Utilizing Pressable Ceramics for a Cosmetic Anterior Case: Part I
Achieving a highly esthetic outcome for a young patient
By Sang K. Jun, CDT
Dental materials and techniques continue to evolve, especially for the fabrication of anterior restorations when an esthetic outcome is of paramount importance. For quite some time, pressable all-ceramic restorations have been recognized as an alternative to porcelain-fused-to-metal, especially with the advent of pressable materials that exhibit not only strength but also the esthetic characteristics needed for discerning technicians offering cosmetic services. Today, we have another fabrication methodology at our disposal that offers increased production efficiencies to the process: CAD/CAM technology. Now many of the restorations that required the hands of a technician for production can be manufactured with the collaboration of modern materials and computer technologies.
The cosmetic restorative case presented here was restored using IPS e.max Press lithium disilicate (Ivoclar Vivadent, ivoclarvivadent.com). The newest generation of this material is denser and stronger (400 MPa) and has become the material of choice for anterior restorations by both dentists and laboratory technicians. Whether pressed or milled to full contour and then stained and glazed or cut back and layered, a highly esthetic outcome is achievable.
Regardless of the production method used, the value of the restoration can become an issue if the correct ingot shade and translucency are not chosen for use. Today this material comes in a wide variety of shades as well as in a wide range of translucencies and opacities, from high- and low-opacity and translucency ingots to high- and low-value ingots; even multi-layer ingots are available. A selection chart is available to help select which ingot is best for each case.
The most important ingredient, however, is the restorative team fully understanding the material and how it behaves in the mouth, and also being knowledgeable on the available techniques that can be used to maximize the material’s esthetic potential.
A 28-year-old female patient presented with esthetically unpleasing resin-bonded indirect composite veneers on teeth Nos. 7 and 10. The patient’s chief complaint was the discoloration of the veneers over time and their asymmetric contra-lateral appearance (Figure 1). The clinician examined the patient and presented a treatment plan to replace the two veneers with crowns, which the patient accepted. Once the clinician removed the composite veneers, it was revealed that teeth Nos. 7 and 10 were underdeveloped peg laterals.
Although the dentin shade of tooth No. 7 was somewhat darker than that of tooth No.10, it was clean and the underlying color of tooth No. 10 was closest in shade to the desired final outcome. After consultation, the restorative team decided to utilize IPS e.max as the restorative material of choice (Figure 2).
The clinician prepared the teeth, took an impression, and sent that information, along with digital images, to the laboratory to begin the restorative process.
Due to the significant color difference in tooth No. 7 between the darker gingival one-half and the incisal, which was a bleach shade, the coping design was waxed up and pressed with an IPS e.max MO-0 ingot (Figure 3).
Although the design of the pressed coping incorporated a cut-back, further refinement of the cut-back was needed in order to include esthetic tooth characteristics as well as a facial margin. Because the pressed core was bright and the gingival area of the preparation was dark, the addition of a porcelain facial margin would prevent the brighter color from showing through in the final restoration (Figure 4).
Following the manufacturer’s instructions, a wash layer of porcelain was applied to the pressed core and fired. The wash overlay works as a bonding agent for subsequent layers of porcelain. A2 dentin was then applied to the margin. Bright dentin and a small amount of orange-yellow mamelon material were mixed and applied onto the heights of the tooth contour (Figure 5) to raise the value, which would be offset later by application of enamel and translucent layers in subsequent firings.
A thin layer of an appropriate dentin porcelain was applied to the incisal one-third. Mamelon powders were then applied onto the incisal tips for characterization (Figure 6), and different enamel colors were alternated across the incisal edge (Figure 7). The restoration was then fired according to the manufacturer’s recommendation (Figure 8). This canvas-like foundation was created in order to match the shade of the adjacent teeth and to harmonize with surrounding dentition (Figure 9).
Now a darker dentin shade was applied onto the gingival one-half and appropriate bright dentin was layered onto the incisal one-half (Figure 10). Further enhancements of internal characterizations were achieved by highlighting the mesial and distal line angles with bright enamel (Figure 11 and Figure 12).
A bluish translucent layer was applied to the distal of tooth No. 7 (Figure 13), and different colors of enamel were layered vertically. A warm enamel color was applied to the gingival area, and an enamel layer was added on the facial (Figure 14).
A layer of warm opaque color, mamelon orange-yellow, was applied onto the palatal area of both restorations (Figure 15), and then lingual marginal ridges were built with dentin. The remaining lingual incisal areas were covered with appropriate enamel (Figure 16).
After the first firing has been completed (Figure 17 and Figure 18), additional layers of porcelains should be applied as necessary (Figure 19 and Figure 20). Once this second layer of porcelains has been completed, it is important to apply a thin layer of dentin or bright dentin all the way around the perimeter of the restorations, especially the interproximal contacts to reflect light as much as possible so the underlying grayness does not show through (Figure 21).
To create a more lifelike appearance, appropriate enamel and translucent layers were applied onto the lingual (Figure 22) and then a mixture of dentin and enamel was applied onto the marginal ridge to create a whitish, frosty appearance often found in nature. The restorations were fired for a second time and prepared for finishing and glazing (Figure 23).
Once finished and glazed, the restorations were tried-in the patient’s mouth for color match and functional assessment (Figure 24).
One Year Later
Figure 25 through Figure 28 show the patient with the restorations in place one year later. It was noted that slight tissue recession had occurred on both restorations, especially on tooth No. 10. However, the patient was extremely happy with the end result, which had helped her regain self-confidence with her overall appearance (Figure 29 and Figure 30).