Stain and glaze question

[wwcanoer]

Has anybody heard about this happening to their cemented porcelain cases that have been in the mouth for a while?

The two assistants who work for my main doctor, both have Emax anterior restorations. I don't know exactly how long these crowns have been in the mouth, but it has been for several years. The issue, is that the glaze and staining that was done when the cases were finished, is completely gone. The surface of the crowns definitely have a matte finish now. They are speculating that the polishing compound, which I believe is a baking soda based product, from the prophy jet that the hygienist uses, has polished it all off. They also have said they have seen this on other cases that have been in the mouth for a while.

If this isn't an isolated case, it's kind of scary to think about, especially on restorations that are done by the press and stain method.

Carol

 

[Gdentallab]

as i know , the stains will last for few years only. We can't rely on them to stay forever.it's something we should expect to happen.

 

[charles007]

Carol, do you know if these were stained and glazed in a 2 firing technique. Stain first firing, then separate glaze firing to seal in the stain........

Charles

 

[Al.]

Carol, do you know if these were stained and glazed in a 2 firing technique. Stain first firing, then separate glaze firing to seal in the stain........

Charles

Hi Charles, this helps a bit but not much.

For all my anteriors after the paint on glaze bake I hand polish the facials.
IMO that is the only way to make the finish match natural teeth.

I found out right away a rubber wheel cuts through the paint on glaze like a warm knife cuts through butter. (But the paint on glaze fills all the pits and I get a very nice mechanical polished finish).

The stain comes of even easier.

For antrior emax I find it necessary to stain the core then layer with incisal, neutral or what ever you choose, then glaze.

 

[charles007]

Al, I wonder what that says about all the one body porcelains that you stain/glaze, not to mention all the thousand + doctors cerec stain/glaze crowns already done. Add in all the inlab labs, and we have a win win situation for all the non cerec inlabs in the country.
There will be so many all ceramic blocks/emax crowns that will need to be remade as the stains wear off, if this crown above is the norm when staining ?

I'm so glad that you told me last year you press the correct shades, rather than stain up ! thanks a million .

Charles

 

[charles007]

Al, at the Atlanta meeting this past weekend, I saw the new Pulse 316 zir porcelain. Only 3 value shades, then you stain ! These are now used in Germany,just hasn't hit the US market yet, will be able to buy later this year.
May rethink any ideas of using one powder porcelains in my lab.

 

[rkm rdt]

Lets all take a deep breath here.

First of all I would like to know why the hygenist is using a profy jet on any glazed restoration.They have access to the Pts charts after all.

Secondly, how long has Empress been on the market?....Don't tell me this would not have been an issue with a leucite based material if it were true.

I smell a rat here......can you say "dwindling market share"?

 

[Al.]

Charles, I dont think it really is an issue with posteriors as long as the original or non stained shade is close.
It seems to me that peoples natural teeth are darkening with age anyway.
An A2 tooth may be a C2 in ten years from coffee etc. A C3 in another 10 and C4 by 60.

The anterior 12 is where I try to keep the stains protected.

One reason I really dislike surface stain is because they photograph terrible.
Similar to looking at them with the Drs overhead light or direct sunlight.

Light dosent penatrate the stains it reflects off them and really magnifies the stain and you can see every brush stroke of stain.

Another note is that when you lay stain underneith the incisal it takes less because the incisal layer seems to magnify the stain. In other words if you stain it exactly the shade you want sometimes it seems to be too dark after you lay incisal over it. Then you are screwed. So err light, more of a light wash stain.

I know for sure that often when I paint a white crack on the core and my incisal layer over it is thin, the crack comes out way too strong so I have learned to keep the crack lines very fine because the layering can work as a magnifying glass, depending on how thick the layer is. If the layer is too thick it will disapear in normal lighting but show back with intense light like flash or direct sunlight.

 

[Al.]

Lets all take a deep breath here.

First of all I would like to know why the hygenist is using a profy jet on any glazed restoration.They have access to the Pts charts after all.

Secondly, how long has Empress been on the market?....Don't tell me this would not have been an issue with a leucite based material if it were true.

I smell a rat here......can you say "dwindling market share"?

Ive also seen plenty of pics Drs have posted of anterior crowns that the patient has worn through the glaze.

They didnt look bad they had a matte finish.

Most natural teeth have a highly polished and matte to semi gloss finish, I dont recieve many pics of teeth with a high gloss finish like the paint on glazed crowns we make.

Look at the difference between young and aged teeth on the facial of the centrals. Young have much more texture and aged much smoother.

I bet alot of crowns get the glaze polished off by hygenists with profy paste.

 

[Gdentallab]

Charles, I dont think it really is an issue with posteriors as long as the original or non stained shade is close.
It seems to me that peoples natural teeth are darkening with age anyway.
An A2 tooth may be a C2 in ten years from coffee etc. A C3 in another 10 and C4 by 60.

The anterior 12 is where I try to keep the stains protected.

One reason I really dislike surface stain is because they photograph terrible.
Similar to looking at them with the Drs overhead light or direct sunlight.

Light dosent penatrate the stains it reflects off them and really magnifies the stain and you can see every brush stroke of stain.

Another note is that when you lay stain underneith the incisal it takes less because the incisal layer seems to magnify the stain. In other words if you stain it exactly the shade you want sometimes it seems to be too dark after you lay incisal over it. Then you are screwed. So err light, more of a light wash stain.

I know for sure that often when I paint a white crack on the core and my incisal layer over it is thin, the crack comes out way too strong so I have learned to keep the crack lines very fine because the layering can work as a magnifying glass, depending on how thick the layer is. If the layer is too thick it will disapear in normal lighting but show back with intense light like flash or direct sunlight.

Do you have pictures ?
Well it's been a while we haven't seen your work.

 

[paulg100]

Done a ceramics course with Ed McLaren a few years back.

He was using some external staining in his technique and i asked him if there were any concerns over the stain comming off after a time and he was of the opinion that it wouldnt.

Also i stain fire, then glaze fire then use a lave and synthetic pummice to get the natural surface finish. you can give it plenty of pressure on the lave without it being enough to get through the glaze and loose the stain so i fail to see how there is enough natural abbrasion in the mouth to get through an anterior facial glaze layer.

 

[sixonice]

this is not an issue. a (competant) hygienist should know full well going into a phophy treatment of where restorations are. taking a very abrasive prophy cream to a crown and then a jet of compressed water is not very smart. taking a little special care to prepare for the cleaning, then NOT buffing and blasting the restoration would be all that is needed. like another member said in an earlier post "What did they expect to happen?". sounds like if the restoration has been in place for a few years it has been through at least a couple cleanings. i would suggest the hygienist spend an extra 2 minutes reviewing the patients chart before treating each tooth as if it were natural. problem solved.

 

[Al.]

Done a ceramics course with Ed McLaren a few years back.

He was using some external staining in his technique and i asked him if there were any concerns over the stain comming off after a time and he was of the opinion that it wouldnt.

Also i stain fire, then glaze fire then use a lave and synthetic pummice to get the natural surface finish. you can give it plenty of pressure on the lave without it being enough to get through the glaze and loose the stain so i fail to see how there is enough natural abbrasion in the mouth to get through an anterior facial glaze layer.

What is lave? And what kind of pummice are you using.

I use rubber wheels and I love the finish I get but it does cut through the glaze fast.

 

[thewhitelab]

Which rubber wheels do you use Al?

 

[wwcanoer]

Charles:

To the best of my memory, these crowns were built up with the layer technique. Staining firing, then glaze firing. Then there was an additional staining required after they were tried in. I don't know if the cores were initially stained, then incisal build up. I didn't make these crowns, as at that point in time, I wasn't doing Emax yet.

After reading everybody's posts to this thread, I guess it's something I just had never really thought about. My concern is that for the majority of my posterior work, I'm using Jensen's Pulse pressed to metal system, which relies heavily on surface staining for the final color. Monday, I'll be giving their tech help people a phone call. And then, what about all the veneers out there that are pressed and stained? Yikes!

Back to you, Charles:

At the beginning of summer, Patterson dental brought up a Cerec system for a demo for the local doctors, of which I attended. It was an interesting demo, and I think I asked the majority of questions, which was starting to irritate him. The one thing really irritated me though, was I did bring up the whole issue regarding their method for staining (it was described as paint on, but not needing to be baked) and the demonstrator basically refused to answer, answered it without answering, my questions about how you could even do that!

sixonice and rkm rdt:

I'm not a hygienist, wouldn't want to be one, yuck, sucking spit and scraping dirty teeth all day (no disrespect intended, as I'm sure they think the same about what we do),but on the other hand, I will come to the defense of the two hygienist in this practice.

Both of you make the comments that they have access to the patient's chart and therefore know where the restorations are and not "polish" them with prophy paste or prophy jet. Yes, I do agree to that the Prophy jet system is much more abrasive, and shouldn't be used on porcelain restorations, but crowns do pick up stains that the patient wants cleaned off. , black teas, blueberries, red wine, etc. etc. and unfortunately, California is such an aesthetic cosmetically driven state it can be a royal pain, even behind the Redwood Curtain. So, what with having a minimum of two cleanings a year, it wouldn't take long to abraid a glaze coating off even with Prophy paste. But what would you recommend as an alternative to Prophy paste for removing stain? (I will ask on Monday)

So needless to say, in part I do agree with you that retraining regarding the polishing technique of porcelain restorations by hygienist's needs to be addressed.

Little long-winded there, sorry about that!

Re: that matte finish; both of the assistance " strongly dislike" the fact that their crowns are no longer "shiny".

 

[rkm rdt]

As I said before ,I don't think this was an issue with Empress which has been around what? 20 years.We would have heard about it by now.

I can see the desire for a matte surface texture with anterior teeth but quite frankly a glazed crown is a hygenic crown.

 

[paulg100]

a lave for polishing like dentures.

Ill get the exact kind of brushes im using and pummice for you on monday but its nothing special, just synthetic pumice.

Gives a really nice plasticy finish like natural teeth and ULTRA smooth, so much so that its hard to keep hold of the crowns with any water on, great for minimal plaque adhesion.

than i tweek the finish with ruber wheel or diamond polishing paste after if need be.

Another neet trick is to put some aluminium oxide into the pumice and then you will get the scratchy surface finish that some teeth have.

i just bought a little diy lave from a hardware store as i dont do much denture work and didnt need the robustness of a proper dental unit.

 

[doug]

Do you mean Lathe?

On the topic of stain coming off, back when we did Dicor that was a real problem and Tommy, who did all of them at the lab I worked at solved the problem so well that there are still some in place that look great. Not real sure but I think he stained to the shade he wanted and then did two over-glaze firings to make sure they were sealed nicely. I'll ask him exactly what he did when I see him again. We used Steele's glaze powder and it did a great job. I had some but it got legs and isn't around here in the lab that I can find anymore.

 

[charles007]

Doug,
Tallidum sold use to sell Steels glaze powder, not sure now. Supposedly glaze powders are better now, not that I know that for a fact ? I don't believe in using glaze powder on pfms.

 

[paulg100]

"Do you mean Lathe?"

yes sorry!