breaking contacts on plastic teeth...

[burbo22]

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I drop the box with a 245 and then use my hatchets (or an esthetic bur when I get impatient) to open up the contacts. But I always get close and then blow them out… any tips?

 

[Mach band]

I drop the box with a 245 and then use my hatchets (or an esthetic bur when I get impatient) to open up the contacts. But I always get close and then blow them out… any tips?

I use a diamond bur (the one smaller than 330, can't remember the number) to drop the box. Then I use a skinny bur to remove the thin contacts. Just hit it with light up stroke several times. When that's done, I use both the skinny diamond and a carbide bur (I think 244) to get the right angle. Hope that helps.

 

[rocknightmare]

is this for fixed? or just operative??

for operative i wedge the teeth a little.. then drop the box with a 330 all the day way to where i see the contacts are broken. now since it is wedged the contacts isn't completly broken when the wedge is removed, then use a hatch to remove the last few 1/10ths of mm ... sometimes i will come in with a marginal trimmer to get the margins..

now for fixed i am still not perfect at this as i just started less than a month ago.. since we can't really wedge the teeth with this dentoform i use a 169l to break contact-- a trick that our professor taught us to prevent from hitting the adjacent tooth is too keep look at the adjacent too and make sure not to hit! you don't have to look at where you are cutting cause you will always cut the tooth.

169l then use a diamond finishing to open up the margins and create the chamfeer

 

[Da Bomb]

Dont use your hatchet like "hatchet" you have to plane the wall of your prep. Use your wrist and let the tool do the cutting. Dont force it. Too much pressure will cause a slip and a blown out floor.

 

[Demeter]

You could use an metal abrasive strip to open the box. You really won't waste your time with this method in clinic, but it works well on plastic teeth and you won't ding the adjacent tooth.

 

[flat4]

You could use an metal abrasive strip to open the box. You really won't waste your time with this method in clinic, but it works well on plastic teeth and you won't ding the adjacent tooth.

+1 on interproximal strips to break initial contact then use the hatchet. And sharpen your hatchet. Makes all the difference.

 

[NUKE]

we used to place matrix bands interproximally to help not hit the adjacent tooth.

 

[ajex]

is this for fixed? or just operative??

for operative i wedge the teeth a little.. then drop the box with a 330 all the day way to where i see the contacts are broken. now since it is wedged the contacts isn't completly broken when the wedge is removed, then use a hatch to remove the last few 1/10ths of mm ... sometimes i will come in with a marginal trimmer to get the margins..

now for fixed i am still not perfect at this as i just started less than a month ago.. since we can't really wedge the teeth with this dentoform i use a 169l to break contact-- a trick that our professor taught us to prevent from hitting the adjacent tooth is too keep look at the adjacent too and make sure not to hit! you don't have to look at where you are cutting cause you will always cut the tooth.

169l then use a diamond finishing to open up the margins and create the chamfeer

a marginal trimmer or a small spoon excarvator will usually do the trick for me if the amount of tooth/plastic structure is thin. in natural teeth, these tools will usually easily fracture off off the thin enamel left over

 

[burbo22]

You could use an metal abrasive strip to open the box. You really won't waste your time with this method in clinic, but it works well on plastic teeth and you won't ding the adjacent tooth.

A metal abrasive strip? I don't get it... I suck at operative.

 

[Sprgrover]

A metal abrasive strip? I don't get it... I suck at operative.

You can use a metal matrix band to protect the adjacent tooth. I find it helpful in pre-clinic to place a Tofflemire matrix band around the adjacent tooth (this can take some time at first, but once you have it down you can slip it on and off in a snap) and then wedge from the lingual or palatal side. This system will protect the adjacent tooth, although if you grind hard or long enough a bur will go through the matrix band, and it will give you enough room to maneuver a gingival marginal trimmer or a hatchet to sharpen or round the margins in your box.

 

[Biogirl361]

i had the most trouble breaking plastic contacts until i tried the real thin, pointy diamond (can't remember the number) to smooth off that little bit of plastic in the contact that never wants to break off. give it a try 🙂

 

[Dentalhopeful]

best thing....wedge that tooth really well to get some good separation. after that place a matrix band on the adjacent tooth...double it up if you have to. if are really slick you could fold that matrix band to a thickness of 3-4 and just place it interproximally....without using the toffelmire.

then start your prep with a 330. what i like to do for class II is...drop the box first....clean it up real well...make sure the walls a divergent gingivally....smooth with hathet or hoe....after you have dropped the box enough, go ahead and take hatchet or hoe...and start trimming the cavosurface margins that would normally remain in contact with the adjacent tooth.

if you are doing aslot prep then you are done....if you are doing a classical GV black class II...carry on the prep to the opposite marginal ridge leaving 2 mm of it.