Performance of conical abutment (Morse Taper) connection implants: A systematic review

Abstract

In this systematic review, we aimed to compare conical versus nonconical implant-abutment connection systems in terms of their in vitro and in vivo performances. An electronic search was performed using PubMed, Embase, and Medline databases with the logical operators: "dental implant" AND "dental abutment" AND ("conical" OR "taper" OR "cone"). Names of the most common conical implant-abutment connection systems were used as additional key words to detect further data. The search was limited to articles published up to November 2012. Recent publications were also searched manually in order to find any relevant studies that might have been missed using the search criteria noted above. Fifty-two studies met the inclusion criteria and were included in this systematic review. As the data and methods, as well as types of implants used was so heterogeneous, this mitigated against the performance of meta-analysis. In vitro studies indicated that conical and nonconical abutments showed sufficient resistance to maximal bending forces and fatigue loading. However, conical abutments showed superiority in terms of seal performance, microgap formation, torque maintenance, and abutment stability. In vivo studies (human and animal) indicated that conical and nonconical systems are comparable in terms of implant success and survival rates with less marginal bone loss around conical connection implants in most cases. This review indicates that implant systems using a conical implant-abutment connection, provides better results in terms of abutment fit, stability, and seal performance. These design features could lead to improvements over time versus nonconical connection systems.

Microbiological Seal of Two Types of Tapered Implant Connections

“…Supporting the present results, Schmitt et al (14) suggested that no cold welding may be obtained in nontapered systems and the tapered interface provides a more precise fit. However, Jansen et al (2) found no difference between 13 combinations of implant/abutment systems, including tapered, non-tapered and tapered indexed, where all combinations showed bacterial leakage in vitro and most samples showed contamination on the first day.…”

“…Schmitt and colleagues (14) demonstrated that the tapered connections were superior regarding their sealing capacity in vitro, more resistant to abutment movement as well as to widening of the abutment/implant interface under load. They also presented greater resistance to fatigue.…”

Evaluation of the Sealing Capability of the Internal Conical Connections of Implants with Titanium and Zirconia Abutments

“…The results of the present investigation agree with those reported by Jansen et al, 30 in which the three conical abutment interfaces evaluated showed evidence of leakage. In a systematic review, Schmitt et al 31 reported that although no connection is 100% effective, conical connections seem to provide a superior bacterial seal. In contrast, however, Dibart et al 9 found no bacterial penetration of the interface from within the implant or from the surrounding bacterial solution, when evaluating the seal of the 1.5° locking taper design at the interface.…”

Effects of different torque levels on the implant-abutment interface in a conical internal connection

“…These design features could lead to improvements compared to nonconical connection systems. 26 Hence, using the appropriate torque in conical internal connection implants and decreasing the gap immediately after the insertion of the abutment can reduce the possibility of any bacterial contamination that occurs simultaneously with the loading of the implant at the time of prosthesis placement, because these factors, together, depending on the patient's sensitivity threshold, could cause trauma to peri-implant tissues.…”