title: Clinical evaluation of marginal bone loss and stability in two types of submerged dental implants.
abstract: OBJECTIVE
  The aim of this prospective clinical trial was to compare the three-dimensional marginal bone level, implant stability, and peri-implant health of two types of submerged dental implants that were restored with matching or platform-switched abutments.
  
  
  METHODS
  Twenty-five subjects were recruited (test group: 43 implants with internal conical connection and back-tapered collar carrying a platform-switched abutment; control group: 50 implants carrying a matched-platform abutment). Implant uncovering and conventional loading were performed after 3 months of healing, and the total observation time was 15 months. Marginal bone levels, resonance frequency analysis, insertion torque, and peri-implant health indices were recorded and analyzed statistically.
  
  
  RESULTS
  The cumulative implant survival rate was 100%. At the second-stage surgery, bone levels were similar between groups. One year after loading, mean crestal bone loss was 0.35 ± 0.13 mm for test implants and 0.83 ± 0.16 mm for control implants, a significant difference. Primary stability was significantly higher in the test group than in the control group, but this difference disappeared after 3 months of healing prior to loading. Between-group differences for peri-implant health indices were negligible.
  
  
  CONCLUSIONS
  Both implant systems had the same survival rates. Implants with a built-in platform switch and conical connection with back-tapered collar design achieved higher primary stability at insertion and less bone resorption after 15 months.
authors.affiliation: Department of Oral Implatology, Faculty of Dentistry, Istanbul University, Istanbul, Turkey. alpergultekin@hotmail.com
authors.forename: B Alper
authors.initials: BA
authors.lastname: Gultekin
authors.forename: Pinar
authors.initials: P
authors.lastname: Gultekin
authors.forename: Binnaz
authors.initials: B
authors.lastname: Leblebicioglu
authors.forename: Cansu
authors.initials: C
authors.lastname: Basegmez
authors.forename: Serdar
authors.initials: S
authors.lastname: Yalcin
mesh_terms: D000328:Adult; D016301:Alveolar Bone Loss / Q000209:etiology* / Q000473:pathology; D000044:Dental Abutments; D059605:Dental Implant-Abutment Design / Q000379:methods*; D003758:Dental Implantation, Endosseous / Q000379:methods*; D015921:Dental Implants; D017267:Dental Prosthesis Design; D019232:Dental Restoration Failure / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D019415:Torque; D055815:Young Adult
chemical_list: D015921:Dental Implants