Bonding vs Luting: What's the difference and why does it matter?

You're listening to the Dr. Phil Klein Dental Podcast from Viva Learning.com. Welcome to the show. I'm Dr. Phil Klein. Today we'll be discussing the difference between bonding and looting in the materials used for each of these procedures. 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, thanks for coming back and joining us on Dental Talk. Thank you so much for having me back. Yeah, so we had a very interesting podcast for those of you who are interested in particle abrasion, how it actually strengthens the material, even helps with hypersensitivity or post-operative sensitivity. And Dr. Vasserman talked about the types of air abrasive materials that he uses. and the instruments that he uses so we talked about the particle size and so forth so tap into that podcast anytime you feel you're interested in learning about particle abrasion today we're going to be talking about bonding versus looting so to begin let me ask you this simple question what is the difference between bonding and looting for our you know just clarification before we get started and why is it important for us to understand this as clinicians so bonding versus looting depends on whether you're using bonding agent think of it that way and the way that I look at it is whether you have enamel or you don't have enamel if you have enamel you could bond to it if you don't have enamel you need to use the older principles of dentistry which is the cohesive dentistry where you're getting your restoration to grab onto the tooth versus simply using bonding agent and resin cement in order to get that adhesive bond. So it's adhesion versus cohesion, whether you're getting a gluing effect like bonding agent or whether you're getting that mechanical retention. Right. So in the old days when we used zinc phosphate, that was obviously strictly looting, right? There was no real bonding process going on. Exactly. Are you implying that dentin itself is not bondable? Like, can we get an effective bond to dentin, or are we looking at that as a looting procedure if there's just no enamel present? You can bond to dentin. However, certain studies have shown that because of the MMPs, metalloproteases, that bond degrades up to 40%. after 12 months. So yes, initially, there are people like Pascal Manier that activate that bond, that do what's called bond seal. And they claim and they do show that yes, you can bond to dentin successfully. However, there are other studies that do show that that bond degrades because there's water inside dentin. There's metalloproteases that degrade the bond. So I personally do not trust that bond strength for a long-term bond. That's why you'll find that veneers, if you start to show through that enamel and you're getting into that dentin, I will typically go then into my cohesive protocols in order to get extra strength. I'm not solely relying on adhesion because most likely you'll get a phone call that that veneer popped off. So you're also a fan of selective etch. Yes. Could you explain that to us a little bit about how that differs from total etch just very briefly and how that follows your viewpoint as far as... you're not completely thrilled with the confidence factor when it comes to bonding to dentin. So when I'm looking at the restoration and I'm seeing, let's say it's a posterior tooth and I'm seeing a big ring of enamel, I will go adhesion and I will etch only the enamel ring and I will bond to that enamel. However, if I'm not seeing that enamel ring, I'm relying on my six degree of taper. I'm relying on four millimeter ferrule, at least two millimeter to structure in order to get that cohesive restoration to grab. Bonding agents are very important. And some of them claim that they do get a bond strength. And yes, you will get a bond strength. initially. Bonding agents like 3M has a great bonding agent. I personally love All Bond Universal from Bisco. It's a great bonding agent because it has the MDP in it, which has been shown to bond to dentin. However, over time, the bond does seem to degrade. So tell us about the clinical process. So you have a tooth, you have this ring of enamel. that you are going to utilize because you know you can get certainly a bond to that. How do you prepare the tooth and what materials do you use typically to cement in an indirect restoration under those conditions? So my protocol is this. I always work under a rubber dam, whether I'm preparing a tooth or I'm cementing a tooth. Once I take out... the old restoration that's in the tooth whether it's an old amalgam or a big composite i evaluate how much of the walls i have left i typically then flatten those in order to utilize as much enamel as possible i'll bevel that enamel and when the restoration comes back either cad cam after i take an impression or scan i will then particle abrade the entire tooth i will etch only the enamel i will then bond typically i will use all bond universal because it does have the mdp in it which increases the bond strength to dentin i will silenate my emacs and i will use some kind of a resin cement i use the one from bisco and then again i will then cement my restoration right over the top. I will tag cure it, clean up the cement, put some kind of a glycerin over it in order to, so it doesn't polymerize the air inhibiting layer. And I will cure through that for about 20 seconds, adjust my occlusion and floss the contact. So on the selective edge part, you stay away from the dentin, but... to that, you use the particle abrasion for all the services that are involved. That's right. That's exactly it. I do not edge dentin, but I particle abrate everything and then I bond everything. Typically 20 seconds of vigorous scrubbing with my All-Bond Universal. Very, very lightly. Just use a little bit of the air to kind of move. I have a separate line that doesn't have the water in it. It's just air. And I will move that bond around, hit it with the light for about 10 seconds, and then go through my bonding protocol. Right. So you're getting a bonding result on the enamel. But even though you put a bonding layer on the dentin, you didn't etch it, but you did particle abrade it. You look at that as a looting process? I'm not really. relying on that bond strength to dentin. If I get any that lasts more than a year or two years just from the bond, it's a plus. I'm primarily relying on that enamel bond. Thank you for that very clear description of the actual clinical technique. So what are the two materials that you're using as far as bonding and cementing? So I used to use... All sorts of materials, but typically right now I found myself using more and more of Bisco's All Bond Universal. And then I will use the Bisco resin cement. It's called Dual Link. It's a great cement. And I'll put that into the crown or the onlay. I'll seed it over, tag cure it for about 20 seconds. First, I'll tag cure it, clean up the cement. use my glycerin, and then cure it for about 20 seconds on all the sides. And what happens when you have a tooth that you're restoring that has practically no enamel on it after it's prepared? In that situation, you rely on those dental school principles, the six degrees of taper, four millimeter ferrule, at least two millimeter tooth structure. If all of those things meet, then it really doesn't matter. what you use. I mean, we've been using zinc phosphate forever. In my practice, I will use either, I will particle abrade it once I have that perfect prep, that retentive prep. I will particle abrade it and I will use either Reliax Unisem or the Therasem from Bisco. Both of those work really well because they do have the MDP in it. Again, because I'm not relying on that Denton bond, I'm more relying on the cohesive principles. Anything works. If you want to go through your bonding principles, Arabraid, bond, at that point, I will then go to my Duolink, which is the resin cement from Bisco, if I want to try to get a Denton bond. Before we wrap up this podcast, Dr. Vasserman, can you go over bonding to zirconia? Or is it possible to get a good bond from zirconia? It is. There are certain studies that have shown that the bond strength to the zirconia increases with MDP. MDP is found in some bonding agents like All Bond Universal, 3M's bonding agent has it. But you want it in a high concentration. You almost want a pure MDP, which is the Z prime from Bisco. It's a great product. You paint it on the intaglio. After you roughen the surface, you paint it on the intaglio of the zirconia. You scrub it, and then you just leave it alone. You don't cure it. You don't dry it. I just kind of leave it there. Then I bond the tooth. selective edge enamel, I particle abrade everything. And that has been shown, that protocol has been shown to increase the bond strength by almost three times versus not using the MDP. So yes, certain studies have shown with the use of MDP, the ability to bond to zirconia. Are you using zirconia primarily for posterior EMAX for? anterior and bicuspids? I am mostly using Emacs everywhere. I feel like the strength of Emax is very strong. It's 400 megapascals of strength. So yeah, I use Emacs almost all the cases except for very heavy clenchers, people that have a lot of parafunction that I can't control. I will go with zirconia. My implants, because Soft tissue likes zirconia. Most of my implants have polished zirconia underneath the restoration. So I will go monolithic zirconia on most of my implants, unless it's in the aesthetic area. Again, Dr. Vasserman, very, very good podcast. We appreciate how articulate you are in describing these clinical techniques. You certainly make it easy for us to understand. And it's interesting to get your perspective on how you treat dentin and enamel completely differently, where some dentists, they believe in dentin bonding as more of a long-term result. And I guess the studies are backing up what you're saying as well. So we'll have to see what happens with that going forward. We'll look forward to more podcasts. I know you're doing one on endo versus doing root canal versus vital pulp capping. And that's going to be interesting. And we look forward to that one. And you're going to do a whole podcast going forward. on zirconia versus emacs which is going to be good too so thank you very much for your time and talk to you soon thank you so much thank you for having me