The Clinical and Technical Implications of "Mixing 'n Matching" Implant Systems and Components

A Professional Newsletter from Marotta Dental Studio, Inc.

Letter from Lenny	The Clinical and Technical Implications of "Mixing 'n Matching" Implant Systems and Components

Having studied with the first graduating class of restorative dentists and surgeons, trained in the Brånemark System® at the University of Toronto in 1984, I do admit to a certain bias regarding the Swedish implant system. And six years of working with all of the osseointegrated implants has only reinforced my opinion that the Brånemark System is the most trouble-free. That is not to say that we haven't had good, esthetic results with other implant systems or with cases involving mixed configurations of parts from different systems and manufacturers, but it seems that the cases most likely to become problematic requiring additional chairside time and adjustments tend to be implants other than the Brånemark System. Continued	It has become a common practice among some dental practitioners to "mix 'n match" the fixtures and components of various implant systems, expecting to achieve the same results as those offered by maintaining the integrity of one particular system. This is no doubt due in part to claims made by manufacturers that their products are exactly the same as another system's parts and therefore interchangeable. The Brånemark System is among the most "copied" implant system, probably because its twenty-five years of documented research and ADA Acceptance makes it the most proven implant design on the market thus far. Also its higher price makes it an easy target for more economical imitations. But our main concern here is whether compatibles truly offer a clinical and technical equivalent. For instance, the long-term documented success of the Brånemark System is based on a thoroughly researched "system approach" that emphasizes the interrelationship between hardware and precisely defined procedures. Therefore any departure from the Brånemark formulain either hardware	Methodologymay compromise the system's integrity, the esthetics and possibly the prognosis. Figure 1 shows the imprecision of a so-called "compatible" abutment. Even this slight displacement may compromise the osseointegration and the overall stability of the implant as there is no way of predicting the long-term effect of torque forces on this post. "Compatible," Castable Abutments By Steven Pigliacelli, CDT Vice President, Marotta Dental Studio An increasingly popular compatible is the castable, UCLA-type abutment, which can be used with Brånemark, IMZ and Calcitek fixtures. Some abutment manufacturers provide a prefabricated component, while others leave the choice of alloy for surgeon to prescribe or for the	laboratory to recommend. Great care should be taken concerning the choice of alloy to be used to case the abutment since little is known about the subgingival use of most alloys. This particular application has little in the way of clinical documentation regarding the biocompatibility and longterm effects. For example, our experience shows that plaque may tend to form more easily around certain "soft" alloys, making them a questionable choice for casted abutments. Some alloys are easily "pitted," while others tend to corrode or release incompatible oxides. Regardless of whether they are fabricated by the manufacturer or by the laboratory, Continued
		Figure 1

-Letter from Lenny

Implant manufacturers generally fall into two categories. There are those who basically ascribe to a "system approach" to implant dentistry. That is, they market fixtures, abutments and all restorative components with the intention that the integrity of their system be maintained.

Some of these same manufacturersas well as other implant companiesalso market products which they claim are exactly like another system's fixtures and components and are therefore interchangeable. I refer to these products as "compatibles."

Between the various systems and the compatibles, the number of possible implant configurations (fixture, abutment, coping, etc.) nearly boggles the mind. Add to that the complexity of cases that involve multiple posts all with mixed component configurations.

For the past four years, I've been collecting extensive data on implant cases for the purpose of documenting procedures, materials and the results of various mixed configurations. In this way, we have been able to evaluate and devise effective laboratory techniques that yield the best esthetic and mechanical results with what I call "mix 'n match" components.

Also, as part of my research, I have acquired Xrays of mixed configurations from customers who have asked to remain anonymous. As you can see from Figures 1 and 2, the so- called "compatibles" may not be as precise as their manufacturers would have you think. Some have a tendency to be problematic. I believe that when using mixed configuration posts or compatibles, doctors should be fully aware of possible clinical risks and technical complications. This too has been one of our research objectives.

Figure 2

Casted abutments also raise concerns regarding the precision of casted vs. milled components. Again we must add that from our years of experience with various implants, it is our opinion that milled components offer a more precise fit than casted parts.

The Complexity of Multiple
Mixed-Component Configurations

Imagine a case, referred to you after all surgical procedures have been completed, where the surgeon had used different combinations and sizes of fixtures and abutmentsall from different manufacturers. For the sake of illustration, we made up this extreme scenario. But as a restorative dentist you could find yourself in a similar situation, made all the more disconcerting if you had not been prepared for it by a preplanning consultation with the surgeon.

In these circumstances, we refer to our four years of documentation on "mix 'n match" cases to discern what effect different abutment angulations and sizes may have on the esthetics and mechanical functioning of the prosthesis. We would also recommend an impression technique we think would provide the most accurate prototype.

For example, the problem shown in Figure 2 could easily have been avoided had the impression coping been prechecked against a real fixture and an analog prior to taking the impression.

Mixed configuration cases generally require modified laboratory procedures to adjust to the varied designs and heights of different abutments. It may even necessitate the fabrication of a custom-made component. At Leonard Marotta Dental Studio, we've developed special laboratory proceduresfrom second stage surgery to finished prosthesisthat yield effective results.

Good esthetics can be achieved with "mix 'n match" implant configurations but they can also result in unexpected technical challenges. Careful case planning and an experienced laboratory can help optimize the esthetic and mechanical potentials of mixed component configurations.

For a consultation or to
arrange a study club presentation on working with “mix and match” configurations, please contact Leonard Marotta at 866-627-6882 or 866-Marotta