title: Internal contamination of a 2-component implant system after occlusal loading and provisionally luted reconstruction with or without a washer device.
abstract: BACKGROUND
  Microbial internal contamination of oral implants has been suggested as being responsible for inflammatory infiltration of peri-implant tissues at the fixture-abutment interface of 2-stage and 2-component implant systems; it is also considered as a potential source of pathogens. The present in vivo study evaluated contamination of the inner abutment-implant retaining screw, after occlusal loading and provisionally-luted reconstruction with or without a washer device.
  
  
  METHODS
  Eight 2-component oral implants sealed with an o-ring silicon washer device and 9 without a seal were placed in 7 patients with high oral hygiene standards. Two months after prosthetic reconstruction, crowns and internal screws were removed, and organic and inorganic screw contamination was examined by scanning electron microscopy and energy dispersive x-ray spectroscopy (EDS) analysis.
  
  
  RESULTS
  An amorphous and crystalline contamination, suggestive of calcium and phosphate compounds, was seen on all screw surfaces. Microbial contamination was more frequently observed in the unsealed group. No differences in bacterial morphotypes were observed between the sealed and unsealed implants. Cocci were the most representative morphotypes, while rods were seldom seen.
  
  
  CONCLUSIONS
  In clinical situations, leakage occurs at the implant-abutment interface, although bacterial contamination is limited in patients with high oral hygiene standards. Contamination may be reduced by using a washer device.
authors.affiliation: Department of Oral Pathology and Medicine, University of Milan, Italy. pib1431@iperbole.bologna.it
authors.forename: L
authors.initials: L
authors.lastname: Rimondini
authors.forename: C
authors.initials: C
authors.lastname: Marin
authors.forename: F
authors.initials: F
authors.lastname: Brunella
authors.forename: M
authors.initials: M
authors.lastname: Fini
mesh_terms: D000704:Analysis of Variance; D017610:Calcium Compounds / Q000032:analysis; D015169:Colony Count, Microbial; D000044:Dental Abutments; D001840:Dental Bonding; D015921:Dental Implants / Q000009:adverse effects* / Q000382:microbiology*; D003763:Dental Leakage / Q000209:etiology*; D003773:Dental Plaque / Q000382:microbiology; D017268:Dental Prosthesis Retention / Q000009:adverse effects* / Q000295:instrumentation*; D019094:Dental Prosthesis, Implant-Supported; D004577:Electron Probe Microanalysis; D004866:Equipment Contamination; D006801:Humans; D008855:Microscopy, Electron, Scanning; D010710:Phosphates / Q000032:analysis; D019415:Torque
chemical_list: D017610:Calcium Compounds; D015921:Dental Implants; D010710:Phosphates