title: The impact of cantilevers on biological and technical success outcomes of implant-supported fixed partial dentures. A retrospective cohort study.
abstract: OBJECTIVE
  To investigate the biological and technical success outcomes of implant-supported fixed dental prostheses with and without cantilevers, after a minimum of one year loading.
  
  
  METHODS
  One hundred and seven subjects with 128 cantilever FDPs (cFDP) supported by 132 implants were compared with 99 individuals with 144 non-cantilever FPDs (ncFDPs) supported by 203 implants. Outcomes such as marginal bone loss from FDP insertion to final follow-up as well as frequency and extent of biological and technical complications were investigated and correlated with patient, site, implant and FDP design characteristics.
  
  
  RESULTS
  The cFDPs were followed for average of 51 months (1551 days, SD ± 977), and ncFPDs for 49 months (1483 days, SD ± 809 days). Implant survival and success rates were 96.7% and 87.9% for implant supporting cFDPs, and 99.5% and 92.6% for ncFDPs. There was no significant difference in overall bone loss between cFDPs and ncFDPs (cantilever side: 0.58, SD ± 1.16 - non-cantilever side: 0.59, SD ± 0.99), but implants in the cantilever group lost significantly more bone in the posterior mandible (0.50 SD ± 1.3 mm for cFDPs and 0.24 SD ± 0.80 mm for ncFDPs). Within the cantilever group, cantilever arm length and implant location had an influence on bone loss. Regardless of the presence of cantilever, implants associated with technical complications had a higher rate of biological complications as well. Furthermore, the length of the cantilever arm was positively correlated with implant failure, technical complications and bone loss ≥1.5 mm (P = 0.011, <0.001, and 0.007).
  
  
  CONCLUSIONS
  Overall implants can be successfully used to support cantilever FDPs. However, there are technical and biological implications which appear inter-related.
authors.affiliation: School of Dentistry and Oral Health, Griffith University, Gold Coast, Australia.
authors.forename: Paul
authors.initials: P
authors.lastname: Kim
authors.forename: Saso
authors.initials: S
authors.lastname: Ivanovski
authors.forename: Neil
authors.initials: N
authors.lastname: Latcham
authors.forename: Nikos
authors.initials: N
authors.lastname: Mattheos
mesh_terms: D016301:Alveolar Bone Loss / Q000453:epidemiology; D003758:Dental Implantation, Endosseous; D017267:Dental Prosthesis Design; D019094:Dental Prosthesis, Implant-Supported; D019232:Dental Restoration Failure; D003779:Denture Design; D003830:Denture, Partial, Fixed; D005260:Female; D006723:Hong Kong / Q000453:epidemiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome
keywords: biological complications; cantilevers; dental implants; implant-supported fixed partial dentures; peri-implant bone loss; technical complications