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Compendium

July/August 2013, Volume 34, Issue 7
Published by AEGIS Communications


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

Barry P. Levin, DMD

Abstract: Immediate restoration of full-arch dental implants in the mandible has become a clinically validated mode of therapy. Converting an existing removable denture to a provisional fixed prosthesis can be an economical option for patients who may have financial restraints. In this case of an elderly patient who desired a fixed restoration for her edentulous mandible, traditional methods of diagnostics and treatment were executed. The case report demonstrates the value of synergy between the periodontist and restorative dentist and the importance of communication and planning to achieve successful, cost-effective treatment.

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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 immediate3-5 and early6,7 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

REFERENCES

1. Tan WL, Wong TL, Wong MC, Lang NP. A systematic review of post-extractional alveolar hard and soft tissue dimensional changes in humans. Clin Oral Implants Res. 2012;23(suppl 5):1-21.

2. Gallucci GO, Morton D, Weber HP. Loading protocols for dental implants in edentulous patients. Int J Oral Maxillofac Implants. 2009;24(suppl):132-146.

3. Arvidson K, Bystedt H, Frykholm A, et al. Five-year prospective follow-up report of the Astra Tech Dental Implant System in the treatment of edentulous mandibles. Clin Oral Implants Res. 1998;9(4):225-234.

4. Moberg LE, Köndell PA, Sagulin GB, et al. Brånemark System and ITI Dental Implant System for treatment of mandibular edentulism. A comparative randomized study: 3-year follow-up. Clin Oral Implants Res. 2001;12(5):450-461.

5. Rasmusson L, Roos J, Bystedt H. A 10-year follow-up study of titanium dioxide-blasted implants. Clin Implant Dent Relat Res. 2005;7(1):36-42.

6. Friberg B, Jemt T. Rehabilitation of edentulous mandibles by means of five TiUnite implants after one-stage surgery: a 1-year retrospective study of 90 patients. Clin Implant Dent Relat Res. 2008;10(1):47-54.

7. Collaert B, De Bruyn H. Early loading of four or five Astra Tech fixtures with a fixed cross-arch restoration in the mandible. Clin Implant Dent Relat Res. 2002;4(3):133-135.

8. Komiyama A, Hultin M, Näsström K, et al. Soft tissue conditions and marginal bone changes around immediately loaded implants inserted in edentate jaws following computer guided treatment planning and flapless surgery: a ≥ 1-year clinical follow-up study. Clin Implant Dent Rel Res. 2012;14(2):1-13.

9. Jung RE, Schneider D, Ganeles J, et al. Computer technology applications in surgical implant dentistry: a systematic review. Int J Oral Maxillofac Implants. 2009:24(suppl):92-109.

10. Engquist B, Astrand P, Anzén B, et al. Simplified methods of implant treatment in the edentulous lower jaw. Part II: Early loading. Clin Implant Dent Relat Res. 2004;6(2):90-100.

11. Wennström JL, Bengazi F, Lekholm U. The influence of the masticatory mucosa on the peri-implant soft tissue condition. Clin Oral Implants Res. 1994;5(1):1-8.

12. Warrer K, Buser D, Lang NP, Karring T. Plaque-induced peri-implantitis in the presence or absence of keratinized mucosa. An experimental study in monkeys. Clin Oral Implants Res. 1995;6(3):131-138.

13. Chung DM, Oh TJ, Shotwell JL, et al. Significance of keratinized mucosa in maintenance of dental implants with different surfaces. J Periodontol. 2006;77(8):1410-1420.

14. Bouri A Jr, Bissada N, Al-Zahrani MS, et al. Width of keratinized gingival and the health status of the supporting tissues around dental implants. Int J Oral Maxillofac Implants. 2008;23(2):323-326.

15. Tarnow D, Emtiaz S, Classi A. Immediate loading of threaded implants at stage 1 surgery in edentulous arches: ten consecutive case reports with 1- to 5-year data. Int J Oral Maxillofac Implants. 1997;12(3):319-324.

16. Wilson TG Jr. The positive relationship between excess cement and peri-implant disease: a prospective clinical endoscopic study. J Periodontol. 2009;80(9):1388-1392.


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Image Gallery

Figure 1 Clear acrylic duplicate of mandibular denture, containing five metal hollow tubes.

Figure 1

Figure 2 Cross-sectional view of proposed implant site in the position of tooth No. 23. The metal sleeve is visualized, and the drilling direction and long axis of the planned 4-mm x 13-mm implant can be appreciated.

Figure 2

Figure 3 Direction indicators (2-mm diameter) were inserted after completing the first twist drill preparation of the five osteotomies to evaluate depth, angulation, and spacing prior to completion of site preparations and implant insertions. The five sites were pre-determined with the guide and CT scan.

Figure 3

Figure 4 Insertion of five fluoride-modified implants in the pre-planned positions. Primary stability, based on insertion torque of at least 45 Ncm, was confirmed.

Figure 4

Figure 5 The impression containing four implant replicas. A soft denture reline material was used to provide an accurate soft-tissue model, but could be removed from the stone model for restorative access.

Figure 5

Figure 6 The five implants received 4-mm-height healing abutments, which were loosely tightened, except for the central implant, which would not support the immediately loaded temporary restoration.

Figure 6

Figure 7 The pre-existing denture was modified, connecting the four temporary
abutments into the acrylic base with cold-curing pink acrylic. The center of the prosthesis was relieved to avoid contact with the healing abutment and premature, off-axis loading.

Figure 7

Figure 8 The mandibular arch is
shown restored with a fixed, hybrid restoration. The acrylic teeth and denture
base was connected to a cast metal framework and screw-retained by the five implants. Bilateral, posterior implant placement in the maxillary arch, facilitating fixed posterior bridges, was done in conjunction with remaking the existing, failing, implant-supported FPD in the incisor region.

Figure 8