Repairing Complete & Partial Dentures P3
2014
In this case, what we did was the tooth was extracted before the patient got to us, and we then went in, after the fact, wanted to add a tooth in this area, add a tooth in this area. So, what we did this time was just basically poured alginate into the underside of the partial so we could take a scalpel and carve this area in the back, add pink acrylic there, and just arbitrarily add the tooth and the pink acrylic.
Dab and dish a liquid and a powder in a paintbrush, trim an appropriate tooth so it’s the right height occlusal cervically, just arbitrarily build up and dollop up some pink acrylic there, keep putting just a little bit of monomer on the pink acrylic until it gets somewhat doughy. When it gets pizza dough like silly putty, you can literally take the tooth and squeeze it or set it right into the partially polymerized acrylic. Paint a little bit more monomer on it, and then you’ve converted this, added a tooth to it. What we did to it is realigned it with the temper soft liner.
Post dam modification. You’ve delivered a denture. The patient comes in and says, “Gee the denture doesn’t stay up very well,” or they’ve worn a denture a long time. They come back in and you look at the record. It was one that somebody made a year ago that’s now graduated so you inherit this case that’s a year or so old, and the student that made it had graduated. The patient says, “It doesn’t stay up very good for me.” So, if the denture doesn’t stay up very good for a maxillary denture, the most common reason is either inadequate extension of the denture on these corners by the two [25:16] or potentially and inadequate posterior palatal seal.
So, if one is going to consider repairing this area on the denture, the very first thing I want to do is take some fluid wax, the stuff that’s called Iowa wax. It doesn’t photograph that well. If you look closely, you’ll see that there is a skin of wax across the posterior aspect of the denture that’s shaped somewhat like a butterfly shape that we try to make for our posterior palatal seal. So, you can see over here it comes slightly through the notch. If I feel that the back corners are deficient, I might actually drag out the dreaded border molding compound and see if I could go ahead and develop these corners just a little bit
Now, the reason that I do that ahead of time is if the patient complains about retention of the upper denture, and I go in either with compound of wax, diagnostically, and rework this posterior area of the denture. Let’s say for the sake of argument that I do that and when I’m done, the retention doesn’t seem any better. I’ve really done it as good as I can, and it still falls right down. Anybody think of possible reasons why a patient’s maxillary denture might have really crummy retention?
The amount of saliva, either they have no saliva or the saliva they do have is extremely serous saliva, the stuff that’s really runny, the stuff that makes the best retention for dentures is the ropy saliva that slaps you on the rubber when you’re doing prophies. You take it out, and there’s this thing that’s about that long but it won’t break. It won’t snap. It just sort of whipping around there.
If someone’s got spit like that, then they’re probably going to do really, really good with an upper denture because that stuff is an interfacial surface tension provider. It stays in real good. If somebody’s got that really, really clear runny stuff that is just lighter fluid, those people are going to have a tougher time. So, they might either have really the wrong kind of saliva or no saliva or are really poor anatomical shape to the maxillary ridge, really flat. Some other people have had trouble whether they’re people with extremely round faces and really tight cheek muscles. It feels like no matter how they move their mouth, their lips at all, their mouth, their vestibule, their cheek muscles are so tight that it lifts off a lot from the denture.
So, people with these really round faces and high, tight cheeks, if this is the depth of the vestibule and that’s the denture flange going up in the depth of the vestibule and this is out toward the cheek, that area out toward their cheek, anytime they more their lips, is flexing up and letting air over the top. With some of situations, reworking my posterior palatal seal isn’t going to do anything for me. So, if I lay on the Iowa wax or do a little border molding or whatever and the retention doesn’t seem to improve significantly, stop. Don’t bother to go any further because you will turn this whole thing to plastic, your retention won’t be any better if it’s good as what you started with.
So, first, if you diagnostically try it on these things, see if the moderate retention improves significantly. The second thing you want to do is if somebody comes in, they complain about retention of the upper denture, the very first thing you do is a slap a PDS in and say we’ll just realign it and that will fix everything. So, you take a realign impression and you send it off to the lab. You get it back. You try it in, and it’s just as crummy as it was before.
So, again, if they come in with a poor retention of an upper denture, what’s one of the first things you can do to see if you’ve got relative intimacy of contact between the denture and the tissue? What’s something you can check with? PIP paste, and so what I would do is put a thin, thin filling of PIP paste on the upper denture, sit it really firmly, and if I have significant unevenness in the burn through pattern, it is okay to grind down the intaglio surface of the denture where you see tons of burn through.
Then, reapply the PIP paste and put it in, at the time you take the denture and you’re getting pretty uniform burn through pattern through the real thin layer of PIP paste you put in, surprisingly many times the retention goes up markedly, a lot. You didn’t send it off to the lab. You didn’t have to realign it. You just made sure the inner aspect of the denture had some semblance of being able to fit.
Now, if the denture’s 20 years old, you’re probably not going to bother doing that because I’m assuming the denture’s probably going to be poor fit, but if the denture’s not that old and they’re having problems, that’s what I’m going to check.
Let’s say for the sake of argument we figure out it’s the post dam. So, we go ahead and pour a plaster index on the inside of the denture. Once the plaster index has been poured, it captures the tissue surface, and you can see where we’ve put our Iowa wax in to give us a little more indentation for the posterior palate seal.
This is the part that freaks students: I go to the dam, and I cut the back denture off completely. They’re like, “What did you do? Oh my god.” So, you set the thing back down on your model. So, you’ve got your model. Now, remember your model did a very good job of capturing intimately the tissue surface of that denture looked like, and this is one of those areas.
Can you see that if I’m trying to paint this entire area across with a dab and dish of liquid, a dab and dish of powder and acrylic, when I’m painting in here, it looks fine, but when I’m trying to paint over the too glossy areas, it wants to go back in the middle? It’s a pain in the butt and takes forever. So, this is one of those things. This is the perfect indication for the use of that triad material. So, what you do here is on the posterior aspect where we cut it back, bevel this. I would bevel the plastic toward the oral side away from the tissue side. I’d put bonding liquid along there. There’s that bonding liquid back with the triad material. It comes in a brown bottle.
So, I’d put bonding liquid there and then cure that and then take a sheet of the pink triad material, cut a strip of it, and very carefully adapt it to this really well. You can do a very beautiful job of doing that, put the air barrier coating on it, put it in and cure it for 10 minutes. Then, you’ve got a new posterior border on your denture. Again, you wouldn’t even bother doing this if you didn’t see a marked improvement and retention when the patient came in complaining of retention and you tried to diagnostically put some fluid wax or something along the posterior aspect in the denture to see if that worked better. If it did, you go through this procedure, and it will give you a new back end on that denture that will give you significantly better retention.
This is one where we took basically a realign of a denture. So, this is the old days where we would do immediate [33:06]. I said, “Okay, but let’s do a realign of the denture. Then, on the inner aspect of the realign, we put the fluid wax.” This is a kind we used to use. It’s called proectowax. It’s what the Iowa wax replaces, and so, we’d have that set up. Here, again, we have the posterior palatal seal, but what is it that that thing’s supposed to do?
In any individual, when they go ahead and use the denture, you want the maxillary denture to stop at the junction of the hard and soft palates. So, the hard and soft palate junction, we want to have a little extra bead of the denture going up in the air. Reason being, when a person sneezes, swallows, yawns, does lots of different things, this area of the soft palate where the uvula hangs can flex up. It goes up in the air. If this area of the uvula goes up in the air, what it can allow is a little bit of air to come over to come over the top edge of the back of the denture, and that can cause the denture to break at suction. So, the working of the posterior palatal seal is to just give us a little extra beading of that area right there so that we maintain seal if the soft palate moves.
So, if you look at the posterior aspect of the denture cross-section, here’s the tuberosity. It goes up to the roof of the mouth. It comes down for the other tuberosity. Then, we go ahead and we build the denture that’s on this. So, we’ve got a denture that’s built here. Here’s teeth, and then here’s our denture flange that’s supposed to fit in this area intimately.
Now, what happens when we process a denture and the denture is removed from the stone cast, turned from wax into plastic, it’s all processed. In the lab, they break away the stone model. What happens to the dimensions of this acrylic looked at in cross-section is it tends to shrink towards the middle just a little bit. So, areas that are out here on the outer aspect would actually pull in tighter and rub tighter. People follow that okay?
The areas that are in here where you got the inner aspect of the hollow vault going up in this area if I blow up the denture, it would tend to pull away a little bit here and here. People follow that okay? So, you’ve got this curved shape of the denture. If it’s going to shrink a little bit to the center where it fits the roof of the mouth, if it shrinks in there it’s going to separate. Can you also see that the deeper a person’s vault is, the more pronounced the pull away is? If a person’s maxilla was as flat as a pool table that it was just straight across, their thing shrunk to the middle. Can you see that would cause no vertical separation? If I had a really V-shaped ridge that almost looks like a submucous cleft so that there’s this incredibly deep vault going there, near vertical, when things shrink to the middle, now I’ve got more problems there. People follow that okay?