Comparison of shear bond strength of orthodontic brackets bonded with a universal adhesive using different etching methods

Abstract

Objective: The aim of this study was to compare the effects of three enamel etching modes - laser-etch, self-etch and acid-etch (5, 10 and 15 s) - on bracket bonding, using a universal adhesive. Methods: Eighty-four maxillary premolars were randomly divided into seven groups (n=12) based on the etching method and the adhesive used for bracket bonding. After water storage and thermocycling, shear bond strength was measured, and adhesive remnant index scores on debonded enamel were determined. Results: There were significant differences between the seven groups regarding bond strength values (p< 0.001). The highest values were observed in universal adhesive with laser etching group, while Transbond XT with acid or laser etching, and universal adhesive used in self-etch mode demonstrated the lowest bond strength. The universal adhesive with the three different etching times presented with statistically similar results, all showing an improvement in bond strength, compared with Scotchbond universal (SBU)/SE. Conclusions: The universal adhesive evaluated in the present study demonstrated statistically similar bond strengths to conventional orthodontic adhesive in self-etch mode. The bond strength can be improved by adding an initial acid etching or laser conditioning step, although enamel damage was observed in some cases.

The Performance of Universal Adhesives on Orthodontic Bracket Bonding

“…27 In agreement with this study, it has been concluded that Scotchbond Universal showed higher bond strength than Transbond XT, and this resulted from the 10-MDP monomer. 6 The main functional monomer of Prime&Bond Universal is PENTA. In a previous study, Prime&Bond Universal presented similar bond strengths when compared with Scotchbond Universal.…”

The Effect Of ER,Cr.YSGG Laser on the Shear Bond Strength of Composite Resin Bonded to Primary Enamel “An in-vitro study”

“…Another interesting study by Shafiei et al (21) , concluded that the usage of universal adhesives was the tipping point in enhancing the shear bond strength of orthodontic adhesive systems to permanent enamel, whether used with acid etching or laser etching without any significant difference between the two methodologies. The authors explained that the presence of 10-MDP copolymer in universal adhesives has been documented to be capable of bonding to enamel and dentin effectively, forming a nano-layer at the adhesive interface.…”

“…Similarly, Bahrololoomi et al (21) , stated that if laser is to be used for tooth preparation, it must be necessarily accompanied by acid etching. And that the maximum bond strength values relative to their study groups belonged to bur and acid-etching preparation in dentin and enamel followed by laser preparation and etching; and laser preparation followed by resin bonding without etching resulted in the lowest bond strength.…”

“…On the microscopic level it was found that Erbium laser when applied to hard dental tissues, it results in thermo-mechanical wear and evaporation of water content. This results in expansion and disposal of organic and inorganic tissues, open dentinal tubules and removal of the smear layer, ultimately leading to a surface with an irregular surface texture and altered calcium-phosphorus ratio, resulting in the development of more stable complexes (20,21) . This decreases the vulnerability of laser treated enamel to acid attacks and dental caries (22) .…”

“…Laser etching of permanent enamel has been extensively investigated and compared to the outcome of acid etching and yet the results came with a wide disparity in terms of comparable (23,24) , higher (25) and lower (26) bond strength values, compared with that of acid etching, depending on the laser type, irradiation parameters and experimental designs (21) . Studies on primary enamel however, are limited and particular attention need to be given to improve the quality of bonding in the presence of its challenging features.…”