IPS Empress®

In this photo essay, I want to demonstrate how I use pre-contouring and depth cuts to ensure that I give my dental technician enough reduction to work his magic. I also wanted to show the details of my temporary technique, which greatly simplifies the process of making thin temporaries. I hope that following these pre-contouring and depth cut steps gives you and your patients more satisfaction in the esthetic dentistry performed.

When the study model is viewed from the occlusal, the alignment problems become more apparent. Tooth #7 is rotated clockwise, causing the distal half of the facial surface to be too visible. Tooth #8 is rotated similarly to tooth #7. Tooth #9 is positioned too far facially and tooth #10 is positioned too far to the lingual. Again, because of the facial position of tooth #9, this patient is not a candidate for no-prep veneers.

Many times I will place an orthodontic arch wire on the study model to help visualize the alignment issues. This allows me to preplan visually the tooth preparation. For example, any tooth structure that is facial to the orthodontic arch wire will be removed through precontouring before any depth cuts are placed.

Here is a facial view of the Diagnostic Wax-Up. As is customary, the lab used white wax on a white stone model, which patients find very appealing. It is a very useful tool in giving patients an idea of what their veneers will look like. The wax-up will also be used to fabricate the temporary veneers for this patient.

Because we are going to use the Diagnostic Wax-Up for the temporaries, we need to clean it up. Using a sharp carving instrument, I remove any excess wax along the gingival margin, carving down to the sulcus on the stone model. The cleaner it is in the gingival third, the easier the temporaries will be to fabricate intraorally because the temporary material will stop right at the gingival margin.

You may have noticed the difference in clinical crown length in tooth #8 and #9. As you can see here, #8 is 10.5 mm long. This is widely considered to be the accepted length for the average maxillary central incisor. For most patients, except for the very short and very tall, 10.5 mm makes for a very esthetic central incisor.

Tooth #9 is 12.2 mm long. On this patient, the two centrals are different lengths, and our first thought is how to fix this. Do we remove tissue from tooth #8 so that it matches #9? Do we graft tissue back onto the cervical of #9 to make it match #8? Fortunately, when we refer to Figure 1, we see the patient's smile line does not show the gingival margins, making it a non-issue that requires no correction.

In order to make a template from the Diagnostic Wax-Up, which can then be used for temporary fabrication, we start with impression putty. This happens to be Capture® from Glidewell Direct. After ensuring that there is no latex powder on my hands, the putty base and catalyst are mixed according to the manufacturer's instructions.

Once the putty is fully mixed, it is rolled into a hotdog shape and pressed down over the Diagnostic Wax-Up. Make sure the putty covers all of the teeth, not just those that have been waxed up. Pushing the putty on the teeth that will not be prepared acts as a seating index when you take the putty matrix into the mouth.

Let the putty set for 4 to 5 minutes on the Diagnostic Wax-Up model. Keep in mind that it takes longer for the putty to set outside of the mouth than it does inside the mouth, due to the mouth's cooler temperatures. As you can see, the shape of the matrix isn't important at this stage.

After the putty has set completely, gently remove it from the model. Using a sharp knife such as a Bard-Parker #15, remove the excess putty material down to within 1 mm of the gingival margin. Repeat on the lingual as well as the facial.

Reline the putty matrix with a light or ultra-light viscosity syringe material. Place this wash material along the entire length of the matrix, making sure that it covers all of the teeth.

Seat the putty matrix, now lined with light-body material, back onto the Diagnostic Wax-Up. You should see lightbody material squirt out from around all the margins. Be sure to wait at least 5-7 minutes to remove this from the model because of the temperature differential from the model to the mouth. After trimming the excess wash material from around the margins, the putty/wash matrix is now ready to be used.

Prior to tooth preparation, and more importantly prior to tooth dehydration, the tooth shade needs to be taken. We are using the VITA EasyShade to check the shade of the teeth to be prepared and the adjacent teeth, as well. This information, in addition to a digital photograph of the teeth preoperatively, will be sent to the lab. We will also include a stump shade photograph and a photograph of the temporaries in the patient's mouth.

The occlusal view of the patient's arch confirms the information seen on the study model. Thinking back to the orthodontic arch wire, I know I'm going to have to do some precontouring on the facial of tooth #9 and the distal half of tooth #8 prior to doing depth cuts if I have any hope of getting them back into the proper arch form. The tooth structure that lies lingual to the orthodontic arch wire will not require any facial depth cuts.

I use an 856-025 bur for the precontouring. My goal is to remove enough facial tooth structure from tooth #9 and the distal half of tooth #8 to bring them in line with the orthodontic arch wire. Then I will place a facial depth cut the same depth as the thickness of the porcelain veneer to ensure this tooth stays within the orthodontic arch wire. In this picture, the precontouring has been accomplished.

This is an MADC 006 bur from the Reverse Preparation Kit (Axis Dental 888-654-2947). This bur is a self limiting 0.6 mm depth cut bur that is used on the facial surfaces of the teeth to be prepared after the precontouring is finished. I place four depth cuts on the facial surface of each tooth to ensure adequate and uniform reduction.

The depth cuts have now been placed in the facial surface of teeth #7-9. Again, notice no depth cuts have been placed in the facial surface on tooth #10 because it lies lingual to the orthodontic arch wire. I can't stress how important it is to do the facial precontouring prior to these facial depth cuts. Many times it is the difference between esthetic success and failure.

The gingival depth cut and the gingival margin are accomplished simultaneously with the 801-021 bur from the Reverse Preparation Kit. This depth cut is performed at the gingival margin, being careful not to lacerate the gingiva with the bur. The depth cut is carried as far mesial and distal as possible. If the adjacent tooth is being prepared, this bur can be used to prepare the gingival margins of both teeth simultaneously.

The incisal edge depth cuts are placed with the MADC 015 bur. This self-limiting depth cut bur places an exact 1.5 mm depth cut in the incisal edge. Notice no incisal edge depth cut was placed in tooth #9 because it was approximately 1.5 mm shorter than tooth #8. Two depth cuts are placed in each incisal edge.

The 856-025 bur is used to blend the incisal edge depth cuts. This is done by holding the bur at a 90-degree angle to the long axis of the tooth. Once you can longer see any of the incisal edge depth cuts, it is time to place the lingual margin. By tilting the handpiece 30-35 degrees to the lingual, I create the long bevel and the mechanical resistance to keep the veneer from popping off during protrusive movements.

The 856-025 bur is used to blend the 0.6 mm facial depth cuts. This is where we also begin to blend the three planes of reduction: incisal, middle and gingival. We do not break contact between the teeth unless we need to shift the midline or if we have major tooth-size discrepancies.

This step is one of the most important, yet one of the more difficult ones to illustrate. Rotate the head of the handpiece so that the tip of the bur moves toward the lingual. We want to prepare the portion of the tooth gingival to the contact area without breaking the contact. This is called the elbow portion of the veneer preparation.

This drawing shows a saggital view of the elbow preparation. As you can see, the preparation wraps interproximally to the lingual while remaining between the contact area and the free margin of the gingiva. If you fail to prepare this area, the veneers might look good from the facial. However, when the smile is seen from the side, the unprepared tooth structure will be visible.

After the elbow preparation has been made, an UltraPak® Cord #00 is placed around the prepared teeth. Because we have not broken contacts, this retraction cord cannot usually be flossed into place. The cord is gently placed interproximally with a cord placement instrument, carried around the facial surface, cut with scissors and the loose end gently packed into the interproximal area.

The four #00 cords have been placed on the facial of teeth #7-10. The entire portion of the cord should be invisible at this point. As you can see, the gingival tissues have been retracted approximately 0.5 mm from where the original margin was placed. This allows us to clearly visualize the margins and drop them the last 0.5 mm so that we will have slightly subgingival margins.

In areas where you have a prepared tooth adjacent to an unprepared tooth, the 856-016 bur is a better choice for prepping the interproximal area and the elbow preparation. The smaller chamfer bur makes it easier to prep interproximal areas without damaging adjacent teeth.

Many of us were taught that a rough finish on a preparation is desirable for micromechanical retention. While true for standard crown & bridge cements, this is exceeded by the bond achieved through resin cementation. Therefore, it becomes desirable to polish the preparations, especially in the area of the gingival margins. A fine grit 850-018 KR bur is my favorite bur for removing the rough edges from the preparations.

You need to be careful of sharp angles on your preparations. The most common place for sharp angles to occur is on the mesial and distal corners of the incisal edge. Here, I am using a 3M ESPE Sof-Lex™ disc to round off the corners of the incisal edge.

The Sof-Lex disc can also be used on the facial surface to blend the three planes of reduction. It is especially important to make sure that the incisal third of the preparation curves back toward the lingual. This will prevent the veneers from looking like buckteeth. In this picture, I use the Sof-Lex disc to achieve reduction of the incisal third of the preparation.

Once the preparation is finished, we place the 2E cord around the prepared teeth. Because we have not broken contact between the teeth, we typically use one piece of retraction cord for all of the prepared teeth.

The top cord in the Two-Cord Impression Technique (Ultrapak Cord #2E) will stay in place for 8-10 minutes. That cord will be removed prior to taking the impression. The bottom cord (#00) will stay in place during the impression to ensure there is no bleeding around the preparations.

A closer look at the finished impression shows that the margins of all the prepared teeth are clearly visible. Equally important is that excess impression material is visible beyond the margin. This impression of the root structure apical to the margin provides the technician with important emergence profile and margin location information.

For porcelain veneers that are 0.6 mm thick (such as these), it is important to take the stump shade into consideration. Ivoclar Vivadent stump shade St9 appears to be the closest match. This photograph will be forwarded to the lab technician, in order to help him or her better achieve the final desired shade through the use of shaded resin dies that the veneers will be placed on.

You will be amazed by the simplicity of this temporary technique. Pick a shade of bisacryl temporary material that is one shade lighter than you think is the proper shade. In this case, I should have chosen two shades lighter. Inject the bisacryl material into the putty/wash matrix in the areas of the prepared teeth.

Place the putty/wash matrix with bisacryl into the patient's mouth. To make sure that the matrix is seated all the way: Put your fingers on the matrix on the areas of the unprepared teeth and push down to ensure the matrix is seated all the way. Sometimes it takes this extra push to ensure the matrix is completely seated.

When you place the matrix, you should see excess bisacryl material above the matrix. Leave the matrix in place for 2-3 minutes. Typically we remove the matrix earlier than this; however, because we are fabricating temporary veneers, we want to mechanically lock them into place. Therefore, the only mistake we can make in this technique is trying to remove the matrix too early.

After removing the putty/wash matrix, this is what you will see. Because we trimmed the Diagnostic Wax-Up in the area of the gingival margin, you can see how clean these temporaries are at the gingival margin. We simply need to remove the excess material, which I am doing here with a cordpacking instrument. If there is excess material in the gingival embrasure, use a thin carbide-finishing bur to remove it.

Here is a shot of the temporaries in place with the patient smiling. The fabrication of the temporaries took less than 10 minutes. For patients who are having 8-10 veneers done and are thinking about choosing high-value veneers, we use bleach shade bisacryl for the temporaries. In cases such as this, in which only four teeth are prepared, we have to make them blend with the adjacent teeth.

This retracted view provides a better look at the temporary restorations. Alignment issues have been corrected because the temporaries were made from an impression of the Diagnostic Wax-Up. Even though the clinical crowns of tooth #8 and #9 are different lengths, the patient's smile line does not reveal this discrepancy.

This photo shows an occlusal view of the temporaries. You can see that, as a result of the precontouring and the use of the Diagnostic Wax-Up for our putty/wash matrix, we have achieved our ideal arch form. An alginate impression will be taken of the temporaries and forwarded to the lab technician, so that he or she can see how the information on the Diagnostic Wax-Up blends into the patient's dentition.

This is a facial view of the patient's temporaries after two weeks. While the shade I chose had too low of a value, the temps have otherwise served the patient well. On this patient, I relearned a lesson that I already knew: Always choose one shade lighter than you think is the correct shade for temporary veneers.

Because the temporary veneers are mechanically locked into place, it is almost always easier to cut them off rather than try to remove them with hemostats. Using a 57 bur, we slice through the facial and incisal aspects of the temporary. To make it easier to see what I am doing, I leave the water off during these cuts. The goal is to section most of the way through the temporary without touching the bur to the tooth.

Once the cuts have been placed in the temporary material, a right-angle crown remover is used to crack the temporaries. Typically, we will make these facial and incisal cuts on every other tooth. That's because when you pop off one veneer, the one next to it comes off as well.

You need to be very careful to remove excess temporary material from the gingival embrasures. When you lock the temporaries into place, material always fills these embrasures. In fact, I believe that these undercuts are why we can mechanically lock these temporaries into place. I use knotted Glide floss to remove the excess material from the gingival embrasures.

I inspect the preparations, wearing my Orascoptic HiRes loupes, to ensure there is no excess temporary material left in or around the teeth. Drying the teeth will also make any excess temporary material more visible.

The veneers are individually tried in the mouth to check for marginal fit without the influence of potential tight contacts. Once we have verified all of the veneers fit individually, they are tried in collectively to evaluate contacts.

The veneers are now tried in with try-in paste, in this case Ivoclar Vivadent Variolink® Veneer. I always start with the translucent shade of the try-in cement, which in this system is known as the Medium Value, or 0, shade. I find that the more translucent the cement, the more natural the restoration looks.

When trying in the veneers, I noticed that white spots on tooth #8 and #9 were visible through the veneers. You can see these spots more clearly in the picture of the preps in Figure 43. Rather than use a more opaque cement under the veneers, I decided to mask the white spots.

The white spots that were so apparent on the before pictures (Fig. 16) diminished as we prepared the teeth; however, they were still somewhat present when the preparations were finished. Using a #1 round carbide under magnification, I began to prepare into the white spots in order to place some composite over them. With minimal preparation, the white spots were removed.

I decided to place a small amount of composite into each of the white spot preparations, making sure not to place enough composite to alter the fit of the veneers. I begin by etching the preparations for 10 seconds and then rinsing.

OptiBond® Solo is then placed into the preparation, thinned with a dry microbrush, and evaporated with oil-free air. The bonding agent is light-cured for 10 seconds.

Point four composite (shade A2) was used to fill the preparations. Notice the difference in how the preparations look in this image when compared to Fig. 43. It will now be possible to use the translucent veneer cement.

The lab has already etched the internal aspects of the veneers with hydrofluoric acid. After rinsing out the water-soluble try-in cement and drying the internal aspect of the veneer to verify the etch, we use a microbrush to place the silane on the internal aspects of the veneer. It is left in place for 60 seconds, then air-evaporated.

We use a unidose pumice (Pumice Preppies™, WhipMix) to ensure that the temporary material, try-in cement and saliva has been removed from the tooth prior to veneer cementation.

The teeth are etched with 37 percent phosphoric acid for 10 seconds on dentin and 15 seconds on any remaining enamel. Care is taken not to leave the etch in contact with gingival tissues; this can cause bleeding if the tissues have been irritated by the temporaries. If the tissues are irritated, I will often place a #00 retraction cord prior to seating the veneers.

The veneers on tooth #8 and #9 are always placed first, and always placed simultaneously. It is critical that these two veneers are placed correctly and match. I will often push gently with an orangewood stick from the incisal and the facial at the same time to ensure the veneer is completely seated.

The veneers are held gently in place from the incisal with an orangewood stick while my dental assistant cures for 2-3 seconds using the "tack-and-wave" technique. I check the cement with an explorer to see if it is in its gel state. If not, my assistant will cure for another 1-2 seconds. Once it is in the gel state, I use an explorer to clean up as much excess as possible and dental floss to clean interproximally.

A safe-sided serrated strip, such as this one from Axis Dental, is invaluable for opening contacts that have been inadvertently bonded closed. If we ever ran out of these strips, I would have to reschedule the patient's seat appointment; that's how important these strips are to properly seating a veneer case.

Once all four of the veneers have been placed and cleaned up with an explorer and floss, it is time to remove the excess veneer cement from the lingual margin and adjust the occlusion. My favorite bur for this is a 7408 12-fluted carbide. The bur's shape helps it to work particularly well on lingual surfaces.

It can be difficult to identify and remove cured veneer cement (especially translucent) from the facial surface of the veneers without damaging the porcelain. I avoid burs at all cost while doing this. Here I am using a One-Gloss disc from Shofu, a composite polishing disc, to remove the resin cement from the veneer without causing any damage to the veneer whatsoever.

Here is a retracted facial view of the veneers immediately after cementation and cleanup. Because of the patient's excellent gingival health, it was not necessary to place a retraction cord prior to cementing the veneers.