Bonding to pmma

[Saluki]

Need some help with bonding multi unit inserts to pmma temp have tried rely-x but it only sticks to metal caps. Comes apart when screw down temp .

 

[Patrick Coon]

You still need to prep the PMMA before cementing. I recommend lightly sandblasting with 100micron ALOX, then clean with compressed air (no water or steam),apply a bonding agent like SR Connect (Ivoclar) according to manufacturer's directions (for SR Connect you apply let set for 60 seconds then light cure),and finally cement with your resin cement (I prefer Multilink Hybrid Abutment Cement (Ivoclar).

Of course you still need to treat the temp sleeves or Ti bases, by sandblasting and using a metal bonder (Monobond + [Ivoclar]) before cementation as well.

 

[JohnWilson]

Patrick nailed it here. We have to remember when we are cementing using a resin cement that it is composite and well we all know composit on its own does not stick to PMMA natively.

Painting the intaglio of the PMMA pattern with a PMMA to composite bonder is the best way to achieve a bond. Adding mechanical retention to the pattern is also something that will be of great benefit and is something I have been doing for years by hand.

What I have been working on is to automate this process in CAM with a Thread cutting tool and I almost have it dialed in perfect on my PM7

 

[zero_zero]

What I have been working on is to automate this process in CAM with a Thread cutting tool and I almost have it dialed in perfect on my PM7

I just use an appropriate size tapping tool, takes 30 seconds...

 

[JohnWilson]

I just use an appropriate size tapping tool, takes 30 seconds...

I assume you are doing it by hand?

 

[Travis]

@Patrick Coon @JohnWilson welcome back guys. Hope all is well with you, stick around abit.

 

[Contraluz]

To add to Patrick's and John's suggestions, I actually 'glue' them in with Telio Lab (well, as long as it last...),which is a powder/liquid acrylic. I do sandblast the inserts, but no monobond. I have done some long term, full arch provisionals and they hold up well.

 

[zero_zero]

I assume you are doing it by hand?

Jig mounted on the paralleling mill , screw channel centers the crown under the tool which can only move vertically ... no monkeying as one might assume

 

[sndmn2]

You still need to prep the PMMA before cementing. I recommend lightly sandblasting with 100micron ALOX, then clean with compressed air (no water or steam),apply a bonding agent like SR Connect (Ivoclar) according to manufacturer's directions (for SR Connect you apply let set for 60 seconds then light cure),and finally cement with your resin cement (I prefer Multilink Hybrid Abutment Cement (Ivoclar).

Of course you still need to treat the temp sleeves or Ti bases, by sandblasting and using a metal bonder (Monobond + [Ivoclar]) before cementation as well.

Patrick. I tried to call Ivo. today but closed. I have been using Multilink Automix for bonding my zirc to ti abutments. What kind of working time do I actually have on the bench ? Thanks.

 

[Saluki]

Thanks for the reply’s appreciate the help.

 

[2thm8kr]

To add to Patrick's and John's suggestions, I actually 'glue' them in with Telio Lab (well, as long as it last...),which is a powder/liquid acrylic. I do sandblast the inserts, but no monobond. I have done some long term, full arch provisionals and they hold up well.

We have stopped using anything except two part acrylic on long term immediate temps. Add some mechanical retention
and blast the intaglio surface of the temps. Clean the copings well. I avoid blasting the copings since it makes the temps look a bit grey in those areas. I soak the intaglio surface with monomer for several minutes before mixing the liquid and powder.

All the bonding agents seem to work for some time on PMMA, but eventually they let go. There is a lot at stake on these types of cases. Cross arch stabilization is just as important on the first day as it is throughout the duration of the restoration. Studies are showing that even one loose screw can compromise the longevity of a large implant case. Popping a ti base or coping loose from a temp puts a lot at risk.....

 

[Contraluz]

I avoid blasting the copings since it makes the temps look a bit grey

So, what I have been doing is adding a pinch of Telio powder opaquer, to counter the greyness.