title: Long-term effect of overdenture bar design on peri-implant tissues.
abstract: OBJECTIVE
  To evaluate factors promoting mucositis and peri-implantitis (plaque accumulation, poor peri-implant soft tissue health, bone loss) with regard to prosthetic attachment systems consisting of implant-supported bar-retained overdentures.
  
  
  METHODS
  Patients who received TiOblast implants to support overdentures retained by either (1) prefabricated bars with or without extensions or (2) cast bars were recalled and examined clinically and radiographically. Plaque Index (PI), Sulcus Bleeding Index (SBI), probing pocket depth (PPD), and peri-implant bone loss were measured. Peri-implant tissue health was assessed, and the presence of mucositis and peri-implantitis was recorded. One-way analysis of variance with the Bonferroni adjustment was used to compare groups (α = .05).
  
  
  RESULTS
  Five to 10 years after prosthetic loading, 107 patients who received 516 TiOblast implants were evaluated; 31 of these patients were treated with 131 implants to support bar-retained overdentures. PI, SBI, PPD, and pathologic bone loss were least common in the group with prefabricated bars, followed by the group with prefabricated bars with extensions, and were most common in the group with cast bars. Plaque accumulation and pathologic bone loss values were higher with implants that supported mandibular bar-retained overdentures than with those supporting maxillary bar-retained overdentures. However, these differences among attachment systems or between maxillary and mandibular implants were not significant (P > .05). Mucositis was observed in one implant in the group with prefabricated bars, four implants in the group with prefabricated bars with extensions, and four implants in the group with cast bars. Peri-implantitis was observed in one implant of the cast bar group.
  
  
  CONCLUSIONS
  Five to 10 years after prosthetic loading, no significant difference in PI, SBI, PPD, pathologic bone loss, or peri-implant tissue conditions among the different bar designs tested was observed.
authors.affiliation: Polyclinic of Prosthetic Dentistry, University Medical Center, Mainz, Germany. karl.lehmann@unimedizin-mainz.de
authors.forename: Karl Martin
authors.initials: KM
authors.lastname: Lehmann
authors.forename: Peer W
authors.initials: PW
authors.lastname: Kämmerer
authors.forename: Julia
authors.initials: J
authors.lastname: Karbach
authors.forename: Herbert
authors.initials: H
authors.lastname: Scheller
authors.forename: Bilal
authors.initials: B
authors.lastname: Al-Nawas
authors.forename: Wilfried
authors.initials: W
authors.lastname: Wagner
mesh_terms: D016301:Alveolar Bone Loss / Q000209:etiology*; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported / Q000009:adverse effects*; D003828:Denture, Overlay; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D057873:Peri-Implantitis / Q000209:etiology; D013280:Stomatitis / Q000209:etiology*; D013997:Time Factors