AUTHOR=Sun Xin , Cheng Kangjie , Liu Yunfeng , Ke Sipeng , Zhang Wentao , Wang Linhong , Yang Fan 

TITLE=Biomechanical comparison of all-on-4 and all-on-5 implant-supported prostheses with alteration of anterior-posterior spread: a three-dimensional finite element analysis

JOURNAL=Frontiers in Bioengineering and Biotechnology

VOLUME=Volume 11 - 2023

YEAR=2023

URL=https://www.frontiersin.org/journals/bioengineering-and-biotechnology/articles/10.3389/fbioe.2023.1187504

DOI=10.3389/fbioe.2023.1187504

ISSN=2296-4185

ABSTRACT=This is a provisional file, not the final typeset article The all-on-4 concept is widely used in clinical practice. However, the biomechanical changes following the alteration of anterior-posterior (AP) spread in all-on-4 implant-supported prostheses have not been extensively studied. This study used a three-dimensional finite element analysis to compare the biomechanical behavior of all-on-4 and all-on-5 implant-supported prostheses with a change in anterior-posterior (AP) spread. A three-dimensional finite element analysis was performed on a geometrical mandible model containing 4 or 5 implants. Four different implant configurations were modeled by varying the angle of inclination of the distal implants (0°and 30°), including all-on-4a, all-on-4b, all-on-5a, and all-on-5b, and a 100 N force was successively applied to the anterior and unilateral posterior teeth to observe and analyze the differences in the biomechanical behavior of each model under the static influence at different positions. The results indicated that adding an anterior implant to the dental arch according to the All-on-4 concept with a distal 30°tilt angle implant exhibited the best biomechanical behavior. However, when the distal implant was implanted axially, there was no significant difference between the All-on-4 and All-on-5 groups. In the All-on-5 group, increasing the AP spread with tilted terminal implants showed better biomechanical behavior.It can be concluded that placing an additional implant in the midline of the atrophic edentulous mandible and increasing the AP spread might be beneficial in improving the biomechanical behavior of tilted distal implants. 104 Medicine (DICOM) format into Mimics software (V21.0; Materialise), and a rough 3D contour of the 105 mandible was obtained by thresholding and masking. The resulting file was exported in STL format 106 and further processed in Magics software (V20.03; Materialise) to segment the dental crown and 107 mandible, resulting in models of the dentition and mandible. The models were imported into 108 Geomagic Studio software (V12; Geomagic) for refinement, where a three-dimensional solid model 109 of the mandible was accurately calculated to obtain a complete and smooth surface. The model was