rust in retainers?

[the lab lady]

I had a doctor call the other day concernede about what looked to be "rust spots" in a retainer i made about six months ago...i had never heard of this but called my wire supplier and asked about this, turns out surface rust can develope in a retiner if there is room for saliva go get in and sit at the wire.

who knew? anyhow, now being extra cautious about the clearance between the wire and model so there is plenty of room for good acrylic coverage.

 

[Inman Labs]

I had a doctor call the other day concernede about what looked to be "rust spots" in a retainer i made about six months ago...i had never heard of this but called my wire supplier and asked about this, turns out surface rust can develope in a retiner if there is room for saliva go get in and sit at the wire.

who knew? anyhow, now being extra cautious about the clearance between the wire and model so there is plenty of room for good acrylic coverage.

Acrylic shrinks away from the wires always..
When the patient swallows it can draw saliva into the space between the acrylic and wire, this is called capillary action or effect. It sure looks like rust and I guess it really can be rust but if you ever remove the acrylic and expose the wire this so called rust usually just wipes away...

I think the "rust" is often just goo suspended in the moisture between the wire and the acrylic but it sure looks bad!

Regards,
Don

 

[trisha]

Thank you Michelle and Don, interesting info, I have not heard of before.

 

[kcdt]

Is this nickle wire or CrCo?

 

[the lab lady]

stainless steel retianer wire from great lakes ortho....weird, i have never come across this before....first time for everything?

 

[kcdt]

Is it near solder?
The other thing that comes to mind is that his particular patient may have a ph that's causing corrosion. People do vary in body chemistry.

 

[labdude]

All of the above.
Happens with Stainless wire, or nickel free wire.
Is mostly because of the small clearance Don describes.
Doesn't happen often at all however.
Fix?
Remake at no charge with explaination of the above reasons.

 

[RetainerDesigner]

Had a doctor of mine say it was bacteria. Just like yall said saliva gets drawn in with all the "food" a bacteria needs it sits on that space between the wire and the acrylic just growing and growing. THat why it just wipes off if you get to it and stinks to high heavan when you grind into it.
We just told the patient it was rust.

 

[Smilewire]

mold/mildew/bacteria it has a reddish look. I see it a lot on TP repairs I do because they spray the seperator on after the wires are bend and the seperator locks between model and wire preventing acrylic to flow.