Abutment mechanical complications of a Morse taper connection implant system: A 1‐ to 9‐year retrospective study

Abstract

Background The fracture of a Morse tapered abutment connection in an osseointegrated implant is one of the most serious mechanical complications, and it is extremely hard to deal with this complication in clinical practice. Purpose The aim of this study was to explore the cumulative mechanical complications focus on abutment of a platform switching Morse taper connection implant system after loading, and to perform a retrospective, approximately 1‐ to 9‐year follow‐up study to identify the predisposing factors. Materials and Methods A total of 495 patients with 945 fitted implants were enrolled in this study with a follow‐up from January 2012 to January 2020. The data of mechanical complications of the abutment, including abutment fracture (AF) and abutment screw loosening (ASL), and possible causative factors were extracted and evaluated statistically. Results A total of 25 out of 945 (2.65%) cumulative abutment mechanical complications occurred. AF was the most common complication (n = 13, 1.38%), followed by ASL (n = 12, 1.27%). For AF, gender, type of prosthesis, abutment design, and implant diameter were identified as the causative factors. AF was mostly observed in the single crown of males in molar areas, while ASL was more likely to occur on an angled abutment than on a non‐angled abutment. Moreover, the abutment with the positioning index (/X) had a higher incidence of fracture than the abutment without the positioning index (C/). Conclusions This study shows that the Morse taper connection is a safe abutment connection. AF occurs more frequently within single crowns in molar area of males, especially with the positioning index (/X), while ASL is more likely to occur in an angled abutment.

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

“…Unfortunately, the index factor was not considered in their study. However, a higher fracture rate of the MT-PS implant system with an indexed abutment was clinically observed in our retrospective study than in the non-indexed one [23]. Several experimental studies have been conducted to investigate the biomechanical performance of implant systems influenced by the presence of the index configuration.…”

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

“…Although there is a large body of literature on Morse taper in internal connections. Of the sixteen papers we included, there were only two relevant clinical studies on Morse taper abutments containing a prosthetic index [ 36 , 37 ] (Table 3 ). Yang et al followed 945 implants from 495 patients for one to nine years and found that the Morse cone connection is a safe abutment connection.…”

“…This is one of the few retrospective clinical studies involving abutment localization indices with Morse taper. It was found that abutment fracture (AF) often occurs in abutments containing a positioning index (/X) [ 36 ]. More clinical studies are needed to produce more valuable evidence-based evidence to support good long-term clinical outcomes.…”

Implant Body Fracture and Abutment Screw Loosening: Is It a Chicken and Egg Situation?

“…2 The implant body fracture and/or the abutment screw fracture are considered to be the most serious mechanical complications and they are very hard to manage clinically. 3 Improper fit of the prosthesis, occlusal interference, inadequate seating of the abutment, and manufacturing errors are some of the causes that can result in an abutment screw fracture. Generally, the abutment screw fractures occur due to the screw loosening.…”

“…The majority of studies 1,3,8-10 have evaluated the incidence rate, the risk factors, and management strategies of the abutment screw loosening and abutment screw fracture. Yang et al 3 retrospectively explored the predisposing factors and the cumulative mechanical complications of the implant-abutment connections at 1-9-year follow-up. A total of 25 (2.65%) cumulative abutment mechanical complications were observed in total of 945 implants in 495 patients.…”