Written by Richard Winter, DDS Tuesday, 30 June 2009 19:00
In our current economic climate, we have to ask ourselves what our patients are going through in their personal financial lives. While many people may put off vacations or other creature comforts, they often arrive at the realization that they must do something about their oral health. Unfortunately, if we are dogmatic with our treatment planning options, or are too zealous with our plans, then these patients may be lost as “long-term” dental patients. They may even resolve themselves to long-term denture use.
“Upgradeable Dentistry” is a concept that allows people the dignity to choose options that will improve their oral health in a sequential fashion; based on their emotional, financial, and personal readiness. If a patient is only given the option of “denture dentistry,” they will lose bone, experience greater mouth discomfort, lose ability to masticate properly, and experience digestive problems. As a result of denture wear, bite force is decreased from 200 psi to 50 psi, and may go down to 6 psi after 15 years of denture use.1 According to Millennium Research Group report2 and Misch,1 34.9 million people were older than 65 years of age in 2000 and 86 million people will be older than 65 years of age by the year 2050. The average rate of total edentulism is 20% at age 60 years for the United States. The percentage of edentulism in one or both arches totals more than 30 million people. These numbers highlight the vast dental disease that we need to address in our practices.
As presented in Part 1 of this article series, dentistry is a dynamic process, not a static event. So the ability of the dentist to help patients within acceptable parameters will allow patients to continually choose an “upgrade path” that will result in complete dentistry being performed at a time frame and cost that is agreeable to the patient.
Figure 1. The patient presented with an upper and lower immediate denture with a “gummy smile.”
|Figure 2. A Lang Duplicate of her denture fabricated in office, with tissue conditioner for diagnostic purposes.|
|Figure 3. A lead foil wrapped circumferentially for a cephalometric analysis of her ridge.||Figure 4. A functionally generated impression of the mandibular denture. Barium sulfate markers are employed to locate the proposed A-P spread and location of the mini-implants.|
Figure 5. The maxillary functional impression with barium sulfate markers and a build-out of the labial neutral zone. The markers are used to visualize anticipated mini-implant location.
Figure 6. Panoramic x-ray showing the barium sulfate markers and their proximity to anatomic landmarks (ie, sinus, mental foramina).
|Figure 7. A ball burnisher was used to identify the mental foramina via palpation with subsequent marking prior to anesthesia.||Figure 8. A finger driver was used to carry and initiate placement of the mini-implants.|
|Figure 9. A thumb driver was used to further deliver the mini-implants.||Figure 10. A ratchet wrench was used to finalize placement with respect to the bone and gingival landmarks.|
A 36-year-old female presented to our office with upper and lower immediate dentures. She could not retain them in her mouth without gagging, had constant pain when they were in place, and was severely depressed over the poor aesthetics and unsatisfactory outcome she had experienced. Her reason for the placement of immediate dentures had been the presence of significant decay. She had no history of periodontal disease. Since extractions were done without alveolar modification, the denture flanges and tooth placement precluded an ideal aesthetic result. The patient made the remark, “If I had known how miserable this was going to be, I would have never let that dentist pull my teeth.” This underscores the importance of educating our patients as to all aspects of edentulism before we pick up the forceps.
This patient was in good general health, without any medical problems. She was financially challenged since she had to pay for the extractions and dentures, and very concerned about her financial situation. In order to allow our patient to afford treatment, we phased her treatment, utilized CareCredit (a nonrecourse payment plan) to allow her to spread out payments “interest-free.” This took care of her financial concerns before we began her treatment.
In Figure 1, the “gummy” smile of our patient’s dentures is apparent. What you cannot see is the lack of retention that she experienced with the denture, and the palatal overextension of the prosthesis.
Upon discussion of the advantages, disadvantages, benefits, risks, and alternatives, we decided to begin her treatment with mini-implant supported overdentures. Typically, a discussion of “Upgradeable Dentistry” will involve traditional implants first with overdentures, hybrid prostheses, or fixed bridgework. The use of mini-implants is another “tool in the shed,” for rehabilitation. They have been approved by the US FDA for long-term use, and are very useful for establishing retentive elements in denture prostheses. In Figure 2 one can see the Lang Duplicate denture that was fabricated to aid in evaluating the bone and creating a barium sulfate stent for radiographic evaluation. In addition, these duplicate dentures were used as a tool for creating functionally generated impressions, a technique for achieving a superior-fitting prosthesis. An integral foundation for ideal full-mouth rehabilitation is to understand complete-denture dentistry. Dr. Jack Turbyfill, one of my mentors, always used to say, “a great dentist should never go through life with a cold spatula.”
The establishment of proper occlusal vertical dimension, aesthetics, phonetics, and function are essential to establishing long-term success. Holes approximating the position for the desired implant placement were drilled using a No. 6 round bur (KOMET USA). Then, clear Triad Gel (DENTSPLY Trubyte) was mixed with BaSO4 2- powder in a ratio of 3 to 1. This was put into a used flowable composite syringe, injected into the intaglio of the denture to the desired pilot depth, and light-cured to establish an optimal A-P spread. Figure 3 shows a lead foil (from a radiographic film), that was wrapped around the lower duplicated denture. This was used to check the angle of the mandibular bone, undercuts, and shape of the ridge with a cephalometric radiograph. (An occlusal film on a tongue depressor blade held across the lower mandible is a suitable replacement.)
Figures 4 and 5 show the functionally generated impressions that were made with a tissue conditioning material (Hydrocast [Kay See Dental]). The barium sulfate markers are seen as white dots through the tissue conditioner. A panoramic x-ray (or a CAT scan) can then be taken to evaluate the barium sulfate markers in relation to anatomic landmarks (Figure 6). Notes can be made as to the need to move an implant forward or back in relation to these markers, in the process of determining ideal implant placement positions. Palpation of the mental nerve with a ball burnisher prior to anesthesia helps confirm this important landmark (Figure 7). Indelible marker (or marking sticks) can be used to transfer all of this information intraorally at the time of surgery.
|Figure 11. Six mini-implants in the mandibular arch, after 3 years in service.||Figure 12. Six mini-implants in the maxillary arch, after 3 years in service.|
|Figure 13. Panoramic radiograph showing the patient immediately post-surgery for mandibular mini-implants.||Figure 14. Panoramic radiograph showing all 12 mini-implants. Note their parallelism.|
Figure 15. The maxillary denture was delivered with hydrocast tissue conditioner at the time of surgery.
|Figure 16. The mandibular denture was delivered with a tissue conditioner at the time of surgery.|
|Figure 17. The mandibular mini-implant supported, metal-reinforced overdenture.||Figure 18. The maxillary mini-implant supported, metal-reinforced overdenture.|
Figure 19. Postoperative smile photo of the final prostheses.
|Figure 20. Full-face photo of the patient, after 3 years in service.|
Patients are anxious to receive dentistry that will help solve their problems. This patient was extremely nervous and distrustful at the onset of treatment. Denture fabrication began with bite blocks, rims, and tooth set up and was approved before any surgical intervention, to ensure that her aesthetic desires could be met. Furthermore, by using Lang Duplicate dentures, we were able to trim extensions, add a tissue conditioner, and to insure that she could in fact tolerate wearing a denture.
As I was confident she would have implants and bridges later in her life, I was extremely reticent to remove bone. Alveloplasty may have made denture set up easier but that bone would be difficult to regenerate at a later date, so we went ahead and it wasn’t until we had full approval of denture aesthetics that surgery was accomplished.
A finger driver was used to deliver the mini-implant after perforation of the cortical plate with the 1.2 mm pilot burr (Figure 8). A thumb driver was used to further advance the implant (Figure 9) and a ratchet wrench was then used to finish implant placement (Figure 10). Ideal mandibular and maxillary arch mini-implant placement was achieved (Figures 11 and 12) as verified in panoramic radiographs that were taken after implant placement (Figures 13 and 14). Parallelism and a great anterior-posterior spread for the implants were achieved. Since mini-implants are used as retentive elements and not meant to support the load of the masticatory forces, the large spread allows the dentures to sit evenly with less of a propensity to rock.
While the protocol for mini-implants allows for immediate loading of the implants at the time of surgery, I prefer to use tissue conditioning material for 4 to 6 weeks to decrease immediate load forces. This also allows for evaluation of the health of the implants and to ensure patient comfort prior to completion of the final prosthesis completion (Figures 15 and 16). It is very easy to finalize the denture by modifying the tissue conditioner until it is even, to verify that the borders are of adequate size and width, and to make sure the “neutral zone” of tooth and gum placement is acceptable prior to final prostheses completion.3,4
My protocol for denture fabrication includes the use of metal bases in order to create thinner and more comfortable prostheses, improve temperature differentiation and tactile sensation, and to increase the strength of the dentures. Metal is used judiciously (Figure 17 and 18) so that relines can be accomplished in the future as peripheries remain in acrylic. In addition, acrylic is left around all keeper caps so that they can be removed in the event an implant is lost in the future. The retentive elements can be picked up directly in the mouth, or fabricated indirectly at the lab.
I removed the palatal vault of the denture and used a metallic U-shaped partial denture design to satisfy the patients’ desires and eliminate her fear of gagging from the dentures. In an article by Tarnow, small diameter implants that are unsplinted can be successful in retaining a maxillary overdenture with partial palatal coverage.5
The patient’s final smile and full-face photos (Figures 19 and 20) show the improved cosmetic outcome. The patient has expressed no desire to continue with further implant dentistry.
While some might not feel comfortable with utilization of mini-implants, it is clear the patient treated in this case had her needs met and was happy with the results. This is a case where we have “done no harm” and have improved a patient’s life.
In a personal communication with Dr. Charles English before he passed away, I asked him if he ever felt the need to offer traditional implants to patients after they have worn mini-implants. He said that he never had to take mini-implants out to offer a different option as his patients were primarily denture patients who loved their outcomes. With baby boomers and younger patients, however, the need to “upgrade” should never be overlooked.
The key to success in these difficult economic times is to help patients move forward. The tools we have to do this involve mini-implants, small diameter 3.0 mm traditional implants, Locator attachments, ERA’s, or other implant retentive devices with or without the use of bars. We can use screw-retained or cementable hybrid prostheses, or fabricate implant-supported bridges, bringing us full circle from edentulism. Our denture patients can become dental patients and eat with chewing forces approaching what they had when they were fully dentate. In future articles, I will expand on these concepts and highlight the need in this economic climate to help patients achieve the dentistry they can afford and desire in sequential fashion.
Dr. Winter would like to thank Ara Nazarian, DDS, for his mentorship and guidance in providing the proper training needed to implement mini-implants in his practice.
- Misch CE. Contemporary Implant Dentistry. 3rd Ed. St. Louis, Mo: Mosby; 2008:5-18.
- Conference proceedings: Dental implants. National Institutes of Health Consensus Development Conference. June 13-15, 1988. J Dent Educ. 1988;52:686-691.
- Turbyfill WF. Impression techniques for removable partial dentures. Gen Dent. 2001;49:358-364.
- Turbyfill J. Excellence in complete dentures. Dent Econ. 1994;84:80-81.
- Cavallaro JS Jr, Tarnow DP. Unsplinted implants retaining maxillary overdentures with partial palatal coverage: report of 5 consecutive cases. Int J Oral Maxillofac Implants. 2007;22:808-814.
Disclosure: Dr. Winter reports no conflict of interest.
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