title: Two-part implants inserted in a one-stage or a two-stage procedure. A prospective comparative study.
abstract: OBJECTIVE
  The aim of this study was to evaluate the feasibility of using a two-part implant system in a one-stage procedure and to monitor the microflora in the peri-implant area in relation to clinical and radiographic outcome.
  
  
  METHODS
  After randomisation, 40 edentulous patients (Cawood & Howell class V-VI) received two IMZ implants in the anterior mandible inserted by either a one-stage (n = 20) or a two-stage (n = 20) surgical procedure for overdenture treatment. A standardised clinical and radiographic evaluation was performed after denture insertion as well as 6 and 12 months thereafter. Twelve months after loading, peri-implant samples were collected and analysed for the presence of putative periodontal pathogens using culture technique.
  
  
  RESULTS
  No striking differences were found between the two groups with regard to the clinical parameters during the evaluation period. The mean bone loss in the first year of functioning was 0.6 mm in both groups. With regard to the gingiva score, plaque score, bleeding score or bone loss between T0 and T12, no associations were found with the presence of the cultured microorganisms. An association was present between pockets >or= 4 mm and the presence of Peptostreptococcus micros in the two-stage group.
  
  
  CONCLUSIONS
  The short-term results indicate that two-part implants inserted in a one-stage procedure may be as predictable as inserted in the common two-stage procedure. The peri-implant sulcus can and does harbour potential periodontal pathogens without significant signs of tissue breakdown.
authors.affiliation: Department of Oral and Maxillofacial Surgery and Maxillofacial Prosthetics, Dental School, Faculty of Medical Sciences, University of Groningen, the Netherlands. k.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: Willy A
authors.initials: WA
authors.lastname: Van Der Reijden
authors.forename: Arie-Jan
authors.initials: AJ
authors.lastname: Van Winkelhoff
authors.forename: Boudewijn
authors.initials: B
authors.lastname: Stegenga
mesh_terms: D015169:Colony Count, Microbial; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D003774:Dental Plaque Index; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003828:Denture, Overlay; D005240:Feasibility Studies; D005260:Female; D005881:Gingiva / Q000382:microbiology*; D006089:Gram-Negative Anaerobic Bacteria / Q000302:isolation & purification; D006801:Humans; D007575:Jaw, Edentulous / Q000000981:diagnostic imaging / Q000534:rehabilitation / Q000601:surgery; D008297:Male; D008334:Mandible; D008875:Middle Aged; D010512:Periodontal Index; D011446:Prospective Studies; D011859:Radiography; D012044:Regression Analysis; D018709:Statistics, Nonparametric
chemical_list: D015921:Dental Implants