title: Nonsubmerged and submerged implants in the treatment of the partially edentulous maxilla.
abstract: BACKGROUND
  Dental implants vary in design and surfaces. In addition, different surgical techniques have been used for implant insertion. The ITI Dental Implant System (Straumann AG, Waldenburg, Switzerland) has always required a one-stage technique, whereas the Brånemark System (Nobel Biocare AB, Gothenburg, Sweden) requires a two-stage technique.
  
  
  OBJECTIVE
  The aim of this study is to compare the outcome of fixed partial bridges in the maxilla supported by both ITI and Brånemark implants in a split-mouth design.
  
  
  METHODS
  Twenty-eight patients with a residual anterior dentition in the maxilla were included in this split-mouth study. The Brånemark implants were used on one side and the ITI implants on the other side of the residual dentition according to a randomization procedure. A blocking size of four was used, giving equal probability of placing ITI or Brånemark implants in the right or left side of the jaw. The surgical and prosthetic procedures followed the guidelines given by the manufacturers. The prosthetic treatment with the two-implant systems was performed at the same time, and for that reason the healing period was 6 months for both systems. The observation period for all patients was 1 year after loading.
  
  
  RESULTS
  Two Brånemark implants (in one patient) were lost before loading, and one ITI implant was lost 1 year after loading. There was no significant difference in survival rate. Radiographic examination of the bone level was performed at the time of delivery of the bridge and after 1 year. The mean marginal bone level at baseline was situated 1.9 mm from the reference point for the Brånemark implants and 1.5 mm for the ITI implants. With regard to the insertion depth used, these bone levels indicate that bone loss had taken place before baseline. However, between baseline and the 1-year examination, there was no significant change of the marginal bone (0.2 +/- 0.08 mm at the Brånemark implants and 0.1 +/- 0.11 mm at the ITI implants). The difference between results with the two implants was not statistically significant. Crater-form bone destructions were seen at some ITI implants, indicating periimplantitis. However, at only two implants were there clinical signs of periimplantitis.
  
  
  CONCLUSIONS
  No significant difference in survival rate or in marginal bone change could be demonstrated between the two systems. At some ITI implants (18%), crater-form bone loss was observed.
authors.affiliation: Department of Oral and Maxillofacial Surgery, University Hospital, Linköping, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Astrand
authors.forename: Bo
authors.initials: B
authors.lastname: Engquist
authors.forename: Bengt
authors.initials: B
authors.lastname: Anzén
authors.forename: Tom
authors.initials: T
authors.lastname: Bergendal
authors.forename: Mats
authors.initials: M
authors.lastname: Hallman
authors.forename: Ulf
authors.initials: U
authors.lastname: Karlsson
authors.forename: Sven
authors.initials: S
authors.lastname: Kvint
authors.forename: Leif
authors.initials: L
authors.lastname: Lysell
authors.forename: Torgil
authors.initials: T
authors.lastname: Rundcrantz
mesh_terms: D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000209:etiology; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants / Q000009:adverse effects; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003830:Denture, Partial, Fixed; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007576:Jaw, Edentulous, Partially / Q000534:rehabilitation* / Q000601:surgery; D008297:Male; D008437:Maxilla / Q000601:surgery; D008875:Middle Aged; D011182:Postoperative Care; D011446:Prospective Studies
chemical_list: D015921:Dental Implants