January 1999	Jorge Pinero, DDS
Contemporary Esthetics
Captek™ Innovative Esthetic Restorations

Esthetics is often the principal concern of a patient undergoing a cosmetic reconstruction of the maxillary anterior arch. Although esthetics is one of the prime concerns for dentists, there are other concerns beyond final esthetics.

Anterior Dentition Restorations

In the restoration of anterior dentitions, many dental materials can be used to give the patient and dentist optimal esthetic results. The question is, do they have sufficient strength to replace a missing tooth?

Strength, Fit, Biocompatibility, Esthetics

It is an absolute must that our restorations are strong enough to withstand the rigors of the oral environment. The fit is equally important, because the effort and expense of the restorations can be compromised by leaky margins and the resultant secondary decay. The materials also must be biocompatible and have an optimal esthetic result. This is often a challenge when selecting materials for specific results that will address all of the above concerns.

Materials of Choice

This article describes the use of two different esthetic restorative systems for the restoration of a patient’s maxillary anterior segment. The chosen materials had to withstand the stress from occlusion and abrasion and yet be extremely esthetic.

The materials of choice were IPS Empress® (Ivoclar Williams) restorations to restore the maxillary incisors and Captek™ (Captek™--a division of Precious Chemicals, Inc.) to restore two bilateral fixed partial dentures (FPDs), replacing the first maxillary bicuspids.

Captek™

Captek™ is a relatively new innovative development in the science of dental materials. It is not a cast metal; instead, it is a dental alloy that is actually a composite material because it is internally composed of two different alloys.

Captek™ is a high-noble alloy comprised of 88% gold and is used in porcelain-fused-to-metal restorations.1 It is stated that composite metals containing metallic matrix and high module of elastic metallic fillers can be structured to have better properties than single-component metals.2

Advanced Fabrication Technology

Captek™ fabrication technology is an advanced metallurgical system that was developed to combine optimal natural esthetics of dental porcelain with the strength of ceramometal to produce accurate restorations on all types of tooth preparation and to provide a biocompatible environment for the oral tissues.

Captek™ precious metal composite alloy can be used to form copings for ceramic crown-and-bridge abutments and any ceramometal porcelain suitable for use with precious cast ceramometal that may be used at the same firing schedule. These components are made in a porcelain furnace from two moldable layers of wax that are impregnated with metal particles. This process results in 22-karat gold copings and frameworks that provide exceptional accuracy, esthetics, and strength.

The Coping Layers

A Captek™ coping is formed in two layers: The first, Captek™ “P,” is a gold/platinum/palladium alloy (Figure 1). After firing, it forms a microscopic, three-dimensional network of capillaries (Figure 2). When processed, the gold alloy second layer, Captek™ “G,” is drawn into the first layer through capillary attraction, forming a yellow-gold alloy that is 88% gold, 4% platinum, and 4% palladium group metals (Figures 3 and 4).

Figure 1 Layer of Capteké over the adhesive and refractory die. Figure 2 Capteké after firing. The metal parts interconnect to form a capillary network. Figure 3 Capteké after firing. Capteké melts over Capteké capillaries and is drawn to fill them by capillary action. Figure 4 Captek™ composite metal after processing. Captek™ “P” be- comes the internal supporting skeleton of the intermediate layer.

Capcon™, Capfill™, Capbond™

Capcon™ and Capfill™ are used to connect copings and pontics to prosthetic structures. Capbond™ is the final component of the Captek™ system. It is a gold-based, gold-colored ceramometal bonder. Capbond™ is used as a very thin paint-on layer that forms a fine and open gold-colored sponge. Porcelain flows well into this sponge-like surface to form a strong bond.3

Marginal Accuracy

Marginal accuracy can be enhanced in the Captek™ system in comparison to conventional materials because of the elimination of errors inherent in the lost-wax technique.4 The resulting composite metal alloy permits the casting to be thinned down to exceptionally fine margins with the load-bearing capacity equivalent to conventional alloys. In a study conducted at Boston University, Dr. Dan Nathanson stated that the microstructure (interpenetrating network), as well as the macrostructural design of the Captek™ bridge, may be responsible for this strength.5

Seeing Red

According to Itzhak Shoher, DMD, the developer of the Captek™ technology, the intense red color of vital dental pulp plays an important role in natural-tooth esthetics.6 In young, more translucent teeth with large pulp chambers, the red color is prominent, as it is in teeth of lighter shades and in those that have undergone bleaching procedures. When the clinician is striving to achieve natural esthetics in dental restorations, it is extremely important to reproduce the optical effect of the pulp and the light-scattering effects of the enamel prisms and dentinal tubules.

Background for Porcelain

The oxide-free, warm gold color of Captek™ copings makes them a highly desirable background for porcelain. Only a 35-mm thickness of opaque porcelain is needed over Captek™, with or without Capbond™, because there are no dark metals or oxides to mask. The opaque porcelain is needed only to bond the metal and to produce the correct porcelain shade. The use of thin opaque helps to avoid the unpleasant, bright, high-value appearance of thick opaque layers often seen at ceramic margins of cast-metal ceramic crowns.6

Excellent Postoperative Results

Clinical studies conducted by Shoher and Whiteman, after 3 years of extensive clinical experimentation, revealed that with the Captek™ system used on crowns and FPDs, there have been no fractures or cracks, and no units needed replacement. Clinical observations also showed less plaque is retained at Captek™ gingival margins than at the gingival margins of natural dentition.7

Figure 5 Preoperative anterior smile view. Figure 6 Preoperative anterior retracted view.

Case Study

A 37-year-old attractive woman, after undergoing temporomandibular joint orthodontic therapy to correct her malocclusion and temporomandibular disorder, wanted to restore her maxillary anterior dentition (Figures 5 and 6). The demands and expectations of the patient were to achieve an extremely esthetic result. She requested the use of all-ceramic restorations.

Figure 7 Preoperative lateral retracted view of patient’s right side. Figure 8 Preoperative lateral retracted view of patient's left side.

Examinations, Patient Concern

After a complete dental, periodontal, and occlusion examination showed significant evidence of parafunctional habits, the author recommended the use of IPS Empress® restorations to restore the patient’s maxillary anterior incisors and a bilateral FPD of Captek™ to restore her missing first maxillary bicuspids (Figures 7 and 8). The patient’s concern was to avoid the use of metal because she felt her previous ceramometal restorations were very unesthetic. The patient was reassured of the final outcome, and treatment was initiated.

Figure 9 Chamfer preparations were designed to be at the height of the gingival crest.

Provisional Impressions, Preparations

The treatment plan was to prepare, impress, and provisionalize her dentition in one operative visit. Maxillary impressions were taken to fabricate her provisional restorations. When this was accomplished, shoulder preparations of all abutment teeth were then completed. Preparations consisted of 1.5-mm circumferential preparation of all teeth with Bluwhite® Diamonds (Kerr® Corporation) at the gingival margin, and 2 mm of circumferential preparation at the incisal one third. Preparations were all at the gingival crest to retain optimal periodontal health (Figure 9).

Occlusal/Interocclusal Records, Impressions

Occlusal records were taken with a Denar Face-Bow and a Denar Centri Check (Denar Corporation), and interocclusal records of centric occlusion and protrusive records were taken with Stat-BR™ (Kerr® Corporation). Maxillary and mandibular impressions were taken with Extrude® Extra (Kerr® Corporation) injection vinyl polysiloxane and putty system.

Shade Selection, Color Mapping

Shade selection was accomplished with an IPS Empress® Shade and Stumpf Guide (Ivoclar Williams). The final color mapping was detailed, and all corresponding records were sent for laboratory fabrication of the restorations.

Figure 10 Provisional restoration esthetics.

Methyl Methacrylate Provisionals

Provisional restorations were accomplished with the methyl methacrylate direct method of provisional fabrication. Because all of these teeth were nonvital endodontically treated teeth, it was safe to use a methyl methacrylate monomer-based system to fabricate the provisional restorations. The provisional restorations required the use of staining modifiers to match the proper shading and character of the patient’s mandibular anterior dentition (Figure 10).

Evaluation, Identical Esthetics

As soon as the restorations were received from the laboratory, they were evaluated on a Denar Combi Articulator and Denar Occlusal Check Instrument (Denar Corporation) to check their occlusal accuracy before patient try-in. The esthetic results of the ceramometal restorations (Captek™) were identical to the all-ceramic restorations (IPS Empress®) (Figures 11 through 14). The esthetics were identical on both types of restorations.

Figure 11 FPD showing casting framework and gold Capteké copings. Figure 12 Final IPS Empress and Captek™ restorations evaluated for occlusion on models. Figure 13 Occlusal view of IPS Empresså and Capteké final restorations on model. Figure 14 Lateral view of final restorations on model demonstrating the ideal esthetics between IPS Empresså and Capteké restorations.

The Moment of Truth

Figure 15 Try-in of final restorations to determine fit, occlusion, shade, and overall esthetics. Figure 16 Final IPS Empresså and Capteké restorations.

Now the moment of truth: The restorations would be in the oral cavity with all of the variables– such as the gingiva, adjacent dentition, oral cavity, and shading– and two dissimilar materials in proximity to each other.

The restorations were tried in for fit, marginal integrity, occlusion, overall esthetics, and patient satisfaction (Figure 15). The shading criteria matched very closely, because the anterior centrals and laterals were to match the shade and value of the lower five anterior natural teeth, and the maxillary canines and bicuspids were to match the lighter shade and higher value of the mandibular bicuspids, together generating a realistic esthetic appearance (Figure 16). After having met these criteria, the restorations were cemented and adhered in place. The material used for cementing the Captek™ restorations was zinc-phosphate improved cement (SS White, Inc.). The adhesive system used for adhering the IPS Empress® restorations was Nexus (Kerr® Corporation).

Nexus

Nexus is a multi-step adhesive system that integrates the technology of OptiBond™ FL (Kerr® Corporation) with a dual-cure paste. Nexus is available in different shades and viscosities tailored for the precise clinical situation evident in this case study’s mandibular and maxillary arch discrepancies.

The Final Evaluation

Final evaluation of this patient resulted in a very pleasing esthetic result; the patient was very impressed with the approximation of shades and values of these restorations (Figures 17 through 20). The author was pleased with the results attained under the reconstruction circumstances.

Figure 17 Close-up detail of final IPS Empresså and Capteké restorations. Figure 18 Occlusal view of IPS Empresså and Capteké restorations showing favorable esthetics Figure 19 Preoperative full smile view. Figure 20 Postoperative full smile view demonstrating ideal esthetics between all-ceramic and ceramometal restorations.

Conclusion

The final restorations exhibited beautiful lip/periodontium/tooth interface, as well as very nice overall esthetics. The patient was extremely pleased with the esthetic result of this restorative treatment. This case has provided the patient a great service for 4 years without any problems, showing excellent periodontal biocompatibility and overall structural and esthetic success.

Acknowledgment

The author would like to thank Rudy Ramirez, CDT, and Glidewell Laboratories, Newport Beach, Calif, for the fabrication of these beautiful restorations.

References
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1. Zappala C, Shoher I, Battaini P: Microstructural aspects of the Captek alloy or porcelain fused to metal restorations. J Esthet Dent 8(4):151-156, 1996.

2. Engineered Materials Handbook, vol 2. Composites. ASM Handbook, 1987.

3. Captek [training manual]. N. Attleboro, Mass. Leach and Dillon.

4. Juntavee N, Nathanson D, Giordano R: A research report on Captek. International Association of Dental Research, pp 1-5, June 1995.

5. Shoher I: Stress analysis in ceramo-metal units and its application in oral rehabilitation. Aust Prosthodont Soc Bull 14:21–31, 1984.

6. Shoher I, Whiteman A: Captek--a new capillary casting technology for ceramometal restorations. Quintessence Int 18:9-20, 1995.

7. Shoher I, Whiteman A: Reinforced porcelain system. A new concept in ceramometal restorations. J Prosthet Dent 50:489-496, 1983.