title: Clinical and radiologic evaluation of 2-stage IMZ implants placed in a single-stage procedure: 2-year results of a prospective comparative study.
abstract: OBJECTIVE
  The aim of this study was to evaluate the feasibility of using a 2-stage implant system in a single-stage procedure and to study the impact of the microgap between the implant and the abutment.
  
  
  METHODS
  Sixty edentulous patients (Cawood class V or VI) participated in this study. After randomization, 20 patients received 2 IMZ implants placed in a single-stage procedure, 20 patients received 2 IMZ implants placed in the traditional 2-stage procedure, and 20 patients were treated with 2 ITI implants (single-stage procedure). The implants were placed in the canine area of the mandible. After 3 months, mandibular overdentures were fabricated, supported by a bar-and-clip attachment. A standardized clinical and radiographic evaluation was performed immediately after prosthesis placement and after 12 and 24 months.
  
  
  RESULTS
  One IMZ implant of the 1-stage group and 1 IMZ implant of the 2-stage group were lost after 6 and 12 months, respectively. Apart from several significant but clinically irrelevant differences, the 3 groups did not appear to differ markedly with regard to clinical parameters during the evaluation period. The mean bone loss within the first 2 years of functioning (1.1 mm IMZ 1-stage, 0.8 mm IMZ 2-stage, 1.2 mm ITI) was comparable for the 3 groups.
  
  
  CONCLUSIONS
  The results of this study suggest that dental implants designed for a submerged implantation procedure can also be used in a single-stage procedure and may be as predictable as when the same implants used in a 2-stage procedure or as 1-stage implants. Placement of the microgap at the crestal level in 2-stage implants did not appear to have an adverse effect on the amount of peri-implant bone loss at 2 years in this study population.
authors.affiliation: Department of Oral and Maxillofacial Surgery and Maxillofacial Prosthetics, University Hospital Groningen, The Netherlands. heydenrijk@kchir.azg.nl
authors.forename: Kees
authors.initials: K
authors.lastname: Heydenrijk
authors.forename: Gerry M
authors.initials: GM
authors.lastname: Raghoebar
authors.forename: Henny J A
authors.initials: HJ
authors.lastname: Meijer
authors.forename: Boudewijn
authors.initials: B
authors.lastname: Stegenga
mesh_terms: D016301:Alveolar Bone Loss / Q000145:classification; D000704:Analysis of Variance; D000044:Dental Abutments; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D003774:Dental Plaque Index; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D003828:Denture, Overlay; D005240:Feasibility Studies; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007575:Jaw, Edentulous / Q000601:surgery; D008297:Male; D008334:Mandible / Q000601:surgery; D008875:Middle Aged; D010512:Periodontal Index; D011446:Prospective Studies; D018709:Statistics, Nonparametric; D013499:Surface Properties; D016896:Treatment Outcome
chemical_list: D015921:Dental Implants