Effect of the prosthetic index on stress distribution in Morse taper connection implant system and peri-implant bone: a 3D finite element analysis

Abstract

Background The combination of a prosthetic index with Morse taper connection was developed, with the purpose of making prosthetic procedures more precise. However, the presence of the index may compromise the mechanical performance of the abutment. The aim of this study is to evaluate the effect of prosthetic index on stress distribution in implant–abutment-screw system and peri-implant bone by using the 3D finite element methodology. Methods Two commercial dental implant systems with different implant–abutment connections were used: the Morse taper connection with platform switching (MT-PS) implant system and the internal hex connection with platform matching (IH-PM) implant system. Meanwhile, there are two different designs of Morse taper connection abutment, namely, abutments with or without index. Consequently, three different models were developed and evaluated: (1) MT-PS indexed, (2) MT-PS non-indexed, and (3) IH-PM. These models were inserted into a bone block. Vertical and oblique forces of 100 N were applied to each abutment to simulate occlusal loadings. Results For the MT-PS implant system, the maximum stress was always concentrated in the abutment neck under both vertical and oblique loading. Moreover, the maximum von Mises stress in the neck of the MT-PS abutment with index even exceed the yield strength of titanium alloy under the oblique loading. For the IH-PM implant system, however, the maximum stress was always located at the implant. Additionally, the MT-PS implant system has a significantly higher stress level in the abutment neck and a lower stress level around the peri-implant bone compared to the IH-PM implant system. The combined average maximum stress from vertical and oblique loads is 2.04 times higher in the MT-PS indexed model, and 1.82 times for the MT-PS non-indexed model than that of the IH-PM model. Conclusions MT-PS with index will cause higher stress concentration on the abutment neck than that of without index, which is more prone to mechanical complications. Nevertheless, MT-PS decreases stress within cancellous bone and may contribute to limiting crestal bone resorption.

The mechanical and clinical influences of prosthetic index structure in Morse taper implant-abutment connection: a scoping review

“…Under vertical and inclined loading, the MT-PS implant system had significantly higher stress levels in the abutment neck and lower stress levels around the peri-implant bone compared to the IH-PM implant system. It concluded that MT-PS with indexing could reduce stresses within cancellous bone, but lead to higher stress concentrations in the abutment neck and greater susceptibility to mechanical complications [ 29 ]. Villarinh's study also supports that indexed tapered abutments may induce greater biomechanical risk in single-crown restorations when under function.…”

“…A previous study evaluated the effects of the prosthetic index on the stress distribution in Morse taper connection implant systems and peri-implant bone. The use of three-dimensional finite element analysis by Zhang et al is a noteworthy advantage because of its ability to accurately display and measure the stress distribution within the implant system and peri-implant bone [ 29 ]. These findings indicated that the Morse taper connection with platform switching (MT-PS) with the index will cause higher stress concentration on the abutment neck than those without index, which is more prone to mechanical complications.…”

“…However, this study also has certain limitations, including the assumption of idealized conditions in the simulations, the failure to take into account the complex mechanical and biological interactions that occur in vivo, and the failure to take into account other factors that may affect the stress distribution, such as implant diameter, length, and thread design. It is worth noting that a variety of other factors may be involved in obtaining different results [ 29 ]. However, a separate study indicated that that the presence of a prosthetic index did not decrease the implants' resistance to fracture [ 28 ].…”

Single missing molar with wide mesiodistal length restored using a single or double implant-supported crown: A self-controlled case report and 3D finite element analysis

“…Bite force has no standard value in the medical profession. Previous studies have used occlusal forces ranging from 100 to 500 N [48][49][50]. The bite-force ratio between the vertical and lateral orientations was 5:1 [51].…”

Finite element analysis of the use of two new types of internal fixation for acetabular fractures

“…Since the load applied in this study was the physiological limit of the human body, the maximum stress experienced by the Bespoke 3D-printed titanium alloy plates was lower than the maximum yield stress of titanium alloy [ 19 ], but the maximum stress experienced by the common reconstruction plate exceeded its maximum yield stress. The design of the Bespoke 3D-printed titanium alloy plates may have allowed the stress to be dispersed throughout the material.…”