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

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°.

Effect of Maxillary Implants Region and Loading Condition in the Stress Distribution of Implant-Supported Full-Arch Prosthesis: 3D-FEA

“…This finding is consistent with the study of previous authors [24], who found that cantilever loading had a large effect on bone stress. Increased bone stress can increase the risk of implant loss due to bone overload [12].…”

“…The results obtained in the present study also indicated that anterior cantilever loading can negatively affect the implant stress magni- implants. Although this stress check exists in several previous studies [12,[20][21][22][23][24][25][26] they did not considered different implant positions as the present models. The literature [20][21][22][23][24][25][26][27] usually reports the maximum forces capable of generating mechanical problems in the bone-implant interface, however, there are no reports showing the cantilever in anterior region similar to this study.…”

Crestal bone stability after flapless placement of sloped implants with immediate temporization in edentulous mandible. A prospective comparative clinical trial

“…The survival of implants with All‐on‐4 concept is well documented and accepted throughout the community of implantologist (Liu et al, 2019; Taruna et al, 2014). However, the degree of implantation of distal abutment is yet to be explored (Liu et al, 2019; Ozan & Kurtulmus‐Yilmaz, 2018; Saber et al, 2015). Moreover, crestal bone loss in the micro‐region of mesial and distal implants has not been reported so far.…”

“…Setting implants at a certain angle cantilevers may be reduced. Tilted implants may help to refuse large lateral and vertical bone augmentation, nerve lateralization and sinus lift with all leading risk of complications (Krekmanov et al, 2000; Liu et al, 2019). Moreover, the procedure allows longer implants where bone‐to‐implant contact is increased, providing primary stability.…”

“…The outcome, however, remains controversial, as some studies report greater crestal bone loss around tilted implants (Queridinha et al, 2016). With no recommended standard fixed implant angle, the question of stability and morbidity on a particular angle remains largely unanswered (Liu et al, 2019). Authors suggests angles for distal implants of between 30° to 45° (Taruna et al, 2014).…”