title: A 3-year prospective clinical study of telescopic crown, bar, and locator attachments for removable four implant-supported maxillary overdentures.
abstract: OBJECTIVE
  To evaluate telescopic crown (TC), bar, and locator attachments used in removable four implant-supported overdentures for patients with edentulous maxillae.
  
  
  METHODS
  A total of 30 maxillary edentulous patients were enrolled in a 3-year prospective study. Ten patients (group A) were treated with overdentures supported by TCs, 10 patients (group B) with overdentures supported by bar attachments, and 10 patients (group C) with overdentures supported by locator attachments. A total of 120 implants were used to restore oral function. During the 3-year follow-up period, implant survival and success rates, biologic and mechanical complications, prosthodontic maintenance efforts, and patient satisfaction were evaluated.
  
  
  RESULTS
  All 30 patients were available for the 3-year follow-up and exhibited 100% implant survival and success rates. Peri-implant marginal bone resorption was not statistically significant for the three groups. There were lower plaque, bleeding, gingiva, and calculus indices in group C compared with groups A and B. The number of prosthodontic maintenance visits revealed eight complications in the TC group, seven complications in the bar group, and four complications in the locator group. However, there were no differences in the clinical effects of the overdentures in the three groups.
  
  
  CONCLUSIONS
  Within the limits of this prospective study, it was concluded that the locator system produced superior clinical results compared with the TC and bar attachments in terms of peri-implant hygiene parameters, the frequency of prosthodontic maintenance measures, cost, and ease of denture preparation. However, longer-term prospective studies are required to confirm these results.
authors.forename: Duohong
authors.initials: D
authors.lastname: Zou
authors.forename: Yiqun
authors.initials: Y
authors.lastname: Wu
authors.forename: Wei
authors.initials: W
authors.lastname: Huang
authors.forename: Feng
authors.initials: F
authors.lastname: Wang
authors.forename: Shen
authors.initials: S
authors.lastname: Wang
authors.forename: Zhiyong
authors.initials: Z
authors.lastname: Zhang
authors.forename: Zhiyuan
authors.initials: Z
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000145:classification; D003442:Crowns; D003728:Dental Calculus / Q000145:classification; D059605:Dental Implant-Abutment Design; D003773:Dental Plaque / Q000145:classification; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003819:Denture Bases; D003779:Denture Design; D003781:Denture Retention / Q000295:instrumentation*; D003827:Denture, Complete, Upper; D003828:Denture, Overlay; D005260:Female; D005500:Follow-Up Studies; D005884:Gingival Hemorrhage / Q000145:classification; D006047:Gold Alloys / Q000737:chemistry; D006801:Humans; D007575:Jaw, Edentulous / Q000534:rehabilitation; D008297:Male; D008875:Middle Aged; D017060:Patient Satisfaction; D010512:Periodontal Index; D011446:Prospective Studies; D016019:Survival Analysis; D016896:Treatment Outcome
chemical_list: D006047:Gold Alloys