class I advice

[Stephie3]

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does anyone have any advice for doing class I preps?

 

[The Hammer]

does anyone have any advice for doing class I preps?

Start with a 330 bur. Sink the bur head 3/4 of the way in. Follow the central groove and make a dove tail (like the end of a dog bone) at the distal pit. Widen the prep with a straight carbide bur like a 55, 56, 57 and pretty up your prep. If you need to use a needle point marker to draw the ideal outline on the occlusal surface of your ivorine tooth before you prep it

 

[aphistis]

Try to stay out of the pulp chamber.

 

[fxteef]

Especially on the Ivorines. . .they have very elusive pulp chambers

For my amalgam prep I like to drop to about 3/4 depth with a 169 and make a conservative outline, then deepen to 2 mm with a 330 while finishing my outline. Then I add divergence with the 56 (could also smooth the floor with it). I'm a 1st year so I'm still figuring out my method too.

 

[lotexigeus]

practice practice practice

 

[1992Corolla]

i dont change burs, takes too long.

#245 bur the whole way, #6 round bur to remove decay.

Do down until you see EXACTLY .5 mm of dentin.

😉

 

[The Hammer]

i dont change burs, takes too long.

#245 bur the whole way, #6 round bur to remove decay.

Do down until you see EXACTLY .5 mm of dentin.

😉

No changing burs doesn't take too much time. Having patients call you in the middle of the night with a hot pulp because you generated too much friction trying to do a simple prep with one bur will though.👍

 

[dentstd]

No changing burs doesn't take too much time. Having patients call you in the middle of the night with a hot pulp because you generated too much friction trying to do a simple prep with one bur will though.👍

Using multiple burs doesn't create less heat. Unless you count the time it takes to change burs, and during this time, the heat slowly dissipates into the air.....

You should run iced water thru your handpiece. I use long island tea in mine. Keeps the working area nice and sterile.

 

[dentstd]

does anyone have any advice for doing class I preps?

What errors are you making?

Do occlusal first.

 

[OceanDMD]

No changing burs doesn't take too much time. Having patients call you in the middle of the night with a hot pulp because you generated too much friction trying to do a simple prep with one bur will though.👍

Thats why you use LOTS of water during any prep.
245 all the way. Its the workhorse for drill and fill dentistry. Cut your ideal prep, excavate decay with slow round burs, modify prep to remove any unsupported enamel, and sometimes I'll go back with a flame diamond to soften any sharp line angles or add bevels.

330 is just so small. In dental school I probably used that burr doing most of my initial prepping, but later switched to the 245.

And don't take for granted the rull of BULL. It will save hours of bite adjustments.

 

[1169]

Thats why you use LOTS of water during any prep.
245 all the way. Its the workhorse for drill and fill dentistry. Cut your ideal prep, excavate decay with slow round burs, modify prep to remove any unsupported enamel, and sometimes I'll go back with a flame diamond to soften any sharp line angles or add bevels.

330 is just so small. In dental school I probably used that burr doing most of my initial prepping, but later switched to the 245.

And don't take for granted the rull of BULL. It will save hours of bite adjustments.

Hmm. How do you all manage to see well with lots of water?

I never use 330. Too small, and I need convergent walls for amalgam preps.

 

[The Hammer]

Thats why you use LOTS of water during any prep.
245 all the way. Its the workhorse for drill and fill dentistry. Cut your ideal prep, excavate decay with slow round burs, modify prep to remove any unsupported enamel, and sometimes I'll go back with a flame diamond to soften any sharp line angles or add bevels.

330 is just so small. In dental school I probably used that burr doing most of my initial prepping, but later switched to the 245.

And don't take for granted the rull of BULL. It will save hours of bite adjustments.

Are we talking about what we would do in practice or what we would tell a D1 to use? I was assuming the OP was a first year.

 

[The Hammer]

Using multiple burs doesn't create less heat. Unless you count the time it takes to change burs, and during this time, the heat slowly dissipates into the air.....

You should run iced water thru your handpiece. I use long island tea in mine. Keeps the working area nice and sterile.

And you've done how many restorations to make this assumption?

 

[Thaxil]

Hmm. How do you all manage to see well with lots of water?

I never use 330. Too small, and I need convergent walls for amalgam preps.

You must use lots of water whenevery you cut a tooth. I rarely smell burning tooth; that is a bad sign. Pulpal tissue is very sensitive and I hate to know that I barbequed someone nerved. The ability to see is a combination of a good assistant and placement of the mirror. Sometimes it is just impossible to see well and you stop and evaluated ever few seconds. Many people will be surprise how little we do see as we work. A lot of seeing occurs thought touch.

As far as the original question, try sticking with on bur. The last time I use a 330 was in dental school. There is no magic bur, it is all done well in an experience hand.

 

[jay47]

Hmm. How do you all manage to see well with lots of water?

I never use 330. Too small, and I need convergent walls for amalgam preps.

330 is a pear shape and therefore should naturally give convergent walls. I don't get it?

 

[Flipper405]

330 is a pear shape and therefore should naturally give convergent walls. I don't get it?

this is what i was thinking as well... we've only been allowed to use 330 and 245 so far, and it was justified for that reason - that it naturally gives convergent walls. It seems perfect for me - for a class II, I'll use 330 for occlusal then 245 for the box. Likewise, I just stick with a 330 for class I. Maybe I just don't know any better 😛

 

[jay47]

this is what i was thinking as well... we've only been allowed to use 330 and 245 so far, and it was justified for that reason - that it naturally gives convergent walls. It seems perfect for me - for a class II, I'll use 330 for occlusal then 245 for the box. Likewise, I just stick with a 330 for class I. Maybe I just don't know any better 😛

Plus, if you get too much more convergent, you will undermine the stability of the enamel rods. Got docked on some on my preps for that as well.....It makes sense to use the pear shaped burs or at least inverted cones (34,35).

 

[The Hammer]

330 is a pear shape and therefore should naturally give convergent walls. I don't get it?

Someone is talking from their ass rather than from experience. I read the same comment and had a laugh.

 

[The Hammer]

this is what i was thinking as well... we've only been allowed to use 330 and 245 so far, and it was justified for that reason - that it naturally gives convergent walls. It seems perfect for me - for a class II, I'll use 330 for occlusal then 245 for the box. Likewise, I just stick with a 330 for class I. Maybe I just don't know any better 😛

For a dental student who is cutting the very very soft Ivorine teeth and learning handpiece control a 330 is a great bur to use. It is naturally convergent and the head is very small so you aren't going to immediately cut away too much of your prep. I tell my students to think of the 330 as the point of a pencil and that they are "drawing" their prep on the tooth. Once they get good hand control then it is time to more up to something more aggressive like a 245 which is a good all around operative carbide.

A 330 is still a great bur to use in practice but it was so rare that I ever saw anything that was small enough for the 330 to be useful. Most of the time I was using a 37 to remove an old amalgam or a double inverted cone diamond to remove composite that had recurrent decay.

 

[The Hammer]

Thats why you use LOTS of water during any prep.
245 all the way. Its the workhorse for drill and fill dentistry. Cut your ideal prep, excavate decay with slow round burs, modify prep to remove any unsupported enamel, and sometimes I'll go back with a flame diamond to soften any sharp line angles or add bevels.

330 is just so small. In dental school I probably used that burr doing most of my initial prepping, but later switched to the 245.

And don't take for granted the rull of BULL. It will save hours of bite adjustments.

I agree with lots of water but water will not stop the clogging or dulling of a bur once you have used it. Especially if you are still using multi-use burs and are running them through the autoclave. When I do quads I never use the same bur on two different teeth and I frequently used multiple diamonds on the same prep depending on the difficultly of the prep. A sharp bur increases your speed and decreases friction. Decreased friction equals decreased heat and a happy pulp is a happy patient👍

Oh and you got me on the rule of BULL. I have never heard of that. What is it?

 

[1169]

You are right, I am not speaking from experience.

It's just that at school we were taught to use 245 for convergent walls, and we haven't touched the 330 since the first days of drilling.

But if the 330 gives convergent walls, and people use it, so be it.

 

[OceanDMD]

I agree with lots of water but water will not stop the clogging or dulling of a bur once you have used it. Especially if you are still using multi-use burs and are running them through the autoclave. When I do quads I never use the same bur on two different teeth and I frequently used multiple diamonds on the same prep depending on the difficultly of the prep. A sharp bur increases your speed and decreases friction. Decreased friction equals decreased heat and a happy pulp is a happy patient👍

Oh and you got me on the rule of BULL. I have never heard of that. What is it?

I use a brand new 245 on every patient. I use brand new (disposable be it) Diamond bur on every crown prep. Not only is a autoclaved bur dull (use them usually only cutting off crowns/sectioning) they also create more friction on the tooth. Friction = sensitivity.

BULL (buccal upper lingual lower) working versus nonworking cusps. Lingual cusps of maxillary posterior are your working/centric cusps, buccal on the lower. Lateral excursions and in a balanced occlusion should reveal no markings on the maxillary buccal cusp nor mandibular lingual cusps (otherwise known as nonworking interferences).

Didnt they teach this in school or is it the acronym?

 

[The Hammer]

I use a brand new 245 on every patient. I use brand new (disposable be it) Diamond bur on every crown prep. Not only is a autoclaved bur dull (use them usually only cutting off crowns/sectioning) they also create more friction on the tooth. Friction = sensitivity.

BULL (buccal upper lingual lower) working versus nonworking cusps. Lingual cusps of maxillary posterior are your working/centric cusps, buccal on the lower. Lateral excursions and in a balanced occlusion should reveal no markings on the maxillary buccal cusp nor mandibular lingual cusps (otherwise known as nonworking interferences).

Didnt they teach this in school or is it the acronym?

Working and non-working cusps of course but if they taught BULL I didn't remember it, but I really like that and will teach it to my students. I'll give you the credit👍

And yeah disposable burs are the only way to go. Sharp every single time greatly increases your speed and that greatly increases your bottom line😀

 

[jay47]

You are right, I am not speaking from experience.

It's just that at school we were taught to use 245 for convergent walls, and we haven't touched the 330 since the first days of drilling.

But if the 330 gives convergent walls, and people use it, so be it.

That's probably because 245 is great for class 2's, which is a majority of what you will do (think I remember reading that they are most common somewhere....). So either way, 330, 245, etc... they will all work for you.

Our school is VERY focused on conservative preps, making sure isthmus is 1mm EXactly, 1.5 mm marginal ridges EXactly, mirror outer margins, shape is dovetail, convergent, divergent, etc....so using a smaller bur is essential to making sure you don't destroy the entire prep; or rather, go over by .2 mm and get an 80. Heck, I use 329 sometimes just to make sure that I don't go too deep.