Evaluation of the adaptation of dental polymers using cross-polarization optical coherence tomography

Abstract

Objective: The purpose of this study was to image gap formation and micro-leakage in restored cervical cavities with three different dental adhesives using cross-polarization optical coherence tomography (CP-OCT). Methodology: Thirty saucer shape class-V cavities were prepared on the buccal and lingual surfaces of extracted human molars. Samples were randomly divided into three groups (n = 10) according to the used adhesive; all-in-one Tetric N-Bond self-etch (TN; Ivoclar/Vivadent, Liechtenstein), G-Premio universal (GP; GC, Japan) in self-etch mode and two-step self-etch Clearfil SE Bond 2 (SE; Kuraray Noritake, Japan). All cavities were bonded and filled with a universal composite (Estelite ∑ Quick, Tokuyama Dental, Japan) and cured by the LED light curing unit. Then, tomographic images were taken under CP-OCT to detect gap formation at the cavity in order to calculate the gap percentage in each group. Result: Mann-Whitney U test showed statistical significant difference among all groups (p < 0.05) with high gap percentage in GP group followed by TN group. SE group showed the highest composite adaptation with the lowest gap percentage. Conclusion: Within the limitation of the study, the restored cavities with two-step self-etch adhesive exhibited fewer microgaps and micro-leakage than one-step self-etch adhesives.