Connection between implant and abutment is one of the crucial factor when it comes to technical and biological responses. From the beginning of the implantology, the connection types were differentiated by needs of the professionals or technical feedbacks. Besides, implant-abutment interface effects directly the joint strength, lateral and rotational stability [1].

In simple terms, connection types are differentiated by the outer or inner connection on above or inner side of the implant. There are two basic connections: external connection and internal connection. External connection pinned the earlier time of the implant journey. External connection is identified with the distinct geometrical extension above the implant body whereas in internal connection is recessed into implant body [2]. Brånemark pinned the implant journey with osseointegrated implants in 1981 [3]. He designed his original implant in external hex connection of 0.7 mm with butt-joint for fully edentulous mandibular restoration [1,4]. By the external connection, prosthetic workflow was simplified in adjustability and compatibility [5]. However, some problems occured prior to screw loosening, screw fraction and dynamic micromovements between implant- abutment interface [5]. As a result of the drawbacks of external implant abutment connections, there arose the trend for internal connections.

Internal connection design ensures the joint stability with distributing intraoral forces deep within the implant [1]. Also, internal connected implants provides superior strength [6].  Different geometrical approaches were used in internal connections such as hexagonal, octagonal, trilobe or conical connections [2]. Internal hexagon connections are widely used ones which have six-sided geometry to provide abutment fitting in every 60 degrees[1].  One of the study performed by Lemos et al. about the connection types, while marginal bone loss and complication rate were both increased with improved biomechanical convenience. However, no significant difference in implant survival rates in their sample space [7].

Friction fit connections, in mostly known as Morse taper or conical connection, is one the commercially used internal implant-abutment junction types. Morse taper implant-abutment connection is an internal joint design between two conical structures [8]. Platform-switching concept can be combined in conical connection implants for provide stabilization of soft tissues and lower bacterial leakage from the microgaps [8]. Also, micromotions at implant neck reduces in conical connection [2]. In addition to this, the Morse taper connection has higher fracture resistance values on internal conical joint compared with other connection types [9].

NUVO has two different implant systems with internal connections. InternalFIT implant systems has internal hexagon connection for stabilization of abutment into implant. ConicalFIT has total 22 degrees conical connection as implant abutment joint types. For more information about NUVO products, please visit NUVO implants website from here.

References:

[1] O Finger, Israel M., et al. "The evolution of external and internal implant/abutment connections." Practical procedures & aesthetic dentistry: PPAD 15.8 (2003): 625-32.
[2] Nikita Agarwal*, Umesh Pai+, Shobha J Rodrigues++, IMPLANT ABUTMENT CONNECTIONS: A REVIEW, Karnata Prosthetic Journal, June 2017, Volume: 1, Issue: 3
[3] Wesley Fernandes Roque, Cibele Cristina Peixoto, Gabriela Juliano Silva, Idiberto José Zotarelli Filho and Marcelo Augusto Rudnik Gomes1,2, “Internal Vs. External Hexagon Implants: Best Match”, ACTA SCIENTIFIC DENTAL SCIENCES (ISSN: 2581-4893), Volume 3 Issue 12 December 2019
[4] 4: Different Implant–Abutment Connections | Pocket Dentistry
[5] Vinhas, Ana Sofia, et al. "Review of the mechanical behavior of different implant–abutment connections." International Journal of Environmental Research and Public Health 17.22 (2020): 8685.
[6] Shetty, Manoj, Naresh HG Shetty, and Raghavendra Jaiman. "Implant abutment connection: biomechanical perspectives." Journal of Health and Allied Sciences NU 4.02 (2014): 047-053.
[7] Lemos, Cleidiel Aparecido Araujo, et al. "Comparison of external and internal implant-abutment connections for implant supported prostheses. A systematic review and meta-analysis." Journal of Dentistry 70 (2018): 14-22.
[8] Macedo, José Paulo, et al. "Morse taper dental implants and platform switching: The new paradigm in oral implantology." European journal of dentistry 10.01 (2016): 148-154.
[9] Szyszkowski, Adam, and Marcin Kozakiewicz. "Effect of implant-abutment connection type on bone around dental implants in long-term observation: Internal cone versus internal hex." Implant dentistry 28.5 (2019): 430-436.