Porcelain Vs. Zirconium + post material - Discoloration & Aesthetics

**JustAguy** · 10-22-2011, 03:04 PM

Hello,

I am not a lab professional but came across this forum and I'd like to ask
a question from you, the pro guys.

I have a front tooth (21) which has discoloured after an accident about 15 years ago. It has been root treated and filled (no post). It's considerably darker than
other teeth (due to damage from the same accident I will have all 4 incisors
porcelained due to chipping, etc - they have a composite currently on).

My dentist plans to put a post in 21 and then a porcelain crown - not decided
yet whether a zirconia or emax (or a different combination is the way to go).

My questions:

1.what material would you recommend for the post/crown which will be placed (tooth 21, considerably dark discoloration; bare in mind issues with transculscency / opacity). - Also keep in mind the neighbouring 11, 22 and 12 will have crowns/veneers but they are not discoloured.

2. what are the issues/benefits with zirconia vs. emax? (besides strength, etc).

When would you use all porcelain press, layering, etc?

Thank you very much for your thoughts/answers/opinions/recommendations.

**rkm rdt** · 10-22-2011, 04:42 PM

My first choice would be Emax because I can achieve good translucency.I can even cover a metal post and core as long as the post has been opaqued to the tooth shade.

My second choice would be porcelain fused to zirconia crowns for basically the same reasons.

My third choice would be porcelain fused to metal crowns.

Sometimes a patient's occlusion dictates material choice as well.

**DMC** · 10-22-2011, 04:58 PM

I've made some Tooth colored Zirconia posts. Scanning impression or pattern of post. This is the only time I think scanning an impression is worth a crap. The post hole hanging down is super easy to capture with scanner. We align that stl file mesh with the top design and cut some data...boolean together and sprue/mill.

Gold looks nice as well for the post material. Warm color if not sandblasted.

Then, any all ceramic...like Zirconia, eMax, Bruxzir, or even a PFM with a butt-margin for the top.

**JustAguy** · 10-22-2011, 05:14 PM

Thank you RKM RDT - I appreciate it.

One problem with translucency in this case is that the darkened matter of the
tooth may be protruding through the translucent crown (two dentists voiced this opinion independently of each other) - regardless of the post and how well
it's matched. Highly unlikely there'll be any metal used. One of them basically said zirconia would be preferred probably because of the durability (but he wasn't sure of the aesthetics).

What are the pressure rating differences between your first (emax) and second choice (porcelain fused to Zirconia)?

Should I worry about the chipping with the first option?

**JustAguy** · 10-22-2011, 05:22 PM

Btw, here's the actual situation (my prep work visit is on Wed Oct26).

**labmanmike** · 10-22-2011, 06:36 PM

Ceramic post is do-able. I've done whats called a cosmo post(all ceramic). then put E-max crowns on them all. Also a cast," ceramic gold " post thats been opaqued. Then use ceramic crowns. Just a quick idea. There are many ways to do this and still make it look good and match A good, caring lab is one of the keys to success. Good luck my friend

**TheLabGuy** · 10-22-2011, 07:26 PM

Ask your Dentist about 'Internal Bleaching'

**DMC** · 10-22-2011, 07:45 PM

You sound like you are in the Dental Industry?

(this thread is sponsored by Ivoclair)

**JustAguy** · 10-22-2011, 08:11 PM

What would be the reason for putting crowns on all 4 them?
As opposed to veneers? If all crowns do they need to have all
Root canals? What's internal bleaching?

**TheLabGuy** · 10-22-2011, 08:23 PM

Your Dentist will know, and if he doesn't, he should!!!!

**DMC** · 10-22-2011, 09:33 PM

Originally Posted by JustAguy

What would be the reason for putting crowns on all 4 them?
As opposed to veneers? If all crowns do they need to have all
Root canals? What's internal bleaching?

It's like tooth whitening, but you go in from the other end.

Check it out.

**paulg100** · 10-23-2011, 06:08 AM

"Ask your Dentist about 'Internal Bleaching' "

roughly 50% success rate, id probably stear clear of that. more time and effort and cost, for a technique without very good success.

best to get your docs opinion on that.

**rkm rdt** · 10-23-2011, 09:25 AM

Originally Posted by JustAguy

What would be the reason for putting crowns on all 4 them?
As opposed to veneers? If all crowns do they need to have all
Root canals? What's internal bleaching?

I would want to make all the teeth from the same material if possible.If I have to mask a discolouration then I need to use an opacious or semi opacious ceramic material.That may be emax or zirconia.When I make a veneer, I want to use a translucent ceramic because it will be much thinner.

I would make my decision based on how much room I have between the lower teeth and the upper prepped tooth.I may need to do a pfm with a thin metal lingual if there is little clearance.

Matching 3 veneers to an opacious crown is tough so another option could be 2 central crowns of the same material and then 2 veneers on your adjacent laterals.

I always prefer to have study models of a patients' situation in my hands so I can make evaluate my options .

I congratulate you on doing your homework.You are asking the right questions.

I would print off this page and give it to your dr and lab for further discussion.

**rkm rdt** · 10-23-2011, 09:33 AM

Internal bleaching is an attempt to remove the internal discolouration of the hole and walls of your root canal.You still need a post and core for structure and retention of the crown.

A tooth coloured post and core is ideal if there is sufficient room however a metal p&c may be required for strength.In that case it would be helpfull to opaque the post with colour.

No need to root canal/post and core healthy teeth.

**TheLabGuy** · 10-23-2011, 10:40 AM

Originally Posted by paulg100

"Ask your Dentist about 'Internal Bleaching' "

roughly 50% success rate, id probably stear clear of that. more time and effort and cost, for a technique without very good success.

best to get your docs opinion on that.

50%? I hadn't heard that and seen some cases that were crazy how dark the tooth was and they looked phenomenal after being done. Just a thought, I don't play Doctor for patients (against the law) so when in doubt as we've both said..."Ask your Dentist".

**JustAguy** · 10-23-2011, 12:02 PM

Thank you so much for your contributions.
I've done a bit of reading on internal bleaching.
I understand the principle now; however there are
risks associated with it and quite a likely chance of
later discoloration again.

As far as no need for root-treating the other healthy teeth is
concerned - they need to be shaved for crowns obviously -
How much shaving and does that pose a risk for sensitivity or other issues or is the whole structure sealed somehow to make sure that doesn't happen?

What's the longevity expectancy With emax and zirconia?
Thank you again!

**paulg100** · 10-23-2011, 03:37 PM

yep Rob, its a very effective technique..when it works.

Its well detailed by Magne in the the "Bonded Restorations in the Anterior Dentition" book and they show some lovely results. They claim aronud 50% success in there though, long term results are a bit hit and miss.

EDIT: were talking complete relapse after maybe only 2-3 years.

"however there are
risks associated with it and quite a likely chance of
later discoloration again."

yep that is right. Which is the last thing you want when you paid alot of $ and had an all-ceramic crown put over the top. Theres no way to determin if that will happen or not, so it wouldnt be my choice really.

**Labwa** · 10-23-2011, 07:47 PM

He can only do as much as he can do. the colour at the margin of the tooth will be dark. at some stage you will probably need to Get an implant. Zirconia abutment. e.max crown. That wont discolour.

**rkm rdt** · 10-24-2011, 05:58 AM

Originally Posted by JustAguy

Thank you so much for your contributions.
I've done a bit of reading on internal bleaching.
I understand the principle now; however there are
risks associated with it and quite a likely chance of
later discoloration again.

As far as no need for root-treating the other healthy teeth is
concerned - they need to be shaved for crowns obviously -
How much shaving and does that pose a risk for sensitivity or other issues or is the whole structure sealed somehow to make sure that doesn't happen?

What's the longevity expectancy With emax and zirconia?
Thank you again!

Us techs expect our work to last forever but foreever is a long time.Proper tooth preparation , cementing techniques ,crown material choice and fabrication ,all contribute to a restorations longevity.

Sometimes the dr will suggest you wear a " nightguard" to protect your teeth if you are a heavy grinder.