title: Mandibular overdentures supported by two Brånemark, IMZ or ITI implants: a 5-year prospective study.
abstract: OBJECTIVE
  The aim of this prospective comparative study was to evaluate the survival rate and the condition of the peri-implant tissues of the IMZ implant system (two-stage cylindertype), the Brånemark implant system (two-stage screwtype) and the ITI implant system (one-stage screwtype) supporting a mandibular overdenture during a 5-year follow-up period.
  
  
  METHODS
  Three groups of 30 edentulous patients were treated with two endosseous implants in the interforaminal region of the mandible. Clinical and radiographic parameters were evaluated immediately after completion of the prosthetic treatment and after 1, 2, 3, 4 and 5 years of functional loading.
  
  
  RESULTS
  The five-year survival rate is 98.3% for the IMZ group, 98.3% for the Brå group and 100% for the ITI group. Mean scores on indices for plaque, calculus, gingiva and bleeding were very low at all evaluation periods. Mean marginal bone loss over a period of 5 years, was 1.4 mm for the IMZ group, 0.7 mm for the Brå group and 0.9 mm for the ITI group.
  
  
  CONCLUSIONS
  It is concluded that two implants placed in the interforaminal region, connected with a bar, supply a proper base for the support of a mandibular overdenture in the edentulous patient. After 5 years no clinically relevant and statistically significant radiographic changes had developed between the three implant systems.
authors.affiliation: Department of Oral and Maxillofacial Surgery and Maxillofacial Prosthodontics, Groningen University Hospital, Groningen, The Netherlands. h.j.a.meijer@kchir.azg.nl
authors.forename: Henny J A
authors.initials: HJ
authors.lastname: Meijer
authors.forename: Rutger H K
authors.initials: RH
authors.lastname: Batenburg
authors.forename: Gerry M
authors.initials: GM
authors.lastname: Raghoebar
authors.forename: Arjan
authors.initials: A
authors.lastname: Vissink
mesh_terms: D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000209:etiology; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants / Q000009:adverse effects; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention / Q000295:instrumentation; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D003826:Denture, Complete, Lower; D003828:Denture, Overlay; D005260:Female; D006801:Humans; D007575:Jaw, Edentulous / Q000000981:diagnostic imaging / Q000534:rehabilitation; D008297:Male; D008334:Mandible / Q000601:surgery; D008875:Middle Aged; D011446:Prospective Studies; D011859:Radiography
chemical_list: D015921:Dental Implants