Biomechanical comparison of implant inclinations and load times with the all-on-4 treatment concept: a three-dimensional finite element analysis

Abstract

The purpose of this study was to compare the effects of implant inclinations and load times on stress distributions in the peri-implant bone based on immediate- and delayed-loading models. Four 3D FEA models with different inclination angle of the posterior implants (0°, 15°, 30°, 45°) were constructed. A static load of 150 N in the multivectoral direction was applied unilaterally to the cantilever region. The stress distributions in the peri-implant bone were evaluated before and after osseointegration. The principal tensile stress (σ_max), mean principal tensile stress (σ_max), principal compressive stress (σ_min) and mean principal compressive stress (σ_min) of the bone and micromotion at the contact interface between the bone and implants were calculated. In all the models, peak principal stresses occurred in the bone surrounding the left tilted implant. The highest σ_max and σ_min were all observed in the 0° model for both immediate- and delayed-loading models. And the 0° and 15° models showed higher σ_max and σ_min values. The 0°models showed the largest micromotion. The observed stress distribution was better in the 30° and 45° models than in the 0° and 15° models.

Keywords:

• “All-on-Four” concept
• immediate loading
• tilted implant
• finite element analysis

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

The National Natural Science Foundation of China (Grant No. 11872135), the Medical Scientific Research Foundation of Health and Family Planning Commission of Chongqing (Grant No. 2017XMSB00012079, 2017MSXML073), the Innovation Team Building at Institutions of Higher Education in Chongqing in 2016, Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, the Medical Scientific Nurture Research of the Stomatological Hospital of Chongqing Medical University (Grant No. PYM201605), and the Chongqing Research Program of Basic Research and Frontier Technology (Grant Nos. cstc2015shmszx0108).