Bur Suggestions for Basic Preps

[Vicviper]

Hey there folks,

I've just started my amalgam class, and I'm hearing lots of conflicting opinions from my instructors on Bur selection. I know it's really a personal preference, but I'm just trying to find Burs that are best to learn the basics with. The overall instructor for the class says to more or less use 56 for EVERYTHING, but I keep finding that my preps are more or less fine, but just slightly too fat. When I talked to my bench instructor after having my preps graded, he suggested using another set of Burs. I've tried starting with a 169 and making a basic outline, and then going in and using the 56 to finish, and while I find that makes the start much easier, I run into the same problem. Looking into some old posts it seems like other schools start their students primarily with the 330, which seems like a smaller version of the 56, so do you think that would help solve my issue? Oh, and the preps we did this week were Class I on 18 and 20, next week we're doing 19 and 21.

Also, another problem I keep running into is accidentally nicking a cusp or a wall on my way out of the prep, any suggestions for that?

Thanks!

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[jmick101]

330 to do 90%, 56 for the rest. For dropping boxes on premolars, 329/55 is a good combo. Good luck!

 

[StudentDentist]

Amalgams fear it

 

[browncrack]

Most restorative I do with 330 or 245 depending on depth, some form of a diamond on margins for composite. Occasionally I'll smooth a floor with a flat end cutting burr. The above pictured burr looks like a good one to use to take out an old restoration - amalgam or composite.

 

[haisha ni narou]

The 330 is popular but I made the switch from the 330 carbide to the 330 diamond. The diamond is a little longer, just over 2mm so you need to calibrate to that but I like the cutting properties better with the diamond over the carbide. I prefer to use a pear shaped bur like the 330 or 245 to get my external preparation walls slightly convergent as you make your buccal/lingual extensions for amalagam whereas the 56 is a straight fissure which will give you parallel walls assuming you cut parallel to the long axis of the tooth. The correct answer at the end of the day is, use whatever works best for you, that is why all of your instructors are giving you different suggestions.

 

[eternalxdemon]

330 to do 90%, 56 for the rest. For dropping boxes on premolars, 329/55 is a good combo. Good luck!

+1 on that. when I first started out I would work with the 329/55 for everything but as the year progressed and my hand skills wer emore under control I switched back to the 330/56. 🙂

 

[Thaxil]

I narrowed my burs down to 1 main bur (1958 or Greatwhite SS#2) these burs are very aggressive but I dont like messing around. Then for finer detail #0.5 round bur and other burs for which I dont know the name. I have not used a 330 since dental school.👎

 

[omaralt]

I narrowed my burs down to 1 main bur (1958 or Greatwhite SS#2) these burs are very aggressive but I dont like messing around. Then for finer detail #0.5 round bur and other burs for which I dont know the name. I have not used a 330 since dental school.👎

+1 i used the 330 almost exclusively in dental school but now prefer the 56 for most of my preps. the 330 is just too small

 

[scottyhoop]

I was a fan of the 56, but I get too wide all the time with them. Since we are doing "ideal" preps now that's a pretty big issue so I stick to 330 for the occlusal and 245 for boxes. I'll still use a 56 to smoothen out floors if I'm too lazy to use hand instruments tho.

Scotty

 

[cda]

330 carbide and #2 round for primary teeth; 245 and 2 or 4 round for permanent. 56 once in a while to smooth the box and floor

 

[aphistis]

332 (high-speed) + whatever size round bur is appropriate (slow speed) + finishing flame tip (optional depending on prep & beveling needs) = finished operative prep

 

[somethinpositiv]

Looking into some old posts it seems like other schools start their students primarily with the 330, which seems like a smaller version of the 56, so do you think that would help solve my issue?

It may seem that way at first glance, but 330 (and 245) are pear-shaped while 56 is straight cylindrical. For a molar I use 330 on the highspeed first (the bur is the perfect depth for a lot of preps, 1.5 mm), and then 245 on the slowspeed, and then 56 to smooth out the walls.

56 is pretty good for preps with plastic teeth, but with real teeth in clinic we probably won't use 56 very much. The pear-shaped 330 and 245 are better for retention.

 

[Vicviper]

Thanks for the tips everybody! 🙂 I've been playing around with the suggestions, and I think I'm most comfortable with the 169 and the 245, the preps just seem to come much easier when I use those, haha. And yeah, when we cut out mounted natural teeth, it's crazy how night and day difference it is from the ivorine teeth - it seems waaay easier to get a decent looking prep in the actual teeth since you've got actually defined grooves and dentin, haha.