A Novel Urethane Acrylate–based Root Canal Sealer with Improved Degree of Conversion, Cytotoxicity, Bond Strengths, Solubility, and Dimensional Stability

• Published in: Journal of endodontics Vol. 37; no. 2; pp. 246 - 249
• Main Authors: Lee, Bor-Shiunn, PhD, Wang, Chen-Ying, DDS, Fang, Yen-Yin, MS, Hsieh, Kuo-Huang, PhD, Lin, Chun-Pin, PhD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.02.2011
• Subjects: Acrylic Resins - chemistry; Acrylic Resins - pharmacology; Analysis of Variance; Dental Stress Analysis; Dentistry; Elastic Modulus; Endocrinology & Metabolism; Humans; Materials Testing; Nitriles - chemistry; Nitriles - pharmacology; Polymers - chemistry; Polymers - pharmacology; Polyurethanes - chemistry; Polyurethanes - pharmacology; Properties; Root Canal Filling Materials - chemistry; Root Canal Filling Materials - pharmacology; root canal sealer; Statistics, Nonparametric; Tensile Strength; urethane acrylate; Zinc Oxide - chemistry; Zinc Oxide - pharmacology; Properties; root canal sealer; urethane acrylate
• ISSN: 0099-2399; 1878-3554
• DOI: 10.1016/j.joen.2010.11.008

Abstract Introduction We have developed new urethane acrylate–based root canal sealers using polycarbonate (PC) as polyol and 2,2-azobis(2-methyl)butyronitrile (AMBN) as a thermal initiator. The purpose of this study was to compare the properties among a group of seven sealers: (1) polybutyleneadipate (PBA) with 2,2-azobis-isobutyronitrile (AIBN), (2) PBA-AMBN, (3) PC-AIBN, (4) PC-AMBN, (5) AH Plus (Dentsply DeTrey GmbH, Konstanz, Germany), (6) Epiphany (Pentron Clinical Technologies, Wallingford, CT), and (7) EndoREZ (Ultradent Products, Inc, South Jordan, UT). Methods Attenuated total reflectance-Fourier transforming infrared spectroscopy was used to analyze the degree of conversion. Cytotoxicity was evaluated using MTT assay. In addition, push-out bond strength, solubility, and dimensional stability were investigated. Results Urethane acrylate–based root canal sealers behaved better than Epiphany and EndoREZ for the properties evaluated in this study. The PC-AMBN sealer exhibited the highest degree of conversion even in the apical third, and its cytotoxicity for nonsetting and aged specimens at 24 hours was comparable to AH Plus sealer. In addition, the PC-AMBN sealer with zinc oxide/thermoplastic polyurethane cones had a significantly higher bond strength than AH Plus with gutta percha. Solubility and dimensional changes of the PC-AMBN sealer conformed to the American National Standards Institute/American Dental Association (ANSI/ADA) standard 57. Conclusions The PC-AMBN sealer has great potential for use in endodontic therapy.