Comparison of the Intraosseous Biocompatibility of AH Plus, EndoREZ, and Epiphany Root Canal Sealers Cássio J. A. Sousa, DDS, MSD, PhD,* Cristiana R. M. Montes, DDS, ‡ Elizeu A. Pascon, DDS, MSD, PhD, ‡ Adriano M. Loyola, DDS, MSD, PhD, † and Marco A. Versiani, DDS, MSD ‡ Abstract To evaluate the intraosseous biocompatibility of AH Plus, EndoREZ, and Epiphany root canal sealers as recommended by the Technical Report #9 of the Fédération Dentaire Internationale (FDI). Thirty guinea pigs, 10 for each material, divided into experimental periods of 4 and 12 weeks, received one implant on each side of the lower jaw symphysis. At the end of the observation periods, the animals were killed and the specimens prepared for routine histological examina- tion. After analyzing both periods, the inflammatory tissue reaction to EndoREZ was considered severe. In the AH Plus group, the reaction changed from severe to moderate, while it was observed biological compatibil- ity to Epiphany with bone formation and none to slight inflammatory reaction. It was concluded that Epiphany root canal sealer was the only material that presented intraosseous biocompatibility within the two analyzed periods. (J Endod 2006;32:656 – 662) Key Words AH Plus, biocompatibility, EndoREZ, Epiphany, obtura- tion S uccess in root canal treatment depends on the complete removal of the infected canal contents, followed by obturation using a material of adequate compatibility to avoid possible irritation to the periradicular tissues (1). Because tissue injury induced by intracanal procedures may result in unfavorable responses to treatment, the practi- tioner’s choice on procedures to be used during root canal treatment should rely on those that are known to cause as little damage as possible (2). It has been demonstrated that foreign materials, such as root canal sealers, trapped into periradicular tissues after endodontic treatment can perpetuate apical periodontitis (3). It has also been shown that biocompatibility to the periradicular tissues is the most important requisite, because any material not biologically acceptable may be respon- sible for failures (1). In regard to the biological properties of endodontic materials, there is a broad range of characteristics that should be considered. The methodologies to evaluate the parameters comprise, initial tests, secondary tests, and usage studies. The initial evaluation should comprise in vitro methods of assessing the toxicity profile of the material. The secondary tests should be performed in vivo, in laboratory animals, and can include implantation experiments. The usage studies are carried out in pri- mates or human beings (4, 5). The materials that are currently used in clinical practice comprised resin-, zinc oxide-eugenol-, glass ionomer-, calcium hydroxide-, and silicone-based endodontic sealers (6). Resin filling materials have steadily gained popularity and are now accepted as root canal sealers (7) and improvements in adhesive technology have fostered attempts to reduce apical and coronal leakage by bonding to root canal walls (8). Thus, the newly methacrylate-based resin sealers EndoREZ and Epiphany have been recently developed. The biological properties of EndoREZ have been previously investigated regarding its cytotoxicity (9) and tissue biocompatibility (6, 10 –12). Otherwise, the biological properties for Epiphany, a dual curable dental resin composite sealer, are poorly investigated (13). It has been stated that the biological basis for root canal therapy is lagging behind the impressive technological advances in Endodontics (14). However, although re- quired before being promoted for clinical use, the majority of the materials lack even basic safety testing. To date, no studies have been conducted to histologically analyze the effect of Epiphany implantation in bone. Thus, the purpose of this study was to evaluate the biological properties of the newly developed methacrylate-based root canal sealers EndoREZ and Epiphany, comparing to a conventional, well established epoxy-amine resin root canal sealer AH Plus, using the protocol recommended by the Fédération Dentaire Internationale (FDI) (15). Materials and Methods The materials evaluated were AH Plus (Dentsply, DeTrey, Konstanz, Germany), EndoREZ (Ultradent Products, Inc., South Jordan, UT), and Epiphany (Pentron Clinical Technologies, Wallingford, CT) root canal sealers. All materials were prepared accord- ing to the manufacturer’s recommendation for their clinical use, and loaded into Teflon carriers (Polytetrafluorethylene, DuPont, HABIA, Knivsta, Sweden), ensuring that air was not entrapped. The protocol for this experiment was reviewed and approved by the Research Ethics Committee of the University of Uberlândia and the experiment was From the *Department of Endodontics, † Department of Pathology, Faculty of Dentistry, Universidade Federal de Uber- lândia, ‡ Department of Endodontics, Associação Brasileira de Odontologia, Uberlândia, Minas Gerais, Brazil. Address requests for reprints to Prof. Dr. Cássio J.A. Sousa, Department of Endodontics, Faculty of Dentistry, Universidade Federal de Uberlândia, Campus Umuarama, Avenida Parã 1720, Bloco 2B, Sala 24, CEP 38.405-320, Uberlândia, Minas Gerais, Brazil. E-mail address: marcoversiani@yahoo.com. 0099-2399/$0 - see front matter Copyright © 2006 by the American Association of Endodontists. doi:10.1016/j.joen.2005.12.003 Basic Research—Technology 656 Sousa et al. JOE — Volume 32, Number 7, July 2006