Comparison of Shear Bond Strength of a Newly Introduced Primer with Conventional Primer Using Two Types of Brackets Bonded to Different Surfaces: An In Vitro Study

Abstract

Background Increasing prevalence of adult orthodontics necessitates improvement in bonding techniques to different intraoral surfaces enamel composite amalgam porcelain. Research focusing on newer materials minimizing bond failures is important as replacing loose brackets is inefficient time-consuming and costly.Objective To compare the shear bond strength SBS and adhesive remnants achieved with the new Assure Plus AP primer versus conventional Transbond XT TXT primer for bonding metalceramic brackets to three different surfaces tooth enamel composite and porcelain-fused-to-metal PFM ceramic.Methods This in vitro study included 40 samples each of extracted teeth Group-1 composite restorations Group-2 and PFM crowns Group-3 mounted on acrylic blocks onto which metal Category-M or ceramic Category-C brackets were bonded using TXT Subgroup-A or AP primer Subgroup-B 10 samples in each class. Their SBS and Adhesive Remnant Index ARI were compared between and within the groups using ANOVA Tukeyrsquos post hoc analysis and Weibull analysis. The level of significance was set at p lt0.05.Results The two primers showed no significant differences in mean SBS within Groups-1 and 2 and in mean ARI within any group p gt0.05. Group-3 showed higher mean SBS with AP primer than with TXT primer BCgtBMgtACgtAM p lt0.001. Failure probability was also lower with AP than with TXT primer.Conclusion AP primer showed significantly greater SBS than TXT primer when used for bonding brackets to PFM crowns. AP primer also showed lower failure probability than TXT primer on all three surfaces tooth enamel composite PFM ceramic.