title: Antimicrobial properties and cytotoxicity of an antimicrobial monomer for application in prosthodontics.
abstract: OBJECTIVE
  This study aimed to investigate the antimicrobial properties and cytotoxicity of the monomer methacryloyloxyundecylpyridinium bromide (MUPB), an antiseptic agent capable of copolymerizing with denture base acrylic resins.
  
  
  METHODS
  The antimicrobial activity of MUPB was tested against the species Candida albicans, Candida dubliniensis, Candida glabrata, Lactobacillus casei, Staphylococcus aureus, and Streptococcus mutans. The minimum inhibitory and fungicidal/bactericidal concentrations (MIC, MFC/MBC) of MUPB were determined by serial dilutions in comparison with cetylpyridinium chloride (CPC). The cytotoxic effects of MUPB at concentrations ranging from 0.01 to 1 g/L were assessed by MTT test on L929 cells and compared with methyl methacrylate (MMA). The antimicrobial activity of copolymerized MUPB was tested by means of acrylic resin specimens containing three concentrations of the monomer (0, 0.3, 0.6% w/w). Activity was quantified by means of a disc diffusion test and a quantification of adhered planktonic cells. Statistical analysis employed the Mann-Whitney test for MIC and MFC/MBC, and ANOVA for the microbial adherence test (α = 0.05).
  
  
  RESULTS
  MUBP presented lower MIC values when compared with CPC, although differences were significant for C. dubliniensis and S. mutans only (p= 0.046 and 0.043, respectively). MFC/MBC values were similar for all species except C. albicans; in that case, MUPB presented significantly higher values (p = 0.046). MUPB presented higher cytotoxicity than MMA for all tested concentrations (p < 0.001) except at 0.01 g/L. Irrespective of the concentration incorporated and species, there was no inhibition halo around the specimens. The incorporation of MUPB influenced the adhesion of C. albicans only (p = 0.003), with lower CFU counts for the 0.6% group.
  
  
  CONCLUSIONS
  It was concluded that non-polymerized MUPB has an antimicrobial capacity close to that of CPC and high cytotoxicity when compared with MMA. The antimicrobial activity of MUPB after incorporation within a denture base acrylic resin did not depend on its elution, but was shown to be restricted to C. albicans.
authors.affiliation: Department of Dental Materials and Prosthodontics, Ribeirão Preto Dental School, University of São Paulo, Ribeirão Preto, Brazil. romuloregis@hotmail.com
authors.forename: Rômulo Rocha
authors.initials: RR
authors.lastname: Regis
authors.forename: Maria Paula
authors.initials: MP
authors.lastname: Della Vecchia
authors.forename: Antônio Carlos
authors.initials: AC
authors.lastname: Pizzolitto
authors.forename: Marco Antonio
authors.initials: MA
authors.lastname: Compagnoni
authors.forename: Pedro Paulo Chaves
authors.initials: PP
authors.lastname: Souza
authors.forename: Raphael Freitas
authors.initials: RF
authors.lastname: de Souza
mesh_terms: D000180:Acrylic Resins / Q000737:chemistry; D000818:Animals; D000890:Anti-Infective Agents / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D000891:Anti-Infective Agents, Local / Q000737:chemistry / Q000494:pharmacology / Q000633:toxicity; D001422:Bacterial Adhesion / Q000187:drug effects; D058491:Bacterial Load / Q000187:drug effects; D002175:Candida / Q000187:drug effects; D002176:Candida albicans / Q000187:drug effects; D041221:Candida glabrata / Q000187:drug effects; D002594:Cetylpyridinium / Q000494:pharmacology; D015169:Colony Count, Microbial; D004396:Coloring Agents; D003819:Denture Bases; D005347:Fibroblasts / Q000187:drug effects; D007739:L Cells; D007780:Lacticaseibacillus casei / Q000187:drug effects; D008422:Materials Testing; D008689:Methacrylates / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D020366:Methylmethacrylate / Q000633:toxicity; D051379:Mice; D008826:Microbial Sensitivity Tests; D058105:Polymerization; D011726:Pyridinium Compounds / Q000737:chemistry / Q000494:pharmacology* / Q000633:toxicity; D000644:Quaternary Ammonium Compounds / Q000737:chemistry / Q000494:pharmacology / Q000633:toxicity; D013211:Staphylococcus aureus / Q000187:drug effects; D013295:Streptococcus mutans / Q000187:drug effects; D013778:Tetrazolium Salts; D013844:Thiazoles
chemical_list: D000180:Acrylic Resins; D000890:Anti-Infective Agents; D000891:Anti-Infective Agents, Local; D004396:Coloring Agents; D008689:Methacrylates; D011726:Pyridinium Compounds; D000644:Quaternary Ammonium Compounds; D013778:Tetrazolium Salts; D013844:Thiazoles; D020366:Methylmethacrylate; C040291:Lucitone; D002594:Cetylpyridinium; C022616:thiazolyl blue