Research Article Cytocompatibility and Antibacterial Properties of Capping Materials Claudio Poggio, 1 Carla Renata Arciola, 2 Riccardo Beltrami, 3 Annachiara Monaco, 4,5 Alberto Dagna, 1 Marco Lombardini, 1 and Livia Visai 4,5 1 Department of Clinical-Surgical, Diagnostic and Pediatric Sciences, University of Pavia, Policlinico “San Matteo”, Piazzale Golgi 3, 27100 Pavia, Italy 2 Research Unit on Implant Infections, Rizzoli Orthopedic Institute, DIMES of the University of Bologna Via di Barbiano 1/10, 40136 Bologna, Italy 3 Department of Brain and Behavioral Sciences, University of Pavia, Via Bassi 21, 27100 Pavia, Italy 4 Department of Molecular Medicine, Center for Tissue Engineering (CIT), INSTM UdR of Pavia, University of Pavia, Viale Taramelli 3/b, 27100 Pavia, Italy 5 Department of Occupational Medicine, Ergonomy and Disability, Laboratory of Nanotechnology, Salvatore Maugeri Foundation, IRCCS, Via S. Boezio 28, 27100 Pavia, Italy Correspondence should be addressed to Claudio Poggio; claudio.poggio@unipv.it Received 24 February 2014; Accepted 24 April 2014; Published 18 May 2014 Academic Editor: Louis M. Lin Copyright © 2014 Claudio Poggio et al. Tis is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Te aim of this study was to evaluate and compare the antimicrobial activity and cytocompatibility of six diferent pulp-capping materials: Dycal (Dentsply), Calcicur (Voco), Calcimol LC (Voco), TeraCal LC (Bisco), MTA Angelus (Angelus), and Biodentine (Septodont). To evaluate antimicrobial activity, materials were challenged in vitro with Streptococcus mutans, Streptococcus salivarius, and Streptococcus sanguis in the agar disc difusion test. Cytocompatibility of the assayed materials towards rat MDPC-23 cells was evaluated at diferent times by both MTT and apoptosis assays. Results signifcantly difered among the diferent materials tested. Both bacterial growth inhibition halos and cytocompatibility performances were signifcantly diferent among materials with diferent composition. MTA-based products showed lower cytotoxicity and valuable antibacterial activity, diferent from calcium hydroxide-based materials, which exhibited not only higher antibacterial activity but also higher cytotoxicity. 1. Introduction Direct pulp-capping is a procedure for covering the exposed surface of the pulp to maintain its vitality and preserve its functional and biologic activities. Te ultimate goal of capping material has been widely recognized as inducing pulp cells to form hard tissue [1]. Several materials such as calcium hydroxide-based materials and, more recently, mineral trioxide aggregate (MTA) are commonly recommended to seal communications between the exposed pulp and the oral cavity [2–6]. Calcium hydroxide-based materials are the most popular agents for direct and indirect pulp-capping, given their ability to release hydroxyl (OH) and calcium (Ca) ions upon dissolution [7–9]. It is assumed that they lead to initial change that causes undiferentiated cells within the pulp to diferentiate into odontoblasts, which then form a hard tissue barrier at the pulp exposure site [10, 11]. Te formation of reparative dentine in response to calcium hydroxide may not be due to the bioinductive capacity of the material, but it is due to the result of a defense mechanism by the pulp induced by the irritant nature of calcium hydroxide [12–15]. Dycal (Dentsply, Milford, DE, USA) is a self-setting (2.5-3.5 min) radiopaque calcium hydroxide-based material employed in direct and indirect pulp-capping procedures. Its alkaline pH (pH 9–11) stimulates the formation of secondary dentine when the material is in direct contact with the pulp. Its toxicity to pulp cells is well documented [16]. Hindawi Publishing Corporation e Scientific World Journal Volume 2014, Article ID 181945, 10 pages http://dx.doi.org/10.1155/2014/181945