How do You test accurate fit of crowns ?

[user name]

True, but its gotta touch down somewhere.

 

[Car 54]

By the way, I use Quick Check spray. If you turn on the suction unit and spray into that, there's no mess. I think Vacalon makes it now, used to be Ney.

Agree.

Jack, also helpful when using the sprays, is to wet the model or die under water first, before steaming it off, and you'll get 97% of the color off.
Otherwise it goes, steams into the pours of the dry die stone and is a little harder to get off the cast or dies then. I can't live without a steamer.

Valacon comes off a lot better than Occlude Red, which is more expensive. I like the intensity of the Occlude red, for me it marks a little more clearly.
When I need to use Occlude for the extra marking power and to keep if from "staining", I do a light coat of Valacon red 1st, then Occlude on top of it.

The Green Valacon works great for a light misting of the cast with your ceramic or FCZ etc units on just to get a general idea of line angles and shapes
in a all the same neutral look. It steams off pretty well, not leaving to much color behind.
It's not as intense as the silver and gold stuff in really picking up detail, but works for a general "look see."

 

[ztech]

I use felt tip water color markers like the old Flare markers. They go on easy and then rinse off completely.

 

[Affinity]

I fit check every case with powder spray, I never assume it fits because it 'should' .. especially if a machine made it.

 

[Wade Bognuda]

Read and follow the instructions that come with your die stone and investment. That's how you dial in your fit. There are a lot of variables that come into play here that can be and have to be controlled. If I have to grind the inside to get it to fit it's because I had a cranio-rectal inversion when I was investing and poured a bubble. I tell people if you see me with a can of that green stuff it's because I screwed up and am in trouble!! If you want, PM me your number if you can't get this problem to go away. Or better yet, call someone who really knows what they are talking about (hopefully),the tech rep for the company you are buying your investment from. It's the same whether it is a C&B case or a cast RPD. When you get all the stars to align no internal adjustments will be needed.

 

[rkm rdt]

I use a device called a microscope.
It has two areas for your eyeballs to look through.

 

[Jenners]

I don't use those type of seating products often, but if there's a fiddly spot that I can't figure out by feel, then I'll use cheap lipstick. It's waterproof enough for finishing with water and will steam off, as long as it doesn't stay on the die for hours.

 

[RileyS]

i love vacalon quick check red (pink) spray. I use it on less than ten% of crowns but it clearly marks the problem area and I zip it off under microscope. Sprays off very well with steamer.

 

[Tayebdental]

The only thing I do after casting is to use a small round head bur on SH under magnification to smooth the internal to seat easily.
Spray stuff is not necessary if you know your magic recipe

 

[user name]

If I didn't trust my equipment, techniques, materials and protocols, you guys would be giving me anxiety about my model-less cases.

 

[Car 54]

If I didn't trust my equipment, techniques, materials and protocols, you guys would be giving me anxiety about my model-less cases.

Good point. Get things worked out and figured out before that day comes, at least in my case not doing model-less yet.

 

[CoolHandLuke]

if you have to 'fit' it after machining youre doing it wrong. model free is easy, guys.

 

[Car 54]

if you have to 'fit' it after machining youre doing it wrong. model free is easy, guys.

My internal fits are probably a little to tight. If I miss a little of the inside clean out before sintering, I have to check it with the spray for a tight spot. Margins are good, just the once in awhile adjust.
I may need to loosen them up a bit.

 

[ps2thtec]

I've never used this spray stuff. If the crown doesn't drop on check with magnification to solve it. Try glasses,
loupes, and a mag light. Maybe there's too many "cooks" in the kitchen !

 

[Car 54]

I've never used this spray stuff. If the crown doesn't drop on check with magnification to solve it. Try glasses,
loupes, and a mag light. Maybe there's too many "cooks" in the kitchen !

 

[RileyS]

If I didn't trust my equipment, techniques, materials and protocols, you guys would be giving me anxiety about my model-less cases.

so if I get 1 out of 20 that needs to be slightly adjusted (1 to 3 pinpoint spots internally) to achieve the correct passive fit and the other 19 are all good, should I loosen the setting up a bit more to ensure 20 for 20 are all good even if I feel the other 19 are now going to be a little looser than needed?

 

[RCKSTR]

I fit check every case with powder spray, I never assume it fits because it 'should' .. especially if a machine made it.

The one thing machines do very well is repeat-ability, get the settings right, let the machine do what it was designed to do.

 

[Car 54]

so if I get 1 out of 20 that needs to be slightly adjusted (1 to 3 pinpoint spots internally) to achieve the correct passive fit and the other 19 are all good, should I loosen the setting up a bit more to ensure 20 for 20 are all good even if I feel the other 19 are now going to be a little looser than needed?

I'm guessing a lot of us are there, at this point in our careers as far as having things dialed in.

For me, it's probably 5 out ot 20 that need to be checked. Beyond zirconia is when
milled leaves a really fine powder inside. It takes a bit more brushing inside to get it all out and can miss a spot here or there, compared to Katana or Zenostar. Which tells me those are probably the zirconias I would want to use for model-less, as it's more like the 1 - 15 fit wise for me using those.

 

[rkm rdt]

make the crown
deliver the crown
if phone rings
the crown didnt fit (too tight)
increase expansion
make new crown
dont answer phone

 

[user name]

so if I get 1 out of 20 that needs to be slightly adjusted (1 to 3 pinpoint spots internally) to achieve the correct passive fit and the other 19 are all good, should I loosen the setting up a bit more to ensure 20 for 20 are all good even if I feel the other 19 are now going to be a little looser than needed?

Im not an expert like 2th, but Id say look at the preps youre scanning. If things are 90% good but just the occasional few that need a tweek, Id guess(?) that its a similar situation on most of them. Maybe its not the spacer but drill comp that needs a bit more. If you can identify a trouble prep, Id rather do some doctoring on it before I scan rather than having to adjust crowns. I know exo lets us adjust mesh, but I haven't dived into that yet.

Im really curious how a case Ive got coming up is going to go. Newish Doctor. Took a failed crown off a super skinny abutment and took an impression. The prep looks as skinny as my bur. Ugh