Three-dimensional in vivo and finite element analyses of peri-implant bone remodeling after superstructure placement.

Abstract

Statement of problem: Understanding the factors affecting loading-induced longitudinal peri-implant bone changes is crucial for successful implant-supported prosthetic treatment.

Purpose: The purpose of the study was to assess the biomechanical factors influencing 3-dimensional changes in the peri-implant bone volume and buccal bone thickness (BBT) with follow-up cone beam computed tomography (CBCT) images and finite element analysis (FEA).

Material and methods: Twelve study participants received dental implants without bone augmentation, resulting in the evaluation of 22 posterior dental implants. Each participant underwent 3 separate CBCT scans: the first at 3 months after loading, followed by scans at 15 months and 27 months after loading. CBCT images were superimposed at each interval with an image-processing software program. The peri-implant buccal bone area was determined as the volume of interest (VOI), and volumetric change in VOI and changes in BBT at 2, 4, and 6 mm below the implant platform were measured. FEA was performed to examine the mechanical stimulation in the VOI with occlusal force data obtained from the Dental Prescale. Interobserver reliability was evaluated by 3 experienced prosthodontists and dentists experienced with dental implants. Linear regression analyses were performed to evaluate the relationship between variables.

Results: Occlusal force and mechanical stimulation (strain energy density [SED]) in the VOI demonstrated a positive correlation; moreover, a positive correlation was observed between SED and bone volume loss in the VOI at 3 and 27months after loading. Similar correlations were observed with BBT, except at a depth of 6 mm under the implant platform. The interclass correlation coefficient values were 0.995 for volume and 0.982 for BBT, thereby indicating a high level of agreement among the observers' measurements.

Conclusions: This combined FEA and clinical study suggested that force-induced bone remodeling depends on the occlusal force in the early phases after superstructure placement.