Repair Bond Strength of Ion-Releasing Versus Conventional Resin Composites

TL;DR

This study compares the repair bond strength of ion-releasing and conventional dental composites, finding that some ion-releasing materials perform as well as conventional ones.

Contribution

The study introduces a comparison of repair bond strength between ion-releasing and conventional resin composites, including an experimental bioactive glass composite.

Findings

ACTIVA BioACTIVE-RESTORATIVE showed the highest repair bond strength (53.8 MPa) and cohesive failures.

Ion-releasing composites had repair bond strengths comparable to conventional composites.

No significant differences were found among several tested materials in the 36.2–46.2 MPa range.

Abstract

With the growing clinical use of ion-releasing resin composites, their repairability has become an important consideration in minimally invasive restorative dentistry. Therefore, this study investigated the repair bond strength of a universal composite restorative to commercially available and experimental ion-releasing resin composite materials. Specimens (n = 8 per group) were produced from three commercially available ion-releasing composite materials (ACTIVA BioACTIVE-RESTORATIVE, Cention Forte, Beautifil II), one experimental ion-releasing resin composite containing 20 wt% bioactive glass fillers, and two conventional resin composites (3M Filtek Supreme XTE, Ceram.x Spectra ST), and aged by thermal cycling in artificial saliva (5000 cycles, 5–55 °C). Substrate surfaces were sandblasted (Al2O3, 50 µm), silanized (Monobond Plus), and repaired using adhesive (OptiBond FL) and universal resin composite (Ceram.x Spectra ST). After further thermal cycling, micro-tensile repair bond strength was assessed and analyzed using one-way ANOVA followed by Tukey’s post hoc test. Failure modes were determined by stereomicroscopy (25× magnification) and statistically compared among the groups. Highest mean repair bond strength values were obtained for ACTIVA BioACTIVE-RESTORATIVE, Beautifil II, and 3M Filtek Supreme XTE (53.8, 46.2, and 43.0 MPa, respectively), which did not differ significantly among each other. ACTIVA BioACTIVE-RESTORATIVE attained significantly higher bond strength than the experimental composite, Ceram.x Spectra ST, and Cention Forte, and showed the highest incidence of cohesive failures (40%). No significant bond strength differences were detected among Beautifil II, 3M Filtek Supreme XTE, experimental composite, Ceram.x Spectra ST, and Cention Forte (36.2–46.2 MPa). In conclusion, ion-releasing resin composites can be repaired with conventional universal composite and show repair bond strength values at least as high as those of conventional composite materials.

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