Development of the foremost light-curable calcium-silicate MTA cement as root-end in oral surgery. Chemical–physical properties, bioactivity and biological behavior

AimAn innovative light-curable calcium-silicate cement containing a HEMA–TEGDMA-based resin (lc-MTA) was designed to obtain a bioactive fast setting root-end filling and root repair material.Methodslc-MTA was tested for setting time, solubility, water absorption, calcium release, alkalinizing activity (pH of soaking water), bioactivity (apatite-forming ability) and cell growth-proliferation. The apatite-forming ability was investigated by micro-Raman, ATR-FTIR and ESEM/EDX after immersion at 37 °C for 1–28 days in DPBS or DMEM + FBS. The marginal adaptation of cement in root-end cavities of extracted teeth was assessed by ESEM/EDX, and the viability of Saos-2 cell on cements was evaluated.Resultslc-MTA demonstrated a rapid setting time (2 min), low solubility, high calcium release (150–200 ppm) and alkalinizing power (pH 10–12). lc-MTA proved the formation of bone-like apatite spherulites just after 1 day. Apatite precipitates completely filled the interface porosities and created a perfect marginal adaptation. lc-MTA allowed Saos-2 cell viability and growth and no compromising toxicity was exerted.SignificanceHEMA–TEGDMA creates a polymeric network able to stabilize the outer surface of the cement and a hydrophilic matrix permeable enough to allow water absorption. SiO−/Si–OH groups from the mineral particles induce heterogeneous nucleation of apatite by sorption of calcium and phosphate ions. Oxygen-containing groups from poly-HEMA–TEGDMA provide additional apatite nucleating sites through the formation of calcium chelates. The strong novelty was that the combination of a hydraulic calcium-silicate powder and a poly-HEMA–TEGDMA hydrophilic resin creates the conditions (calcium release and functional groups able to chelate Ca ions) for a bioactive fast setting light-curable material for clinical applications in dental and maxillofacial surgery. The first and unique/exclusive light-curable calcium-silicate MTA cement for endodontics and root-end application was created, with a potential strong impact on surgical procedures.