Physiochemical properties of a bioceramic-based root canal sealer reinforced with multi-walled carbon nanotubes, titanium carbide and boron nitride biomaterials

Aim: Bioceramic-containing root canal sealers are the most recently introduced sealers in endodontics. The present work reported experiments on a bioceramic-based root canal sealer with the objective of improving its physiochemical properties via reinforcement with each one of the three different nanomaterials: multi-walled carbon nanotubes (MWCNTS), titanium carbide (TC) or boron nitride (BN) in two weight percentages (1 wt% and 2 wt%). Methodology: Each nanomaterial was added to a definite weight of BioRoot root canal sealer (BioRoot™ RCS, Septodont, Saint-Maur-des-Fossés, France). Three composite groups of each weight percentage were prepared for evaluation: BioRoot/MWCNTS, BioRoot/TC and BioRoot/BN. The initial and final setting times, solubility, elution and pH values of the freshly-mixed and set samples were evaluated and compared to pristine BioRoot™ RCS. Setting times were evaluated using Gilmore needles. Solubility and elution were determined after immersion in water for 24 h. Scanning electron microscopy was used to examine the microstructure of the composite materials. Results: The 1-wt. % composites possessed significantly shorter initial and final setting times compared with the pristine BioRoot™ RCS (p < 0.05). The 2-wt.% composites exhibited longer initial setting times but significantly shorter final setting times than BioRoot RCS (p < 0.05). Most of the composites had relatively lower solubility and elution profiles, with BioRoot/1-wt.% TC and BioRoot/1-wt.% BN being the lowest (p < 0.05). BioRoot™ RCS and all composites exhibited an alkaline pH profile over a period of 4 weeks and a significantly higher alkaline pH (p < 0.05) was recorded for BioRoot/1-wt.% and Bioroot/2-wt.% TC. Conclusions: A bioceramic-containing root canal sealer (BioRootTM RCS) with a shorter setting time, an alkaline pH profile, and a relatively lower solubility may be developed by incorporation of nanomaterials.