title: Clinical and radiographic comparison of implants in regenerated or native bone: 5-year results.
abstract: OBJECTIVE
  The aim of this study was to test whether or not implants associated with bone regeneration show the same survival and success rates as implants placed in native bone in patients requiring both forms of therapy.
  
  
  METHODS
  Thirty-four patients (median age of 60.3 years, range 18-77.7 years) had been treated 5 years before the follow-up examination. Machined screw-type implants were inserted following one of two surgical procedures: (1) simultaneously with a guided bone regeneration (GBR) procedure, which involved grafting with xenogenic bone substitute material, autogenous bone or a mixture of the two and defect covering with a bio-absorbable collagen membrane (test) and (2) standard implantation procedure without bone regeneration (control). For data recording, one test and one control implant from each patient were assessed. Examination included measurements of plaque control record (PCR), probing pocket depth (PPD), bleeding on probing (BOP), width of keratinized mucosa (KM), frequency of situations with supra-mucosal location of the crown margin, implant survival assessment and radiographic examination. Radiographs were digitized to assess the marginal bone level (MBL). Differences between groups were tested using the one-sample t-test. The estimation of survival rate was based on Kaplan-Meier analysis.
  
  
  RESULTS
  The follow-up period of the 34 GBR and 34 control implants ranged from 49 to 70 months (median time 57 months). Cumulative survival rates reached 100% for the GBR group and 94.1% for the control group without statistical significance. No statistically significant differences for clinical and radiographic parameters were found between the two groups regarding PCR, BOP, PPD, KM and MBL.
  
  
  CONCLUSIONS
  The present study showed that, clinically, implants placed with concomitant bone regeneration did not performed differently from implants placed into native bone with respect to implant survival, marginal bone height and peri-implant soft tissue parameters.
authors.affiliation: Clinic for Fixed and Removable Prosthodontics and Dental Material Science, Center for Dental and Oral Medicine and Cranio-Maxillofacial Surgery, University of Zurich, Zurich 8032, Switzerland.
authors.forename: Goran I
authors.initials: GI
authors.lastname: Benić
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Jung
authors.forename: David W
authors.initials: DW
authors.lastname: Siegenthaler
authors.forename: Christoph H F
authors.initials: CH
authors.lastname: Hämmerle
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000534:rehabilitation*; D000818:Animals; D001857:Bone Matrix / Q000637:transplantation; D001861:Bone Regeneration / Q000502:physiology*; D018786:Bone Substitutes / Q000627:therapeutic use; D002417:Cattle; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants / Q000706:statistics & numerical data*; D005500:Follow-Up Studies; D016557:Guided Tissue Regeneration, Periodontal / Q000379:methods; D006801:Humans; D007575:Jaw, Edentulous / Q000000981:diagnostic imaging / Q000534:rehabilitation*; D008334:Mandible / Q000000981:diagnostic imaging / Q000502:physiology / Q000601:surgery; D008437:Maxilla / Q000000981:diagnostic imaging / Q000502:physiology / Q000601:surgery; D008875:Middle Aged; D008903:Minerals / Q000627:therapeutic use; D016348:Osseointegration / Q000502:physiology*; D011859:Radiography; D016019:Survival Analysis; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: C077540:Bio-Oss; D018786:Bone Substitutes; D015921:Dental Implants; D008903:Minerals