Effect of Indirect Pulp Capping Materials On Regional Dentin Seal

Purpose: The aim of this in-vitro study was to evaluate the effect of different indirect pulp capping (IPC) materials on bond strength to surrounding dentin.
Materials and Methods: Fifty-six human third molars were used in this study. Occlusal dentin of 42 teeth was exposed. Dentin surfaces (n = 6) were left uncovered (control) or received a 1 × 1 mm central IPC (KL: Kerr life, DY: Dycal, TC: Theracal LC, CL: Calcimol LC, BD: Biodentine, and PR: ProRoot MTA) and were then bonded with Scotchbond Universal adhesive and restored with a composite resin build-up (Filtek™ Z250). After 24 h of water storage, the specimens were cut into sticks, which were marked red (1 mm distance from IPC spot), green (2 mm distance), and blue (3 mm distance). Consequently, µ-TBS tests were performed and analyzed using one-way ANOVA (P 0.05) for normal distributions and Mann–Whitney U-test (P 0.05) for non-normal distributions. Pretesting failures were recorded as 0 MPa. Fracture modes were analyzed under a fluorescence microscope, and interfaces and surfaces of 14 additional specimens were visualized under a scanning electron microscope (SEM).
Results: A significant reduction in peripheral seal was only observed for KL (Mann–Whitney U-test, P 0.05). All groups showed increasing bond strengths from the IPC area to the periphery, indicating a certain contamination potential of IPC materials.
Conclusion: IPC materials being applied in very deep cavity areas except Kerr Life do not harm peripheral seal to dentin. Especially, hydraulic cements can be used without a negative effect on the peripheral dentin seal. Keywords: adhesive bond strength, dentin adhesives, lining, microtensile bond strength, surface characteristic