title: A comparison of implant-supported, bar- or ball-retained mandibular overdentures: a retrospective clinical, microbiologic, and immunologic study of 10 edentulous patients attending a recall visit.
abstract: OBJECTIVE
  Clinical, microbiologic, and immunologic comparisons of the peri-implant health in edentulous volunteers wearing long-standing implant-supported ball- or Dolder bar-retained mandibular overdentures were performed.
  
  
  METHODS
  Ten age- and gender-matched individuals (mean age, 71 years) with either ball- or bar-retained complete mandibular overdentures, scheduled for an annual implant recall examination, were investigated an average of 7 years after implant placement. Plaque and gingival crevicular fluid samples were obtained from the peri-implant sulcus. The groups were compared with regard to peri-implant probing depth; plaque and bleeding on probing scores; sulcular fluid flow rates; implant stability measurements (Periotest device); relative concentrations of Actinobacillus actinomycetemcomitans, Prevotella intermedia, Fusobacterium nucleatum, Porphyromonas gingivalis, Tannerella forsythensis, and Treponema denticola assessed by polymerase chain reaction analysis; and sulcular concentrations of interleukin-1beta and prostaglandin E2, assessed by enzyme-linked immunosorbent assay.
  
  
  RESULTS
  No statistically significant differences were found for any of the examined parameters between both study groups.
  
  
  CONCLUSIONS
  Within the limitations of this study, both ball attachments and Dolder bars can be recommended for overdenture retention, with either one showing satisfying clinical, microbiologic, and immunologic findings in the peri-implant tissues after several years of service in healthy recall patients with good oral hygiene habits.
authors.affiliation: Department of Prosthodontics and Dental Material Science, Eberhard-Karls-University, Tuebingen, Germany. stefan.lachmann@med.uni-tuebingen.de
authors.forename: Stefan
authors.initials: S
authors.lastname: Lachmann
authors.forename: Evi
authors.initials: E
authors.lastname: Kimmerle-Müller
authors.forename: Kristina
authors.initials: K
authors.lastname: Gehring
authors.forename: Detlef
authors.initials: D
authors.lastname: Axmann
authors.forename: German
authors.initials: G
authors.lastname: Gomez-Roman
authors.forename: Georg
authors.initials: G
authors.lastname: Watzek
authors.forename: Heiner
authors.initials: H
authors.lastname: Weber
mesh_terms: D000368:Aged; D015921:Dental Implants / Q000382:microbiology*; D003773:Dental Plaque / Q000382:microbiology; D017268:Dental Prosthesis Retention / Q000295:instrumentation* / Q000379:methods; D019094:Dental Prosthesis, Implant-Supported / Q000382:microbiology*; D003828:Denture, Overlay / Q000382:microbiology*; D015232:Dinoprostone / Q000032:analysis; D005260:Female; D005883:Gingival Crevicular Fluid / Q000276:immunology / Q000382:microbiology; D006801:Humans; D053583:Interleukin-1beta / Q000032:analysis; D008297:Male; D010446:Peptide Fragments / Q000032:analysis; D012189:Retrospective Studies
chemical_list: D015921:Dental Implants; D053583:Interleukin-1beta; D010446:Peptide Fragments; C052994:interleukin-1beta (163-171); D015232:Dinoprostone