Parameters associated with marginal bone loss around implant after prosthetic loading

Abstract

This study evaluated retrospectively the association among occlusal, periodontal and implant-prosthetic parameters and marginal bone loss (MBL) around implants and survival rate at 5.7 ±3.2 years of follow-up after prosthetic loading. Eighty-two patients received 164 external hexagon implants. After the standard healing period (3 to 6 months), the implants were restored with single-tooth or up to three splinted crowns. All patients were followed according to a strict maintenance program with regular recalls and clinically evaluated by a calibrated examiner. The MBL measurements taken from standardized radiographs made at permanent crown placement (baseline) and after the last evaluation were calculated considering occlusal, periodontal and implant-prosthetic parameters. Veneer fractures and abutment loosening were not considered failure. Two implants failed during the follow-up period, resulting in a survival rate of 98.8%. Cox regression analyses showed MBL associated with non-working side contacts (p=0.047), inadequate anterior guidance (p=0.001), lateral group guidance involving teeth and implants (p=0.015), periimplant plaque index (p=0.035), prosthetic design (p=0.030) and retention (p=0.006). Inadequate occlusal pattern guide, presence of visible plaque, and cemented and splinted implant-supported restoration were associated with greater MBL around the implant.