Repair Bond Strength of Aged Composite: Effect of Thermocycling and Surface Treatment Publisher



Yarmoradian S ; Ranjbar Omrani LR ; Ahmadi E ; Rafeie N ; Abbasi M ; Shahabi ND
Source: Journal of Research in Dental and Maxillofacial Sciences Published:2025

Abstract

Background and Aim: A variety of surface preparation techniques have been applied to increase the repair bond strength of composite restorations. The current study aimed to assess how silane and/or plasma application, bur roughening, sandblasting, and thermocycling would affect the microshear bond strength (µSBS) of composite repair employing a universal adhesive. Materials and Methods: The current in vitro study utilized 128 composite specimens (10 x 10 x 10 mm) that were stored in 37°C water for 4 weeks and then randomly divided into two groups (n = 64) for surface treatment by sandblasting or bur roughening. Then, each group was divided into four subgroups (n=16) and received surface treatments as follows: No plasma or silane, plasma application, silane application, plasma and silane application. The new composite was then bonded to each specimen using G-Premio Bond. Half of each subgroup (n=8) underwent 5000 thermal cycles, while the other half was stored in water for 24 hours. Finally, the repair µSBS was measured. Four-way ANOVA was used for data analysis (alpha=0.05). Results: Thermocycling significantly decreased the µSBS (P=0.000). Significantly greater µSBS (13.35±3.82 N; P=0.014) was achieved when physical methods were used alone without plasma or silane. Silane reduced the repair µSBS following sandblasting, but significantly increased the repair µSBS after bur roughening. Plasma treatment did not have a significant effect on µSBS (P>0.05). Conclusion: Sandblasting greatly enhanced the repair µSBS. The repair µSBS of the roughened composite samples was unaffected by plasma treatment. The type of physical treatment determines how well silane improves the repair µSBS. © 2025 Elsevier B.V., All rights reserved.