Effects of Different Combinations of Er:YAG Laser-Adhesives on Enamel Demineralization and Bracket Bond Strength

Abstract

Objective: The purpose of this study was to investigate the demineralization around brackets and shear bond strength (SBS) of brackets bonded to Er:YAG laser-irradiated enamel at different power settings with various adhesive systems combinations. Methods: A total of 108 premolar teeth were used in this study. Teeth were assigned into three groups according to the etching procedure, then each group divided into three subgroups based on the application of different adhesive systems. There were a total of nine groups as follows. Group 1: Acid + Transbond XT Primer; group 2: Er:YAG (100 mJ, 10 Hz) etching + Transbond XT Primer; group 3: Er:YAG (200 mJ, 10 Hz) etching + Transbond XT Primer; group 4: Transbond Plus self-etching primer (SEP); group 5: Er:YAG (100 mJ, 10 Hz) etching + Transbond Plus SEP; group 6: Er:YAG (200 mJ, 10 Hz) etching + Transbond Plus SEP; group 7: Clearfil Protect Bond; group 8: Er:YAG (100 mJ, 10 Hz) etching + Clearfil Protect Bond; group 9: Er:YAG (200 mJ, 10 Hz) etching + Clearfil Protect Bond. Brackets were bonded with Transbond XT Adhesive Paste in all groups. Teeth to be evaluated for demineralization and SBS were exposed to pH and thermal cyclings, respectively. Then, demineralization samples were scanned with micro-CT to determine lesion depth values. For SBS test, a universal testing machine was used and adhesive remnant was index scored after debonding. Data were analyzed statistically. Results: No significant differences were found among the lesion depth values of the various groups, except for G7 and G8, in which the lowest values were recorded. The lowest SBS values were in G7, whereas the highest were in G9. The differences between the other groups were not significant. Conclusions: Er:YAG laser did not have a positive effect on prevention of enamel demineralization. When two step self-etch adhesive is preferred for bonding brackets, laser etching at 1 W (100 mJ, 10 Hz) is suggested to improve SBS of brackets.

The Use of Laser Energy for Etching Enamel Surfaces in Dentistry—A Scoping Review

“…Studies compared laser conditioning with conventional 37% phosphoric acid, revealing that the two methods can provide similar shear bond strengths [ 28 , 31 , 32 , 35 , 36 ]. There are certain studies revealing even a higher bond strength for laser etching [ 30 , 33 ]. The laser helps in improving shear bond strength values when bonding orthodontic brackets to the enamel surfaces by using a self-etching adhesive system [ 33 ].…”

“…There are certain studies revealing even a higher bond strength for laser etching [ 30 , 33 ]. The laser helps in improving shear bond strength values when bonding orthodontic brackets to the enamel surfaces by using a self-etching adhesive system [ 33 ]. Nd:YAG and Diode lasers also help improve the adhesion of self-etching systems in cavities [ 15 ].…”

Effect of different bonding protocols on degree of monomer conversion and bond strength between orthodontic brackets and enamel

“…According to Usumez (2002), 35 the literature is controversial as to the most desirable type of failure. Some authors 36 suggest that a smaller amount of adhesive remaining in the enamel results in a shorter clinical time for cleaning and polishing the teeth after brackets removal. However, other authors 37 prefer having a greater amount of adhesive remnant on the enamel surface, as the residues can be carefully removed with specific burs and this prevents cracks and fractures.…”