IPS e.max®

In this clinical case, we will utilize a product from Ivoclar Vivadent called IPS e.max CAD. We will be placing crowns on teeth #6-11 and no-prep veneers on the first and second bicuspids, if the patient would like to do so.

The patient just had an endodontic procedure done, so we will be placing some core.

This is an area where no-prep veneers come in handy — when you are doing some restorative dentistry, but it's not a full-arch case. No-prep veneers are a fantastic way to finish off a smile, for example, from second bicuspid to second bicuspid.

You will really see the difference on the anterior teeth and the bicuspid for cases in which you are restoring anterior teeth. Prepping teeth is not required, so we are able to go in and improve the smile. Patients are really open to this, too, when they learn that no-prep means no shots, no drilling and (hopefully) no pain.

This is a simple, conservative way to finish off a smile. One thing to consider: Whenever we do restorations, the teeth tend to get bigger. This can be illustrated by measuring models. This happens because dentists tend to under-reduce from the ideal dimensions provided by the dental lab.

We remove some gutta-percha with a post drill and then place a 3M ESPE fiber post into this area.We have come back to more flexible posts over the years.

We are shying away from stiff posts because of concerns with root fracture. Also, we now know that teeth actually do flex! For this reason, we prefer something like the fiber post that I try in here.

We prefer a flexible post because if something bends or the patient takes a blow to the mouth, the tooth does flex; there is not something stiff inside that could cause root fracture.

Root fracture is something we do not have answer for in dentistry — short of an implant, of course.

We are placing 3M ESPE RelyX Unicem into the canal. We use this cement because it has the lowest expansion, which is a great for preventing root fracture.

You can see that the post is a little bit longer than it needs to be (it will be cut back later). First, however, we want to get the post in the tooth. This is a dual-cured cement, so we light cure the cement for one minute. Tack it down and hold it in place once it is adjusted to an ideal position and once it has gone through the setting reaction. If the post does not move again, we cut it a little bit shorter, as we have done here.

And then we will go ahead and do our buildup around this. The ease and simplicity of being able to place a post and then do an immediate build up and cure makes a big difference.

We have removed the excess cement, and we etch this with some Ultra-Etch® from Ultradent. We will leave the Ultra-Etch in place for 10 seconds on a dentin and 15 seconds on an enamel. We are etching the entire post, as well.

One of the nice things about using a fiber post is that we will get a nice bond between the composite buildup material and the post itself. The trend, in the past, was to use stiffer and stronger posts, such as zirconium posts. You cannot bond composite to zirconia, so you had to rely on mechanical undercut and the post itself. It's preferable to have something that will bond to composite.

Because there is dentin exposed, we are placing Optibond® bonding agent.

Let the Optibond evaporate for a couple of seconds. You can see the air tip moving around quickly. You don't want to blow it off. Just let the air evaporate the solvent.

And we are going to cure it with Ti-Core, a dual-curing material. LuxiCore is another option. Ti-Core seems to be a little bit harder when you go and do a prep.

We place an incremental layer, cure it, and once it's set and we have a good foundation, we add more buildup material.

We are going to build this up incrementally. Build it up in stages to maintain control over the anatomical shape by adding an increment, curing it and then adding another increment.

You can better achieve something that more closely resembles what the final shape of the tooth by slowly adding buildup material. Spending more time on this step means less prep.

Tooth #7 had some endodontic treatment as well. Again, we go in with a post drill to prepare for a fiber post. We place that post and continue with our caries control on the other teeth.

Based on the amount of caries seen here, it is not surprising that two of the teeth need endo treatment. One or two others might need endo, too. This is a great reason to use a caries indicator, whether it is Seek from Ultradent or another product.

There is discoloration here that, with the round bur, makes it a little hard to see the difference between infected dentin and affected dentin. So it really does help to go in there and see the difference between the two when preparing the tooth.

We continue to buildup the other teeth, doing some caries control, etching the dentin for 10 seconds and then placing Ti-Core. Most places have enough undercuts that we don't have to worry about pins because of the way decay spreads at DEJ, and we hollow it out. We have enough mechanical retention to hold this buildup material in place.

Many of the buildups are smaller than the post, so we don't have to worry about shaping it too much. Pre Med Dental offers a crown former that does a great job of simulating the final prep shape.

Of course, the Reverse Preparation Technique, which you will see in Figure 27, takes care of this for you. However, in order to start the Reverse Prep Technique, you do need some anatomical landmarks.

The first step of the Reverse Preparation Technique is to break contacts with a 57 carbide bur. You can see we are making some space here. This is done first because, with this technique, an Ultrapak Cord #00 is typically placed at this time.

However, because we are not going to take our final impression today, we will continue using the Reverse Prep Technique minus placement of a cord. We use a 801-021 round bur along the gingival margin, which cuts a perfect half circle. This takes care of our gingival reduction.

We use a ruler to measure how much we need to reduce from the gingival. These are 10.5 mm in length, which is what the final crown length will be. So in a case where you want the final restoration to be the same length as the tooth, you will need to reduce 2 mm on the incisal edge. If these were 9 mm long, for example, and we wanted them to be 10.5 mm long, we need to reduce accordingly. If they are too long, we might want to reduce even more.

Here we reduce the incisal edge in accordance with a 2 mm depth cut. And it is really necessary to do a 2 mm reduction if you desire final restorations that exhibit a natural, esthetic look.

Nine times out of 10, depth cuts achieve the desired result. The placement of depth cuts also forces you to determine how much you want to remove because you have to take out the right depth cutter. It forces you to slow down a little bit and measure the teeth.

Again, it is important to start with the end in mind. This way you you won't over reduce or, more typically, under-reduce a tooth, which both will lead to ugly restorations and gingival issues. Underpreparation is one of the bigger problems we see at the dental lab.

An 856-025 bur is used to blend the depth cuts. Because the bur is so big, it helps to turn the cut by the round bur into a perfect deep chamfer or shallow shoulder. This bur does a great job of that and, because this bur has such a large circumference, it sits and preps the tooth very well.

In lieu of using the Reverse Prep Technique to check whether we have enough reduction, you can also try in a plastic stent. Because we use BioTemps for our temporaries, when the lab makes the pre-op models, it also makes a stent — a suck-down vacuum-formed stent of the preps so that you get an idea of how much you have reduced.

Sometimes it's not about achieving enough reduction, as we reduce the cusp tips here. It is more about the fact that BioTemps are splinted together. In the end, this is going to be single-unit IPS e.max crown. So it is more about path of insertion and draw. In other words, crowns have to draw as though we are making a permanent 6-unit bridge.

In reality, we will not have a 6-unit bridge. We are going to have 6 single-unit IPS e.max crowns that don't have to draw. However, they have to for the purpose of the BioTemps Provisionals. For this reason, we use this stent. It's now time to try on the BioTemps. Ninety-nine out of 100 times, the BioTemps Provisionals will fall into place.

Just like they fall into place here. Nice passive fit. Not binding on any of the teeth. Not rocking from side to side. Actually a loose fit. The term passive fit refers to the fact that it is not binding anywhere. You can see all the gingival margins look good and embrasures all look closed.

We open those gingival embrasures a little bit when we reline this bridge because we don't try to make BioTemps look perfect in the gingival aspect. In fact, we'd rather have it open just slightly so that the patient can rinse with Tooth & Gum Tonic (Dental Herb Company) to keep the embrasures clean. That is why we do not impress on this appointment. In an anterior case, you never know what effect the temporaries will have on tissue.

We are just discing off some areas on the lower teeth where we know there will be little bit of interference with the BioTemps. We straighten those out with a Sof-Lex disc (3M ESPE) to ensure the sharp areas, sharp cusps, don't cause any damage to the BioTemps.

We won't impress at this appointment, however, because we want to make a master impression and put on BioTemps or any kind of temp. We don't want the papilla to disappear and black triangles to appear when we do final restorations, which is we temporize on the first appointment and impress on the second appointment for big esthetic cases, such as this.

We mix Jet Acrylic to the consistency of cold honey, and my assistant places into the BioTemps. You can see six of these are splinted together. We know it's a passive fit. My assistant presses down into place; all the gingival margins will seal just as they should.

There are times the margins don't seal because they had to guess where the prep had to be. This is common when you have old crowns in place, and they are not sure what it will look like when they prep it.

The margins should be closed when you have regular teeth in place. As it reaches the doughy state, we remove the excess cement. For other cases we don't remove the excess when we have to build the margin with our reline. Here everything works fine.

We pump the provisional up and down to keep the tooth preparations cool and to ensure the BioTemps don't get locked down into any undercuts.

You can see how nice the BioTemps look. BioTemps are much faster than chairside temps. They are far more esthetic. Some dentists will say, "Yes, but they are more expensive than chairside temps?" Well, yes, they are – but they look like it, too.

For anterior esthetic cases, BioTemps provide the your most discerning patients with the feeling of excitement and satisfaction. There is really no better way to excite your patients about their new smiles than with BioTemps.

Here are the relined BioTemps. My assistant uses a disc from Axis Dental to open those embrasures. Here, our goal is not to make BioTemps look perfect. Our goal here is not to make BioTemps in the gingival third to look like the final restorations.

There is too great a chance that we will cause a papillae to recede, especially if we impress on the first appointment. In fact, at this point, if we have a papillae that recedes a little bit, it's not a big deal. We can always drop that margin a little more at the next appointment.

The BioTemps are trimmed. Tooth #8 and #9 have a nice area open on the gingival embrasure, which is one of the most important papillae in the smile. With that space open, patients may use a floss threader during provisionalization.

We ask the patient to swish around some Tooth&Gums Tonic. The important thing is we don't want to push the papillae back up; that can cause recession, especially if you are impressing on the first appointment.

We use the KaVo SONICflex Scaler to remove the Durelon from these preparations. Durelon, when used on temporaries, will never come off. You will never have any leakage. The tissue is going to be healthy, the teeth are going to look great. There is no better temporary cement than Durelon.

If you place temporaries with Durelon and do not use the SONICflex scaler, you are going to be unhappy. The scaler gets the Durelon off very quickly. If you try to scrape this off by hand, it will easily take up to 45 min. Do not use Durelon without the KaVo SONICflex Scaler (or a scaler like it) to remove Durelon from the tooth.

We now place the Ultrapak Cord #00 (Ultradent). This is a small, hollow cord. It just disappears into the tissue. Note how the combination of BioTemps and Durelon has given us some healthy tissue. There is no bleeding present.

If you remember when this patient first came in, the tissue was not this healthy and the teeth looked thrashed. As we turn this corner on this central incisor, there is some inflamed tissue and there was some caries subgingivally, so we need to be careful here.

Here is our 856-025 fine bur with the red stripe on the bur. This is the one we used to smooth out all the preparations. Why do we smooth it out? Well, it looks nice. It is easier for the dental lab to read. The idea of rough tooth surface for micromechanical retention of preps held true only 15 years ago, when cement did not have any natural bond to the dentin structure as it does today.

RelyX Luting Cement Plus bonds well to the tooth. It doesn't matter if the tooth is smooth – RelyX will bond to the dentin. When you go to remove the crowns, you will be amazed by the nice bond. The Ultrapak Cord #2 now gets placed on top of the #00 cord on the teeth we are going to impress.

That is an ROEKO Comprecap anatomic. I call this the miracle worker because it saves almost any bad situation. We don't have bad situations here, but you know what it's like when you are trying to prep tooth #19 or #30 and the patient has an open contact for a couple of weeks and things are bleeding and tissue looks bad.

You put the Comprecaps on, which are available from all dental dealers, and have the patient bite down for 8 to 10 min. When you return to remove it, the tooth and tissue look new! Comprecaps do a good job of holding the cord in place and stoping the bleeding by applying pressure. Some dentists have asked me before if the tooth becomes dehydrated from having cotton on top. Contrary to popular belief, the answer is no.

The assistant pulls the top cord, Cord #2.

Here we express the medium-body material. We use medium-body material instead of light-body material because of the Two-Cord Impression Technique. With this technique, the impression material is injected at least 2 mm subgingival to get great subgingival impressions.

We always use a custom tray for impressions, in this case a perforated custom tray. Custom trays save you money and impression materials, and you know that the trays are going to fit. There is no better way to take an impression.

Again, we take the impression material 2 mm subgingival. If we had used a light-body material, it might have torn. You need mechanical retraction of the tissue with the Two-Cord Impression Technique: Take out the top cord, the medium-body material goes really far subgingival, and most of the impression material won't tear on its way out.

The impression is poured in the laboratory, and the master model is scanned. This is part of the CAD/CAM procedure, to be able to design these crowns and make virtual dies. The lab can also now scan the preps in the mouth so you don't have to take an impression. We are showing the process this way because nine out of 10 dentists still take conventional impressions, and they will continue to do so for the next five to 10 years.

The technician can spin the model 360 degrees. You can see how large it is on the screen. This image of the scan really gives the technician an opportunity to enlarge the tooth, which is something you cannot do when working with the actual model.

The technician designs the crown using Computer-Aided Design software. Tooth #11, the highlighted one, is the tooth she is working on. Redoing some of the contours and being able to spin it around, and again, the size of it is huge. It is like being able to work wearing 10x loupes.

Here is the IPS e.max CAD block. This product, and the material it is made from, has proven to be excellent. These crowns look fantastic.

You will be be blown away by the esthetics of these IPS e.max crowns. The fact that they are milled from a block is amazing. And, for dentists who own a CEREC unit, these crowns can also be milled chairside. However, if you don't want to pay more than $100,000 to purchase a unit and mill in your office, we can do it for you in the lab.

The crowns are milled to full contour and cut back. You can see some ceramic material being added here to give the crown nice incisal edge translucency. You can see that it has been cut back and porcelain is applied to those teeth.

Then the crown will be baked. But on posterior teeth, you can just have the lab mill it to full contour and then polish it. On the anterior teeth, it is little different. We want to take advantage of the technician's artistic ability, so we have them do that for us.

You can see how nice the crown looks as the oven temperature rises. Again, this crown is milled from a lithium disilicate block with a little porcelain added to the facial for incisal effect.

These are the crowns that have been milled. You can see how nice they look.

We now anesthetize the patient. The STA injection system is used during this appointment.

Here we remove the BioTemps provisionals and then try in the IPS e.max crowns.

We try the crowns in individually to ensure they fit, make sure they look good and that contacts are there. The fit with these units has just been great.

Because of the strength of this lithium disilicate ceramic material, we are able to use conventional cementation. So we will conventionally cement, using RelyX Luting Plus, tooth #8 and #9.

We use the ubiquitous orange wood stick for seating restorations. With no-prep veneers you have to be more careful when pressing, but with crowns we press a little harder. We don't really need to press these, but we do so to hold them in place.

We are cementing tooth #8 and #9 first because they are most critical to the smile. If these two crowns don't work, the others won't work. This is in lieu of placing teeth #6-10 later. Watch out for cement getting on the lateral. Pay close attention to that and pop it off as it starts to set, and we will put two crowns on either side. And this is how we will do it. And even if we were doing second bicuspid to second bicuspid, we'probably put these on first and then place two more.

It is easier to find contact problems using this technique. When you try-in crowns, this is obviously where the contact issues are; however, until the crowns are cemented, it makes it a little difficult to see these. So when you put on tooth #8 and #9, for example, you may want to try tooth #6 and #7 again to get a better idea of contact issues.

So we have six units cemented in place. The gums are just a little beat up around tooth #8 where we did some cement. But as you take a look here at how those look, and when you take a look at the before and after pictures, you can see the great improvement. The exciting thing with IPS e.max CAD is that we are not hiding any coping. Because it is a monolithic material, the crowns are all the same shade, there is no coping, throughout the material.

All in all, this is a great case that was made possible through CAD/CAM and IPS e.max CAD lithium disilicate blocks.

This is an occlusal view of the veneers. Notice how the facial alignment has been improved as compared to Fig. 14. The pre-contouring of the teeth prior to placement of the depth cuts makes this possible.