstract

Objective: To evaluate the effect of using sodium hypochlorite (NaOCl) on the bond characteristics of orthodontic metal brackets bonded to enamel surface using three adhesive systems. Methods: One hundred twenty premolars were selected and randomly divided into two equal groups of 60 teeth/ each (Groups I and II). The teeth of Group I were left untreated while those of Group II were exposed to 5.25% NaOCl for 1 minute. The teeth in either group were randomly subdivided into three equal subgroups of 20 teeth/ each (A, B and C), according to the type of adhesive system used to bond the brackets. In Subgroup A, phosphoric acid + Transbond XT primer and adhesive were used. In subgroup B, Transbond Plus self-etching primer (SEP) + Transbond XT adhesive were utilized. In subgroup C, phosphoric acid + SmartBond LC adhesive were used. The shear bond strength (SBS) and the degree of adhesive penetration to enamel surface were assessed. Data analyses were performed using ANOVA, post-hoc (LSD), t and chi-square test. Results: Transbond XT had significantly higher SBS than SmartBond LC (p< 0.05). Phosphoric acid provided significantly higher SBS and degree of adhesive penetration than SEP (p< 0.05). NaOCl significantly increased SBS and degree of adhesive penetration in Subgroups B and C (p< 0.05). Conclusion: Adhesion quality of Transbond XT adhesive is better than SmartBond LC. Phosphoric acid is more effective than SEP. NaOCl enhances the bond characteristics.

Evaluation of the Effect of Enamel Deproteinization Combined with a Self-etching Primer on the Adhesion of Orthodontic Brackets: An In Vitro Study

“…The shear resistance was considered adequate for clinical use, even though sodium hypochlorite did not impact the shear force. This finding contradicts some laboratory studies that evidenced sodium hypochlorite as a promoter of the adhesion force [22,26].…”

“…A significant difference was observed in the shear force between the two bonding systems used, showing better results for the self-etching system when compared to the conventional method. This finding contradicts some studies that evidenced better results than traditional acid conditioning [26,35]. These results also contradicted some studies, which showed that both bonding systems presented similar results [32,36].…”

“…Using 5% sodium hypochlorite before the use of 37% phosphoric acid significantly improves the etched area and the acid pattern [14,25,26]. But the use of sodium hypochlorite before the self-etching prime still requires more information.…”

Testes de controle de qualidade realizados em comprimidos de hidroclorotiazida provenientes do Programa Farmácia Solidária de Maringá (PR)

“…Tabela 1-Resultados da comparação intergrupos da força de cisalhamento (ANOVA a um critério de seleção e teste de Tukey). A resistência ao cisalhamento de todos os grupos foi considerada adequada para o uso clínico, entretanto o hipoclorito de sódio não demonstrou nenhum impacto na força de cisalhamento, esse achado é contrário a alguns estudos laboratoriais que evidenciaram o hipoclorito de sódio como promotor de um aumento na força de adesão (MAHMOUD et al, 2019;PANCHAL et al, 2019).…”

“…Uma diferença estatisticamente significativa foi notada na força de cisalhamento entre os dois sistemas adesivos utilizados, apontando melhores resultados para o sistema autocondicionante, se comparado ao convencional. Esse achado é contrário a alguns trabalhos que evidenciaram melhores resultados para o condicionamento ácido convencional JOHAL;PANDIS, 2012;MAHMOUD et al, 2019) e contrariam também alguns estudos que mostram os dois adesivos como apresentando resultados semelhantes (ALAVI; EHTESHAMI, 2019;BAYAR BILEN;ÇOKAKOĞLU, 2020). Objetivando uma unanimidade e maior respaldo entre os trabalhos, faz-se necessário o desenvolvimento futuro de estudos clínicos controlados.…”