C&B Occlusion Consistency Problems

J

johnny

New Member
Messages
1
Reaction score
0
Can someone please help me out? I have been having problems with crowns and Bridges being too high. I used to use these little black plastic "ball and hinge" articulators in conjunction with base formers that have a groove in the base to glue the "ball receiver". Then I switched to Artimax articulators and dentists send me triple-trays. I have even used these nifty magnetic articulators using stone to mount the models. I am still having problems. I thought to switch from 40 micron articulating paper to 200 micron articulating paper. I ensure that there is virtually no occlusal contact on the models. I have some cases that fit just fine, and I have cases that are just too high in the patients' mouths.

Please HELP!!!! Suggestions are welcome...

Thanks in advance
 
araucaria

araucaria

Balanced
Full Member
Messages
1,219
Reaction score
78
Check the quality of the antagonist impressions first. Along the occlusal area (esp. stock trays-perforated) there can sometimes be a separation of the impression material from the tray. This can be caused by bad withdrawal or by poor retention. The retention issue can be created by the doctor placing fingers over the retention holes and not allowing the imp' material to grip sufficiently. Sometimes the material has not had time to set fully and may undergo a little deformation.
The result of the material separating from the tray is a model with an occlusal surface that is not where it's supposed to be. It's like a slightly under-erupted tooth if you like. The consequence of this is that you'll make a crown or bridge on the opposing model that'll have an occlusal surface that's 'equally over-erupted' in order to meet the antagonist.
= high/opened bite.
Everything can look just fine when you receive the prescription, it's sometimes a matter of knowing how to interpret the information you have available. You must inspect the Imps closely esp if you have model makers working in your lab. Hope this may help.
 
amadent

amadent

http://amadent.net/Home.p
Messages
829
Reaction score
1
the age old ?
why are occlusions high in the mouth

Are you getting full arch impressions, i dont always get them, but i do find that when we do high occlusion is not an issue, you can not get a proper arc of closure with a quad impression
we must all remeber what seems very slight on the model is huge in the mouth
.01mm equats to 1mm in the mouth

not trying to pass the buck, but if your DR.s temps are out of occ then your restorations are going to be high, teeth are always in motin looking for a stable place- proper occlusion is that place

I like to use a felt marking pen on the occusal table of my opposing while i build up to let me know exactly where I am and where I am not in occusal contact
 
Gdentallab

Gdentallab

Active Member
Full Member
Messages
340
Reaction score
0
are you sure that the crowns are well seated in place? In the patient's mouth.
Well to make sure about this, make a wax coping, remove the top of the crown, then cast it.
Now you can check and the dentist can check if the crown is well seated if it's not clear on the margin.
 
C

charles007

Well-Known Member
Full Member
Messages
3,897
Reaction score
453
Throw out the 40 mic paper.
Equilibrate your models, and be consistent, like grinding in 3 to 4 times. This closes the bite down and helps a lot. Always make 2nd molars slightly out of occlusion..... Doctors have told me for years that 2nd's are always high...
Give more disclusion..... around the areas where you have occlusion.
I now use Bausch Progress 100.........and double it......Its pretty good at not leaving false marks.....
Once I finish grinding in and ready to glaze, I knock off the articulator and check occlusion again... Many times crowns are high just slightly, plus you end up seeing crowns that may have been articulated wrong......

Charles
 
TheLabGuy

TheLabGuy

Just a Member
Full Member
Messages
6,223
Reaction score
817
Two things should solve your problem, high expansion die stone and equilibrating your model work.
 
subrisi

subrisi

Active Member
Full Member
Messages
454
Reaction score
7
I equilibrate every model, removing any high spots on inclines until I have an even occlusion mark all around the arch. Most of the time I get the occlusion on crowns right on, but then all of the sudden there is a series of too high crowns and I do the same every time. It drives me nuts because I can't figure out what is different. Often I see rocking on full arch models at the premolar areas. This is the spot I have to adjust the most. Can someone explain what happens here? I suspect the alginate impression is the cause, but would like to know why and how to avoid this?
Any ideas please?
 
TheLabGuy

TheLabGuy

Just a Member
Full Member
Messages
6,223
Reaction score
817
Alginates on fixed work? kind of archaic if you ask me.
 
C

charles007

Well-Known Member
Full Member
Messages
3,897
Reaction score
453
Rob, most of my doctors use alginates, what do you recommend ?
 
R

rmcmanus

Member
Full Member
Messages
41
Reaction score
0
The only way to mount a triple tray impression is to pour up both sides while they are still in the impression then mounting both sides on an articulator and only AFTER mounting would you separate the two sides. My limited experience with Artimax is that they will not allow you to do this. (I do love my Artimax magnetic articulator however & wish I had it 30 years ago). There are several companies that allow you to properly use/pour a triple tray impression. The best one I have seen are the WOW articulators but I am sure there are other good ones. The WOW is so easy to use that you will welcome any triple tray impressions into your lab. Drop me a note at mcmanus****@yahoo.com & I'll send you a couple to try. (I have no $ interest in this articulator; they just work very well and will make YOU look good). If you pour a solid model of the impression side of the triple tray and use shim stock to adjust the contacts(no scraping of contact areas!) on the solid model you will develop a dentist base that would never leave your lab in a million years.

The high crown/bridge problem is a universal issue that occures when you do not use a triple tray. I have only discovered one way to eliminate it and that is to have a metal/framework try-in. At this appointment the framework is returned from the lab to the dentist based on the initial bite relationship then the dentist grinds the framework (they are always high) so that case is not high and retakes another bite with duralay. Then the porcelain phase is completed at his new bite relationship and returned to the Doc. There is so much less occlusal adjusting at this insert appointment that the dentist looks good too.
Richard McManus
 
R

rmcmanus

Member
Full Member
Messages
41
Reaction score
0
my yahoo address will not print because the abbreviation of Richard is a "bad name". however I bet you can guess what the 4 letter abbreviation for Richard is = di*k. My email is mcmanusdi*k@ yahoo.com. Just replace the "*" with a "c".

di*k mcmanus
 
TheLabGuy

TheLabGuy

Just a Member
Full Member
Messages
6,223
Reaction score
817
Dr. McManus,
I think you are confused about Artimax. I use this system with all my triple trays and it's exactly like the WOW articulator system you are speaking about. You cannot separate the two without having both sides poured/mounted at the same time. The WOW system is the same as the Artimax system, please look here Artimax Hope that helps.
 
R

rmcmanus

Member
Full Member
Messages
41
Reaction score
0
Lab Guy
You, sir, are correct. I was thinking of my Artex articulator because of the reference of the magnetic mounts. I have used triple trays for single and ocassionally two units since 1988 and nothing works better than this technique as far as satisfying the occlusion. Also, they cheap to mail (I mail my stuff); but you do have to rise above the academic bull *hit that surrounds their use.

Can you explain the equilibration steps you take?

Thanks
Richard McManus
 
Last edited:
dmonwaxa

dmonwaxa

Well-Known Member
Full Member
Messages
2,740
Reaction score
233
I seen a lot of triple trays where the bite is off in varying degrees. The theory of an impression and a bite all in one is great; in theory. But I've seen my fair share of missed bites and distorted impressions.Free end distal extensions and the occlusal is off doc? For real? I dont understand why that would happen.
 
TheLabGuy

TheLabGuy

Just a Member
Full Member
Messages
6,223
Reaction score
817
Ahhh, no problems, Artex, Artimax, sound so similar, innocent mistake. I like the Artimax for the triple tray just for all the reasons you stated, the full mouth version I'm not totally sold on though, especially with multiple anterior units.

As for equilibrating, it's very similar to what you would do clinically (- leaf guage). I use Accufilm II articulating paper and then place my models together in centric with the paper in place. Usually it hits in a few places, I will go ahead and very lightly relieve those areas that the paper marked. Keep in mind this is only if I have a client that is having issues with high occlusion, but I would also do the same thing in working excursion (balancing doesn't work with triple trays). This makes a very solid bite and helps in making sure you don't miss any little positive bubbles/voids that may be leaving your centric bite a little high (resulting in high crowns).
Do you think this is a good technique?....maybe overkill? What would you do?
 
JohnWilson

JohnWilson

Well-Known Member
Full Member
Messages
5,487
Reaction score
1,575
This has always been the techs nightmare. We always want to point the finger at the client especially if they are one of the few you work for that are experiencing this phenomenon. Lots of great advice on this thread lets make some bullet points that we can agree on and learn from.

1) Triple trays are only as accurate as the person using them

2) The soft flexible white trays that that are used are horrible and are a huge issue with distortion If your client likes to use this technique refer them to metal reusable trays or at the very least suggest the most rigid plastic tray that will solve a lot of headaches.

3) High bites are not exclusively the tipple trays fault, its more that the client is too lazy to verify that the patient has not slid prior to removing the impression. Suggest that the client takes a check bite over the prep and this will allow you to double check if the patient slid in the impression.

4) Equilibration does work. Hitting on incline planes most definitely will cause you to think your crown is out of occ but in reality the PDL is compressing and your models are not. There is a certain sound a model makes when it is equilibrated properly. Learn that sound, and how to make it happen and your home free. Spotting in your models will make your crowns O.O.O. more often than not if you equilibrate and have your occ paper slide in centric on your models. Is it time consuming? Hell yeah, but it does work.

5) All of this extra work is pointless if your client makes poor temps.
 
J

johnny

New Member
Messages
1
Reaction score
0
Wow, lots of great advice here! Thank you all for your replies! I will try equilibrating my models and report back.
 
J

johnny

New Member
Messages
1
Reaction score
0
Equilibrating the models has helped tremendously! Thank you all for the help!
 
Top Bottom