title: Strain of implants depending on occlusion types in mandibular implant-supported fixed prostheses.
abstract: OBJECTIVE
  This study investigated the strain of implants using a chewing simulator with strain gauges in mandibular implant-supported fixed prostheses under various dynamic loads.
  
  
  METHODS
  Three implant-supported 5-unit fixed prostheses were fabricated with three different occlusion types (Group I: Canine protected occlusion, Group II: Unilaterally balanced occlusion, Group III: Bilaterally balanced occlusion). Two strain gauges were attached to each implant abutment. The programmed dynamic loads (0 - 300 N) were applied using a chewing simulator (MTS 858 Mini Bionix II systems, MTS systems corp., Minn, USA) and the strains were monitored. The statistical analyses were performed using the paired t-test and the ANOVA.
  
  
  RESULTS
  The mean strain values (MSV) for the working sides were 151.83 µε, 176.23 µε, and 131.07 µε for Group I, Group II, and Group III, respectively. There was a significant difference between Group II and Group III (P < .05). Also, the MSV for non-working side were 58.29 µε, 72.64 µε, and 98.93 µε for Group I, Group II, and Group III, respectively. One was significantly different from the others with a 95% confidence interval (P < .05).
  
  
  CONCLUSIONS
  The MSV for the working side of Groups I and II were significantly different from that for the non-working side (Group I: t = 7.58, Group II: t = 6.25). The MSV for the working side of Group II showed significantly larger than that of Group III (P < .01). Lastly, the MSV for the non-working side of Group III showed significantly larger than those of Group I or Group II (P < .01).
authors.affiliation: Department of Prosthodontics and Dental Research Institute, Seoul National University Dental Hospital, School of Dentistry, Seoul National University, Seoul, Korea.
authors.forename: Byoung-Sup
authors.initials: BS
authors.lastname: Sohn
authors.forename: Seong-Joo
authors.initials: SJ
authors.lastname: Heo
authors.forename: Jai-Young
authors.initials: JY
authors.lastname: Koak
authors.forename: Seong-Kyun
authors.initials: SK
authors.lastname: Kim
authors.forename: Su-Young
authors.initials: SY
authors.lastname: Lee