Inside Dental Technology
Making Combination Cases Work
Achieving harmonious esthetics in a single case using Ivoclar Vivadent’s IPS e.max all-ceramic and InLine One metal-ceramic.
By Rafael Santrich, CDT
Historically, dentistry has always faced the challenge of finding ways to combine two incom-patible materials in a synergistic way. In the past, dental professionals may have struggled to blend metal with metal-ceramic or achieve a harmonious look in combination cases that involve porcelain-fused-to-metal and all-ceramic restorations. But with the introduction of smarter materials like Ivoclar Vivadent’s IPS InLine One metal-ceramic and IPS e.max lithium disilicate, they now have the means to overcome some of those obstacles. These innovative products enable laboratory technicians to fabricate restorations for combination cases using materials that still offer esthetic appeal, strength, and efficiency.
IPS InLine One is a leucite-containing veneering ceramic for conventionally layering PFM restorations and is ideal for the fabrication of metal-ceramic restorations fired at temperatures higher than 900 °C (1652 °F). Only one application of a combined IPS InLine One Dentcisal dentin/incisal material with the desired chroma and translucency is required, which can enhance productivity. The balanced coordination of translucency and shade saturation ensures restorations that demonstrate the optimum optical properties and a consistent, true-to-nature shade. IPS InLine One materials are easy to apply and do not require special knowledge about layering techniques.
IPS e.max lithium disilicate enables fabrication of full-contour restorations from one high-strength ceramic. The versatility and performance of lithium disilicate allows laboratories to optimize their efficiency using lost-wax pressing. Ivoclar’s recently introduced Impulse ingots increase the range of esthetic applications with five new shades. These include three new Value shaded ingots that allow for immediate translucency in smile design cases, and two new Opal shades that demonstrate a high level of natural opalescence to mimic the look of natural dentition. Demonstrating a flexural strength rating of 400 MPa, IPS e.max lithium disilicate can be used in single-tooth restorations, bridges in the anterior and premolar regions, and for implant substructures. It is also ideal for combination cases in which PFM restorations are required.
A case received at VM Lab Technologies provided the author the opportunity to demonstrate the esthetic compatibility of Ivoclar Vivadent’s metal-ceramic and all-ceramic materials. The case presented here illustrates how natural esthetics can be achieved using IPS e.max when the two adjacent single-unit crowns are fabricated with IPS InLine One metal-ceramic. First, a wax-up of the preparation was created using a silicone matrix that was placed over the prepared tooth model. Wax was injected using a hot wax injection pump to reproduce the form and position of the preparation in the final wax-up. The wax-up was sprued onto the ring former, then it was invested and burned out, and the low translucency (LT) IPS e.max ingot was pressed onto the wax-up. The coping created from this pressing was removed from the investment and fitted to the master model (Figure 1).
The crown restoration was built up with the application of IPS e.max Ceram powder in shade A3 (Figure 2), and characteristic facial banding was created by applying IPS e.max Opal Effect 3 (Figure 3). The same IPS e.max Opal Effect 3 powder was applied to increase the brightness of the line angles and mamelons, and to increase light in the incisal third (Figure 4). IPS e.max Transpa Clear Enamel was applied to the incisal edge (Figure 5), after which IPS e.max TI 3 Enamel was applied to the entire restoration (Figure 6).
Occlusal Dentine Orange was applied to the lingual fossa, and the lingual arms were created using a combination of TI 3 and Opal effect 3 IPS e.max powders (Figure 7). Prior to firing, shape, color, and characterizations were evaluated and corrections were made. The restoration then underwent the first and only bake (Figure 8 and Figure 9). After baking, the surface morphology and facial contour of the lithium disilicate crown restoration underwent modification using adjusting diamonds (Figure 10). The restoration was glazed, and a final firing was completed at 725° F (Figure 11 and Figure 12). Not only did the combination of the IPS e.max crown with the IPS InLine One PFM restorations make the process easier, more predictable, and more productive (Figure 13 and Figure 14), but it also produced seamless results and a harmonious look (Figure 15 through Figure 18).
Rafael Santrich, CDT, is president and owner of VM Lab Technologies in Aventura, Florida.