Marginal Bone Stability Around Tapered, Platform-Shifted Implants Placed with an Immediately Loaded Four-Implant-Supported Fixed Prosthetic Concept: A Cohort Study

Int J Oral Maxillofac Implants. May-Jun 2016;31(3):643-50. doi: 10.11607/jomi.4354.

Abstract

Purpose: To longitudinally evaluate marginal bone remodeling around tapered, platform-shifted implants placed for total arch rehabilitation with fixed hybrid prostheses.

Materials and methods: A retrospective cohort study was designed that evaluated radiographic data from patients undergoing implant surgical procedures with an immediately loaded four-implant-supported fixed prosthetic concept in a single clinic setting during a 36-month period. The primary outcome variable was the change in marginal bone levels during a 12- to 36-month follow-up postloading with the definitive prosthesis. All measurements were performed on matched and calibrated periapical radiographs obtained at: (1) the time of placement of the definitive prosthesis (baseline) versus (2) 12 to 36 months following definitive loading (follow-up). Other study variables, including duration of follow-up, implant position, maximum insertion torque, implant angulation, and implant diameter, were assessed for their association with changes in marginal bone levels.

Results: One hundred sixty-nine patients (n = 856 implants) with a mean age of 59.5 ± 10.5 years were included in this study. Two implants failed, resulting in a 99.8% overall survival rate (mean follow-up: 15.2 ± 4.8 months, range: 12 to 36 months). The radiographic mean bone levels at baseline and follow-up were 1.16 ± 0.71 mm (n = 805) and 1.31 ± 0.93 mm (n = 805), respectively. The mean marginal bone loss from baseline to follow-up was 0.14 ± 0.59 mm (n = 805). The duration of follow-up had no effect on the extent of marginal bone loss (P = .154).

Conclusion: Within the limitations of this large-scale retrospective cohort study, it was concluded that the use of tapered, platform-shifted implants for total arch rehabilitation with the use of the All-on-Four protocol yields very favorable radiographic outcomes, at least after a minimum of 12 months in function.

MeSH terms

  • Adult
  • Aged
  • Alveolar Bone Loss / pathology
  • Bone Remodeling / physiology*
  • Bone-Implant Interface / physiology*
  • Dental Arch / surgery
  • Dental Implants*
  • Dental Prosthesis Design*
  • Dental Prosthesis Retention / standards*
  • Dental Prosthesis, Implant-Supported*
  • Dental Restoration Failure
  • Female
  • Follow-Up Studies
  • Humans
  • Immediate Dental Implant Loading* / methods
  • Male
  • Middle Aged
  • Mouth, Edentulous / rehabilitation*
  • Retrospective Studies
  • Torque
  • Treatment Outcome
  • Young Adult

Substances

  • Dental Implants