Optimal Strategies for Custom Implant Abutments and Bars

We have gone from waxed and casted UCLA gold abutments to machined abutments with a much higher level of precision. Innovations with angulated screw channels allow for the potential of correcting angulation. With bars, a perfect example of the evolution is a double structure with a bar made from titanium or even zirconia and a suprastructure made from zirconia; the fit of these two components can be very intimate and truly detailed and accurate, to the point that they become almost one. The entire process, from surgical planning to restorative, has become more streamlined, so the success rate of these types of restorations has increased significantly.

First, titanium requires a certain type of spindle and strength specifications in order to mill properly without damaging your machine. Second, when you work with a milling center, you do not need to worry about the potential of a failure and starting over from scratch, which costs time and money; you are just paying for the end result. Third, along those same lines, when you partner with a milling center, you do not need to occupy one of your mills for up to 3 or 4 hours on a bar, for example; that is time that could be spent milling crowns. Unless you have a dedicated mill for abutments and bars, outsourcing them typically allows your laboratory to be more productive.

We are restoring something that behaves in a way that it needs to function physically and biomechanically. There is a lot more torque in the posterior than in the anterior, so how you distribute those forces will make or break the restoration. Someone not fully versed in those principles could make something look very esthetic, but it may not function or last long in the mouth. For example, a hard understructure with a softer overstructure will ultimately fail. Fortunately, continuing education in this area is available from a number of sources, including institutions such as the Kois Center.

As more and more general practitioners place implants, laboratories have a tremendous opportunity to align with their needs and partner with them for success. Everything comes back to education. At the end of the day, the implant realm is about engineering more than anything else because the geometries, stability, and biomechanical rules such as anterior-posterior spread are critical in achieving a long-lasting restoration.

Daniel Alter, MSc, MDT, CDT, is a professor of restorative dentistry at New York City College of Technology in Brooklyn, New York, and executive editor of Inside Dental Technology.