Rocking, Rocking, ROCKING!

TheLabGuy

TheLabGuy

Just a Member
Full Member
Messages
6,223
Reaction score
817
THEN...... take some 8 guage (3mm length),sprue that to your connectors.........
THEN...... take some 10 guage (same length as bridge),use that as a runner bar
THEN.......take some 10 or 12 guage for sprue leads to connect to the base former of the investment ring.

Oops.........
Thanks to Troy (dmonwaxa) for pointing this out. The numbers I put should be reversed.....like the way in the picture is correct. Sorry for the confusion.

Personal Dislaimer: Don't believe anything I say unless you have taken the time to research it or have prior factual knowledge to the particular subject. I'm hoping this gets me out of the idiot box for awhile....lol
 
dmonwaxa

dmonwaxa

Well-Known Member
Full Member
Messages
2,740
Reaction score
233
OK Rob, you can come out and play now....LOL. could have happened to any one.
 
TheLabGuy

TheLabGuy

Just a Member
Full Member
Messages
6,223
Reaction score
817
OK Rob, you can come out and play now....LOL. could have happened to any one.

I can't believe it took this long for someone to say something......geez folks, you could of called me out on it a little sooner...lol :) Someone has to keep me honest.
 
desertfox384

desertfox384

Active Member
Full Member
Messages
684
Reaction score
74
What do you all use for your pontics? I'm taking a string of 12 gauge spool wax and filling in pontic areas.

Ive had a few more bridges rocking recently, still trying to figure out what is going on. Most of them do not have any kind of massive rock its usually a tiny tiny lift on the distal margin. I am generally waxing slow (i think) adding small amounts at a time (adding a dab of sticky wax to connectors then waiting 3 -4 minutes or so to cool) but when you have a huge pontic or need to wax a big case in a rush I cant seem to find a way around waxing quickly and not getting big rocks.

I had a case the other day it was a 4 unit bridge with a big pontic, 3 metal occlusal and a full cast molar 12-15. Waxed it twice - First time i went slow a careful and it came out with a rock, pulling up on the distal of 15. Ok so rewaxed this time quicker since its due date is creeping up and i noticed a rock on the working model in wax. Sooo i cut it waited a few minutes to cool and reattached slowly and the exact rock came back time and time again so i finally cut it and attached it with glue. Rock was gone in wax, I attach sprue leads (8 ga on this big one but usually 12ga) slowly attach sprues to preformed runner bar just like lab guys in the picture. In metal rock was back. I find myself wanting to pull my hair out again! I thought i had this problem solved and cant figure out what has changed.
 
Last edited:
TheLabGuy

TheLabGuy

Just a Member
Full Member
Messages
6,223
Reaction score
817
Can you explain your burnout technique to me? Fast burnout? Investment used? Are you induction casting or centrifuge? Do you notice it using one alloy versus another? Quick cooling, using water? I'm assuming propane/oxygen combination? If you're spruing right, and you double checked your margins before spruing then it has to do with investing/casting, the only thing left. Answer some of those questions so some of us may be able to help you out, nothing more frustrating than a bridge rocking with metal occlusals........grrrr
 
dmonwaxa

dmonwaxa

Well-Known Member
Full Member
Messages
2,740
Reaction score
233
Here we go again..... Rob,,,,glad you came up for air. Be careful what you say, I'm watchin U....lol. So far it seems you're the one asking questions.hehe

Desertfox,,,,suggestion; I know you can wax , we all know you can wax, so you have nothing to prove by us or anyone else. Work smart, and its not cheating,,, why don't you make some premade pontics and have them ready and on hand.
1. It would speed up the process.
2. You would minimize the amount of heat being introduced in the wax, more heat=more melting=more shrinkage/contraction=distortion.
3. Dont use spool wax in the connector areas, too soft.

There are premade molds for sale but you can easily make your own, just a suggestion.

Seems theres always time to do things over but never have time to do it right the first
time.
 
Last edited:
L

lil_leftee

New Member
Messages
9
Reaction score
0
Not to say this is a solution you should get comfortable with, but in rush cases, why not cut/solder if it rocks instead of remaking?
 
Al.

Al.

Well-Known Member
Full Member
Messages
3,664
Reaction score
904
Ill second the premade pontics. It will cut your wax time way down.
I like Kerr's bio pontics.
Plus its a really hard wax. It dosnt move easy.
Also I second, not using sprue wax rods it is waaaaaaay to soft.

Using that technique of connecting with sprue wax and building pontics to them would be challanging for me to make bridges that dont rock.
 
CatamountRob

CatamountRob

Banned Member
Full Member
Messages
7,384
Reaction score
1,531
This was a tip I got a long time ago from an Ivoclar metalurgy guy (actually it was Williams then). Use dental floss and sticky wax to "lash" the abutments down to the solid model, then connect them together, sprue them, connect them to an 8ga. sprue bar. Let it cool, remove the floss, lift the bridge (now connected to the bar),check the margins, invest and cast. It can't warp if the abutments can't lift, just make sure the pontic isn't touching the model. Rob
 
Al.

Al.

Well-Known Member
Full Member
Messages
3,664
Reaction score
904
Porc is going on this sweet thing tomorow.

ai46.photobucket.com_albums_f116_CDLAB_wax1_1.jpg
ai46.photobucket.com_albums_f116_CDLAB_wax2_1.jpg
ai46.photobucket.com_albums_f116_CDLAB_wax3.jpg
ai46.photobucket.com_albums_f116_CDLAB_wax1_1.jpg ai46.photobucket.com_albums_f116_CDLAB_wax2_1.jpg ai46.photobucket.com_albums_f116_CDLAB_wax3.jpg
 
dmonwaxa

dmonwaxa

Well-Known Member
Full Member
Messages
2,740
Reaction score
233
Al. you're a man after my own heart,,,, Kerr good stuff
 
desertfox384

desertfox384

Active Member
Full Member
Messages
684
Reaction score
74
Can you explain your burnout technique to me? Fast burnout? Investment used? Are you induction casting or centrifuge? Do you notice it using one alloy versus another? Quick cooling, using water? I'm assuming propane/oxygen combination? If you're spruing right, and you double checked your margins before spruing then it has to do with investing/casting, the only thing left. Answer some of those questions so some of us may be able to help you out, nothing more frustrating than a bridge rocking with metal occlusals........grrrr

Usually an overnight burnout, using fast fire investment, centrifuge and no diff between alloys that ive noticed - Quick cool with Non Precious (water) but no other metals and yes you assume correctly propane and 02. Im using maves inlay wax for the majority of waxups with an ivoclair margin wax for the base wax.

The problem is that i have seen a few with rocks in the wax - So ill cut the connector and re attach but it will still rock. After reading the rest of the posts above (thanks for your prompt replies) I'll try some premade pontics.

Let me ask one more question, how long do you generally spend on a bridge wax up? I might actually start it in the early morning and not finish til the afternoon since i wax up many cases in a day i try to space out the bridges so that they have plenty of cooling time - Im not causing any problems waxing that way am I ?
 
desertfox384

desertfox384

Active Member
Full Member
Messages
684
Reaction score
74
Al, do you wax pontics directly to the tissue?
 
dmonwaxa

dmonwaxa

Well-Known Member
Full Member
Messages
2,740
Reaction score
233
I'm seeing too many variables, and it looks like you may need to develop a system that produces the desired result. Soft wax when pulled will bend, simple as that. Fast fire is just that fast fire, if you're doing an overnight burnout why use fast fire? So you may have to use adjust materials for your adopted technique. Minimize the variables.
 
Last edited:
Al.

Al.

Well-Known Member
Full Member
Messages
3,664
Reaction score
904
Al, do you wax pontics directly to the tissue?
The pontics come in sections of 4.
I seperate the one I want but make it so there is only a small space between the abuttments.
I set it on the ridge. Sometimes there is space some times I heat the underside and mash it on the ridge, it depends on the space.

I connect one side only and let that cool and shrink (2 or 3 minutes)usually that will lift the pontic off the ridge slightly.
Then I connect the other side and finish my wax up, on anteriors I usually add wax underneith like on the bridge above. Later I grind back the metal and releive the stone slightly so the pontic fits snug to the tissue.

I always cut the bridge with a warm razor to releive stress. Then I remove the pontic area (stone section) and then I trim back the dipped wax and seal the margins.

Then I seat the dies and wax only, back on the model everything else goes in the pan.
I tack the connection first on the gingival areaUsually the lingual side first. I use only a small drop and my tip is set at 400 so it is hot enouugh for the wax to suck through or into the cut not sit on top. I dont touch the wax up with my tip just let the drop of wax touch it.

I usually give it 3 to 5 minutes and tack the other side at the facial gingival.
Then the occlusal lingual then the facial occlusal.

A bridge like the one posted above your looking at 30 minutes of waxing time to get it ready for sprues.

For most straight simple bridges up to 6 units rocking should be the exception.

Once you start waxing around the curve of the mouth or have multiple abuttments or over 6 units it seems like a 50 50 chance to solder (for me).
 
B

BruceQuality

New Member
Messages
47
Reaction score
0
The best solution we've found for rocking bridges is our lazer welder! Our metal dept. can get almost every rock out by carefully hitting the opposite side of the warp with the lazer.

When waxing bridges our metal dept. uses pre-poured pontics as well. This is definitely a time saver and helps keep the wax cool while waxing such large amounts.
 
JohnWilson

JohnWilson

Well-Known Member
Full Member
Messages
5,487
Reaction score
1,575
The best solution we've found for rocking bridges is our lazer welder! Our metal dept. can get almost every rock out by carefully hitting the opposite side of the warp with the lazer.

When waxing bridges our metal dept. uses pre-poured pontics as well. This is definitely a time saver and helps keep the wax cool while waxing such large amounts.

Bruce the first time i dewarped a bridge with out sectioning I felt like a little kid when he sees Santa at the mall. Its an amazing tool that I often ask myself how I ever got along with out it.
 
Al.

Al.

Well-Known Member
Full Member
Messages
3,664
Reaction score
904
It sounds alot better than tapping on the underside with a lab knife and a jewlers hammer.
 

Similar threads

I
Replies
17
Views
287
Flipperlady
Flipperlady
JKraver
Replies
14
Views
638
M
D
Replies
6
Views
411
tuyere
T
T
Replies
20
Views
1K
Laura Feng
L
Top Bottom