Influence of cantilever position and implant connection in a zirconia custom implant-supported fixed partial prosthesis: in silico analysis

Abstract

Introduction A better tension distribution on implants and abutments in implant-supported fixed partial prosthesis is essential in the rehabilitation of posterior mandible area. Objective: To evaluate the influence of cantilever position and implant connection in a zircônia custom implant-supported fixed partial prosthesis using the 3-D finite element method. Material and method: Four models were made based on tomographic slices of the posterior mandible with a zirconia custom three-fixed screw-retained partial prosthesis. The investigated factors of the in silico study were: cantilever position (mesial or distal) and implant connection (external hexagon or morse taper). 100 N vertical load to premolar and 300 N to molar were used to simulate the occlusal force in each model to evaluate the distribution of stresses in implants, abutments, screws and cortical and cancellous bone. Result: The external hexagon (EH) connection showed higher cortical compression stress when compared to the morse taper (MT). For both connections, the molar cantilever position had the highest cortical compression. The maximum stress peak concentration was located at the cervical bone in contact with the threads of the first implant. The prosthetic and abutment screws associated with the molar cantilevers showed the highest stress concentration, especially with the EH connection. Conclusion: Morse taper implant connetions associated with a mesial cantilever showed a more favorable treatment option for posterior mandible rehabilitation.

Finite Element Analysis of Stress in Anterior Prosthetic Rehabilitation with Zirconia Implants with and without Cantilever

“…In all considered positions, the cervical palatal region of the implant was where the highest concentrations of the maximum principal stress occurred, with the worst result for the Zr (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) group where the highest values of the maximum principal stress occurred (2.05 MPa). The best result was found in the Zr (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21) group where the lowest values of the maximum principal stress (1.53 MPa) occurred (►Fig. 2).…”

“…Fig. 2 Vestibular view of the implants showing the distribution of the maximum principal stress on the implants in the groups (A) Zr (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21), (B) Zr (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22), and (C) Zr (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22).…”

“…Zr (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21): implants in regions 11 and 21 with cantilever. Zr (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22): implants in regions 12 and 22 without cantilever.…”

“…Zr (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22): intercalated implants in regions 11 and 22. The implants were positioned parallel to their long axis on the bone base from tomography, and the implant platform was positioned at the height of the bone crest with standardization of the bone ridge.…”

“…Finite element analysis (FEA) is used in Dentistry to study how an implant and prosthodontics structures will respond to complex stress loading and to predict any possibility of structural failure. 2,9,[11][12][13][14] Thus, the aim of the present study was to verify the stress distribution in the implant, crown, and bone tissue in zirconia implants (single-body configuration) placed in different positions in the anterior region of the maxilla (12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22) in rehabilitation with and without a cantilever. The tested hypothesis is that implants placed on central incisors (11-21; with cantilever) would have lower mechanical performance compared with the other groups.…”