Effects of Different Abutment Connection Designs on the Stress Distribution Around Five Different Implants: A 3-Dimensional Finite Element Analysis

Abstract

The stability of the bone-implant interface is required for the long-term favorable clinical outcome of implant-supported prosthetic rehabilitation. The implant failures that occur after the functional loading are mainly related to biomechanical factors. Micro movements and vibrations due to occlusal forces can lead to mechanical complications such as loosening of the screw and fractures of the abutment or implants. The aim of this study was to investigate the strain distributions in the connection areas of different implant-abutment connection systems under similar loading conditions. Five different implant-abutment connection designs from 5 different manufacturers were evaluated in this study. The investigation was performed with software using the finite element method. The geometrical modeling of the implant systems was done with CATIA virtual design software. The MSC NASTRAN solver and PATRAN postprocessing program were used to perform the linear static solution. According to the analysis, the implant-abutment connection system with external hexagonal connection showed the highest strain values, and the internal hexagonal implant-abutment connection system showed the lowest strain values. Conical + internal hexagonal and screw-in implant abutment connection interface is more successful than other systems in cases with increased vertical dimension, particularly in the posterior region.

Is the internal connection more efficient than external connection in mechanical, biological, and esthetical point of views? A systematic review

“…Concerning stress distribution, clinicians should consider the mechanical behavior of different implant connection types when selecting them, since the stress transmitted to the bone [3], and it is essential that the selected connection satisfactorily resists them [3,22]. The conical design has high stability and tends to dissipate less stress to the abutment screw when compared with external [23] and internal hexagon [3,5], improving fracture resistance.…”

“…Concerning the internal hexagon implants, Palmer et al [20] attested that these connections provided lower bone loss during the first 2 years of function. Biomechanical factors and stress distribution were evaluated through finite element analysis by simulated load under different connection and retention systems [22][23][24] ( Table 4). The external hexagon exhibited higher strain values than internal hexagon and Morse taper connection [23].…”

“…The external hexagon exhibited higher strain values than internal hexagon and Morse taper connection [23]. On the contrary, Pessoa et al [22] found that the implant-abutment connection design did not significantly affect the biomechanical behavior of immediately placed implants. These authors indicated that implant overloading must be avoided to ensure an initial intraosseous stability.…”

Abutment screw loosening of endosseous dental implant body/abutment joint by cyclic torsional loading test at the initial stage

“…Looseness of the abutment screw causes poor fit of the superstructure, and can lead to fracture of the abutment screw and superstructure damage or detachment, as well as fracture of the implant or resorption of the periimplant bone. A study using finite elements analysis reports that an implant system with external connection showed the highest stress values on the abutment screw and the implant-abutment connection during loading 18) . In loading tests and fracture tests, tube-in-tube implant connection systems are reported to show greater strength than systems with shallow connections 19) .…”

Influence of parafunctional loading and prosthetic connection on stress distribution: A 3D finite element analysis

“…11 Marginal bone loss may be affected by factors such as characteristics of the implant platform surface 12,13 or the prosthetic connection. [14][15][16][17][18][19] Thus, stability of the connections among different parts of the implant also contributes to the longevity of the implant-supported prosthesis, particularly in single posterior restorations where a resilient interface between the abutment and the implant is necessary. 20 Some researchers have found that the configuration of the platform connections would reduce the stress concentration in the peri-implant bone.…”