Comparative evaluation and influence of new Optibond eXTRa self-etch Universal adhesive and conventional Transbond XT on shear bond strength of orthodontic brackets—An in vitro study

Abstract

INTRODUCTION: The demand by dental practitioners for adhesives led to the innovation of newer self-etched universal adhesive systems. The objectives were to evaluate the shear bond strength (SBS) of metal brackets bonded with Optibond eXTRa Universal self-etch adhesive and Transbond XT primer and also to assess the adhesive remnant index (ARI). MATERIALS AND METHODS: A total of 100 extracted human premolar tooth samples were divided into 2 groups (n = 50) according to the adhesive system employed: Transbond XT (3M Unitek) and Optibond eXTRa Universal (KaVo Kerr). In group A, Transbond XT primer was applied, and in group B, Optibond eXTRa was applied, and metal brackets (American Orthodontics) were bonded with the Transbond XT adhesive, followed by photopolymerization with LEDition. The samples were preserved in artificial saliva for 30 days. SBS was tested using a universal testing machine (DAK Series7200, India). The ARI was assessed at 10× magnification under a stereomicroscope (Meiji Techno, Japan). The SBS scores were subjected to independent sample t-test and ARI scores to Pearson's Chi-square test. RESULTS: The mean SBS and standard deviation of Transbond XT is 12.11 ± 2.6 MPa and that of Optibond eXTRa Universal is 11.36 ± 2.8 MPa, revealing a statistically nonsignificant difference. Transbond XT displayed higher ARI scores and was statistically significant ( P = 0.001). CONCLUSION: The Optibond eXTRa Universal adhesive appears to be preferable for orthodontic bonding as it exhibited clinically acceptable SBS and performed better in terms of the ARI.

Shear bond strength of a RMGIC for orthodontic bracket bonding to enamel

“…This adhesive provided a stronger adhesion than a conventional adhesive. [33][34][35][36][37] Finally, all the groups tested in our study had bond strength values well above the minimum needed for bonding orthodontic brackets as de ned by Reynolds 3 (between 5.9 and 7.8 MPa); therefore, they were clinically applicable for the three materials evaluated.…”

“…32 Contrary to conventional self-etching adhesives, universal adhesives provided micromechanical and chemical adhesion by the interactions of functional monomers with the calcium of hydroxyapatite, which could explain the increase in the SBS values obtained. [33][34][35][36] For the groups using TXT, the application of a universal adhesive after enamel etching signi cantly increased the SBS values (29.30 MPa for Group 9 (H 3 PO 4 + SU + TXT) vs. 19.38 MPa for Group 6 (TSEP + TXT) and 21.6 MPa for Group 8 (SU + TXT)). These results agreed with those of several authors who have shown an increase in the adhesion value with acid etching prior to the application of a universal adhesive but no signi cant difference between the application of a conventional self-etching system and a universal adhesive without prior etching.…”

“…These results agreed with those of several authors who have shown an increase in the adhesion value with acid etching prior to the application of a universal adhesive but no signi cant difference between the application of a conventional self-etching system and a universal adhesive without prior etching. [33][34][35][36][37] In the case of a universal adhesive, acid etching polarized the enamel surface and exposed hydroxyl groups on its surface, helping to increase the chemical interactions of functional monomers, such as 10-MDP, with the calcium of the hydroxyapatite. This adhesive provided a stronger adhesion than a conventional adhesive.…”

“…Groups 8 and 9 achieved high SBS values, and it is widely accepted that high SBS values are indicative of the quality of the bonding interface, with a correlation between a high SBS and mixed or cohesive failure within the enamel. [33][34][35] Cerone et al 37 evaluated three universal adhesives and a self-etch primer for bonding orthodontic attachments and showed that there was little or no adhesive remaining on the enamel surface at debonding, showing preferential failure at the enamel/adhesive interface. This nding suggested that it was relatively easy to clean the adhesive after debonding and that there was a greater risk of enamel fracture during bracket debonding when using a universal adhesive than when using a self-etching primer.…”

Shear bond strength of a RMGIC for orthodontic bracket bonding to enamel

“…In restorative dentistry, authors showed a high SBS value with acid etching and universal adhesive application prior to the application of a RMGIC on composite resin or dentin [35]. Contrary to conventional self-etching adhesives, universal adhesives provided micromechanical and chemical adhesion by the interactions of functional monomers with the calcium of hydroxyapatite, which could explain the increase in the SBS values obtained [36][37][38][39].…”