Implant Overdentures

Michael Tischler, DDS


While I still believe overdentures are a valid option for a patient for full-arch tooth replacement, I now treatment plan overdentures either as a transitional option toward a zirconia implant bridge or as a final option for patients who just can’t afford anything else.

This month’s Implants Today topic is implant overdentures. Overdentures are one of a few different and important prosthetic options to replace a patient’s entire arch of teeth. Why would a clinician choose this removable option for their patient over other fixed-implant prosthetic alternatives? The answer to this question could be based on the financial cost to the patient, the clinician’s experience, the operator comfort level in providing this option, the choice for the patient with respect to manual dexterity related to hygiene issues, the use of an overdenture as a transition to a fixed prosthetic alternative, or a combination of all of these concepts.

It is important to keep in mind that overdentures are a full-arch implant prosthetic solution, and from that context, other full-arch implant prosthetic solutions have to be evaluated as part of the patient’s treatment plan. Ten years ago in my practice, 50% of my full-arch cases were bar overdentures as a full-arch tooth replacement solution. I appreciated the fact that implants were splinted with a bar, and the overdenture was mostly supported by the implants instead of soft tissue—a patient could have second molar occlusion, and a bar overdenture would fulfill the parameters of lip support, aesthetics, occlusion, and other prosthetic solutions. In 2009, I was fortunate to be featured on the cover of Dentistry Today with a model of a bar overdenture in my hand for an article entitled “The Future of Implant Dentistry for General Dentists.” The future of implant dentistry in my practice has evolved to doing more screw-retained, full-arch zirconia implant bridges instead of overdentures as a final prosthetic option. I have found that the success rate is much higher with this option than with acrylic hybrid bridges, by a large margin. There is also less maintenance with regard to the prosthesis with a screw-retained zirconia implant bridge. Overdentures, due to their inherent removable nature, create wear and tear on retentive parts. The time needed by a clinician to replace overdenture parts should be taken into consideration from a treatment planning and practice management standpoint. Discussion of the time and costs to maintain overdenture parts is important when treatment planning with a patient. There are advantages and disadvantages with each prosthetic option.

While I still believe overdentures are a valid option for a patient for full-arch tooth replacement, I now treatment plan overdentures either as a transitional option toward a zirconia implant bridge or as a final option for patients who just can’t afford anything else. As with every prosthetic option in implant dentistry, treatment planning is the most important starting point. Treatment planning is about explaining the available options to a patient while considering the individual’s lifestyle, age, economic situation, health, career, and more. As clinicians, we are looking for the right prosthetic fit for each patient.

From a clinician’s standpoint, the prosthetic steps to create an implant overdenture parallels the steps for a Misch classification fixed prosthetic 3 (FP3) option on many levels. The FP3 classification indicates that a prosthetic pink gingival area is being utilized to address bone loss from either alveoloplasty or natural causes. Patient records, impressions, verification jigs, try-ins, and other steps all have to be done. From a surgical standpoint, there are also many similarities, including similar implant positions and performing adequate alveoloplasty, to allow for prosthetic thickness. These similar prosthetic and surgical steps allow for an easy transition between overdentures and FP3 zirconia, porcelain, or acrylic options. These parallel steps between overdentures and a FP3 prosthesis become important with respect to treatment plans and how clinicians transition implant cases.

Another advantage of utilizing overdentures for treatment is the choice of utilizing a bar for overdenture support or just using overdenture attachments. This allows for much flexibility in treatment planning with a large difference in costs to the patient. Misch classifies these 2 removable restoration choices as RP4 and RP5; the RP4 overdenture is primarily supported by a bar and the RP5 is partially supported by soft tissue. Even more flexibility for the clinician exists with attachment choices for either RP4 or RP5 overdentures. Different attachments are available with regard to retention, height, and angulations. This flexibility that overdentures offer allows for ideal transitioning options as a step toward a fixed-implant prosthetic option. Often, patients can’t afford a more expensive fixed option, and an overdenture allows for transitional support of a denture that can later be converted to a fixed implant-supported prosthesis. The fixed prosthesis following an overdenture would have to be a FP3 screw- or cement-retained implant bridge, though. The only exception for overdentures being a transitional step toward a fixed implant-supported prosthesis is when the overdenture is supported by mini dental implants or implants with a fixed ball or retentive attachment. Once mini implants or fixed attachment implants are placed, the patient is then committed to a removable prosthesis. This is a very important treatment planning decision for a patient, as the future prosthesis for an arch is basically permanently decided.

This issue’s Implants Today has 2 great articles that represent many of the concepts and other information that I have alluded to in this introduction. One of our distinguished Implants Today advisory board members, Dr. Tim Kosinski, presents the article entitled, “A Sequential Approach to Implant-Supported Overdentures.” This clinical case report article exemplifies the concept of transitioning a patient to a nonsplinted RP5 overdenture from a dentate starting point. The treatment planning concepts of utilizing a CBCT scan for planning and placing implants in ideal positions with regard to the anterior-posterior spread are discussed. Dr. Paresh Patel’s article entitled, “Maximizing Stability and Prosthetic Durability,” outlines the surgical and prosthetic steps to create a screw-retained full-arch zirconia implant bridge. The implant positions, impressions, verification jigs, and try-in steps are very similar to the steps to create an overdenture.

The overdenture options available to our dental patients allow for very powerful choices for a clinician pertaining to either transitional or the final full-arch replacement. The commonality between the surgical and prosthetic steps for an FP3 prosthesis and an overdenture allows for a seamless interchangeability for treatment planning choices. An important strength of every overdenture option is the value in transitioning our patients toward a less affordable but more successful FP3 option. While every prosthetic full-arch option has advantages and disadvantages, the overdenture option has a firm hold in treatment plans for full-arch, implant-supported tooth replacement.

A Sequential Approach to Implant-Supported Overdentures

Timothy Kosinski, DDS, discusses a variety of advantages in prescribing implant-supported overdentures.

Maximizing Stability and Prosthetic Durability
Paresh B. Patel, DDS, demonstrates how implants can be used in combination with monolithic zirconia to deliver fully edentulous patients an aesthetic and long-lasting solution.

The Single-Stage Implant Procedure: Science or Convenience?
Dale R. Rosenbach, DMD, MS, addresses the question of whether there is a strong clinical rationale for immediate implant abutment placement. The risks and benefits of delayed implant abutment placement versus immediate abutment placement are reviewed. This article is peer reviewed and available for 2 hours of CE credit.