Current Clinical Solutions For a Single Missing Tooth: MID Techniques

The single missing tooth always presents treating dentists with multiple treatment options to consider and present. Even though implants have proven to be a highly successful restorative option, there are many patients who are not good candidates, or who do not wish to pursue that option. When a patient has a single missing tooth and is not a surgical candidate the treatment options begin to narrow. Then, when the edentulous area is between 2 teeth that have never been restored, the conservative-minded dentists have very limited options. One option that is appealing in this clinical situation is the inlay bridge. It allows for maximum preservation of natural tooth structure, while being able to replace the missing tooth using a fixed prosthetic solution.
The following is a case history of a single missing posterior tooth in a patient who was not interested in a surgical solution and how it was resolved to the satisfaction of the patient and the dentist.

CASE REPORT

Figure 1. Preoperative condition; missing tooth No. 13.

A 40-year-old female presented in our office with a missing tooth No. 13 (Figure 1). The patient was given the option of a single-tooth implant. She was adamant that she did not want any surgery, and she stated that she would prefer no treatment if an implant was the only option. Given the patients stance on possible implant treatment, the option of placing a bridge was presented and she was very interested in this option.
Since the teeth mesial and distal to the edentulous area were not previously restored, there was some hesitancy to prepare these teeth for a conventional 3-unit bridge. The patient was presented with the option of having a 3-unit conventional full coverage PFM bridge, or an inlay bridge. The risks and benefits of each were discussed. The idea of the inlay bridge appealed to the patient and this was decided to be the course of treatment.

A Brief History Conservative Inlay-Retained Bridges
Inlay bridges using fiber-reinforced composite have shown to have an acceptable clinical track record. Jain and Cobb1 reported satisfactory results for more than 4 years with this type of restoration. Freilich, et al2 demonstrated similar findings. Numerous case studies have been published demonstrating the use of this type of restoration. In 1997, Nixon3 and Jackson4 both published clinical examples of this technique. Later, from 1999 to 2000, Vocaturo,5 Ritter,6 and Trushkowsky7 published similar cases. All of these cases used similar techniques, used conservative principles, and had highly aesthetic results. In 2000, Crispin and Onodera8 published a case in which he placed an indirect composite resin inlay bridge with a metal substructure. This presented yet another option in inlay bridge designs.

Doctor-Technician Consultation: Material Selection and Prep Design
In consultation with our dental laboratory technician, both of the above options were discussed. The use of fiber-reinforced composite for this type of conservative bridge design has been used for a number of years with success. However, as we discussed the case in more detail, each of us became more comfortable with the idea of using a metal-reinforced inlay bridge. The dental technician explained that recently they had had great success bonding indirect composite to a high-noble gold metal substructure. As a doctor-technician team, we concluded that we liked the idea of the increased rigidity and the ability to create ideal contour in the pontic substructure. The ideal contour of the substructure would allow for proper support of the indirect composite material and for the prosthesis to withstand the higher oc­clusal forces in the posterior region. The preparation design for this case was very simple, consisting of placing 2 inlay preparations of appropriate depth, width, and that are parallel to one another (Figure 2).

Figure 2. The final inlay bridge preparations.	Figure 3. The high-noble gold substructure (Captek [Precious Chemicals]).

Because the restoration was opposing natural dentition, an indirect composite was indicated due to its minimally abrasive qualities. The metal substrate chosen was a high-noble gold material (Captek [Precious Chemicals]). This material can be designed in such a way to fit the inlay preparations, and to also allow for proper bulking and contouring of the pontic in order to provide sufficient support for the overlying indirect composite resin (Figure 3). In addition, the manufacturer of Captek has developed a special UCP coupling agent which, when applied to the gold substructure, enhances the bond strength of the indirect composite resin to the metal.
The overlying material chosen is a new indirect composite, Premise Indirect (Kerr). This material has exceptional wear characteristics and is highly aesthetic. This material has been shown to have a wear rate of 1.2 µm per year on average, based on a 5-year clinical study.9,10 This is exceptionally close to the wear of natural enamel. Combined with the improved polishability, and high clinical gloss, the biomimetic properties of this new material make it a great choice for a conservative restoration.

Figure 4. The metal substructure, shown with the layer of opaque indirect composite material applied.	Figure 5. The final restoration (Premise Indirect [Kerr]) on the model.

An opaque layer of the composite was first placed by the dental technician in order to mask the color of the metal substructure (Figure 4). Then, several more varying shades of composite were added to create a natural aesthetic appearance to the final restoration (Figure 5).

Patient Delivery

Figure 6. Two-week postoperative photo of the final restoration.

The restoration was returned to the dental office for delivery to the patient. She was anesthetized, the temporary bridge removed, and the preparations cleaned with a slurry of plain pumice (Preppies [Whip Mix]). The restoration was tried-in and evaluated for fit and aesthetics. The inlay bridge was then bonded into place using a dual-cured translucent composite resin cement (NX3 Nexus Third Generation [Kerr]). Next, the occlusion was adjusted so that there was only contact in centric occlusion. Finally, the indirect composite was repolished with a series of polishing discs (OptiDisc and Opti­Brush [Kerr]). The patient was pleased with the final result; a minimally invasive aesthetic bridge (Figure 6).

CONCLUSION
Most clinical situations present with multiple clinical solutions. Often times, there can be more than one good solution. Dentists should always remember that their dental laboratory technicians are “partners” in their practice and in their success. The success of this case can be directly attributed to the mutual respect and open communication between the clinician and the dental technician. It is also important to stay abreast of the latest material developments which will help us in meeting our patients’ expectations. This article presented an excellent clinical example of “marrying” 2 different restorative materials, Captek and Premise Indirect, to successfully create a great final result.

Acknowledgement
The authors would like to thank the artistic talents of Roger Burgess of the Dental Arts Laboratory Signature Team (Peoria, Ill) for fabricating the restoration presented in this article.

References

1. Jain P, Cobb D. Evaluation of a glass-fiber-reinforced, bonded, inlay-supported fixed partial denture – 4-year results. Compend Contin Educ Dent. 2002;23:779-792.
2. Freilich MA, Meiers JC, Duncan JP, et al. Clinical evaluation of fiber-reinforced fixed bridges. J Am Dent Assoc. 2002;133:1524-1534.
3. Nixon RL. The advent of metal-free dentistry: a versatile new fiber and polymer-glass system. Pract Periodont Aesthet Dent. 1997;9(suppl):1-7.
4. Jackson RD. Aesthetic dentistry systems: positioning advanced materials in a modern dental practice. Signature. 1997;4:6-7.
5. Vocaturo AJ. Creating a predictable and aesthetic 3-unit inlay bridge using minimally invasive techniques. Contemp Esthet Restorative Pract. 1999;3:12-18.
6. Ritter RG. Timing is everything for single tooth replacement. Contemp Esthet Restorative Pract. 2000;4:60-64.
7. Trushkowsky RD. Esthetic posterior tooth replacement using a fiber reinforced bridge. Compend Contin Educ Dent. 2000;21:80-84.
8. Crispin BJ, Onodera Y. Polymer-glass-over-metal inlay-retained FPD: a conservative alternative. Contemp Esthet Restorative Pract. 2000;4:78-84.
9. Suzuki S, Cox CF. 5-year study. UAB Internal Report to Kerr Corp, February 29, 1996.
10. Givan DA, O’Neal SJ, Suzuki S. 8-year study. J Dent Res. April 2000;79(spec issue): Abstract No. 1523.

Dr. Radz maintains a private practice, Cosmetic Dentistry of Colorado, in downtown Denver. Currently, he is on faculty at the University of Colorado School of Dentistry’s Restorative Department. Over the course of the last 14 years, Dr. Radz has lectured internationally teaching the materials and techniques used in cosmetic dentistry. He has published more than 120 articles and serves on the editorial board of 8 dental publications including the Journal of Cosmetic Dentistry. He can be reached at (303) 298-1414 or visit radzdds.com and garyradz.com.

Disclosure: Dr. Radz reports no conflict of interest.

Mr. Stubblefield has more than 27 years of experience as a dental technician with Dental Arts Laboratories (DAL), Inc. He currently is the technical director of the DAL Signature Restorations Laboratory, a division of DAL specializing in highly aesthetic restorations. As an experienced and highly talented technician, Mr. Stubblefield’s primary focus is in cosmetics and reconstructive cases. He has received extensive training from the Spear Institute, the Dawson Center for Advanced Dental Study, the Ross Nash Institute, Cranham Dental Seminars, the Midwest Center for Advanced Dental Education, and the Aesthetic Advantage Midwest. He also works very closely with such esteemed practitioners as Drs. Ross Nash, Robert Lowe, John Cranham, and Gary Radz. As both a guest lecturer and a DAL representative, he travels nationally for DAL, attending as many as 20 seminars each year. He is also a published author. He can be reached at jstubblefield@dentalartslab.com.

Disclosure: Mr. Stubblefield reports no conflict of interest.