Number of dental abutments influencing the biomechanical behavior of tooth-implant supported fixed partial denture: a finite element analysis

Abstract

Background. Local or systemic issues may prevent the installation of a sufficient number of dental implants for fixed prosthetic rehabilitations. Splinting dental implants and natural teeth in fixed dentures could overcome such limitations. Therefore, this study aimed to evaluate the influence of the number of dental abutments in the biomechanics of tooth-implant supported fixed partial dentures. Null hypothesis was that increasing the number of abutment teeth would not decrease the stress over abutments and surrounding bone. Methods. Left mandibular lateral incisor, canine, premolars, and molars were reconstructed through computed tomography and edited using image processing software to represent a cemented fixed metal-ceramic partial denture. Three models were set reducing the number of abutment teeth: 1) lateral incisor, canine, and first premolar; 2) canine and first premolar; 3) first premolar. Second premolar and first molar were set as pontics and second molar was set as implant abutment in all models. Finite element analyses were performed under physiologic masticatory forces with axial and oblique loading vectors. Results. After simulation of axial loads, the stress peaks on bone around the implant, bone around the first premolar, and prosthetic structures did not experience major changes when the number of abutment teeth was reduced. However, under oblique loads, decreasing the number of abutment teeth led to increased stress peaks on the surrounding bone and denture. Conclusion. Increasing the number of dental abutments in tooth-implant supported cemented fixed partial denture models led to the reduction of stress on its constituents, favoring the prosthetic biomechanics.

Keywords: Dental Prosthesis, Finite Element Analysis, Fixed Partial Denture, Implant-supported