Reparability of giomer using different mechanical surface treatments.

S Arami,Pa Oskoee,Ma Kahnamoii,S Kimyai,M Bahari,M Daneshpooy,S Rikhtegaran

doi:10.4317/jced.53591

S Arami, Pa Oskoee + Show 5 more

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https://doi.org/10.4317/jced.53591

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Abstract

BackgroundIn the repair process achieving high bond strength between the new and old resin based materials is necessary for clinical longevity. This study compared the effect of three different mechanical surface treatments (air abrasion, Nd:YAG laser and diamond bur) on the repair bond strength of giomer.Material and MethodsIn this in vitrostudy, 125 cylindrical giomer samples were used. The giomer samples were randomly assigned to 5 groups (n=25). In group 1, the samples did not undergo any surface treatment. In groups 2 to 4, the samples underwent surface treatments with air abrasion, Nd:YAG laser and a diamond bur. The samples in group 5 were prepared to measure giomer cohesive strength. Subsequently, the new giomer was bonded to the existing giomer in groups 1 to 4. Then the repair bond strength of the samples was measured. One-way ANOVA and post hoc Tukey test were used to compare the bond strength. ResultsThere were significant differences between the different surface treatments (P<0.001); the repair bond strength in the air abrasion group was significantly higher than that in the Nd:YAG laser group, in which it was significantly higher than that in the diamond bur group, which was in turn higher than that in group 1 (no surface treatment) (P<0.001). In addition, the cohesive strength of giomer was significantly higher than the repair bond strength in the 4 other study groups (P<0.001).ConclusionsOf all the surface treatments, air abrasion and Nd:YAG laser, in descending order, yielded the highest repair bond strength values, with the repair bond strength values of 60‒70% of the giomer cohesive strength. Key words:Air abrasion, bond strength, giomer, Nd:YAG laser, repair, surface treatment.

Highlights

Composite resins are materials with widespread use in direct restorative procedures
The results of the present study showed that the repair bond strength of giomer after mechanical surface treatments increased significantly, which is consistent with the results of previous studies on resin-based materials, indicating that mechanical roughening of the substrate surface is an important factor in increasing the repair bond strength [9,10,11,17]
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 results in its removal to produce surface irregularities [12]

Summary

Introduction

Composite resins are materials with widespread use in direct restorative procedures. The majority of composite resin restorations undergo defects such as abrasion, fatigue or discoloration after some service due to mechanisms such as mechanical and physical degradations, because of contact with water or physical processes such as enzymatic, hydrolytic and acidic reactions or temperature degradation. It is necessary to achieve a high bond strength between the new and old composite resins for clinical longevity [1,3]. In the repair process achieving high bond strength between the new and old resin based materials is necessary for clinical longevity. This study compared the effect of three different mechanical surface treatments (air abrasion, Nd:YAG laser and diamond bur) on the repair bond strength of giomer. In groups 2 to 4, the samples underwent surface treatments with air abrasion, Nd:YAG laser and a diamond bur. Results: There were significant differences between the different surface treatments (P

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