Physicochemical Properties and Cytotoxicity of a Prototype Pediatric Pulpectomy Filling Material

Purpose: To compare the physicochemical properties and cell viability of NuSmile NeoPEX, a novel prototype pediatric pulpectomy filling material, to intermediate restorative material (IRM), Metapex and Metapaste. Methods: The flow, radiopacity and pH were evaluated for NeoPEX, Metapex, Metapaste and IRM according to the test methods of the International Organization for Standardization (ISO) 6876:2012. Cell viability was assessed through the MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide] Assay. Results: NeoPEX, Metapex and Metapaste showed similar flow and radiopacity and met the ISO 6876:2012 requirements for root canal sealers. NeoPEX and Metapaste maintained a high alkaline pH (greater than 10.5) for 28 days, unlike Metapex and IRM. NeoPEX also demonstrated higher cell viability than Metapex, Metapaste and IRM after 7 days. Conclusions: Based on these in vitro results, NuSmile NeoPEX is a promising alternative pulp-filling material for primary teeth. Its favorable flow, radiopacity, sustained alkalinity and improved biocompatibility suggest potential clinical advantages over traditional materials. Further in vitro and in vivo studies are needed to evaluate its resorption profile and long-term performance.