title: In vitro evaluation of resonance frequency analysis values to different implant contact ratio and stiffness of surrounding material.
abstract: OBJECTIVE
  The present study was aimed to evaluate the influence of implant contact ratio and stiffness of implant-surrounding materials on the resonance frequency analysis (RFA) values.
  
  
  METHODS
  Seventy resin blocks that had the different amounts (100, 50, 30, 15%) of resin-implant contact (RIC) were fabricated. Ten silicone putty blocks with 100% silicone-implant contact were also made. The implants with Ø5.0 mm × 13.0 mm were placed on eighty specimen blocks. The RFA value was measured on the transducer that was connected to each implant by Osstell Mentor. Kruskal-Wallis and Scheffe's tests (α=.05) were done for statistical analysis.
  
  
  RESULTS
  The control resin group with 100% RIC had the highest RFA value of 83.9, which was significantly different only from the resin group with 15% RIC among the resin groups. The silicone putty group with 100% contact had the lowest RFA value of 36.6 and showed statistically significant differences from the resin groups.
  
  
  CONCLUSIONS
  Within the limitations of this in vitro study, there was no significant difference in the RFA values among the resin groups with different RIC's except when the RIC difference was more than 85%. A significant increase in the RFA value was observed related to the increase in stiffness of material around implant.
authors.affiliation: Department of Prosthodontics, Graduate School of Clinical Dental Science, The Catholic University of Korea, Seoul, Republic of Korea.
authors.forename: Mu-Seung
authors.initials: MS
authors.lastname: Kwak
authors.affiliation: Department of Prosthodontics, Samsung Medical Center, College of Medicine, Sungkyunkwan University, Seoul, Republic of Korea.
authors.forename: Seok-Gyu
authors.initials: SG
authors.lastname: Kim
keywords: Resin-implant contact; Resonance frequency analysis value; Stiffness of surrounding material