Original article Antimicrobial activity and surface properties of an acrylic resin containing a biocide polymer Marco A. Compagnoni 1 , Ana C. Pero 1 , Stella M. M. Ramos 2 , Juli ^ e Marra 3 , Andr  e G. Paleari 1 and Larissa S. Rodriguez 1 1 Department of Dental Materials and Prosthodontics, Araraquara Dental School, Univ Estadual Paulista - UNESP, Araraquara, S~ ao Paulo, Brazil; 2 Laboratoire PMCN – CNRS UMR 5586, Universit e Lyon 1, Universit e de Lyon F-69622, Lyon, France; 3 Department of Prosthodontics, Paulista University, UNIP, Goi^ ania, Goi as, Brazil Gerodontology 2012; doi: 10.1111/ger.12031 Antimicrobial activity and surface properties of an acrylic resin containing a biocide polymer Objective: To evaluate the antimicrobial activity and surface properties of an acrylic resin containing the biocide polymer poly (2-tert-butylaminoethyl) methacrylate (PTBAEMA). Background: Several approaches have been proposed to prevent oral infections, including the incorpo- ration of antimicrobial agents to acrylic resins. Materials and methods: Specimens of an acrylic resin (Lucitone 550) were divided into two groups: 0% (control) and 10% PTBAEMA. Antimicrobial activity was assessed by adherence assay of one of the microorganisms, Staphylococcus aureus, Streptococcus mutans and Candida albicans. Surface topography was characterised by atomic force microscopy and wettability properties determined by contact angle measurements. Results: Data of viable cells (log (CFU + 1)/ml) for S. aureus (control: 7.9 Æ 0.8; 10%: 3.8 Æ 3.3) and S. mutans (control: 7.5 Æ 0.7; 10%: 5.1 Æ 2.7) showed a significant decrease with 10% of PTBAEMA (Mann–Whitney,p < 0.05). For C. albicans (control: 6.6 Æ 0.2; 10%: 6.6 Æ 0.4), there was no significant difference between control and 10% of PTBAEMA (Kruskal–Wallis, p > 0.05). Incorporating 10% PTBA- EMA increased surface roughness and decreased contact angles. Conclusion: Incorporating 10% PTBAEMA into acrylic resins increases wettability and roughness of acrylic resin surface; and decreases the adhesion of S. mutans and S. aureus on acrylic surface, but did not exhibit antimicrobial effect against C. albicans. Keywords: acrylic resins, antimicrobial, roughness, wetting Accepted 7 November 2012 Introduction According to a recent review 1 , despite the lower- ing effect of declining rates of edentulism, in a global perspective large numbers of edentulous individuals are in need of rehabilitation, particu- larly among the elderly. It has been also reported that population ageing is a fact in both developed and developing countries, and the need for complete denture service will remain substantial for a long time, particularly among elderly people 1 . Given these perspectives, there is an increasing interest in the maintenance of the denture wear- er’s oral health. The material commonly used for denture fabrication is poly (methyl methacrylate) (PMMA) acrylic resin. Although this material exhibits adequate physical, mechanical, aesthetic properties 2 , PMMA acrylic resins have been shown to be reservoirs for microorganisms and are a potential source of biofilm formation 2 . Considering that many denture wearers are elderly people with limited skills and special needs, several attempts to incorporate antifungal agents or antiseptics into tissue conditioners and denture acrylic resins have been reported to avoid the biofilm formation on denture surfaces 3–6 . The microbial growth on the denture surface may be related to the adherence of microbial cells promoted by surface roughness and from hydro- phobic interactions between Candida species and oral bacteria, mostly Candida albicans and oral © 2012 The Gerodontology Society and John Wiley & Sons A/S 1