An in vitro micro‐CT assessment of bioactive restorative materials interfacial adaptation to dentin

Abstract

Background: The background of this study was to improve the longevity of a restoration and
optimal adaptation of restorative material to the prepared cavity walls is crucial. The study aimed
to evaluate the interfacial adaptation of Activa, Micron, and Predicta bulk bioactive restorative
materials to coronal dentin using micro‑computed tomography (CT) analysis.
Materials and Methods: In this in vitro micro‑CT assessment study, Class II mesio‑ and disto‑occlusal
cavities were prepared on 60 extracted human mandibular molar teeth. After etching and bonding
procedures, all the mesial cavities (n = 60) were restored with Tetric N‑Ceram and the disto‑occlusal
cavities with Activa or Micron or Predicta bioactive (n = 20 each) restoratives. Interfacial gap
percentages were evaluated under micro‑CT before (baseline) and after thermo‑mechanical load
cycling (TMC). Acquired data were analyzed statistically using one‑way analysis of variance, Paired
t‑test, and Tukey’s multiple post hoc procedures, at P < 0.05 level of significance.
Results: The interfacial gap percentages were lowest for Predicta bioactive and highest for
the Micron group (P < 0.05). The number of gaps increased significantly after TMC in all the
groups (P < 0.05). The adaptation of tested materials was inferior to axial wall and pulpal floor,
whereas considerably better adaptation was observed on buccal and lingual walls.
Conclusion: Predicta bioactive followed by Activa bioactive has shown superior interfacial
adaptation, whereas Micron bioactive demonstrated maximum microgaps compared to nanohybrid
composite. Artificial aging with TMC has a negative influence on the internal adaptation of all tested
materials.
Key Words: Activa bioactive, interfacial gaps, micro‑computed tomography, micron bioactive,Predicta bioactive