Crown Preps: Those Damn Interproximals

Interproximals STRESS ME OUT when I’m prepping teeth for crowns. There’s way too much crap to worry about such as: I can’t hit the tooth next door; I can’t over reduce the mesial and distal axial walls; I can’t over taper the mesial and distal axial walls; I can’t wreck my margin/chamfer; I can’t hurt the patient; I can’t I can’t I can’t (it’s no wonder some of we dentists go nuts and have to spend extraordinary amounts of money at Disney World!).

And back when I was a damn, dirty, diseased University of Minnesota preclinical dental student who would never amount to anything (jury is still out on that one) I was taught to take my big ass diamond crown prep bur and cut each interproximal a little at a time from the buccal, then the lingual, then the buccal again, then the lingual again, etc., and all the while: I can’t hit the tooth next door; I can’t over reduce the mesial and distal axial walls; I can’t over taper the mesial and distal axial walls; I can’t wreck my margin/chamfer; I can’t hurt the patient; I can’t I can’t I can’t. ENOUGH ALREADY!!! So, find a lazy ass way to do it (well, it’s more like find a comfortable and efficient way to get the job done WELL and RIGHT but it’s always more fun/rebellious to think I find lazy ass ways to get things done).

With a 245 carbide bur I know I can drop a perfect mesial and distal box (Class II preps) in my sleep AND I can do it without: hitting the tooth next door; over reducing the mesial and distal axial walls; over tapering the mesial and distal axial walls; making a horrible gingival seat; hurting the patient. So now when I do a crown prep I START my prep with a 245 carbide bur and prep perfect mesial and distal Class II boxes that have a perfect mesial/distal width of 1mm from cavosurface margin to axial wall and have a perfect gingival contact opening of at least 0.5mm. I will push my buccal and lingual proximal walls a bit further to the buccal and lingual (think inlay/onlay prep) because those walls have to go away anyway for a proper crown prep. Further, I will add a little tiny bit of taper to my mesial and distal axial walls (once again think inlay/onlay prep with a path of draw/insertion). Next I will get my big ass diamond crown prep bur and prep the occlusal and buccal/lingual axial walls. And finally I will use my big ass diamond crown prep bur to gently incorporate my already prepped interproximals into the crown prep (I turn those gingival seats into beautiful chamfers and finalize the entire path of draw/insertion). This all saves me a whole lot of extra stress because: I don’t hit the tooth next door; I don’t over reduce the mesial and distal axial walls; I don’t over taper the mesial and distal axial walls; I don’t make horrible interproximal margins/chamfers; and I don’t hurt the patient. OK, that’s a whole lot of DON’T but those are good DON’Ts that I can live with (we dentists are such curious folks…or at least I am).