title: Structural and quantitative analysis of a mature anaerobic biofilm on different implant abutment surfaces.
abstract: BACKGROUND
  The longevity of dental implants depends on the absence of inflammation in the periimplant tissue. Similar to teeth, pathogenic bacteria can adhere on implant abutment surfaces and cause periimplant disease and consequently implant loss.
  
  
  OBJECTIVE
  The purpose of this in vitro study was to evaluate the influence of physical and chemical properties of 2 common materials used as implant abutments, titanium (Ti) and zirconia (ZrO2), and the use of bovine enamel (BE) as a positive control on biofilm formation.
  
  
  METHODS
  Biofilm formation was analyzed by growing Porphyromonas gingivalis and Fusobacterium nucleatum as monospecies and mixed species biofilms on the surfaces. The mean roughness (Ra) and surface free energy were evaluated for each material. Mature biofilm, formed after 7 days of incubation, was analyzed quantitatively and qualitatively by colony-forming unit and confocal laser scanning microscopy.
  
  
  RESULTS
  The mean roughness in all disks was ≤0.21 μm and did not affect the bacterial adhesion. Titanium showed a greater degree of hydrophilicity compared with BE after 90 minutes of immersion in saliva. The surface free energy did not show differences, with the highest values for BE. Monospecies biofilms formed by P. gingivalis on Ti, and mixed species biofilm on ZrO2 exhibited small numbers of cells on disk surfaces. By confocal imaging, the mixed species biofilm appeared as a thin layer on ZrO2 surfaces.
  
  
  CONCLUSIONS
  Material surfaces could have a significant impact on biofilm formation. ZrO2 implant abutment surfaces showed a decrease in anaerobic biofilm compared with Ti and BE.
authors.affiliation: Postdoctoral Fellow, Department of Dental Materials and Prosthodontics, School of Dentistry at Araraquara, São Paulo State University (UNESP), Araraquara, Brazil. Electronic address: erica.fobusp@yahoo.com.br.
authors.forename: Erica Dorigatti
authors.initials: ED
authors.lastname: de Avila
authors.affiliation: Professor, Department of Microbiology, Institute of Biomedical Science, University of São Paulo, São Paulo, Brazil.
authors.forename: Mario Julio
authors.initials: MJ
authors.lastname: Avila-Campos
authors.affiliation: Professor, Department of Dental Materials and Prosthodontics, School of Dentistry at Araraquara, São Paulo State University (UNESP), Araraquara, Brazil.
authors.forename: Carlos Eduardo
authors.initials: CE
authors.lastname: Vergani
authors.affiliation: Adjunct Professor, Department of Physiology and Pathology, School of Dentistry at Araraquara, São Paulo State University (UNESP), Araraquara, Brazil.
authors.forename: Denise Madalena Palomari
authors.initials: DM
authors.lastname: Spolidório
authors.affiliation: Adjunct Professor, Department of Dental Materials and Prosthodontics, School of Dentistry at Araraquara, São Paulo State University (UNESP), Araraquara, Brazil.
authors.forename: Francisco de Assis
authors.initials: Fde A
authors.lastname: Mollo
mesh_terms: D001422:Bacterial Adhesion; D018441:Biofilms; D059605:Dental Implant-Abutment Design; D015921:Dental Implants / Q000382:microbiology*; D003764:Dental Materials / Q000737:chemistry*; D006801:Humans; D013499:Surface Properties; D014025:Titanium
chemical_list: D015921:Dental Implants; D003764:Dental Materials; D014025:Titanium