Hemorrhage control in restorative dentistry:
This is tough sometimes. You've got a patient that has less than ideal hygiene and when you drop the box for your prep below the gingival margin, inevitably you get some bleeding right into where you're working. Here are some tips to help you out.
1. Viscostat Clear on a cotton ball - Viscostat Clear is an excellent product that is comprised of 25% Aluminum Chloride to help control minor hemorrhage. Emphasis on "minor". It will not stop the gushers from gushing but it will keep minor hemorrhage at bay. However... if you saturate a small cotton ball with it and use pressure against the hemorrhaging area for about 3 minutes, you will be able to push the tissue back and control bleeding at the same time. Excellent for working that tissue distal to mandibular 2nd molars on crown preps or deep restorations. This saved my bacon on a CAD/CAM crown 2 days ago! You could use another hemostatic agent, but Viscostat Clear is what we use at Eielson.
2. Injecting surrounding gingiva with anesthetic - This was a trick I learned in my AEGD residency and it's saved me more than once. Here's how it works. Anesthetic has epinephrine in it to constrict the blood vessels so that the anesthesia stays in the areas we want it to stay. But this effect of epinephrine can also be utilized to control localized hemorrhaging. Let's say you are prepping a crown on #14 and the mesial marginal area is sub gingival and none of your hemorrhage control methods have worked. Take some anesthetic and insert the needle directly into the facial side of the papilla between #13 and #14 and inject 1/4 to 1/2 of the carpule with a fair amount of pressure. This forces epinephrine into the tissue and can keep hemorrhage at bay long enough for you to refine the prep and get a good impression. The best is to use a high concentration of epinephrine (1:50,000) but traditional anesthetic works well, too (1:100,000).
Note: Do NOT inject straight into the area that is hemorrhaging. The fact that you're stabbing pissed off gingival tissue will sometimes make it worse.
This is a very stressful procedure for dental students and new dentists. You're taking away a lot of tooth in hopes that you can reduce a tooth enough for clearance of your material but not so much that compromise resistance and retention. Here are some tips to help you out!
1. Pick a more aggressive bur - If you pick a moderately coarse or medium grit bur, you're going to notice quickly that you sometimes want to push the bur faster than it will cut. I've found that using a very aggressive bur allows me to push at a constant rate and get into a "flow", if you will, of prepping instead of constantly feathering off the prep to let the bur speed up again. If you have an electric handpiece, you may notice that this isn't as relevant, as you can maintain pressure and not worry about stalling out the bur. However, I like to move quickly but smoothly. I never prep out of control.
2. Prep a wider margin - Another tip from my AEGD. I don't think I've ever had a case that I said "crap, my margin is about 0.2mm too wide on this one". A wider margin helps you out in several ways: 1) Easier for you to tell that you actually have adequate margin everywhere 2) easier for lab to discern between gingiva and margin and give you a good product 3) a wider margin gives you some "play" room in case the impression is less than perfect or there's some sort of issue in building the crown all the way out to the margin. If for some reason you'd need to enameloplasty the margin back after crown cementation, a wide margin gives you room to do this. Crowns don't fail from having adequate axial thickness. :)
3. Reduce occlusion a little more - In my opinion, you're better off reducing that extra 0.3mm than fighting for the wall height if you can avoid it. Not to mention, the area we tend to under-reduce is right in the middle of the prep which has no bearing on how tall the surrounding axial walls are. Get a #330 bur and carve depth grooves into the occlusal table and go down to them. Then smooth everything up! Now, this is not a blanket statement condoning negligent over-reduction, but if you're on the fence and are unsure, reduce a little more. This is especially true when prepping for CAD/CAM crowns that will be bonded into place.
4. Change burs only three times/don't prep the same area twice - This is how I prep, and it results in very fast and efficient crown preps without me having to waste my bur trimming tooth structure from two angles. Here's what I mean.
If you do your occlusal reduction first, you are inevitably reducing the occlusion on areas that will eventually be prepped away when you go to do your axial reduction (example: you reduce the entire occlusion and then end up prepping off the circumferential areas for the axial prep that you just reduced the occlusion on!). Don't do that! The axial reduction is virtually independent of occlusal clearance so do your axial reduction first. I always start "in the open", as I like to call it, on a nice wide area of the tooth that's easy to see. I prep the margin down to the most acceptably apical position depending on the material I'm using.
Let's take a #19 e.max for example (assuming it's ready to prep and doesn't need a core, etc.). I would start with my aggressive flat ended tapered bur mid-facial ("in the open"... a nice wide area of the tooth) and work my way towards the mesial until I broke through all the way to the ML line angle, keeping the bur as deep into the tooth as necessary to make a complete axial reduction with 1 pass. Notice how I never switched burs to pass through the inter proximal area? This touches on two principals: 1) I'm going to prep the interproximal area away anyway so I don't step up with skinny burs, I just push through it with my regular bur 2) prep a wider margin. So, I work through to the ML angle and then I come back to my starting point mid-facial. Then I work the same pattern, this time towards the distal until I break through and get to the DL line angle. Then I connect the DL and ML line angles across the lingual. Margin and axial reduction are done.
Occlusal reduction is next. Switch burs (first change) to the #330, or a bur of your choice with reference points, and cut the depth groves I mentioned in tip #3. Now switch back to the first bur again (second change) and level it all out to the depth of the grooves. Now switch to a fine version of your first bur (third change) and smooth everything. Done!
The problem with doing the occlusal reduction first is this: You are using false reference points on the outer edges of the occlusal table. If you reduce the occlusion, you don't yet know exactly which areas you're going to end up prepping off when you do your axial reduction. So do your axial reduction first so you have your smaller "true" occlusal table, and then reduce it.
Caveat: I am not an oral surgeon but I do routinely perform IV sedations and extract impacted wisdom teeth. I don't do the crazy ones, but I've seen enough to help me become more proficient at taking out all kinds of teeth.
1. Remove more bone - Don't be scared to take some bone away! Now, this is not a general rule, but it's true most of the time. On anterior cases, patience is going to serve the patient better than reflecting a flap and buzzing away 4 mm of bone to get that root tip out. But... for posterior teeth, you should recognize that if the tooth isn't moving now, it's not going to be moving much later. Do yourself and the patient a favor and remove some more bone on the facial aspect of the tooth and try again.
2. Section the tooth - This can seem scary for a new doc, but sometimes it's what we have to do. I was recently extracting a severely carious #30 and the tooth kept breaking into pieces while I was trying to get leverage from the mesial. I had great visualization, so I took the handpiece and sectioned the tooth from F to L across the furcation, broke the tooth in half, and plucked both roots out in less than 20 seconds.
3. Use an endo file - Huh? Ok, so I've seen this trick before and finally had a chance to try it a few months ago. A patient had facial trauma and had fractured #7. The problem is that there was a horizontal root fracture so the root tip was lying a good 3mm apical to the crestal bone. I got a set of endo files and took the largest file that would engage the root tip at least 1 full clockwise rotation. I wrapped floss around the handle of the endo file and twisted the file to engage the canal of the root tip. I pulled gently on the floss until, about 3 minutes later, the root tip popped right out. (Notice the clean and unused blade?)
|Extracting #7 with an endo file|
So that's it for today. I'll try to catalog some more tips and do some more of these posts from time to time. Are there any other topics you guys would like my to discuss or give input on? Just another dentist trying to learn!