Morse taper internal connection implants: would abutment reseating influence retention?

Abstract

Aim: To investigate whether the removal and reseating of the abutment influences the retention of Morse taper implant system. Methods: Two Morse taper implant systems were selected: Bicon Dental Implant TM system (Bicon, LLC, Boston, MA, USA) and Kopp Implant ® system (Kopp ® , Curitiba, PR, Brazil). In both systems, the abutment is connected to the implant with a locking taper. To seat the abutment, the same vertical force was applied in both systems. It was measured the compressive force necessary to engage effectively the locking taper connection and the tensile force to displace it. Results: The compressive force was determined by four activations in each abutment-implant set, and the sum of these forces was 21 N and 17 N in the Bicon TM and Kopp® systems, respectively. Next, a tensile test was performed, revealing that the Bicon TM system presented a 208 N resistance, whereas it was 194 N in the Kopp ® system. Other three rounds of compression and tensile loads were applied, removing and reseating the abutment. We obtained the following tensile values: 367 N, 500 N and 756 N in the Bicon TM System and 336 N, 360 N and 420 N in the Kopp ® system. Conclusions: When the sets were subjected to repeated rounds of compressive and tensile forces, displacing and reseating the abutment, the tensile value increased.

The effect of thermomechanical aging on the retention of a conometric system in a chewing simulator

“…As a result, the first null hypothesis was rejected. After compressive loading, Rabelo et al 18 measured the tensile force of two Morse taper implant systems (the Kopp and Bicon systems). It was observed that higher compressive forces generated higher tensile strengths in both implant systems.…”

“…18 Therefore, a positive correlation between compressive loading and removal forces was observed. 18 There is no data in the current dental literature on the long-term effects of chewing forces on the retention and stability of an indexed conometric system (Acuris conometric system) between indexed cap-abutment. As a result, the purpose of this in vitro study was to evaluate the retention force of this conometric system following thermomechanical aging in a chewing simulator.…”

Evaluation of tensile strength after insertions andremovals of abutments on frictional Morse taper implants

“…Kopp friction system consists of a cylindrical abutment with less than 2° between the inner walls of the implant and the outer walls of the abutment, which when coupled to the implant requires a removal force greater than the insertion force (Steiner et al, 2009;Ricciardi Coppedê et al, 2009;Rabelo et al). This Morse taper interface is related to the phenomenon of cold welding, which occurs through the intimate contact between the surfaces of the prosthetic abutment and the implant, leading to an interlock between the parts and, consequently, greater friction retention and stability (Steiner et al).…”

“…The FMTI has some advantages, such as the possibility of adequate aesthetics in the cervical region and a lower number of prosthetic components, with consequent reduction of costs, ease in clinical procedures, and increased resistance to fracture of the prosthetic abutment (Rabelo et al, 2015). Stability of the abutment is fundamental to achieve aesthetics and longevity of the prostheses, which is fundamental to the success of and satisfaction with the rehabilitation (Rack et al;Aguirrebeitia et al, 2014;Rabelo et al). Although this system promotes interlock between the components, the professional may need to remove the abutment for some reason.…”

“…If this occurs, the question is whether this procedure would compromise the retention of the abutment to the implant. Moreover, deformation of the Morse taper could occur after several loosening events (Feitosa et al, 2013;Rabelo et al). Therefore, the present study aimed at evaluating the tensile strength of frictional Morse taper implants of a specific brand after a sequence of insertions and removals (SIR), as well as evaluating possible deformations in the head of the implants using scanning electron microscopy (SEM).…”