Enhancing Fixed Partial Denture Gingival Architecture

Introduction
The aesthetic quality at pontics, especially of long-span fixed partial dentures (FPDs), can be problematic. While fabricating a 3-unit bridge can be an easier situation in which to achieve more lifelike outcomes, especially when accomplished in conjunction with an extraction and immediate provisionalization, traditional pontic designs can still fall short from an aesthetic standpoint.¹ When presented with a situation in which a long-span FPD is treatment planned that includes both extraction and long edentulous ridge components in the anterior maxilla, an extremely challenging state of affairs can result.

This article will describe a case with just such challenges, outlining the protocol that was used to meet the patient’s functional and aesthetic expectations.

CASE REPORT
Diagnosis and Treatment Planning
A 45-year-old male first presented to our office for a problem-focused examination regarding mild spontaneous discomfort and edema at tooth No. 10. This tooth was one of the abutments of a 4-unit bridge also anchored by the other upper lateral incisor, tooth No. 7 (Figure 1). A radiograph revealed periapical pathology at tooth No. 10 with the possibility of apical fracture (Figure 2). An endodontic consultation confirmed that the tooth was hopeless, and the patient was then reappointed for his new patient examination.

At the new patient examination visit, it was determined that he had no significant periodontal disease or occlusal pathology, and his medical history was unremarkable.

Next, at the case presentation consultation visit, called the “diagnosis appointment”² in my practice, the patient was presented with a complete restorative treatment plan. Given that tooth No. 10 would need to be extracted (thus rendering his existing FPD useless), as part of this treatment plan, the patient was given all options for its replacement. These options included a removable partial denture, bridgework, and dental implants. After considering all these options, and due mostly to balancing costs with the desire to have a fixed solution for this problem, the patient elected to proceed with a new FPD.

This option presented both functional and aesthetic challenges. The patient had lost both his upper central incisors decades earlier due to trauma. Since it was obvious that tooth No. 7 would not be an adequate lone right side abutment for a bridge of this length, teeth Nos. 6, 7, and 11 were treatment planned to anchor the new prosthesis. The ridgelap pontic design used for the original FPD, while an adequate aesthetic concept in dentistry at the time (mid-1980s), is no longer state-of-the-art aesthetics in this author’s view. So, the treatment plan called for a 6-unit bridge that would include 3 serial pontics (at the teeth Nos. 8, 9, and 10 positions), one of which would be at an immediate extraction site, and 2 of which would be at a long edentulous segment of the maxillary anterior ridge.

Obtaining a natural emergence profile from the gingival architecture at an extraction site using immediate provisionalization and socket preservation with the ovate pontic design is readily achievable.³ However, attaining the same type of gingival contours at a long edentulous site would be a more formidable task, especially in this case where the patient refused ridge augmentation due to cost considerations (in light of the 2 more units that the new FPD would need). However, with this case, the resorption of the upper anterior ridge at the central incisor area was minimal compared to similar cases I had seen in my career, and I considered it sufficient to provide the requisite scaffolding needed for adequate soft-tissue support. “Sounding” the abutment teeth also indicated that the hard- and soft-tissue foundation here would be acceptable with regard to attaining the desired porcelain contours.⁴ This, along with the fact that the patient’s upper canine apices were effectively long enough to support the planned bridge, made the case, in my opinion, feasible within its limitations.

Figure 1. The patient’s clinical presentation at his first visit.	Figure 2. The radiograph revealed periapical pathology at tooth No. 10 with a possible apical fracture.
Figure 3. The provisional fixed partial denture (FPD) in place 2 weeks after surgery.	Figure 4. The provisional FPD in place 12 weeks after surgery.
Figure 5. A frontal view of the patient’s final sulcular development.	Figure 6. A right lateral view of the patient’s final sulcular development.
Figure 7. A left lateral view of the patient’s final sulcular development.	Figure 8. A frontal view of the patient’s definitive FPD at 6 months post-placement.
Figure 9. A right lateral view of the patient’s definitive restoration at 6 months.	Figure 10. A left lateral view of the patient’s definitive FPD at 6 months.

Clinical Treatment
The protocol in proceeding with this case included atraumatic extraction of tooth No. 10, which required coordination with an oral surgeon. If I ever have any doubts about my ability to atraumatically extract a tooth in an aesthetically sensitive case, I always refer the patient to my oral surgeon. I discussed this case with the surgeon, outlining the need for atraumatic extraction and socket preservation at the extraction site, also requesting that he create 2 sulci at the teeth Nos. 8 and 9 positions using a tissue punch.⁵ I intended to develop these sulci into an aesthetically appropriate gingival form and preserve the gingival architecture of the tooth No. 10 extraction site using immediate fixed provisionalization in the ovate pontic design.

Proper communication with the dental laboratory team tasked to create the fixed provisional prosthesis was essential to the success of the case. The patient was appointed at our office between the surgeon’s consultation and the surgery date to take all the records needed for fabrication of the fixed provisional bridge (BioTemps [BDL Prosthetics]). While it is routine for a laboratory technician to remove a tooth from a stone model and to create a sulcus to that reference point, instructing laboratory personnel on placement of the proposed sulci to be created in the mouth on the edentulous portion of that same stone model is another matter. Detailed marking of the model with an in-depth explanation to the laboratory coordinator of the rationale and parameters for the procedures involved is a must. In this way, a provisional FPD was created that would fulfill its purpose in the development and preservation of the soft-tissue shapes desired.

Next, coordination of visits between our office and the oral surgeon’s was critical. Appointments were made at the 2 offices such that the patient arrived for preparation of the abutment teeth and placement of the provisional prosthesis about 20 minutes after the surgery was completed. Then, the process of soft-tissue development was begun. Throughout approximately 4 months, the provisional bridge was augmented and recontoured as necessary to promote the establishment of the desired marginal and papillary appearances (Figures 3 and 4). At this point, it should be noted that there are some who say that true papillae cannot be produced through this process as, by definition, using the term papilla implies an attachment to the proximal hard structures that cannot occur in this instance. Rather, the created gingival configurations should be characterized as “tissue triangles,” in their view.⁶ Others believe that there is an attachment of sorts fashioned here, as the created sulci epithelialize around the ovate pontics, molding into an attachment like a suction cup intimately covering first the acrylic of the provisional, and then the porcelain of the definitive FPD.⁷ They contend that this type of attachment prevents the invasion of debris and plaque under the ovate pontics. With the latter in mind, I instructed the patient to floss only on either side of the abutment teeth to prevent disruption of the epithelial attachment.

As with any smile design case, I advised the patient to evaluate the provisional bridge on a daily basis as an aesthetic reference point from which he could make decisions about any changes that he might wish to make in the definitive bridge. As this aesthetic assessment by the patient should never be rushed, the 4-month healing time period here served a dual purpose.8 After healing of the extraction site was complete and development of the soft tissue had been fully realized (Figures 5 to 7), the patient had also decided what aesthetic changes he wished to make in the definitive prosthesis. These changes included subtle contour modifications along with a slight shade alteration. Interestingly, the patient’s natural canines had unusually extensive cingula that were not reflected in the provisional FPD. The patient requested that they be present in the definitive bridge.

At this juncture, the patient was appointed to redefine the margins of the abutment preparations and have the final impression taken for the definitive bridgework. The master cast generated from this impression (EXAMIX NDS [GC America]) clearly displayed the gingival contours that had been produced by the provisional FPD. A soft-tissue model was also generated to further refine and imitate the porcelain (Elite Porcelain System [Arrowhead Dental Laboratory]) of the ovate pontics to the resulting gingival framework. At the next appointment, after the aesthetics of the definitive bridge (Captek Bridge [Argen]) had been approved by the patient and its functional parameters verified, the prosthesis was luted to place (RelyX Luting Cement [3M ESPE]), with no adjustment required.

CLOSING COMMENTS
While oftentimes, traditional ridge lap pontics have been used for anterior bridges over long edentulous spans, especially on the maxilla, there is a more effective way to enhance the aesthetics of such cases. When an extraction site and immediate provisionalization are also involved under these circumstances, this type of situation can be an even greater challenge. However, with reasonable case selection, creative treatment planning, proper sequencing, timely interdisciplinary coordination, and precise implementation, a more natural-looking result can be produced. Although this protocol requires significant time and patience, the outcome achieved more than justifies the length of treatment time. It gives the patient an ample opportunity to fully assess whether his or her aesthetic desires are being fulfilled in the contours, shade, and alignment of the prosthesis even as the soft-tissue framework is being developed. This results in a marriage of soft tissue and porcelain that appears as a continuous whole (Figures 8 to 10).

The dental clinician will often be presented with a case in which older bridgework exhibiting an erstwhile aesthetic standard needs to be replaced. In those instances in which the patient does not opt for dental implants, a new approach is required to meet the current standard of vitality. While such situations can be challenging (especially if other limitations are involved), proper treatment planning, laboratory communication, and clinical implementation will create a result that both satisfies the patient and is rewarding to the doctor.

Acknowledgements
Dr. McArdle would like to thank Dr. Daniel DeTolla for his expertise in oral surgery while collaborating on this case, Mr. Josh Gall and his talented team of technicians at BioTemps dental laboratory for the provisional restoration shown in this article, and Mr. Ray LeGendre and his talented team of ceramists at Arrowhead Dental Laboratory for the definitive restoration shown in this article.

References

1. Johnson GK, Leary JM. Pontic design and localized ridge augmentation in fixed partial denture design. Dent Clin North Am. 1992;36:591-605.
2. Barnes R. Creating the successful cosmetic practice [Lecture]. Presented at: Seacoast Esthetic Dentistry Association; October 4, 2002; Portsmouth, NH.
3. McArdle BF. Creating natural gingival profiles using the ovate pontic technique. Dent Today. 2004;23:97-101.
4. Tarnow DP, Magner AW, Fletcher P. The effect of the distance from the contact point to the crest of bone on the presence or absence of the interproximal dental papilla. J Periodontol. 1992;63:995-996.
5. Kinsel RP, Lamb RE. Development of gingival esthetics in the edentulous patient prior to dental implant placement using a flangeless removable prosthesis: a case report. Int J Oral Maxillofac Implants. 2002;17:866-872.
6. Smith RB. Implant dentistry from start to finish: a combined surgical and prosthetic approach to modern esthetic implant reconstructions [lecture]. Presented at: Seacoast Esthetic Dentistry Association; May 4, 2012; Portsmouth, NH.
7. Weigl P. Current concepts in implant dentistry [lecture]. Presented at: Goethe University; June 26, 2012; Frankfurt am Mein, Germany.
8. McArdle BF. Co-diagnosis in smile design: involving patients in the ownership of their outcomes. Dent Today. 2008;27:136-138.

Dr. McArdle graduated from Tufts University School of Dental Medicine in 1985 and has been practicing general dentistry on the New Hampshire seacoast ever since. He has served on the active medical staff in dentistry of Concord Hospital in Concord, NH, and on the board of directors of Priority Dental Health (prioritydental.com), the New Hampshire Dental Society’s Direct Reimbursement entity. He is a co-founder of the Seacoast Esthetic Dentistry Association (dentalesthetics.com), which is headquartered in Portsmouth, NH. He is the founder of Seacoast Dental Seminars (seacoastdentalseminars.com), also headquartered in Portsmouth. He has authored numerous other articles internationally in major peer-reviewed publications. He can be reached at (603) 430-1010, via e-mail at drmcardle@seacoastdentalseminars.com, seda@dentalesthetics.com, or by visiting mcardledmd.com.

Disclosure: Dr. McArdle reports no disclosures.