title: Mandibular two-implant overdentures: prosthodontic maintenance using different loading protocols and attachment systems.
abstract: OBJECTIVE
  The aim of this research was to determine the long-term prosthodontic maintenance requirements of mandibular two-implant overdentures using different loading protocols and attachment systems.
  
  
  METHODS
  A total of 106 participants were allocated randomly to one of four different implant systems (Steri-Oss, Southern, Straumann, or Branemark). Three different loading protocols (2, 6, and 12 weeks) were used with six different ball abutment patrices and their respective matrices (Steri-Oss rubber, Straumann gold, Straumann titanium, Branemark gold, Southern plastic, and Southern gold/platinum). Prosthodontic maintenance events were documented prospectively from baseline until the 8-year recall according to predefined categories.
  
  
  RESULTS
  After 6 years, 90 participants attended recall and, thereafter, 68 participants were followed for 8 years. No significant differences were found between the number of prosthodontic maintenance events and the loading protocol used. Steri-Oss rubber matrices had the highest mean number of maintenance events at 32.2 ± 14.5 events, followed by the Branemark gold matrices at 28.8 ± 12.6 events. The Southern plastic matrices had a significantly lower mean number of maintenance events (8.7 ± 4.2) when compared with all other groups. Over a 6-year period, the matrices with the best longevity were Straumann gold at 3.9 ± 2.1 years. Straumann gold matrices also lasted significantly longer than all other matrices (P < .05). Southern gold/platinum, Branemark gold, and Southern plastic matrices all lasted significantly longer than the Straumann titanium and Steri-Oss matrices (P < .05). The mean time to reline for overdentures was 3.37 ± 2.06 years; remaking of overdentures peaked by year 7, with a mean time to remake of 5.81 ± 2.04 years.
  
  
  CONCLUSIONS
  Early loading protocols do not influence long-term prosthodontic maintenance requirements of unsplinted mandibular two-implant overdentures. By contrast, attachment systems do influence prosthodontic maintenance, particularly with regard to the type of matrices used.
authors: Andrew
authors: A
authors: Mackie
authors: Karl
authors: K
authors: Lyons
authors: W Murrary
authors: WM
authors: Thomson
authors: Alan G T
authors: AG
authors: Payne
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D003834:Denture Precision Attachment; D003823:Denture Rebasing; D003780:Denture Repair; D003827:Denture, Complete, Upper; D003828:Denture, Overlay; D005500:Follow-Up Studies; D006801:Humans; D057893:Immediate Dental Implant Loading; D008875:Middle Aged; D011446:Prospective Studies
chemical_list: D015921:Dental Implants