2023, Vol. 27 ›› Issue (3): 398-405

Effect of three abutment materials on bone stress around maxillary angle implant under dynamic loading

Wang Junxiang, Sun Jiangwei, Bai Bujiafu·Yellisi, Wang Zhaoxin, Nijati·Turson   

Abstract: BACKGROUND: In oral implant restoration, patients with single missing maxillary anterior teeth often have alveolar bone absorption and defect due to different reasons. To avoid the risk of bone grafting, inclined implants are often used to avoid the alveolar bone absorption area. The angle abutment is used to restore the normal overcovering relationship of patients. The size and distribution of the influence of different abutment materials on the occlusal force transfer of the implant and the surrounding bone were studied.  
OBJECTIVE: To compare the influence of time on the peak value of bone stress around the implant with three abutment materials under simulated dynamic loading under three implantation conditions.  
METHODS: Cone beam CT data of a healthy adult undergoing implant restoration of maxillary central incisor were selected. Minics software was used to cut the jaw bone. Solidworks 2018 was used to establish the implant, jaw bone, and angle abutment (angle 0°, 15°, and 25°).   Base stations materials included pure titanium, zirconium dioxide, and alumina), central screw, and zirconium dioxide full porcelain crown model. Assembly was complete, for embedded in the original maxillary fang root cutting direction 0° angle, then simulated palate to tilt 15° and 25°, no implanted implant thread exposure. According to different implant angles, they were divided into 0°, 15°, and 25° groups. Dynamic loading was performed for 0.2 seconds, to obtain the time-dependent relationship between the peak value of equivalent stress of bone around the implant prosthesis of each material abutment.  
RESULTS AND CONCLUSION: (1) All abutment implant restorations had the same peak distribution of surrounding bone stress when they were subjected to occlusal force, all of which were located in the bone cortex of the implant neck. The fastest time period for the increase of bone stress around abutment implant restorations of each material was within 0.025-0.05 seconds. The range of high stress value of cortical bone in the 15° group was larger than that in the 0° group. The initial stress value of cortical bone of implant in the 25° group was significantly higher than that of the other two groups. The residual stress value of cortical bone was higher after loading. After titanium abutment implantation, the bone stress around the prosthesis had the largest increase, and the range of high stress value was relatively concentrated. (2) In the 15° group, the peak value of bone stress around the implanted prosthesis on the abutment of the three materials was located in the neck of the implant. The increase in bone stress around the titanium abutment implanted prosthesis was relatively large but not obvious, and the distribution range of high stress was relatively consistent. Compared with the other two groups, the high stress value of the 25° group was more concentrated; the initial stress value was higher and the range of change was greater, among which the bone stress around the implanted prosthesis on the dialumina abutment increased the most within 0-0.1 seconds. At 0.2 seconds, the peak value of bone equivalent stress of zirconia abutment decreased to 0, and high residual stress remained in the bone around the implants of the other two abutments. (3) It is concluded that based on the analysis of the distribution of different influences of the implant angle and abutment material on the bone interface, the bone stress of the implants using zirconia abutment was relatively stable at all time points in the three groups.  
Key words: implant, dynamic loading, angle abutment, bone stress, restorations