title: Impact of implant diameter on bone level changes around platform switched implants: preliminary results of 18 months follow-up a prospective randomized match-paired controlled trial.
abstract: OBJECTIVE
  This prospective randomized match-paired controlled trial aimed to evaluate the impact of implant platform diameter on marginal bone level around implants restored according to the platform switching (PS) concept.
  
  
  METHODS
  A total of 24 implants were examined in 12 patients. All patients received two adjacent implants inserted at the crestal level: 4.3 mm (control group) and 4.8 mm (test group) in diameter. Mesio-distal implant position was randomly performed. According to the PS concept, for restoration, a 3.8 and 4.3 mm diameter abutment was used, respectively in the control and test groups, resulting, in both groups, with 0.25 mm of implant/abutment mismatching. Implant restorations were splinted. Eighteen months after final restoration, periapical standardized digital radiographs were taken to evaluate marginal bone level alterations after loading. The Wilcoxon Signed-Rank Test was selected to identify differences between groups.
  
  
  RESULTS
  At the last follow-up, control implants exhibited a mean bone loss value of 1.10 mm (SD: 0.47 mm); the test group showed a mean value of 1.09 mm (SD: 0.08 mm). No statistically significant differences were found between test and control groups.
  
  
  CONCLUSIONS
  Within the limits of this study, the present results suggest that bone resorption is mostly related to biologic (biologic width re-establishment) rather than to biomechanical factors (implant platform diameter). Furthermore long-term studies with a wider sample size are needed to confirm the platform diameter influence on hard tissue response around implants restored according to the PS concept.
authors: lugicanullo@yahoo.com
authors: Luigi
authors: L
authors: Canullo
authors: Giuliano
authors: G
authors: Iannello
authors: Miguel
authors: M
authors: Peñarocha
authors: Berta
authors: B
authors: Garcia
mesh_terms: D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging / Q000503:physiopathology*; D001862:Bone Resorption; D059605:Dental Implant-Abutment Design; D015921:Dental Implants; D019094:Dental Prosthesis, Implant-Supported; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D010027:Osteotomy; D011446:Prospective Studies; D011859:Radiography; D012307:Risk Factors; D018709:Statistics, Nonparametric
chemical_list: D015921:Dental Implants