A Team Approach to Cost-Effective, Full-Arch Immediate Loading

Due to predictable changes of edentulous sites following tooth extraction,¹ edentulous patients often become intolerant of their removable denture(s). The ridge resorption associated with edentulism results in ill-fitting prostheses as the underlying osseous topography becomes less accommodating of the denture. When this scenario occurs, an implant-supported fixed prosthesis can be viewed as a life-changing therapy that enhances the patient’s quality of life. One of the challenges for these patients, however, is managing their oral situation between the initiation of implant treatment and its conclusion.

Over the past decade, immediate restoration of full-arch dental implants in the mandible has become a clinically validated mode of therapy.² Various implant systems have demonstrated high survival rates for implants and prostheses used in immediate^3-5 and early^6,7 loading protocols. Options range from conversion of existing dentures into fixed provisional prostheses to digitally engineered restorations. A topic frequently omitted from the literature, however, is the reality that many of these patients arrived at their current state as a result of financial constraints, and these constraints may continue to be a factor at the time of implant therapy.

The conversion of an existing removable denture to a provisional fixed prosthesis may be less costly than some of the computer-aided design/computer-aided manufacturing (CAD/CAM) solutions currently being touted. The fabrication of a radiographic guide from processed acrylic and the manual insertion of drilling tubes can also be a means of limiting laboratory costs.

Patient Case

The patient described in this case report is an 84-year-old woman who desired a fixed restoration for her edentulous mandible. Traditional methods of diagnostics and treatment were executed. The case demonstrates the teamwork performed by the restorative and surgical treating doctors.

The patient presented to the periodontist with the chief complaint of intolerance to her mandibular denture and maxillary removable partial denture. She had been treated more than 15 years prior in another office with implant therapy to replace her four maxillary incisors with two implants and a four-unit fixed partial denture (FPD). After the periodontal dental team reviewed her medical and dental history and performed a comprehensive oral examination, the patient returned to her restorative dentist for evaluation. He fabricated a well-fitting mandibular denture and a clear acrylic duplicate denture, in which he used a mechanical drill press to place hollow metal tubes for radiographic identification of proposed implant sites and to serve as a surgical template (Figure 1).

The patient wore this well-fitting guide for a cone-beam computed tomography (CBCT) scan (GALILEOS®, Sirona Dental Systems, Inc., www.sirona.com). This facilitated identification of the proposed implant sites and relevant anatomic structures associated with these sites. It also facilitated implant planning with the appropriate software (SICAT, Sirona) (Figure 2).

Surgical Procedure

Following administration of local anesthesia, a full-thickness flap was elevated, preserving keratinized mucosa on both the buccal and lingual aspects. The same guide used for radiographic evaluation was sterilized and used to position five fluoride-modified implants (OsseoSpeed™, DENTSPLY Implants, www.dentsplyimplants.com) (Figure 3 and Figure 4).

After implant placement and prior to closure, an open-tray impression was performed (Figure 5). A soft denture reline material (GC RELINE™ Soft, GC America, Inc., www.gcamerica.com) was used to provide an accurate soft-tissue model, but could be removed from the stone model for restorative access. This impression intentionally omitted the central implant, which would serve as a “back-up” implant in the event that one of the four immediately loaded fixtures failed to osseointegrate. The model was poured in the surgical office while tall, loosely fastened healing abutments were placed, and the site was sutured (Figure 6).

At the completion of surgery, the patient presented to her restorative dentist with the poured stone model. The existing mandibular denture was modified on the benchtop rather than intraorally, incorporating four temporary abutments (TempBase, DENTSPLY Implants) (Figure 7).

After a healing period of about 10 weeks, the provisional restoration was removed for the first time. All five implants were immobile, and healthy peri-implant mucosa was evident. Impressions were taken and a fixed, implant-supported restoration was delivered (Figure 8). The maxillary arch was restored with posterior, bilateral implant placement (two fixtures on each side) and fixed restorations. The pre-existing, malpositioned implants in the lateral incisors were restored, as per the wishes of the patient, who preferred not to have these implants removed and begin treatment with new, more favorably positioned fixtures.

Discussion

The case presented demonstrates the possibilities of teamwork between the periodontist and the restorative dentist. Relatively cost-effective alternatives to other, digital methods of stent fabrication,⁸ implant insertion,⁹ and restorative therapy¹⁰ have resulted in favorable outcomes. The relatively easy process of impression taking at the time of implant placement facilitated fabrication of a screw-retained provisional restoration extraorally and without the time and costs associated with using a dental laboratory. The patient experienced the virtues of implant therapy from the very beginning of treatment without having to endure a relieved and relined provisional removable denture. The literature demonstrates that this mode of implant loading is well supported.

Several points of interest relevant to this specific patient’s situation are worth mentioning. First, the edentulous ridge was of adequate dimension for standard implant placement without the requirement of bone augmentation and achieving primary stabilization. Second, the state of soft-tissue dimensions regarding keratinized mucosa did not require grafting to provide the adequate soft-tissue thickness and keratinization necessary for long-term maintenance. While this issue is not an absolute criterion for success,¹¹ studies have demonstrated healthier soft-tissue conditions and less inflammation in those sites demonstrating peri-implant keratinized mucosa.^12-14

Also worth noting is that once the immediately delivered prosthesis was in fact delivered, it was not removed at any time during the early period of osseointegration. Tarnow¹⁵ demonstrated this to be advantageous regarding success of immediate, full-arch loading treatments. The decision to provide a screw-retained, temporary restoration obviated the need for cement and the possibility of early de-cementation and biologic complications related to submucosal presence of cement.¹⁶

Conclusion

This case report shows how the synergy between the periodontist and restorative dentist can result in a favorable and expedient outcome for a severely compromised dental patient. Communication and planning are paramount for this type of treatment to be successful.

ACKNOWLEDGMENT

All restorative steps, both temporary and definitive, were performed by Gregg Rothstein, DMD, Richboro, Pennsylvania.

ABOUT THE AUTHOR

Barry P. Levin, DMD
Clinical Associate Professor, University of Pennsylvania School of Dental Medicine, Philadelphia, Pennsylvania; Private Practice, Elkins Park, Pennsylvania

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