When new Dentures break

JMN

JMN

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I don't fabricate new dentures in my lab, I have enough headaches.
What I like to do is fix things. Sometimes I get things that shouldn't have happened.

Some people need a nudge to start thinking about problem solving methods, and so this is another thing that will eventually go into my tech training manual, and it's a bit rough, sorry.


This case had a denture base thickness in the .8-1.7mm range across the entire palatal region. It was less than a year old, had cracked 2x and had broken in 2pcs when I got it this time. Doctor decided it was time to do something more long lasting. But mesh was out. And it didn't need a reline. Occlusion was verified at the appointment the patient presented with the first crack in the denture since it was so new.

Hmmmm2Hmmmm2Hmmmm2

So I "relined" the lingual side.

Sheet of wax ( @rc75 new color is much nicer, thanks) warmed and pressed home over the teeth and totally in contact with the pink acrylic and cut flush with the distal.
20170613_215130_Burst01.jpg
and blended as it wraps around to the buccal
20170613_215137.jpg

Now the fun part. This has to 'rhyme' with the previous techs work, so follow along as much as possible with that festooning and flame gently-trying to keep the teeth clean. Whatever is wax will be replaced with acrylic.

20170613_215827_Burst01.jpg

And it still looks like freeze dried poop...(don't ask)

Well, they guy paid for a decent denture (probably),let's see if we can make this one.

I have box of those Keystone nifty palate wax patterns. Hmm...
Warm it up gently and press it home. Yeah, it'll probably get a few air bubbles, use a scalpel to release them or just leave some of them as nothing perfect looks real- your call.

20170613_220618.jpg

Cut along the distal again, adjust the festooning again and use Ralph before very gently flaming to merge layers at the teeth.

Oh, here's Ralph. His bristles have been on things that'd make me puke. So Ralph.
(he gets cavicide-ed A LOT)
20170613_220916.jpg

Mix putty of your choice and press home on the entire "outside" of the denture. Be certain to get it packed into the teeth, around the blend line and over the distal to keep the postdam. Verify there are no teeth poking through or weak spots, if there are, mix a bit more and overlay it. Putty sticks very well to itself if no separator is used.
20170613_221848_Burst01.jpg


Gently wiggle the denture free of the matrix and remove the completely by the method of your choice.
I sing old TV show themes till it runs away of it's own accord. Flip the matrix 'occlusal up' so nothing gets in it.
Prepare/grind and roughen the entire area the wax covered including around to the buccal at the merge point, but not the periferal roll, and especially not the distal edge, only the lingual of it. This is not a reline. Don't want to move the palatal seal at all.

Make sprue holes per IFU. Mix and apply/Pour/Inject material per IFU.

This is where knowing your materials comes into things. Get accustomed to them, learn them, take them out to dinner and have a chat. I've been using the same material so long that I know how it behaves, what it will do when and how it will react at what time. I know I can mix it at the proper ratios, pour it into a Monoject 412 syringe (with the tip cut shorter) and squirt it in if I do it fast and with minimal added hand warmth. This material is not marketed as a pour PMMA either.

412s do not have a luer lock, and will not accept a needle of any type, no legal issues anywhere, ever.
Used also to feed some baby animals.
https://www.amazon.com/Syringe-Only-12mL-Curved-Monoject/dp/B01IO8U7UC/

Cure at the temp indicated, under the pressure indicated, for the time indicated.

Break out of putty and see how big a mess you have made :D

Remove sprues, blend thicknesses at join points, polish, QC.
20170614_000141[1].jpg

Finished and ready for sanitization. Join points imperceptible but by shade change. Shade change was made "slow" by having a gradually thickening layer of wax at those spots until it becomes entirely the 'new' color.

20170614_022200.jpg 20170614_022217_Burst01.jpg 20170614_022226_Burst01.jpg


Bill, and Grin.

Edit: I was explicitly not authorized to modify the buccal thinness that is noticeable in the images.
 
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Doris A

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Why not just rebase the palate? thicken the palate with wax, make a putty model, invest in bottom of a flask, top the denture with putty, isolate and then fill the second half of flask with stone, retrieve the denture after the stone sets up, cut out the palate and pack.
 
JKraver

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Why not just rebase the palate? thicken the palate with wax, make a putty model, invest in bottom of a flask, top the denture with putty, isolate and then fill the second half of flask with stone, retrieve the denture after the stone sets up, cut out the palate and pack.
No, 6 minute abs!
 
JKraver

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I would pour in stone, add wax, putty matrix, remove palate, inject, deflask, finish. Only use cold cure for breaks, tooth pops.
 
Doris A

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I would pour in stone, add wax, putty matrix, remove palate, inject, deflask, finish. Only use cold cure for breaks, tooth pops.
I don't think he has an injection unit, and I meant heat cure rebase in my reply.
 
JMN

JMN

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I don't think he has an injection unit, and I meant heat cure rebase in my reply.
You are right, he doesn't have one. And it never crossed my mind is the best answer I have.
 
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kytoothdude

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Good right up. What about the root cause of the break? Single C/ going against natural lowers? C/C? Occlusal checks in office are generally centric only and not working, balancing, or protrusive.
 
TomZ

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Dentures don't fracture from the palate forward, they break from the flange back.
To stem the fracture from reoccurring I use silanated e-glass fiber and reinforce perpendicular to the fracture at the propagation site.
Its too late when the fracture reaches the palate.
 
JMN

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Dentures don't fracture from the palate forward, they break from the flange back.
To stem the fracture from reoccurring I use silanated e-glass fiber and reinforce perpendicular to the fracture at the propagation site.
Its too late when the fracture reaches the palate.
This one was way too thin all the way around. Actual minimum measurement was .5mm. It was a immediate and the licensee did not want to adjust [or modify] the flanges at all [for aesthetic concerns].
Not my call, nor my choice either.

[edits]
 
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JMN

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Good right up. What about the root cause of the break? Single C/ going against natural lowers? C/C? Occlusal checks in office are generally centric only and not working, balancing, or protrusive.
Thanks. It is an immediate c/ vs natural. As far as clinically, this is the most demanding and technically aware dentist I know. Not one that lets steps slip.

This fracture was assumed to be induced by eating a non-local very hard type of nut. The cracks previously presented at similar time intervals of such consumption.

Another issue is here possibly compounding this is that Pt education and compliance across linguistic and national upbringing boundaries are always an added challenge if there are not 'cultural translators' in the patients care loop or life to assist in the mutual understanding of phrases and lexical shortcuts we take for granted as being clear from the assumption of a shared experiencial dataset.

Not blaming the patient, our assumptions of what constitutes a 'hard food' are colored culturally, and can be communicated more effectively. This was also discussed with the head assistant.

I think that covered everything, happy to expand if there is anything I left out that you intended me to address.
 
JMN

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denturist-student

denturist-student

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Dentures don't fracture from the palate forward, they break from the flange back.
To stem the fracture from reoccurring I use silanated e-glass fiber and reinforce perpendicular to the fracture at the propagation site.
Its too late when the fracture reaches the palate.
I agree with this 100% the fracture usually starts at the labial flange where the labial frenum is relieved and then propagates backwards into the palate...I agree that adding some fibre mesh in the labial flange will help....Failing that I have seen a metal palate placed and that worked quite well. What about relines you say? Well my experience both literary and practical has shown to me that resorption occurs on the buccal aspect of the buccal flanges and labial flange....Not that much in the palate.....So the metal palate is reusable.....My first question would be are the teeth lingualized or are the buccal cusps touching?...Are there any premature buccal contacts? Remember that the thicker the palate the greater the risk of gagging.
 
TomZ

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Pin Bridging using Perma Ret pins from Preat
placement is at the bottom of the notch directly opposing the propagation point (A)


pin bridge0.jpg
 
JMN

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Pin Bridging using Perma Ret pins from Preat
placement is at the bottom of the notch directly opposing the propagation point (A)


View attachment 26606
I may be misunderstanding somewhat, but looks like that would effectively focus the force upon those two Perma Ret pins. Has that ever shown to be true or a problem?
 
TomZ

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They never come back.
The glass and net are silanated and embedded in acrylic.
The pins are also embedded.
 

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