ResearchArticle Stress Distribution Pattern in Mini Dental Implant-Assisted RPD with Different Clasp Designs: 3D Finite Element Analysis Chaiy Rungsiyakull , 1 Pimduen Rungsiyakull , 2 Kullapop Suttiat , 2 and Nut Duangrattanaprathip 3 1 DepartmentofMechanicalEngineering,FacultyofEngineering,ChiangMaiUniversityChiangMai, ChiangMai50200,ailand 2 DepartmentofProsthodontics,FacultyofDentistry,ChiangMaiUniversity,ChiangMai50200,ailand 3 ProsthodonticsSection,DepartmentofRestorativeDentistry,FacultyofDentistry,NaresuanUniversity, Phitsanulok65000,ailand Correspondence should be addressed to Kullapop Suttiat; kullapop@hotmail.com Received 20 October 2021; Revised 30 January 2022; Accepted 18 February 2022; Published 11 March 2022 Academic Editor: Paolo Francesco Manicone Copyright © 2022 Chaiy Rungsiyakull et al. is is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Introduction. e removable partial denture (RPD) components, especially the retentive arm, play a major role in the loading characteristic on supporting structures. Objective. To evaluate and compare the effect of different clasp designs on the stress distribution pattern, maximum von Mises stress, and average hydrostatic pressure on abutment teeth, as well as edentulous ridges, mini dental implants (MDIs), and peri-implant bone between the conventional removable partial denture (CRPD) and mini dental implant-assisted distal extension removable partial denture (IARPD) using a three-dimensional finite element analysis (3D FEA). MaterialsandMethods. 3D FEA models of mandibular arches, with and without bilateral MDI at the second molar areas, and Kennedy class I RPD frameworks, with RPA, RPI, Akers, and no clasp component, were generated. A total of 200 N vertical load was bilaterally applied on both sides of distal extension areas, and the stress was analyzed by 3D FEA. Results. e stress concentration of IARPD with RPI clasp design was located more lingually on abutment teeth, MDI, and peri-implant bone, while the other designs were observed distally on the supporting structures. e maximum von Mises stress on the abutment root surface was decreased when the RPDs were assisted with MDIs. e CRPD and IARPD with the Akers clasp design showed the highest von Mises stress followed by the designs with RPA and RPI clasp, respectively. e average hydrostatic pressure in each group was in approximation. Conclusion. e placement of MDIs on distal extension ridges helps to reduce the stress con- centration on denture supporting structures. e maximum von Mises stress is affected by the different designs of clasp components. e CRPD and the IARPD with RPI clasp provide the least stress on supporting structures. 1. Introduction Among modern dental treatment modalities, the restoration of partial edentulous ridges with removable partial denture is accepted as a standard treatment option [1]. However, the compromise in denture retention and stability, especially in the mandible with distal extension base, is the most common clinical drawback for many patients [2, 3]. e difference in bearing capacities of the supporting tissues in the distal extension arch leads to the classic disadvantage of a re- movable partial denture, moving the denture and abutment torquing during function [4]. To overcome this inherent problem, functional impression technique has been applied to record the tissue in functional form as it reduces torque on supporting structures due to the difference in resiliency between the abutment teeth and soft tissue covered on edentulous ridges [5–7]. Clasp assembly design is the other promising strategy for altering the load distribution on the supporting structures [8–12]. e retentive component design based on stress breaker concept such as RPI or RPA clasp has been rec- ommended by many clinicians for distal extension case. e Hindawi International Journal of Dentistry Volume 2022, Article ID 2416888, 10 pages https://doi.org/10.1155/2022/2416888