Interfacial characteristics of Biodentine and MTA with dentine in simulated body fluid

Objectives: Newer tricalcium silicate cements (TSC) may offer biocompatibility with improved working properties. This study aimed to evaluate: (1) the occurrence of mineral deposition at the interface between dentine and two TSC (ProRoot (R) MTA and Biodentine (R)) in simulated body fluid, and (2) to investigate the nature of interfacial layer. Methods: Six root dentine segments of 1.5 mm thickness were obtained from extracted human teeth and were instrumented with Gates-Glidden drills. The specimens were then randomly filled with either MTA or Biodentine. The specimens were placed in the simulated body fluid containing the same phosphate concentration as blood plasma. After 4 weeks, the specimens were examined with Scanning Electron Microscope (SEM) and Energy Disperse Xray Spectroscopy (EDX) to measure the thickness of the interfacial layer and Ca/P ratio. Transmission Electron Microscope (TEM) and Selective Area Electron Diffraction (SAED) were conducted to examine the interface ultramicroscopically and to determine the nature of the crystalline structure within interfacial layer. Results: The thickness of interfacial layer was significantly higher in the MTA group (14.5 mu m vs 4.8 mu m) (p < 0.001). However, there was no significant difference between MTA and Biodentine in Ca/P ratio of interfacial layer (4.1 vs 2.7) (p > 0.05). From TEM examination, amorphous calcium phosphate (ACP) was observed in the interface along with the surface of dentine. Conclusions: As an alternative to MTA, Biodentine displayed bioactivity by producing an interfacial layer on the root canal dentine even though its thickness was significantly lower than MTA. ACP was observed in the interfacial layer of both biomaterials. Clinical significance: Biodentine could be considered as an alternative to MTA due to comparable bioactivity which creates interfacial layer between root canal dentin and Biodentine. (C) 2014 Elsevier Ltd. All rights reserved.