Dr. Michael DiTolla
As restorative dentists, we are constantly faced with the task of determining which restoration will best suit our patient in any particular case. At times, the overriding concern is aesthetics, while in other cases, strength is our main concern. Based on our ability to achieve a dry field, the need for a restoration that can be conventionally cemented might drive our decision. Perhaps the subgingival location of a crown margin, or the unhealthy appearance of the gingiva would dictate choosing a material that demonstrates less bacterial accumulation than any other material, including enamel.
When choosing a ceramometal crown for a particular patient, many dentists simply think in terms of ceramic materials and almost no consideration is given to which metal substructure is most appropriate. Most clinicians have observed that all-ceramic restorations provide better aesthetics than most ceramometal crowns placed on anterior teeth. The aesthetic shortcomings of most ceramometal crowns, however, are almost always a result of the metal coping itself. On the other hand, many dentists have shown a reluctance to embrace all-ceramic restorations, either due to concerns about strength and longevity, or concerns about having to bond the restoration rather than cement the restoration. As a result, anterior ceramometal restorations will continue to be prescribed in large numbers for a long time to come.
The good news for ceramometal fans is that Captek overcomes all of the objections mentioned above. Captek is an 88 percent gold composite alloy coping that serves as the substructure in a porcelain-to-Captek crown. Specifically, the gold composite alloy coping consists of approximately 88 percent gold, 4 percent platinum, 4 percent palladium, 3 percent silver, 1 percent iridium, and 1 percent ruthenium. The copings are fabricated utilizing replicated master dies composed of a proprietary refractory material. A thin sheet of wax — Captek P — impregnated with platinum/palladium /gold-alloy particles is used to coat the refractory die. The die is then placed in a porcelain oven and during this cycle, the alloy particles undergo a fusing process that creates a sintered, porous, solid-metal coping while the wax is eliminated. Upon removal from the oven, the solid platinum/palladium/gold coping is attached to the refractory die, after which another thin layer of wax — Captek G — containing 97 percent pure gold particles is placed over it. During the next firing cycle, the wax is again eliminated while the gold particles melt and infiltrate the pores in the underlying coping. During the melt/infiltration process, the gold penetrates the entire width of the coping, which produces an internal and external gold surface.