Part 1: The Single Central Dilemma

The dental team does not typically address tissue damage. Figure 6 shows a patient with a previous restoration who attempted to solve his dental trauma, but he had an unsatisfactory result. On examining the restoration more closely, it was obvious that the tissue heights of the two centrals were different, which made the restoration appear to have a completely different form. Figure 7 shows the removal of the previous restoration and the obvious discrepancy between tissue heights. Prior to the surgical procedure to achieve the desired tissue height, the tissue was marked to visualize the ideal outcome (Figure 8). Once the tissue was trimmed to the desired height, a custom temporary abutment was placed to preserve the new tissue contour (Figure 9). A PMMA temporary was then placed on the temporary abutment (Figure 10). At recall the dental team can examine the progress of the tissue recontouring; it is important to check with the patient on any esthetic concerns he or she may have before moving to the final ceramic restoration. The final ceramic crown was placed and checked meticulously under polarized light conditions to determine if any color corrections would need to be applied (Figure 11). Once the crown was cemented in place, it was easy to see that the driving variable in the success of this case treatment was the recontouring of the gingiva to allow for adequate form of the tooth being restored (Figure 12). The restoration was a harmonious match under many lighting conditions, particularly fluorescent, due to the high-fluorescent ceramic (GC Initial™ Zr-FS, gcamerica.com) that was used to layer the restoration (Figure 13). Using the same fluorescent ceramic on the shoulder of the abutment also yielded a nice tissue response to light (Figure 14).

In many situations tooth form can also become an issue for the success of a case. In implant cases in which a tooth has been knocked out, the surrounding dentition often shifts toward the open space, leaving less room for the final restoration. Figure 15 shows a patient temporized and ready for a final restoration to be fabricated. The surgical team members did a great job preserving the tissue; however, they left the restoring dentist with unequal proportions on the central incisors. The shade was then taken for the ceramic layering under polarized light (Figure 16). The restorative team then digitally mocked up an exact copy of the natural incisor for the patient to understand that in order to have intraoral harmony, a slight overlap may be required in the final restoration. The final restoration was then taken to completion and tried in. At the try-in appointment the patient was not satisfied with the black triangle at the cervical. The dentist used temporary cement (NoGenol™, GC America) to monitor the tissue response. At recall the tissue filled the space nicely, and the crown could be cemented permanently (Figure 17). The seated restoration was checked under polarized light (Figure 18), regular light, and fluorescent light (Figure 19) to determine if it blended successfully with adjacent dentition (Figure 20).

In veneering single central incisors, it is of the utmost importance to understand the underlying color of the restoration and how it can either help or hurt the final restoration. Figure 21 shows a patient with an old composite restoration. After the composite was removed, the dentist used a conservative facial preparation, which yielded a nice value match that could be used in the final color outcome of the veneer. The only consideration the technician had to take into account was blocking out the demarcation line from preparation to veneer (Figure 22). At shade selection under polarized lighting, the desired ceramic was chosen using visual_eyes (Emulation, emulation.gr) and fluoro_eyes (Emulation) (Figure 23 and Figure 24). visual_eyes allows the technician to see the color of wet unfired ceramic on sight to best choose the proper colors for layering, and fluoro_eyes enables the dentist to choose the right composite to use when bonding the veneer. An image of the final veneer shows how the feldspathic veneer was layered to take advantage of the underlying tooth color while blocking out the demarcation line. The final restoration under standard lighting, polarized light, and bounced light demonstrates a successful outcome (Figure 25 and Figure 26). The restoration can then be observed from different angles to check the details of the veneer in the intraoral environment. The final veneer can also be checked under fluorescent light to observe that the restoration exhibits the same fluorescent properties as the surrounding natural dentition (Figure 27). Looking at the before and after, it is clear that the underlying tooth color helped the restorative team achieve a successful outcome with minimal removal of natural dentition (Figure 28).

Editor’s Note
Part 2 of this series will appear in the next issue of Inside Dental Technology.

Acknowledgments
Dentistry was performed by Dr. Barry Polansky, Dr. Mike Monokian, Dr. Devon Conklin, and Dr. Ben Ross.