Non-Oxidizing Metal Ceramics – A Clinical Approach to Esthetic, Healthy and Practical Solutions

by Mariano Limonciello, MDT (Naples Italy)

Even though the choices of restorative materials have evolved and expanded, it is still important for a clinician and laboratory to identify materials that will satisfy the esthetic, functional and biological challenges unique to each case. For many situations, contemporary all-ceramic solutions have simplified achieving esthetic outcomes, yet, in many common clinical situations, a metal-based solution such as Captek Nano (Argen Corp., San Diego, CA) can be an invaluable restorative tool. A non-oxidizing, thin, warm gold colored metal coping can enable a ceramist to eliminate the influences of disconcerting colors in the underlying preparation while still allowing clinicians to utilize their margin preparations of choice and to remain conservative in their tooth preparations. In this clinical article the nature of metal composite and the updated Captek Nano materials are demonstrated indicating simple esthetic, stable and biologically friendly restorative solutions.

Captek Nano is the re-engineered formula of the original Captek metal composite technology first introduced in the dental literature in 1995.1 The purpose of metal composite technology is to combine the full benefits of high purity gold with the strength factors of low gold alloys. With traditional alloys, when elements are combined in the melting process, the unique benefits of gold, such as color, corrosion resistance, and resiliency, are decreased so as to achieve higher strength factors. Metal composite technology overcomes this dilemma by utilizing uniquely designed metal particles, arranged in a specific approach in a non-casting fabrication process. The Captek laboratory process has been reviewed in many articles.2 What is important to the dental practitioner is that the final results combine the best properties of gold while achieving very high porcelain bond strength3 and strength factors.4 When viewed in cross section, one can see how the high purity gold is internally reinforced with hard, thermally stable particles of platinum and palladium. (Fig. 1) This unique structure, far different from a homogenous cast alloy, maintains the beautiful color5 and desired resiliency of pure gold while its tough internal structure supports high load-bearing capacity. With significant advances in nano manufacturing and particle technology, the Captek Nano materials now have double the number of internal particles supporting the gold6 compared to the original Captek. This allows far more thermal stability and stiffness7 than the original materials and higher strength factors in thinner core dimensions.

There are three specific core thicknesses for Captek Nano copings, ranging from a material just under 0.3mm (designed to handle high loads for large molars, in bruxers, with bridge abutments and for implant restorations), to an ultra thin less than 0.2mm (designed to maximize anterior esthetics). (Fig. 2).

All the Captek Nano materials consist of high purity gold that is corrosion-free8, oxides-free and clinically proven to reduce harmful bacteria in the sulcus.9

The absence of harmful oxides, increased plaque resistance and a precise marginal fit,10 assists the dentist and the technician to positively influence the health of the gingiva and the stability of the crown marginal seal. These benefits are important for all patients, but are crucial for patients with periodontal disease.11 The absence of harmful oxides, the thinness of the material, and warm gold color, make the management of unesthetic tooth abutment coloration possible and create natural-appearing esthetics even at the restorative margins.

CASE 1 
DARK ABUTMENTS 
Endodontically treated teeth can present a significant esthetic challenge.12 (Fig. 3) The left central incisor (female patient age 58) was prepared for a full coverage restoration. The lab technician received the case accompanied by a photo showing the characteristics of the right central that needed to be mimicked in the restoration. The patient was not interested in orthodontic treatment or root bleaching, yet had high esthetic expectations. The Captek Nano technique was selected and the technician decided to bring the warm-colored gold metal to the restorative margin in order to completely eliminate the unesthetic influence of the dark underlying tooth structure (Fig. 4 a,b). The lab technician took care to match both internal and external coloration of porcelain, tooth alignment and prominent profile of the existing contralateral central. (Fig. 5) Case courtesy Dr. Guosue Calabria (Naples, Italy)

CASE 2 
MATCHING CROWNS AND BRIDGES
A middle aged female patient desired to restore her smile (Figs. 6, 7) The patient exhibited bruxism, various unesthetic and failing restorations, and a bridge that had dislodged and was now lost. The patient refused surgery to alter gingival asymmetry, yet had high esthetic expectations. The treatment plan included full upper arch restoration with Captek Nano crowns and bridges with the purpose of achieving an esthetic, stable, and predictable result. The laboratory manufacturing process involved in fabricating the Captek Nano internally-reinforced restorations is demonstrated. First, refractory dies are formed . Then the Captek Nano internal skeleton of hard particles of platinum and palladium is developed to the die (Fig. 8). Finally, high purity gold is melted in and through the internal structure (Fig. 9). The Captek copings are tried in (Fig. 10). The Captek Nano Anterior Copings were designed with horizontal ridges for additional strength.

Captek Nano bridges are developed in several unique steps. First the Captek Nano copings are developed on the abutments. Then a custom pontic is waxed, cast, and indexed to the copings. A duralay pick up index is affixed to the bridge components inside the mouth, removed, and then secured with small amount of plaster to eliminate setting distortion prior to sending it to the laboratory where the indexing model work will be completed. The Captek bridge is connected in the laboratory and prepared with the recommended Captek technique (Fig. 11) and readied for porcelain application. Once the restorations were inserted into the patient’s mouth, the final results met the patient’s expectations for esthetics, comfort and function (Fig. 12). In order to protect the restorations, a night guard was fabricated for the patient. Case courtesy of Dr. Giovanni Capone (Naples Italy).

CASE 3 
ESTHETIC RESTORATION OF IMPLANTS 
Captek Nano materials have been designed to combine strength, biocompatibility, and esthetics. These features are utilized to help solve the many challenges presented by implant dentistry. Dentist-Technician teams routinely utilize Captek Nano crowns and bridges over implant infra-structures. Six months after implant placement and temporization, the soft tissue status around the implant appeared irritated, dark, and un-esthetic. (Fig. 13) A high noble alloy custom cast abutment was fabricated. The abutment surface that would be in direct contact with the soft tissues was coated with Captek Nano materials. (Fig. 14) The gold color blocked out the underlying implant abutment color and imparted a warming effect to the overlying gingiva. Captek Nano particles are non-corrosive and resistant to harmful bacteria encouraging tissue health and stability. The remaining abutment surface was opaqued to mimic the color of the natural tooth. A lithium disilicate crown was fabricated over the abutment. At three years, the recall exhibits esthetic results and healthy and stable soft tissues. (Fig. 15)

CONCLUSION
It is essential to have access to clinical materials so clinicians can restore dentition esthetically, functionally and biologically in the most straightforward and simple manner. The all important team of the restorative dentist and the skilled laboratory technician can utilize innovative technologies such as the Captek Nano metal composite system to predictably d
eliver cases that meet all the clinical challenges and overcome existing concerns. OH

ACKNOWLEDGEMENTS
Mariano Limonciello would like to thank the lab team at Limonciello Laboratorio Odontotecnico (Naples, Italy), Dr. Giosue Calabria, (Naples Italy), Dr. Giovanni Capone (Naples Italy) for their clinical contribution in these cases. Mariano Limonciello would like to thank Bruno D’Innocenzo, MDT (Andover, NJ) and Romeo Pascetta, MDT (Chieti, Italy) for their Captek Technology training and guidance.

Mariano Limoncielo was born in San Vitaliano, Naples, Italy, in 1965. He graduated as a dental technician in 1985 and currently is the the owner and practices in his own lab in San Vitaliano.

Specializing initially in removable prosthesis and later in permanent ones, he pays particular attention to precision, aesthetics and the use of a stereo microscope. He attended numerous professional development courses both in Italy and overseas. For the past three years he has used Captek-nano with particular attention to precision and the stability in creating both simple and complex structures. He formed a group recently with other dentists where they create both bridges and crowns with Captek- nano.

Oral Health welcomes this original article.

REFERENCES:

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