Comparison of microleakage of Scotchbond™ Universal Adhesive with methacrylate resin in Class V restorations by two methods: Swept source optical coherence tomography and dye penetration

Abstract

Background: One of the most important factors in restoration failure is microleakage at the
restoration interface. Furthermore, a new generation of bonding, Scotchbond Universal (multi‑mode
adhesive), has been introduced to facilitate the bonding steps. The aim of this study was to compare
the microleakage of Class V cavities restored using Scotchbond™ Universal with Scotchbond
Multi‑Purpose in two procedures.
Materials and Methods: Eighteen freshly extracted human molars were used in this study.
Thirty‑six standardized Class V cavities were prepared on the buccal and lingual surfaces. The teeth
were divided into three groups: (1) Group A: Scotchbond Universal with “self‑etching” procedure
and nanohybrid composite Filtek Z350. (2) Group B: Scotchbond Universal with “total etching”
procedure and Filtek Z350. (3) Group C: Scotchbond Multi‑Purpose and Filtek Z350. Microleakage at
enamel and dentinal margins was evaluated after thermocycling under 5000 cycles by two methods
of microleakage assay: swept source optical coherence tomography (OCT) and dye penetration.
Wilcoxon’s signed‑rank test and Kruskal–Wallis test were used to analyze microleakage.
Results: In silver nitrate dye penetration method, group A exhibited the minimum microleakage
at dentin margins and group C exhibited the minimum microleakage at enamel margins (P < 0.05).
Furthermore, in OCT method, group C demonstrated the minimum microleakage at enamel
margins (P = 0.047), with no difference in the microleakage rate at dentin margins.
Conclusion: Scotchbond Universal with “self‑etching” procedure at dentin margin exhibited more
acceptable performance compared to the Scotchbond Multi‑Purpose with the two methods.
Key Words: Microleakage, optical coherence tomography, universal adhesive