Umm, yeah, so where in the heck do we start prepping a bridge? I’m sure there are a plethora of opinions (and probably even some evidence based research crap that someone had to do to get a Master’s or Doctoral degree). Me? I always seem to gravitate toward the lazy ass way of doing things (someone once suggested I work smarter and not harder…yeah right…). So let’s get right to it (BTW, this write-up will pertain to a posterior bridge prep).
1. I prep the occlusals of all abutments.
2. I prep the functional cusp bevels of all abutments (and I am hoping that the angulations of my functional cusp bevels end up being somewhat the same on each abutment but is always dependent on individual patient conditions).
3. I will prep the buccal axial walls of all abutments. By prepping all buccals at the same time I can make all of my buccal axial walls have the same amount of reduction/taper. BTW, the buccals are, for me, easy (relatively speaking) to access and kind of become the cornerstone for my entire path of draw/insertion.
4. I will prep the lingual axial walls of all abutments and I will use the angulation of my buccal axial walls to give me the proper angulation of my lingual axial walls. I always like to picture equal but opposite angles…3 degrees of taper on the buccal means a negative 3 degrees of taper on the lingual for a total taper of 6 degrees (my taper usually ends up being 10 to 12 degrees of total taper…5 to 6 degrees on the buccal and negative 5 to 6 degrees on the lingual…and that is well within “acceptable” to pass a practical exam AND Boards…Lord I hope to NEVER take another Board exam…XANAX PLEASE!!!). And by prepping all of my lingual axials at the same time I can ensure that all of those lingual axial walls have matching reduction/taper (and play well with my buccal axial walls…I should see a good path of draw/insertion between all buccal axials and lingual axials at this point). BTW, one of my previous blog postings (Cusp Tips on Crown Preps) has some suggestions for prepping axial walls in a way to get optimal reduction and a great path of draw with just depth cut measurements (lazy ass).
5. I will prep the distal axial wall of the mesial abutment and the mesial axial wall of the distal abutment (assuming there are only two abutments). Why prep those surfaces now? Cuz they’re easy to get to cuz a tooth is missing in between them therefore I don’t have to fight to do ideal preps on those axial walls (lazy ass). And now by accessing/prepping all of the easy-to-get-to (relatively speaking) axial walls I can actually use all of those walls to nail down a path of draw before I tackle the hard-to-get-to in-between-the-teeth axial walls (it doesn’t always work out that I can get a path of draw early on but when I do it takes so much pressure off of establishing a path of draw on the mesial axial wall of the mesial abutment and the distal axial wall of the distal abutment).
6. I will prep the mesial axial wall of the mesial abutment and the distal axial wall of the distal abutment. I will initiate my preps with an ideal MO box prep on the mesial abutment and an ideal DO box prep on the distal abutment using a 245 bur (I can drop Class II box preps in my sleep…please see a previous blog posting about how I do interproximal preps on crowns). After creating ideal Class II box preps then I can quickly/easily (relatively speaking) blow through those cleared out proximals with my crown prep bur. Finally, I will make fine adjustments to those axial walls to incorporate them into the path of draw/insertion I’ve already established with the easy-to-get-to (relatively speaking) axial walls.
7. I will finish things up with establishing my nonfunctional cusp bevel and tapering/connecting my functional and nonfunctional cusp bevels into the central groove mid-mesial and mid-distal at the occlusal/axial line angle.
And with that, may we all find that path of draw/insertion that we all deserve and will lead to treatment success. Namaste’
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