Implant Fixture and Abutment Considerations

Michael Tischler, DDS


While as clinicians, our goal is the final prosthetic result, what lies behind that goal is the implant fixture itself along with the many parts and associated pieces to make that happen. We provide our patients with the foundational support that they will live with daily.

This month’s Implants Today topic is “implant fixture and abutment considerations,” which creates a multitude of discussion points about implant dentistry in general. While as clinicians, our goal is the final prosthetic result, what lies behind that goal is the implant fixture itself along with the many parts and associated pieces to make that happen. Dentistry Today’s Implant Advisory Board members Drs. Edward Kusek and Michael Scherer both offer articles this month with excellent examples of how dental implant prosthetic attachment connections can change our patients’ lives through the appropriate choices with overdenture options. These outstanding articles present the variety of choices in overdenture attachments and how each clinical choice made by a clinician allows for the right decision for the patient, based on the desired clinical result. Both articles exemplify the importance of how the engineering choices within treatment planning result in ideal patient treatment. With the masticatory and aesthetic prosthetic goals in mind, we provide our patients with the foundational support that they will live with daily; that support system is the implant fixture and accompanying abutment or attachment choice.

Every implant prosthetic outcome for a patient is supported by an osseointegrated dental implant fixture, which is the basis for the final patient result. There are many considerations when choosing which implant supports the final prosthesis, and there are hundreds of implant companies offering various implant design options. How does a clinician choose the correct implant fixture with such a myriad of choices? It depends on the clinical situation in which the patient presents, while taking into consideration the final prosthetic end result. Although that answer only raises other questions, these are questions the clinician must answer prior to making this choice. A clinician must consider many implant design factors that relate to not only bone morphology but also soft-tissue considerations. Both the presenting bone and condition of the soft tissues dictate the choice of an implant fixture.

The clinically presenting bone morphology of a patient can vary extensively. Bone morphology could be abundant or deficient in height, width, or density. It is up to the clinician to choose the appropriate implant body design to match the presenting bone condition. The variable implant design considerations for a clinician to choose from relate to implant thread pitch design, implant thread and coronal surface design, basic implant shape design (tapered versus straight), implant length options, implant width options, implant apical design, implant crestal design, and more. It is imperative for the clinician to comprehend bone biology and anatomy so that the correct implant design can be chosen based on the bone morphological situation.

In addition to bone morphology considerations, the clinician must consider the surrounding soft-tissue factors in relation to implant fixture choices. The design of an implant with relation to soft tissue correlates to the crestal aspects of the implant design. These soft-tissue-related implant design considerations include implant crestal taper design, implant surface design at the crestal area, abutment attachment design, and more. The often-debated concept of platform switching is an example of the need for a clinician to understand the importance of this abutment-implant connection. As with bone considerations, it is imperative for a clinician to understand soft-tissue biology when considering implant design choices.

The last consideration with regards to the correct clinical implant choice is the connection of the abutment to the implant. There are many connection choices available, varying from internal connections, external connections, and a variety of shapes of these connections. Different implant manufacturers make arguments for the many connection designs and to the advantages of their brand. While many abutment connections exist with advantages to each, an important consideration for the clinician is the final prosthesis goal, and the available parts from the manufacturer to connect the prosthesis to the implant fixture. An example of considering the final prosthesis with regards to available implant adjunctive parts is the use of multiunit abutments to raise the implant platform or change its direction. Some implant companies have limited or no multiunit parts available, and this could hinder treatment with some screw-retained prosthetic situations.

In conclusion, when choosing an implant fixture and abutment, a clinician should be knowledgeable of not only the prosthetic end result but also the science and anatomy of the clinically presented hard and soft tissues. In addition, the clinician must have knowledge of the available parts from a manufacturer and how they relate to the clinical situation at hand. Ideal treatment of tooth replacement with implants requires not only a good clinician, but also that the clinician is a knowledgeable consumer. The science of implant dentistry is truly multidisciplinary on many levels, including a blend of science and engineering knowledge. An implant dentist, as a consumer, must consider many disciplines of knowledge in order to make the right clinical decision for the patient.

Removable Prosthetics: Bad Attachments or Bad Design?

Edward R. Kusek, DDS, discusses implant fixture and abutment considerations.

Simplifying Implant Overdentures: Contemporary Overdenture Abutment and Attachment Systems
Michael D. Scherer, DMD, MS, shares materials and techniques that will serve to simplify implant- supported overdentures.

A New Approach for Treating Peri-Implantitis: Reversibility of Osseointegration
Eduardo Anitua, MD, DDS, PhD, discusses peri-implantitis and presents a new clinical protocol for treating this problem. This article is peer-reviewed and available for 2 hours of CE credit.