Effect of bioactive glass‑containing dentin adhesives on microshear bond strength of composite restorations

Abstract

Background: In general, bioactive glasses (BAGs) can react with tissue minerals and promote
remineralization. However, the application of BAG in bonding agents and its impact on bond strength
remain uncertain due to insufficient information and limited research in this area.
Materials and Methods: This study employed a randomized controlled design to assess
the effects of composite‑bonding agents with varying BAG contents on shear bond strength
and fracture pattern in sound and demineralized teeth, with and without thermocycling. Thus,
80 healthy third molars were randomly divided into two groups: sound teeth and demineralized
teeth. Five bonding agents were applied to the prepared dentin surfaces, including four
experimental composite‑bonding agents with varying BAG content (0, 0.2, 0.5, and 2 wt%) and
the Adper Single Bond commercial bonding as control. The shear bond strength of all samples
was measured using a universal tester. The type of failure of each specimen was determined
using a stereomicroscope. Kruskal–Wallis nonparametric test was performed on the obtained
shear bond strength data followed by Mann–Whitney post hoc test with Bonferroni correction
to determine statistical significance. The level of significance was considered P ≤ 0.05 for all tests
and was adjusted by Bonferroni correction.
Results: Demineralization significantly decreased shear bond strength in the teeth samples.
Adper Single Bond exhibited the highest shear bond strength values. The addition of BAG
did not have a significant influence on shear bond strength, regardless of demineralization or
thermocycling condition. Adhesive failure was the predominant type of failure in all groups.
Conclusion: The incorporation of BAG filler up to 2 wt% did not result in significant changes
in shear bond strength. Experimental adhesive bonding agents with 2 wt% BAG content
demonstrated shear bond strengths comparable to the commercial bonding agent in sound
nontreated, sound thermocycled, demineralized nontreated, and demineralized thermocycled
groups.
Key Words: Dentin bonding agent, permanent dental restoration, shear strength, tooth demineralization

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Parsa Rezvanian: Pubmed,Google Scholar