How to perfect dentistry by adjusting temporaries
Posted by: Dr. Glenn DuPont
So a quick tip when working on provisionals is probably nothing new to you, it's something you've heard. It's to follow The Dawson Academy checklists and to follow the order and to never go out of order.
If you follow the order of checking your provisionals, it's the same order of checking your occlusion on anterior restorations. We follow the same process step-by-step.
Centric stop on the lingual of the upper.
So the first step is the centric stop on the lingual of the upper. Now that warrants that you had the lower teeth where you want them, whether they're natural or they're composite. Now, that allows you to position that centric stop on the upper.
Once we have that, then we look at the emergence profile next of how it comes out of the tissue. The lip closure path is critical. All of these are really involved with the neutral zone in the muscles, so the way that lower lip comes over that edge for the lip closure path is the third thing that I check.
And then we can combine the centric stop with that position of the incisal edge. That's why you have to determine the incisal edge prior to developing the envelope of function and that lingual contour. So once we develop that centric stop then that facial contour, we can develop that lingual concavity with the envelope of function and check out that for comfort and stability.
When looking at the provisionals below, you can see I adjust the anteriors first.
I'm adjusting centric stops and I can add to them or I can takeaway. I want those to be exactly positioned. Once I get my centric stop, I can start adjusting my emergence profile and my lip closure path. Because I use Luxatemp or Protemp, I can fix this, I can add the bubbles, I can add with flowable composite so it makes it nice and easy.
If we don't provide accurate provisionals to the lab, they will have to guess and the guess is never accurate. The guess is always not what we want it to be. And so we have to provide that incisal edge position, facial contour, and centric stop in the vertical dimension to the lab.
So once we get that emergence profile, we'll start working out our lip closure path.
So this is the third thing and with that, we're going to ask the patient to count 50 to 60. We're going to look and make sure that edge is in the vermilion border, right inside that lower lip, and we're going to ask the patient how that feels.
If a patient says that it feels too long, very often it's not too long esthetically. It's not the vertical position; it's the horizontal position. So very often when the patient says it feels too long, it's because we have to tip in, adjust in that facial emergence profile where the lower lip comes over it.
This is a post-orthodontic, post-orthognathic surgery where I'm restoring the anterior teeth. So we're going to watch the F sounds and listen for that S sound. Then I tell them to go ahead and big smile, now count 50, 51, 52, 53.
Developing a clear S and F position helps position the horizontal position of the incisal edge.
So you can see in the picture here, once we have our centric stops, once we have our horizontal position of the incisal edge with the F position, then we can start developing our guidance. We're going to go from the dot of the centric stop to the inside border of that incisal edge.
And you can see here, straight lines, and as we work with it, we can develop some lines that go up the marginal ridges. Notice the guidance we have on the cuspids. And only then with provisionals will I then start adjusting the gingival embrasures and the other non-functional parts of the provisional.
Round out edges and polish the provisionals
So we can see we're developing the incisal embrasures so they're not all the same, that we round them out. You can see we're developing some texture on that provisional so when we polish it, it has a little bit of texture, a little light reflection.
And so to sum up, we can see that we've got:
- The centric stop
- The emergence profile
- The F position, lip closure path, counting 50 to 60
- The envelope of function.