The way in which dental implants are marketed to dentists leads clinicians to believe that the only option for restoring a crown and bridge case is to use the stock abutments that are manufactured to match the specific brand of implant.
In fact, certain implant manufacturers sell all of the components necessary to restore an implant packaged along with the implant. I have to admit, it is convenient. But, do stock abutments produce the aesthetic results that the patient is seeking? Let’s explore this concept.
Custom Implant Abutments vs. Stock Abutments
You may have never given it any thought. Like many dental practitioners, I just assumed that using the stock abutments that were machined to accompany the implant was the only restorative choice. In reality, prefabricated abutments are very limited in their use and are inappropriate for many crown and bridge restorations, particularly those in the anterior portion of the mouth.
They do not always allow for the proper tissue support, emergence profile, or contour for the restoration. As the result, patients complain about crowns with an unpleasant appearance, poor gum architecture, and problems with food impaction.
When you get right down to it, restoring an implant with a crown should follow the same parameters that every dentist learned about using crowns to restore natural teeth. The problem is, we lose sight of everything that we learned when the tooth no longer looks like a tooth and has been replaced by a dental implant.
For an aesthetic, functional, and hygienic implant crown preparation, the following criteria must be satisfied:
- Implant width must approximate the diameter of the root that it replaced at bone level
- The abutment must create a natural emergence profile for the crown
- Crown margin position should be customized to support the soft tissue contour
- Properly aligned restorations allow for improved oral hygiene and improved aesthetics
- Zirconia and gold-hued abutments yield enhanced aesthetics of the final restoration
When given the choice between using a custom abutment vs. a stock abutment, implant custom abutments consistently provide better results.
Pros and Cons
Stock abutments are manufactured to a predetermined number of standardized sizes. This means that they can be used on a variety of implant restoration types, including tissue-level and bone-level implants. They are designed to be user-friendly, which allows the clinician to take impressions with ease, and are the most economical method for restoring dental implants. And there are valid reasons for using this type of abutment.
Stock abutments are available in straight configurations and with angulations that never seem to quite match the actual angulation required to yield a proper profile. Because their shape is limited, often the crown must be over or under-contoured in an attempt to cover up for the fact that we are not dealing with an ideal crown preparation.
The gingival tissue will conform to the shape of the implant abutment. If a stock abutment is used in the aesthetic zone, it is very difficult for the lab technician to achieve an optimal emergence profile and have the gingival tissue be supported properly with respect to the adjacent teeth, putting your patient at risk for peri-implantitis. Margin placement of the crown is also predetermined and cannot be precisely controlled to achieve the best results possible. Therefore, the best use for stock abutments is away from the aesthetic zone.
Additional Factors for Consideration
The cost of machined stock abutments ranges from $50 to $175, on average, depending upon its manufacturer, size, and angulation.
Stock abutments are typically titanium abutments and are made from the same material used to manufacture the vast majority of dental implants.
Stock abutments are appropriate for removable denture cases, screw-retained hybrid dentures, and can be used effectively in the posterior regions of the mouth where crowns are meant to be functional and aren’t expected to look perfect.
Pros and Cons
An implant custom abutment will fit perfectly on the implant, will support the gum tissue similar to a natural tooth, and is milled to precise specifications from either titanium, zirconia, or gold-colored noble metals.
A custom fabricated abutment allows for an ideal crown preparation with proper angulation corrections and a more lifelike emergence profile. The margin is able to rest at the most aesthetic level with the tissue, making it much easier for the patient to cleanse and maintain healthy gingiva around the implant. Custom fabricated abutments may be used with both bone-level or tissue-level implants.
The restorative dentist captures the position of the implant and the shape of the surrounding gum tissue with an impression. The dental laboratory then manufactures an abutment that resembles the emergence and shape of a natural tooth of the individual patient.
There are no clinical downsides of using implant custom abutments. An improved, more natural-looking result is always achieved. The reason that many dentists don’t use custom-made abutments is they require additional steps to perform and they must charge their patients more for the service.
Additional Factors for Consideration
The average lab fee for a custom abutment is around $325 per implant. Custom implant abutments also add additional appointments, making the cost for the entire case significantly greater than a comparable case that utilizes stock abutments.