title: Antimicrobial activity of conventional and plant-extract disinfectant solutions on microbial biofilms on a maxillofacial polymer surface.
abstract: BACKGROUND
  Dentists often note problems with infection in patients with maxillofacial prostheses. Conventional disinfection protocols are not always effective and may alter the properties of the polymer used in the prosthesis. Thus, the search for improved disinfection methods is important.
  
  
  OBJECTIVE
  The purpose of this in vitro study was to evaluate and compare the antimicrobial activity of conventional disinfectant solutions (water and neutral soap and 4% chlorhexidine) and plant extracts (Cymbopogon nardus and Hydrastis canadensis) on specimens of maxillofacial silicone contaminated with Candida albicans and Staphylococcus aureus biofilms.
  
  
  METHODS
  Seventy-two silicone (MDX4-4210) specimens were fabricated (5×2 mm) and sterilized. Thirty-six were contaminated with C albicans (10(6) cells/mL) and 36 with S aureus (10(8) cells/mL) to evaluate the antimicrobial activity of the cleaning protocols. After incubation (37°C/72 hours), the specimens were divided into 5 groups: not disinfected (positive control), soaking in saline solution for 10 minutes, soaking in 4% chlorhexidine for 10 minutes, soaking in C nardus for 10 minutes, soaking in H canadensis for 10 minutes, and washing by hand with water and neutral soap for 30 seconds. The viability of cells was evaluated by XTT (2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) assay and by scanning electron microscope analysis. The results were analyzed by ANOVA and the Tukey HSD test (α=.05).
  
  
  RESULTS
  All disinfection solutions provided a statistically significant reduction in biofilm viability compared with the control group for both microorganisms (P<.05). Washing with water and neutral soap was significantly more effective in reducing biofilm viability than immersion in the disinfection solutions, with persistence of viable microorganisms between 1.05% for C albicans and 0.62% for S aureus after this cleaning protocol. Photomicrographs revealed that 4% chlorhexidine altered the surface of the polymer.
  
  
  CONCLUSIONS
  Within the limitations of this in vitro study, it was concluded that the cleaning protocols with different disinfectant solutions produced a significant reduction in the viability of C albicans and S aureus biofilms on the silicone polymer. Washing with water and neutral soap was the most effective protocol against both microorganisms.
authors.affiliation: Assistant Professor, Department of Dental Materials and Prosthodontics, Araçatuba Dental School, São Paulo State University (UNESP), São Paulo, Brazil. Electronic address: aimee@foa.unesp.br.
authors.forename: Aimée Maria
authors.initials: AM
authors.lastname: Guiotti
authors.affiliation: Graduate student, Department of Dental Materials and Prosthodontics, Araçatuba Dental School, São Paulo State University (UNESP), São Paulo, Brazil.
authors.forename: Bruno Guandalini
authors.initials: BG
authors.lastname: Cunha
authors.affiliation: Graduate student, Department of Dental Materials and Prosthodontics, Araçatuba Dental School, São Paulo State University (UNESP), São Paulo, Brazil.
authors.forename: Marcela Borghi
authors.initials: MB
authors.lastname: Paulini
authors.affiliation: Titular Professor, Department of Dental Materials and Prosthodontics, Araçatuba Dental School, São Paulo State University (UNESP), São Paulo, Brazil.
authors.forename: Marcelo Coelho
authors.initials: MC
authors.lastname: Goiato
authors.affiliation: Assistant Professor, Department of Dental Materials and Prosthodontics, Araçatuba Dental School, São Paulo State University (UNESP), São Paulo, Brazil.
authors.forename: Daniela Micheline
authors.initials: DM
authors.lastname: Dos Santos
authors.affiliation: Assistant Professor, Department of Pediatric and Public Health, Araçatuba Dental School, São Paulo State University (UNESP), Araçatuba, São Paulo, Brazil.
authors.forename: Cristiane
authors.initials: C
authors.lastname: Duque
authors.affiliation: Doctoral student, Department of Pediatric and Public Health, Araçatuba Dental School, São Paulo State University (UNESP), São Paulo, Brazil.
authors.forename: Karina Sampaio
authors.initials: KS
authors.lastname: Caiaffa
authors.affiliation: Assistant Professor, Department of Surgery and Integrated Clinic, Araçatuba Dental School, São Paulo State University (UNESP), São Paulo, Brazil.
authors.forename: Daniela Atili
authors.initials: DA
authors.lastname: Brandini
authors.affiliation: Doctoral student, Department of Dermatologic, Infectious and Parasitic Diseases, Medical School of São José do Rio Preto (FAMERP), São Paulo, Brazil.
authors.forename: Derly Tescaro
authors.initials: DT
authors.lastname: Narciso de Oliveira
authors.affiliation: Biologist, Department of Dermatologic, Infectious and Parasitic Diseases, Medical School of São José do Rio Preto (FAMERP), São Paulo, Brazil.
authors.forename: Natália Seron
authors.initials: NS
authors.lastname: Brizzotti
authors.affiliation: Professor, Department of Dermatologic, Infectious and Parasitic Diseases, Medical School of São José do Rio Preto (FAMERP), São Paulo, Brazil.
authors.forename: Margarete Teresa
authors.initials: MT
authors.lastname: Gottardo de Almeida
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology*; D018441:Biofilms / Q000187:drug effects*; D002176:Candida albicans / Q000187:drug effects; D031743:Cymbopogon / Q000737:chemistry; D019551:Dental Disinfectants / Q000494:pharmacology*; D005147:Facial Bones; D006801:Humans; D039321:Hydrastis / Q000737:chemistry; D008437:Maxilla; D010936:Plant Extracts / Q000494:pharmacology*; D019736:Prostheses and Implants / Q000382:microbiology*; D012828:Silicones; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D000890:Anti-Infective Agents; D019551:Dental Disinfectants; D010936:Plant Extracts; D012828:Silicones