The Implant-Retained Overdenture: Transitioning a Hopeless Maxillary Arch

INTRODUCTION
Cone beam CT (CBCT) imaging has been the foundation of my complete dental examination since 2009. Incorporating the digital technology of CBCT imaging and producing a computer-assisted surgical guide for safe and precise implant surgery provides a direct patient benefit unmatched by 2-D imaging and conventional implant surgery. The enhanced 3-D imaging becomes the basis for any clinical decisions rendered and helps me manage treatments for even the most complex problems created by catastrophic dental disease. Replacing and restoring a decimated dentition with an implant-retained overdenture can be accomplished without difficulty, even though these types of cases require extensive treatment to overcome the complexities of advanced breakdown of both hard- and soft-tissue anatomy. Success comes by mastering the plan before executing the plan.

Outline of the Clinical Protocol and Objectives
The initial patient visit at my office will include all the conventional diagnostic modalities, a review of the patient’s medical history, an oral examination, clinical and periodontal charting, 2-D periapical x-rays, diagnostic casts, photographs, and a patient interview. Indications for the use of CBCT imaging in my office are complex dentistry and full-mouth rehabilitation, as CBCT provides indispensable information when diagnosing and treatment planning these cases.1,2
My goal for each and every patient I work with is to do the following:
1. Perform a proper diagnosis.
2. Educate patients as to what their problems are, address their chief complaints, and determine what their desires are and how I can provide solutions for their conditions.
3. Create a customized, pragmatic treatment plan with low risk.
4. Gain case acceptance.
5. Deliver optimal and successful dental treatment.
6. Provide positive patient experiences and create patient advocates for modern dentistry.
The following case report will describe how a complex dental case was managed and will also demonstrate the important contribution that digital technologies provided in achieving a superior outcome. I will delve into all the procedures and treatments rendered to one devastated and desperate patient who was returned to form and function with a transformed smile. Managing these types of cases can be overwhelming if a pragmatic approach is not developed that treats the patient from both a physical and psychological standpoint.

CASE REPORT
Diagnosis and Treatment Planning
A 53-year-old female presented with a failing and painful dentition and a lack of confidence and desire to smile again (Figure 1). Life’s circumstances had precluded treatment to improve her condition prior to visiting our office. The patient’s initial oral examination and radiographs showed extensive bone loss and extremely hyper-erupted posterior teeth (Figure 2). The gingival tissue was inflamed and bled readily upon probing. Periodontal pocketing was generalized at 5.0 to 9.0 mm, and multiple teeth exhibited Class II mobility with pain upon mastication. She knew something had to be done and she was finally ready to proceed with treatment. It had been many years since she had last seen a dentist and, at that time, periodontal therapy was attempted to maintain her dentition. Unfortunately, the treatment was ineffective and painful, causing her to become more fearful of any additional dental treatment. Struggling with painful, unaesthetic, and mobile teeth left her with few choices to improve her condition. Her diagnosis of advanced periodontitis would lead to the eventual loss of all remaining maxillary teeth. This left her with only 3 options: an immediate complete upper denture, a removable implant-retained prosthesis, or a fixed implant-retained prosthesis.

Figure 1. Initial intraoral view.	Figure 2. Periapical radiograph of teeth Nos. 2 and 3 showing severe bone loss.
Figure 3. The 3-D panoramic radiograph: the initial implant proposal.	Figure 4. The postoperative bone grafts pan view.
Figure 5. The implant planning report.	Figure 6. A cross-sectional view of the virtual implant at the site of tooth No. 5.

The patient’s confidence was gained when I explained that we would proceed as fast, or as slow, as she desired. Also, based upon her financial budget, we would devise a logical treatment plan to improve her condition and satisfy her psychological and physical needs. During our initial conversation, she made it clear that it was not an option to plan her treatment with full-arch extractions and an immediate complete upper denture. Emotionally, she was not ready to become edentulous. A possibility of retaining 3 to 5 natural teeth was considered. Extensive periodontal treatment, including osseous surgery, and retaining any missing teeth via a removable partial denture was deemed a poor option. The remaining natural teeth would not be very useful retainers for the partial denture and she quickly declined this choice. Her budget, and fear of more extensive oral surgery, would not allow for sinus augmentations that would be necessary for a fully fixed implant-retained prosthesis. So, the option of a conventional 8 or 9 implant-retained case type was not possible, nor was an All-On-4 case type. The only feasible option for this patient was an implant-retained overdenture.
In our office, we always begin our diagnostics with an enhanced 3-D scan in complex cases (Figure 3). Utilizing the concept of co-diagnosis through a 3-D interactive visual analysis, in conjunction with a non-confrontational dialogue, the clinician provides the patient with the appropriate information to make an informed and educated decision. Conveying a sense of optimism and hope gave our patient the assurance that we were the right dental team to improve her smile and to give her back the confidence she had lost as her dentition worsened. Through co-diagnosis, the patient became a partner in her own dental care. We could now explore the options available by providing solutions for her desires while addressing her concerns. Our patient’s budget may have impeded a fixed rehabilitation at this time, but I had planned to keep this option open if finances became available in the future to upgrade into this treatment. The initial and long-term goals included improving her appearance; removing any painful teeth; and inserting a replacement prosthesis that improves chewing capabilities and is stable, retentive, and functional. Significant treatment is usually necessary in these cases, and we planned to minimize complications and treat without surprises by using the benefit of practicing with the 3-D difference. Assessing the bone volume and quality prior to and after bone grafting is critical for the dentist to make evidence-based clinical decisions. Our patient was not ready to become edentulous and preferred to be eased into a complete upper overdenture. I planned on transitioning the maxillary arch into a fixed-provisional prosthesis while strategically removing useless natural teeth, bone grafting, and preparing for the implant dentistry. Implant dentistry was the only viable option to retain a replacement prosthesis and avoid a conventional complete upper denture.3
Urgent care was rendered by extracting teeth Nos. 2 and 15. The first CBCT scan was obtained after the patient’s chief complaint was addressed. Next, tooth No. 3 was removed and grafted. I sent mounted diagnostic casts to Glidewell Laboratories (Newport Beach, Calif) to fabricate a BioTemps fixed provisional bridge for teeth Nos. 4 to 13. A number of in-office temporaries were fabricated until teeth Nos. 5, 11, and 12 were removed and grafted with a mineralized allograft material (Puros Bone [Zimmer Biomet]). The patient remained in these temporaries for 4 months while the bone grafts matured.4

The Implant Plan and Implant Surgery
The definitive implant treatment plan was to place 4 implants while avoiding vital structures (ie, maxillary sinuses) and making use of the bone volume present (Figures 4 to 6). The CBCT imaging revealed that we could not implant in the upper left quadrant posterior to the No. 11 and 12 sites, as it would penetrate the maxillary sinus. The CBCT scan obtained with 7 remaining natural teeth was used to facilitate the production of a tooth-supported surgical guide (SICAT CLASSICGUIDE [Dentsply Sirona]). Immediate implants were virtually planned and actually placed with a concomitant bone augmentation to ensure 2.0 mm of buccal bone thickness. Since the buccal plate is usually 1.0 mm or less, adjunctive bone grafting would be necessary to provide the 2.0 mm of labial thickness that is required to protect the crestal implant periodontium.5-7 The posterior implants were installed in grafted bone and placed anterior to the maxillary sinuses. NobelActive (Nobel Biocare) implants (5- x 10-mm fixtures for the No. 5 and 12 sites, a 4.3- x 15-mm fixture for the No. 7 site, and a 4.3- x 13-mm fixture for the No. 10 site) were placed and torqued to 35 Ncm. Both diameter fixtures utilize the same prosthetic platform and can accommodate a simple LOCATOR Abutment (Zest Dental Solutions), allowing the clinician to take advantage of a wider fixture and gain more surface area for increased bone-to-implant contact. These tapered implants have an aggressive thread design and can be placed in undersized osteotomies to increase initial stability during immediate implantation. Cover screws were placed, and the implants and bone were covered by a resorbable collagen membrane8 (Figures 7 to 11).

Figure 7. An arch ready for implants with new provisional crowns in place.	Figure 8. The fitted tooth-supported surgical guide (SICAT CLASSICGUIDE [Dentsply Sirona]).
Figure 9. The guided implant osteotomy at the tooth No. 12 site.	Figure 10. Immediately following post-implant placement at the sites of teeth Nos. 5, 7, 10, and 12.
Figure 11. The cross-sectional view of the immediate implant and contour buccal bone graft in at the tooth No. 10 site.	Figure 12. BioTemps (Glidewell Laboratories) fixed provisional.
Figure 13. Transitioning into the overdenture, showing the LOCATORS (Zest Dental Solutions) and pick-up of female housing caps for the provisional.	Figure 14. Pick-up of LOCATORS to retain the provisional prosthesis.

The surgical guide ensured the accurate transfer of the virtually planned implant positions and that the osteotomies performed into the extraction sockets were properly drilled and did not drift to the labial, preventing the potential fenestration of the apical extent of the preparation.7 Guided implant surgery was completed successfully, and the provisional (BioTemps) was cemented on the remaining natural teeth—Nos. 4, 6, 8, 9, and 13.9 This would be used as an interim prosthesis to allow for the complete integration of the 4 installed implants (Figure 12). The patient was premedicated with amoxicillin 500 mg (2 doses one hour prior to the appointment and one TID for 7 days); 800 mg Ibuprofen one TID, as needed for pain; and a Medrol 4-mg dose pack taken, as directed, to control inflammation. The use of preoperative antibiotics may be helpful in preventing early implant failures.10

All-Acrylic Interim Overdenture
In preparation for the next phase of treatment, a complete denture was set up to maintain the vertical dimension of occlusion (VDO) with the interocclusal space needed for an implant-retained overdenture. Using a removable overdenture requires at least 10.0 mm or more of interocclusal space so that individual retainer abutments can be used. The 4 LOCATOR Abutments, previously selected based upon the existing sulcular depth, were torqued into the implants. Then, 4 male processing housings were picked up in the processed overdenture using Quick Up Luting Material (VOCO America). The 5 remaining natural teeth were removed and bone grafted prior to the conversion, thus completing the transition from natural teeth to an implant-retained all-acrylic overdenture. This interim overdenture served as a trial prosthesis used to evaluate phonetics, function, occlusion, and aesthetics (Figures 13 to 16). We monitored the result of treatment to determine if alternatives would be necessary.
At a follow-up appointment, the patient reported that she was very happy with her smile and stated that her new teeth were working great, looked and felt natural, and functioned better than her own. The patient realized how neglecting herself and not presenting for treatment earlier led to the detrimental consequences and loss of her maxillary set of teeth. A bar overdenture was not considered because of the short VDO, and the case functioned well with individual freestanding LOCATORS.

Definitive Implant-Retained Overdenture
The final phase of treatment would be to produce a definitive implant-retained overdenture. A 4-month utilization trial period passed, and then we proceeded to impress at the LOCATOR Abutment level for the lab to create a new cast-reinforced horseshoe-design overdenture prosthesis. The occlusal scheme and smile design, accepted previously by the patient, was duplicated. The interocclusal space was adequate to accommodate a 10.0-mm crown height for the central incisors. The resultant aesthetic smile erased years of neglect to her overall appearance. This maxillary overdenture utilized tissue support and extended the flanges like a complete denture. An adequate anterior-posterior spread was achieved with 4 implants, and some rotation during function was expected to occur in the incisal region. Lip support was achieved and the prosthesis was stable and retentive. The patient was set up to return at 3-month intervals for maintenance (Figures 17 to 21).

Figure 15. The all-acrylic overdenture.	Figure 16. LOCATORS inserted onto implants Nos. 11 and 12.
Figure 17. Ready for the definitive prosthesis.	Figure 18. The impression transfers on the LOCATOR Abutment.
Figure 19. Final impression for the definitive prosthesis, which is ready for pouring.	Figure 20. Comparison of the overdentures.

Figure 21. The final prosthesis resulted in an aesthetic and confident smile.

CLOSING COMMENTS
The overall success of this case was predicated upon a proper diagnosis and developing a pragmatic treatment plan that was executed with precision. A positive patient experience was facilitated by using the advanced technologies of CBCT imaging and guided implant surgery with true digital interdisciplinary treatment planning. CBCT imaging was especially important when determining that bone grafting would be necessary for specific tooth sites at Nos. 5 and 12 and that implants would be delayed until adequate bone volume was present. I planned and immediately implanted the anterior sites of Nos. 7 and 10 successfully with the aid of the computer-assisted surgical guide.11-13 The transition from hopeless natural teeth to a fully edentulous implant-retained overdenture went seamlessly and was devoid of any complications. The review of high-definition imaging and the interactive 3-D analysis of the maxillofacial anatomy during the co-diagnosis visit breaks down obstructive barriers by capturing the patient’s attention and helping them understand what will be necessary to bring their dentition back to form and function. We practice life-changing dentistry by utilizing transparent diagnostics and providing solutions for even the most complex dental problems. This case satisfied all of my goals—which were set forth before any treatment was rendered—and improved the quality of this patient’s life.

References

1. Farman AG, Levato CM, Scarfe WC. A primer on cone beam CT. Inside Dentistry. 2007;3:90-93.
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3. Misch CE. Dental Implant Prosthetics. 2nd ed. St. Louis., MO: Elsevier-Mosby; 2015:130-178.
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10. Balevi B. Patients who received preoperative antibiotics showed fewer early implant failures. J Am Dent Assoc. 2014;145:1068-1070.
11. Wöhrle PS. Predictably replacing maxillary incisors with implants using 3-D planning and guided implant surgery. Compend Contin Educ Dent. 2014;35:758-768
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Dr. Ramirez has a DDS degree from New York University College of Dentistry (1983). He is a Master of the Academy of General Dentistry, a Diplomate of the International Congress of Oral Implantology, a key opinion leader for Dentsply Sirona, a CEREC Doctors mentor, a CEREC trainer, and an attending physician at New York Methodist Hospital. He maintains a practice in Brooklyn, NY, focusing on cosmetic smile design and implantology. He utilizes 3-D CBCT imaging and CEREC CAD/CAM technologies to promote a fully integrated digital dental practice and improve quality of life for his patients. He can be reached at (718) 748-3003 or via info@dranthonyramirez.com.

Disclosure: Dr. Ramirez has no disclosures to report.