In Vitro Biocompatibility Evaluation of a Root Canal Filling Material That Expands on Water Sorption

• Published in: Journal of endodontics Vol. 39; no. 7; pp. 883 - 888
• Main Authors: Eid, Ashraf A., BDS, MSc, Nikonov, Sergey Y., DDS, Looney, Stephen W., PhD, Didato, Anthony, DMD, Niu, Li-na, DDS, MS, Levin, Martin D., DMD, Rueggeberg, Frederick A., DDS, MS, Pashley, David H., DMD, PhD, Watanabe, Ikuya, DDS, PhD, Tay, Franklin R., BDSc (Hons), PhD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01-07-2013
• Subjects: Absorption; Acrylic Resins - chemistry; Acrylic Resins - toxicity; Acrylonitrile - chemistry; Acrylonitrile - toxicity; Adsorption; Alizarin red S; alkaline phosphatase; Alkaline Phosphatase - drug effects; Animals; Apoptosis - drug effects; biocompatibility; Biocompatible Materials - chemistry; Biocompatible Materials - toxicity; Calcification, Physiologic - drug effects; Cell Differentiation - drug effects; Cell Line; Cell Membrane Permeability - drug effects; Cell Survival - drug effects; CPoint; Dentistry; Endocrinology & Metabolism; Extracellular Matrix Proteins - drug effects; flow cytometry; Gutta-Percha - chemistry; Gutta-Percha - toxicity; Materials Testing; Microscopy, Electron, Transmission; MTT assay; Nylons - chemistry; Nylons - toxicity; Odontoblasts - drug effects; Osteogenesis - drug effects; Phosphoproteins - drug effects; Polytetrafluoroethylene - chemistry; Polytetrafluoroethylene - toxicity; Polyvinyls - chemistry; Polyvinyls - toxicity; Pyrrolidinones - chemistry; Pyrrolidinones - toxicity; qRT-PCR; Rats; Root Canal Filling Materials - chemistry; Root Canal Filling Materials - toxicity; Sialoglycoproteins - drug effects; Surface Properties; Up-Regulation; vital cell staining; Water - chemistry; biocompatibility; qRT-PCR; alkaline phosphatase; flow cytometry; CPoint; MTT assay; Alizarin red S; vital cell staining
• ISSN: 0099-2399; 1878-3554
• DOI: 10.1016/j.joen.2013.03.003

Abstract Introduction CPoint is a polymeric endodontic point that takes advantage of water-induced, non-isotropic radial expansion to adapt to canal irregularities. This study evaluated the effects of CPoint on the viability and mineralization potential of odontoblast-like cells. Methods The biocompatibility of CPoint and commercially available gutta-percha points was evaluated by using a rat odontoblast-like cell line (MDPC-23). Cell viability was evaluated with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay, flow cytometry, and confocal laser scanning microscopy. The mineralization potential of MDPC-23 cells, in the presence of the root-filling materials, was evaluated by examining the changes in osteogenic gene marker expression (quantitative real-time polymerase chain reaction), alkaline phosphatase activity, alizarin red S assay, and transmission electron microscopy. Results CPoint showed higher initial cytotoxicity compared with gutta-percha and Teflon ( P < .05), which became nonsignificant after 4 immersion cycles. Significant differences were also found between eluents from CPoint and gutta-percha at 1:1 concentration ( P < .05) but not at 1:10 or 1:100 concentration. Both materials induced minimal apoptosis-induced alteration in plasma membrane permeability, as evidenced by flow cytometry and confocal laser scanning microscopy. Compared with the Teflon negative control, CPoint and gutta-percha groups showed up-regulation of most osteogenic gene markers except for dentin sialophosphoprotein, which was down-regulated. Alkaline phosphatase activity and alizarin red assay for CPoint and gutta-percha were both significantly higher than for Teflon but not significantly different from each other ( P > .05). Transmission electron microscopy showed discrete nodular electron-dense mineralization foci in all 3 groups. Conclusions The  in vitro biocompatibility of CPoint is comparable to gutta-percha with minimal adverse effects on osteogenesis after elution of potentially toxic components.