RESTORATIVE CHALLENGE: A 28-year-old female patient presented with large diastemas on her anterior maxillary teeth. She disliked her overall tooth display and "gummy" smile, and the disharmony between her left and right buccal corridors (see Figure 1). Following a complete diagnostic examination, it was apparent that the patient exhibited premature wear and slight—although uniform—discoloration of her maxillary dentition. The patient had no pre-existing restorations.
Restorative team: Nelson Rego, CDT, Smile Designs By Rego, Downey, California and Brian McKay, DDS, Seattle,Washington
Treatment plan: To enhance the patient's smile and address her esthetic concerns, the treatment plan involved soft tissue contouring for crown lengthening using a soft tissue diode laser (Ivoclar Vivadent's Odyssey), followed by placement of 10 pressed all-ceramic 3/4-crowns on her maxillary dentition. Given the size of the diastemas, veneer restorations were not appropriate because Dr. McKay had to heavily prepare the distal aspects of each tooth so the restorations could be fabricated in the correct proportions. Additionally, teeth #6 and #11 were prepared for pressed ceramic full crowns in order to provide the freedom necessary to increase cuspid guidance and restore the patient to proper protrusive/excursive movement.
IPS Empress® Esthetic from Ivoclar Vivadent was chosen because it's a simple metal-free system with enhanced color, clarity, strength and leucite crystal distribution for restorations with superior optical properties and improved strength. The system was particularly ideal for this case because the pressed ceramic enabled the flexibility of using a cutback and layering technique for the fabrication of the 3/4-crowns so that the patient's esthetic expectations could be satisfied. Additionally, the full contour waxup of the proposed restorations provided the opportunity to perfect the contours.
Case study: Before preparing the patient's teeth, Dr. McKay took impressions and forwarded them to Smile Designs by Rego—along with a detailed narrative describing the patient's esthetic demands—for the creation of a diagnostic waxup. Once approved, Dr. McKay used a matrix of the waxup to fabricate the provisional restorations, which enabled the patient to "test drive" her new smile. The waxup also formed the basis for the final restorations.
Once Nelson Rego received models of the approved temporary restorations, he used them to create a putty incisal edge matrix (with Ivoclar Vivadent's Sil-Tech) and, ultimately, to design the waxup of the final restorations to the optimal shape, esthetics and function. Preparation models were tried into the matrix to ensure that adequate, equal reduction had been achieved.
The completed waxup was sprued, invested and burned out and the IPS Empress Esthetic ingots were pressed into the molds. After pressing, the ceramic was fit to the dies, contacts between the restorations were adjusted, and the overall contour was verified (see Figure 2).
For this case, Rego performed a cutback to reduce the incisal edges of the restorations to enable layering of effects powders. Depth cuts and incisal edge reduction were necessary to create a subtle framework onto which the enamel porcelains could be applied, but Rego was careful to ensure that the shape of the final tooth form was maintained. He then layered different enamel effects—such as Amber and Bamboo, in addition to some White and Blue—onto the restorations (see Figure 3) and fired them (see Figure 4).
Rego recontoured the incisal portions of the restorations to remain consistent with the gingival segment (see Figure 5) and verified the occlusion and overall length of the restorations using the putty matrix. He glazed the restorations and seated them back on the model to confirm fit, contacts, form and color. The final restorations were returned to the clinician for definitive placement (see Figure 6)