Effect of different mechanical and chemical surface treatments on the repaired bond strength of an indirect composite resin

Abstract

This study compared the effects of two mechanical surface preparation techniques, air abrasion and Nd:YAG laser, with the use of two adhesive systems, self-etch and etch and rinse, on the repair bond strengths of an indirect composite resin. One hundred fifty cylindrical samples of an indirect composite resin were prepared and randomly divided into six groups (n = 25). In groups 1-3, the composite resin surfaces were respectively prepared as follows: no roughening, roughening by air abrasion, and roughening by Nd:YAG laser, followed by application of an etch-and-rinse adhesive. In groups 4-6, the preparation techniques were respectively the same as those in groups 1-3, followed by application of a self-etch adhesive. Subsequently, a direct composite resin was added and repair bond strengths were measured. Data were analyzed with two-way ANOVA and post hoc Tukey's test. Mean bond strength value was significant based on the preparation technique (P < 0.001), i.e., in air abrasion and Nd:YAG laser groups, bond strengths were significantly higher compared to no-preparation groups (P < 0.0005). There were significant differences in bond strength values between air abrasion and Nd:YAG laser groups, with significantly higher values in air abrasion groups (P < 0.0005). However, there were no significant differences in bond strength values between the adhesive systems. Furthermore, the cumulative effects of the adhesive system and the surface preparation technique were not significant. Surface preparation of the indirect composite resin with air abrasion and Nd:YAG laser resulted in a significant increase in the repair bond strength, with air abrasion being more effective. There were no significant differences in bond strength between the two adhesives.

Reparability of giomer using different mechanical surface treatments

“…SEM and AFM images in the present study confirmed this. Previous studies (9,12,21) have shown that roughening the surface with air abrasion results in an increase in the repair bond strength of composite resins. Contrary to the results of the present study, Alizadeh et al (10) reported that use of air abrasion did not result in an increase in the repair bond strength of silorane-based composite resin.…”

“…Since giomer is a biphasic material, consisting of a resin matrix and filler particles, it is possible to believe that the mechanism of the effect of laser on composite resins holds true in the case of giomer, too. In this context, previous studies have shown that surface roughening with Nd:YAG laser results in an increase in repair bond strength of indirect (12) and silorane-based composite resins (8). However, in a study by Akyil et al , use of Nd:YAG laser alone did not result in an increase in repair bond strength of feldspathic ceramic (19).…”

“…The negative control group samples exhibited more smooth surfaces compared to other groups, which might explain the lower repair bond strength in this group. In addition, it has been shown that subsequent to roughening, the surface energy and wettability of the adhesive agent increase (5,11,12). …”

“…It has been reported that irradiation of the surface of a composite resin with Nd:YAG laser leads to the dispersion of the laser energy by silica filler particles; an increase in the absorption of this energy by the resin component of composite resin gives rise to localization of this energy near the substrate surface, modifying the heat of the composite matrix, which finally results in its removal to produce surface irregularities (12). Giomers use pre-reacted glass filler technology, in which pre-reaction of fluroaluminosilicate glass fillers with polyacrylic acid results in the formation of a stable phase called “wet siliceous hydrogel”, which is then freeze-dried, milled, silanized and ground to produce PRG fillers.…”

Improving shear bond strength of temporary crown and fixed dental prosthesis resins by surface treatments

“…The findings of the current study demonstrate the importance of sandblasting and micromechanical retention in the bis-acryl temporary resin repair. Some studies have also shown that micromechanical retention is the most significant factor in the filling composite resin repair [5,16,17]. However, some investigations have reported the reduced repair bond strength after sandblasting in the filling composite resin repair [18][19][20].…”