Particle Abrasion: How it Helps Your Direct and Indirect Restorations

You're listening to The Dr. Phil Klein Dental Podcast from VivaLearning.com. Welcome to the show. I'm Dr. Phil Klein. Today we'll be discussing particle abrasion on CAD-CAM materials such as Emacs and Zirconia. Our guest is Dr. Alex Vasserman, a cosmetic dentist who practices minimally invasive painless dentistry in the Upper East Side of New York City. He is an active member of several dental associations, including the American Academy of Cosmetic Dentistry and COIS-trained Dentist. Dr. Vasserman, it's a pleasure to have you on Dental Talk. Hello, thank you so much for having me. We're excited to have you. This is an interesting topic, something we haven't covered on previous podcasts. So what is particle abrasion and how does it relate to our CAD-CAM restorations? Particle abrasion increases the bond strength of the restoration to the tooth. It's when rough particles... are sprayed out of a device under high pressure onto either the tooth or the intaglio of a restoration and again the intent is to roughen or alter the surface in order to increase the bond strength or even to clean. You can use either standalone devices that plug right into your chair or you could use particle abrasion like in the hood where you put your arms in and then there's a pen and it sprays. either aluminum oxide or other materials under high pressure in order to roughen the material. So is there a difference between different particle abrasion instruments that are available? Yes, a big difference. I started out by using like a small little etch master from Grohman. They're great. really good product it plugs right into your airline into your hand where the handpiece would go the keys to turn the water off and then they have this tip that you can change in and in that tip it's a white bulb if you will and in that white bulb there's different particles 27 micron aluminum oxide 50 silica you could have even smaller aluminum oxide in order to remove stains. The trouble I found with it is that you're always are looking for a different bulb. Now I switched to something that's called a prep start. It's great. It's a machine and you can control the air pressure as well as the volume of air that's moved. And it's really great. It's very small tip, so it doesn't leave a mess. And I use it in the mouth and I use it for my restorations. I don't use the aluminum oxide on the Intaglio of Emacs, but I do use it on the Intaglio of Zirconia and any metal ceramic restorations. Yeah, so that was actually my next question. Can you particle abrade Emax? And the same applies to zirconia. So tell us about that a little bit. It all depends on the material that you are abrading. If you're going to use it on the intaglia of an Emax, you can use silica. Think of the particles that you're using as... Aluminum oxide, if you look at it microscopically, looks like rocks. They're irregular shaped. Some of them are sharp. Some of them have sharp line angles. Silica or glass is very soft. It looks, under an electron microscope, it looks like little tennis balls. So if you're using aluminum oxide on the intaglio of Emax, you're going to put little... micro cracks on the inside and you're increasing the risk of Emax fracturing, especially under pressure. But it's perfect for cleaning. Zirconia, on the other hand, you can use aluminum oxide, 27 or 50 micron aluminum oxide, and that cleans and it also roughens the surface, which increases the bond strength. So tell us the procedure of how you use this. Like what's the actual protocol when this abrasion occurs and how it's applied? What's the environment where you do it? You mentioned you do it in the mouth at times. Can you just go over that whole process? Perfect. If I'm restoring teeth, I almost use it. I use it almost for every single procedure. I use air abrasion when I'm placing composite. I'll take out the decay. I'll air braid enamel, I'll air braid dentin. When I'm prepping for crowns, right before putting on a temporary, I will air braid it. If you look at dentin microscopically, it has these microtubules that are filled with water. And when you air braid that, the particles, the 27 micron aluminum oxide hits the dentin. roughens it, and some of them actually get embedded in the dentin. So it decreases sensitivity. It increases bond strength. On enamel, it does the same thing. It makes it irregular and rough. So when you're putting your bonding agent on it, when it's a rough surface, bonding agent can, once it's polymerized, it can actually grab on a lot better. Some studies have compared roughened, dentin to non-roughened, and it could increase the bond strength up to three times and decrease the sensitivity. So I use it for almost everything under a rubber dam. This is before the bonding agent is placed, obviously. So if you're doing a direct composite, for instance, you're going to go through a particle abrasion process before you use any bonding, any light cured bonding agent system. That's right. The first thing I do once I'm done with my prep, I clean the prep with water. I dry it. And then I run my air braiding unit, my prep start over the enamel and then over the dentin. Then I'll clean it again with the water. I'll air dry it. Then I'll use my etch only on the enamel. I personally select a etch. And then I will again clean and dry. And then I will paint my bonding agent both on the enamel and on the dentin. And with your CAD CAM restoration, what's the process there? So if it's a zirconia, I will use 27 micron aluminum oxide. I will air abrade the intaglio of my zirconia. I will air abrade the dentin. I will air abrade the enamel. And then I will cement the tube. If it's Emax, I do not air abrade the intaglia of the crown. I just clean it, silenate it, but I will particle abrade the dentin and the enamel on the tooth and then either go through my looting or my bonding technique. Excellent. So that's actually a good segue into another podcast that we're going to be doing, Dr. Vasserman, which is differentiating between bonding and looting. And what's the difference? Why do we need to know? And how does that affect our procedures? So we're going to be covering that in another podcast. So please tune in to that. I'm talking to the audience now. Dr. Vasserman, thank you very much for your time. I appreciate it. We learned a lot about particle abrasion. We're looking forward to your next podcast. Thank you so much. Thank you for having me.