Esthetic options with material selections

March 21, 2012
Peter Pizzi, CDT, MDT
Peter Pizzi, CDT, MDT

Issue 7

In today’s option-filled world of dental technology, some of our design decisions are made based on the time frame allowed for our cases, or should I say rushing the case through before the patient has to leave on the space shuttle. Others are made based on our comfort level with material choices, while yet others are made based on our ability to access alternative solutions such as outsourcing or processes of our cases. In all scenarios, it’s up to us to have a toolbox to draw from for esthetic options for every case situation.

In today’s option-filled world of dental technology, some of our design decisions are made based on the time frame allowed for our cases, or should I say rushing the case through before the patient has to leave on the space shuttle. Others are made based on our comfort level with material choices, while yet others are made based on our ability to access alternative solutions such as outsourcing or processes of our cases. In all scenarios, it’s up to us to have a toolbox to draw from for esthetic options for every case situation.

Recently a “rush” case was pre-scheduled in my laboratory. All seemed as the doctor described-a simple 6-unit veneer case. Yes, I try to pre-schedule all veneer cases and any large cases but must admit my system to pre-schedule doesn’t always work as well as I would like.

When my “pre-scheduled” case arrived, instead of it being 6 veneers, it was 5 veneers and an implant. So here’s where the challenges come in. With a short time frame and a pre-booked case, the added implant raises the question: What do I do from a time frame and from an esthetic parameter?

From the esthetic view point, in the anterior region (depending on the tissue type and placement position) zirconia normally would be my choice. Let’s remember esthetics are created by the combination of white and pink (teeth and the gingival tissue), so our focus should be to keep the tissue as esthetic as possible.

For me, the implant type is the second issue, although most implants today can be fabricated in custom milled zirconia. When the implant diameter is small (3.5 mm or less), we must consider the functionality of the tooth. For example, a lateral will not have the same functional stresses as a cuspid will in a normal Class I bite registration.

For this case, the No. 6 cuspid was replaced as an implant-retained restoration and needed to harmonize with the veneer restorations. As we looked at all of our options and the limited time frame, I decided to go with a cast metal abutment with a porcelain-fused-to-metal restoration. This is in my comfort zone as far as matching the porcelain to metal and the veneer, both of which were done with the same veneering materials. The only other issue to consider is the metal abutment showing through the thin tissue type (Fig. A).

The solution

Based on all the previous information, my case plan became to fabricate 5 refractory veneers, a porcelain-fused-to-metal restoration with a ceramic shoulder and a cast metal abutment with a ceramic shoulder to support the tissue and harmonize with the porcelain to metals ceramic margin.

The metal abutment was waxed and cast and cut back to receive ceramic in the marginal area (Fig. B). At this point, we can and should contour the tissue in the shape of the root to be replaced. This then can be used to help us guide the marginal placement on the cast.

The tissue is modified to the ideal root emergence (Fig. C). The ceramic margin is built on the abutment to the modified soft tissue (Fig. D). Ideally, we would like our margins to be placed 0.5 mm below the tissue, which makes cement clean up easier.

The margin is verified for an approximate margin finish line and checked for its height below the tissue with a measuring tool (Fig. E). Ceramic is now behind the tissue, which will help the light transmission (Fig. F).

Once we have completed this process, we can create a simple metal coping with the appropriate support. One of the keys here is to bring this back to a 6-unit veneer case so our workload can be treated from an esthetic point of view. The metal coping can be created on the abutment (Fig. G) and then cut back for ceramic margin placement (Fig. H). The coping is then opaqued with a base color and the ceramic marginal material is applied and fired (Figs. I, J, K and L).

Normally I would finish the abutment and the coping before even starting a case like this, then build the coping only with opacious dentins and dentin to emulate the dentin shade of the veneer stumps. In truth, with the time frame I decided to build the 4 incisors (laterals and centrals) while the abutment was fabricated. This saved me some time and allowed me to build the cuspids together. Although this isn’t the norm, it can work because of the contra lateral position of the teeth, where as the centrals match centrals, laterals match laterals, etc.

After firing the 4 veneers, contour is checked (Fig. M). Then we can build tooth No. 6 to the correct stump shade of the existing teeth (Fig. N), and the metal coping is ready to build to match the contra lateral side (Fig. O).

The final buildup is done on the cuspids and harmonized into the veneered arch (Figs. P and Q) and the final photos are taken on the cast and our “rush” case with the surprise implant is completed (Figs. R, S and T).

Again the key to overcoming some of the curve balls that come our way always will depend somewhat on our resourcefulness, but it also is important for us to have the knowledge to create the resources from. With today’s option oriented prosthetics we must have the ability to use some common sense and change material processes to build our laboratories and create a comfort zone for our cliental.