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

To evaluate and compare the effect of different enamel deproteinizing agents on topographic features of enamel and shear bond strength before acid etching.

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% H₃PO_4, 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.

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).

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.