dental materials 24 ( 2 0 0 8 ) 1343–1351 available at www.sciencedirect.com journal homepage: www.intl.elsevierhealth.com/journals/dema An in vitro biological and anti-bacterial study on a sol–gel derived silver-incorporated bioglass system A. Balamurugan a , G. Balossier b , D. Laurent-Maquin c , S. Pina a , A.H.S. Rebelo a , J. Faure b , J.M.F. Ferreira a,* a Department of Ceramics and Glass Engineering, University of Aveiro, CICECO, 3810-193 Aveiro, Portugal b INSERM ERM 0203, Laboratoire de Microscopie Electronique Analytique, Universit´ e de Reims, 21 Rue Cl´ ement Ader, 51685 Reims Cedex 2, France c INSERM ERM 0203, 1 Rue Mar´ echal Juin, Universit´ e de Reims, 51096 Reims Cedex 2, France article info Article history: Received 11 May 2007 Accepted 11 February 2008 Keywords: Sol–gel Bacteriostatic Silver Biomaterial abstract Objectives. The purpose of this study was to evaluate the in vitro antibacterial and biological activity of silver-incorporated bioactive glass system SiO 2 –CaO–P 2 O 5 –Ag 2 O (AgBG). The bac- teriostatic and bactericidal properties of this new quaternary glass system along with the ternary sol–gel glass system SiO 2 –CaO–P 2 O 5 (BG) have been studied using Escherichia coli as a test micro-organism. The AGBG system thus appears to be a promising material for dental applications, since similar effects might be produced on a film of bacteria and mucous that grows on the teeth. Methods. The SiO 2 –CaO–P 2 O 5 –Ag 2 O and SiO 2 –CaO–P 2 O 5 glass systems were synthesized by the sol–gel technique and characterized for their physicho-chemical properties. The antibacterial activity and biological properties were evaluated by determining the minimum inhibitory concentrations (MICs). Release of Ag + into the culture medium was measured by inductively coupled plasma (ICP) analysis. Results. The in vitro antibacterial action of the SiO 2 –CaO–P 2 O 5 –Ag 2 O was compared with that of its ternary counterpart glass system. The concentrations of Ag-bioglass, in the range of 0.02–0.20 mg of Ag-bioglass per millilitre of culture medium, were found to inhibit the growth of these bacteria. The Ag-bioglass not only acts bacteriostatically but it also elicited a rapid bactericidal action. A complete bactericidal effect was elicited in the early stages of the incubation at Ag-bioglass concentration of 20 mg/ml and the ternary glass system had no effect on bacterial growth or viability. The antibacterial action of Ag-bioglass was exclusively attributed to the leaching of Ag + ions from the glass matrix. Significance. One of the major advantages of incorporating silver ions into a gel glass system is that the porous glass matrix can allow for controlled sustained delivery of the antibac- terial agent to dental material, used even under anaerobic conditions such as deep in the periodontal pocket. This glass system also provides long-term action required for systems which are constantly at risk of microbial contamination. © 2008 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved. ∗ Corresponding author. Tel.: +351 234 370242; fax: +351 234 370204. E-mail address: jmf@cv.ua.pt (J.M.F. Ferreira). 0109-5641/$ – see front matter © 2008 Academy of Dental Materials. Published by Elsevier Ltd. All rights reserved. doi:10.1016/j.dental.2008.02.015