Lava™ Crowns & Bridges

This patient had an unesthetic PFM on tooth #9, with a gray line at the margin and a shape that didn't blend in. Additionally, there was an old crown on tooth #4 and both old crowns are replaced with Lava crowns.

The shape of the crown itself does not really blend in with the rest of the dentition.

There is an old crown on tooth #4 that we will remove, as well. Both of these will be single-unit Lava crowns. This is a Razor bur from Axis Dental and, with a few short strokes, I should be able to effortlessly go through both the porcelain and the metal.

I don't think there is a safer or more effective way to remove an old crown than using the Razor bur. We created our slot there, put in a crown spreader and popped off this old crown. Let's see what we have underneath.

You never know what you are going to find when you take this off. How much decay, what kind of buildup, what kind of post. You can only hope that the dentist before you did a reasonable job and did not drop the margin 3 mm to 4 mm subgingival.

We do see a reasonable job, which is nice. So I am going to floss this #00 cord in before I pack this into place. Usually we will floss in on one or both contacts because it is very easy to get subgingival here. We are simply going to work this #00 cord around the tooth and the sulcus.

This cord goes into place very easily. It is small and hollow. It is a plain cord — there is no medication on it. And this cord will be in place for approximately 35 to 40 minutes.

After waiting that period of time, we have retracted the gingival 0.5 mm to 0.75 mm by the virtue of the cord. Now we go around with a #856-025 bur (if we have the room) and refine the preparation and deepen the margin a little bit.

We are going to the next of the teeth recontouring and a little polishing, too. We would like the lab to match something that looks nice. At this point, the preparation on tooth #9 is essentially done.

So we are going to place a #2E top cord, and this cord is only going to be in place for about 8 minutes. We place this cord on top of the #00 cord, and the #2E cord is going to provide the retraction of the gingival needed to give us a successful impression with the Two-Cord Impression Technique.

The bottom #00 cord is going to stay in during the impression, which is also a big part of this technique's success. Doing so ensures that there is no bleeding.

You can see that we leave loose ends with the #2E cord and we have a preparation with a nice big margin. There is no mistake as to where the margin is when using this method. In fact, with the Two-Cord Impression Technique, you are pretty much guaranteed to get an impression material beyond the restorative margin and into the sulcus and onto the root of the tooth.

So, we are going in with a composite polishing wheel and just rounding off any angles we have there.

We almost don't have to use an Anatomic Roeko Comprecap, but I decide to use it anyways. We ask the patient to bite down, doing so just because of the fact that it tends to work magic. That being said, I don't think we need any magic — things are looking pretty good here.

We remove the #2 cord and you can see the visible sulcus that is open for us.

We are going around four to five times. I go around six times because I have a single tooth. Don't make the mistake of going around only once; there is inherent moisture in the tooth and the dentin that will get trapped in the area you go around, causing a pull.

So we put that in. We are using a full-arch impression here, as you can see.

We wait three minutes and slowly wiggle that out. PVS needs to be removed slowly in case there are undercuts. We try to minimize the amount of deformation that can happen here. As opposed to alginate, this is supposed to be snapped out of the mouth.

We examine the detail on that impression. You can see the margin all the way around and the whole rim of material that sticks out into the sulcus. There is no reason why, when using a detailed impression such as this, that the crown should not fit perfectly. You can demand much better work from your laboratory when you send a flawless impression.

Here, the temporary is in place. My assistant left it just a bit shorter than it needs to be, which certainly is preferable than it being too long.

Now we cut off tooth #4. This crown turned out to be stainless tell, not cast metal as previously thought!

We now flatten the contact and polish an amalgam on the tooth behind it.

We will place our #00 cord here. There is no need for the Reverse Preparation Technique on these teeth because they both had crowns.

However, this makes it more difficult for me to judge whether I have enough reduction. Sure, I can judge on the occlusal surface by having the patient bite together. But I can't judge on the axial wall whether we have enough reduction at the gingival. This is because we lost our orientation when we started with a tooth that has already been prepared.

Once we have had a chance to finish these margins, we do the best we can to ensure that we have enough reduction. We pack in the #2E cord. This goes all the way around the tooth, a full 360 degrees, and does not overlap the other end. There is not enough room for that.

After patient bites down with Anatomic Roeko Comprecaps for 8-10 minutes, we pull the top cord and express the impression material around the tooth. We'll take an impression of that, too.

If you are wondering if I could have impressed at the same time as I did tooth #9, the answer is yes. That would have been fine. However, we decided to do it separately.

This is the QUAD-TRAY® from Clinician's Choice. So we are going to provide a separate bite registration here. The best bite registration produced is when the patient bites together.

Here is a look at Lava crown on tooth number #9. Notice how it blends much better than the original crown. Especially look at that frontal retracted view; that is the most difficult view in dentistry and it looks pretty darn nice.

Here is what tooth #9 looked like before the Lava restoration was placed. It looks flared and seems a little bulky with the metal margin. Now you can you see how it blends in with rest of the teeth. Just a great restoration.

The lab nailed the surface texture and the anatomy. They got everything right on this tooth. In this case, you've seen tooth #9 restored using a Lava crown, and it is evident that it lives up to its promise. It is strong and it looks very nice as well.