The Good, The Bad and The Ugly – Case of the Week: Episode 54
Chairside Magazine: Volume 9, Issue 2
article by Michael C. DiTolla, DDS, FAGD
The images that follow feature three impressions presented as the Case of the Week for Episode 54. They were lying on the desk of a quality-control specialist in the Crown & Bridge department, and are worth sharing for their own unique personalities. It’s a tale of the good, the bad and the ugly.
Figure 1: Let’s start with the good. This is an impression from a doctor who practices in California. It’s a simultaneous impression where both materials are squirted in at the same time, as opposed to separately, and you can tell that because of how nicely they blend. This is in that QUAD-TRAY® Xtreme™ (Clinician’s Choice; New Milford, Conn.) impression tray that I like so much because it’s nice and stiff.
Figure 2: You can tell this is the Two-Cord Impression Technique because of the fact that we have impression material beyond the margin all the way around. It’s a little thin on the mesial right there, but that may have torn off when the stone was removed. In fact, there’s a lot of material present, considering that the model has already been poured and separated and the crown has been made and shipped back to the doctor.
Figure 3: You can see all the contact here between the unprepped teeth. Without even holding it up to the light, you can view thin areas here where you know the patient was in maximum intercuspation. Personally, I might have used a little more of the light-body material on these other teeth, but then again, I get my impression material for free, so I tend to dispense it as if I was still in dental school.
Figure 4: This is just a gorgeous impression when you get down to it; no tray impingement anywhere. It doesn’t get any better than that. The doctor said it dropped in with no adjustment. All we can do is ensure it fits the model before it leaves the lab; whether or not it fits the patient’s mouth has everything to do with whether or not the contacts and occlusion were correct on the temporary.
Figure 5: If it doesn’t fit in the patient’s mouth, and then the doctor tries it on the solid model and it also doesn’t fit that, obviously we screwed up there and it was our fault. But if it fits the solid model and it doesn’t fit the patient’s mouth, then something shifted from the time it was made. For this case, it lined up well.
Figure 6: Now, let’s look at the bad. I don’t know if you recognize those colors (you might, depending on how many of my clinical videos you have watched), but these purple and yellow colors are Capture® impression material from Glidewell Laboratories. This is one of my impressions. It was sitting on the quality control person’s desk because there was an issue with my impression.
Figure 7: I asked: “What’s the issue? Is it up for an international award?” And she said: “No, the issue is we’ve got a pull here. And look: There’s inclusion of some fluid here.” And I was like: “Oh, snap! Yeah, we’ve got an issue there. We’re going to have to take this again.”
Figure 8: Things just aren’t looking like they should. Things look decent in other places, but still just not like they should.
Figure 9: I don’t know if you can tell, but this is not a Two-Cord Impression Technique. This was an area where I used the diode laser, and then tried to use a cord-free retraction paste. I play around with those from time to time because I’m always looking for something easier than the Two-Cord Impression Technique, but I believe in my heart that there is nothing better. If something ever comes along that does even 90 percent of what the two-cord technique does in terms of retraction but is 60 percent easier, then that would be a big step in the right direction. So far, nothing has come close to knocking it off.
Figure 10: This impression is one of those sneaky ones where you might have taken it out of the mouth, glanced at it real quick and, I don’t know, maybe happened to not see it. Maybe I walked out of the room, and my assistants didn’t see it either or thought I had looked at it. But the mistake got caught after they poured it up and saw it on the stone model.
Figure 11: I’m calling this the bad impression. The good is from the other doctor; mine is the bad one. That’s embarrassing because I do nothing but work with technicians. So I had to fall on my sword and say: “I did not see that. Please, please, please believe that I didn’t think that was an acceptable impression.” They’ve forgiven me and we’ve moved on from it. So I’m calling myself out: I get the bad award this week for that impression.
Figure 12: At least I’m glad I didn’t get the ugly, because here’s what we got from one doctor.
Figure 13: If you’ve seen me lecture in the last couple of years, you know we have a doctor who we’ve christened “Tiny Impression Guy.” This is probably his first cousin. This guy uses slightly more material — and by slightly, I mean, like, 15 percent more material — than Tiny Impression Guy. So this guy is slightly larger, but not by much. This doctor doesn’t even warrant being called “Medium Impression Guy.” What we’ve got here is still tiny.
Figure 14: And look at what happened over here: all those bubbles. It looks like this impression was taken adjacent to molten lava. I’ve never seen this kind of look before. What would make it bubble like that?
Figure 15: There really is a crown that was prepped in there, with the impression material squirted around the crown prep and a tooth on either side of it.
Figure 16: And over on this side, the patient did bite together, so we do have some occlusal registration of the teeth across from it …
Figure 17: … but there is no tray used. It’s kind of a flexible impression. I don’t know if the thinking was: “Boy, them trays are expensive. Who wants to go to all the expense of doing one of these?” Maybe they had to do this on a desert island, or in the back of a car where trays weren’t readily available. I don’t know what the thinking is, when you’re doing an $800 crown or a $1000 crown (or maybe the crown is free?) that justifies not using a tray.
Figure 18: It seems kind of crazy. Obviously, when we see something like this, it’s where we draw the line. We try to work with every doctor. We try not to call and critique doctors and say, “Hey, look, this isn’t going to work for us.” But this is a difficult one to deal with. We don’t have tiny little articulators that are only this big, where we can take tiny little models and articulate them and work with them.
Figure 19: So this is the ugly impression of the week, and this is a wonder. It’s hard to believe that a licensed dentist here in the U.S. would send this in. The worst part is we see dentists who will take impressions for bridges like this! Which is arguably a bigger sin. But this is pretty lazy, and there’s really no excuse for this.
Figure 20: So here’s hoping that all your impressions look like the good; here’s hoping that your lab will forgive you if you do what I did, and every once in a while send in the bad; and here’s hoping that you have a conscience and could never be tempted to send in the ugly.