Effects of different deproteinizing agents on topographic features of enamel and shear bond strength - An in vitro study

Abstract

OBJECTIVES:To evaluate and compare the effect of different enamel deproteinizing agents on topographic features of enamel and shear bond strength before acid etching.MATERIALS AND METHOD:In total, 120 sound human maxillary premolars were taken and divided into three groups: Group 1 control (37% phosphoric acid (H3PO4), Group 2, (5.25% Sodium Hypochlorite (NaOCl)+ 37% H3PO4, and Group 3, (10% Papain gel + 37% H3PO4). These groups were further divided into A and B subgroups. In subgroups 1A, 2A, and 3A (n30) topographic features were evaluated using Scanning electron microscope (SEM) at different magnifications. Insub-groups 1B, 2B, and 3B (n90) metal brackets were bonded with Transbond™ XT, and all the samples were subjected for Shear Bond Strength (SBS) evaluation using universal testing machineat a cross speed of 0.5 mm2/min. The failure mode was analyzed using adhesive remnant index (ARI). Statistical analysis was done using one-way ANOVA for the shear bond strength, and Kruskal-Wallis test followed by Mann-Whitneywas performed for ARI scores.RESULTS:SEM showed predominance of type 3 etching pattern in control Group (1A) and type 1 and type 2 in deproteinizedGroups (2A and 3A). Mean values of shear bond strength showed statistically significant differences between evaluated groups (P < 0.005). The lowest and highest shear bond strength was attributed to Group 1B (Control) and 3B (10% papain gel), respectively. Statisticallysignificant differences were noted for the mean ARI scores between control and deproteinized group (P < 0.05).CONCLUSION:10% papain geland 5.25% NaOCl can be used as deproteinizing agents on enamel surface before acid etchingto enhance the shear bond strength of orthodontic brackets.

Anais do I Congresso Internacional Interdisciplinar da Uningá: Resumos Expandidos

“…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).…”

Enamel Deproteinization: Will It Save The Shear Bond Strength For The Sake Of Preventing White Spot Lesions?

“…In groups II,III and IV the deproteinization was followed by rinsing with distilled water for another 20s, [15,21] then acid etching as in group I.…”

“…On the other hand, the antimicrobial effects of the nano-silver modified orthodontic adhesives were not utilized due to the reduced bond strength and bond failure they provide [1] Enamel deproteinization, using NaOCl, to improve adhesive bond strength was discussed in the literature, [2,15,21,25] and its application offered an opportunity for taking both benefits. Further, the use of citric acid and PEG 400 was attempted as a first in the literature.…”

“…NaOCl is an agent of high redox potential, inducing widespread destabilization of the protein tertiary structure. Its alkaline pH allows hydrogen atom abstraction at the αcarbon; resulting in fragmentation of the protein backbone and a stronger adhesive junction [21,[30][31]. Justus et al [2] reported comparable results; nevertheless the increase was more on using resin modified glass ionomer rather than composite.…”