Effects of Different Positions and Angles of Implants in Maxillary Edentulous Jaw on Surrounding Bone Stress under Dynamic Loading: A Three-Dimensional Finite Element Analysis.

Xiaqing Liu,Xiaohua Cui,Fang Pang,Xuelian Yang,Ying Li,Qi Yang,Yuan Yue,Hui Jia

doi:10.1155/2019/8074096

Xiaqing Liu, Xiaohua Cui + Show 6 more

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https://doi.org/10.1155/2019/8074096

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Abstract

Purpose To evaluate the effects of different placements of mesial implants and different angles of distant implants in maxillary edentulous jaws on the stress on the implant and the surrounding bone tissue under dynamic loading. Materials and Methods Cone beam computed tomography was used to acquire images of maxillary edentulous jaws. Using Mimics 17.0, Geomagic, and Unigraphics NX8.5 software, three-dimensional models were established: two mesial implants were placed vertically in the anterior region of the maxilla (bilateral central incisor, lateral incisor, and canine), and two distant implants were placed obliquely in the bilateral second premolar area at different inclined angles (15°, 30°, and 45°). The established models were designated I–IX. The models were subjected to dynamic load using Abaqus 6.12, with the working side posterior teeth loading of 150 N and simulation cycle of 0.875 s. Results During the second to fourth phases of the mastication cycle, the stress was mainly concentrated on the neck of the distal implant. The stress of the distal implants was greater than that of mesial implants. Stress levels peaked in the third stage of the cycle. The stress of the distal cortical bone of distal implant of Model I reached the maximum of 183.437 MPa. The stress of the distal cortical bone and cancellous bone of distal implant of Model VIII represented the minima (62.989 MPa and 17.186 MPa, respectively). Conclusions Our models showed optimal stress reductions when the mesial implants were located in the canine region and the distal implants tilted 30°.

Highlights

Economic and social development has accelerated the overall aging of the population, so dental prostheses have become necessary for improving the quality of life
All nine implant models produced equivalent stress cloud diagrams (Figure 4) in which the stress was mainly concentrated on the neck of the distal implant and gradually decreased to the apex. e stress on the distal implants was greater than that on the mesial implants; equivalent stress cloud diagrams were found for all nine maxillary models (Figure 5). ere, the stress was mainly concentrated on the cervical margin junction and cortical bone of the distal implants. e stress on the distal bone of the distal implant was greater than that on the mesial bone of the distal implant. us, the stress on the distal implant and its distal cortical and cancellous bones are described in more detail below
The stresses on the distal implants and bones graphed in Figure 6 showed a trend of canine region < lateral incisor region < central incisor region

Summary

Introduction

Economic and social development has accelerated the overall aging of the population, so dental prostheses have become necessary for improving the quality of life. Implant-based edentulous jaw restoration is becoming more and more important in dentistry. Compared to traditional complete dentures, implant restoration can more effectively improve oral/jaw function in patients with edentulous jaws, visibly improving their quality of life. Oblique implants have the following advantages: the ability to reduce or even avoid incremental bone surgery [7]; greater initial stability for longer implants; and a shorter cantilever beam that prevents stress concentration. Given these advantages, work by Soto-Penaloza et al documented a survival rate of implants surviving over 24 months of 99.8% [8]

Results

Discussion

Conclusion