CEREC Dental Assistant Training Basics - Single Crown Setup, Imaging, Design - Overview

This is an introduction to CEREC. CEREC is the technology that many dental offices use to create same-day restorations including crowns, bridges, veneers, inlays, onlays. The machine that you see here is what we call the Omnicam and this is one version of the acquisition unit. There are other versions including the Bluecam, the Redcam, of course the Omnicam, and now there's a new one that's come out just in the last few months called the PrimeScan. But the most frequently used currently is still this particular unit, the Omnicam. So what is the Omnicam? Well this is the Omnicam. You can see Omnicam right here and this is actually where most of the magic happens. This is a camera. It's a very expensive camera. Inside this camera there are a series of lenses that connect of course to the computer itself which allows us to generate 3D models from imaging some sort of a surface whether it's teeth or otherwise. So I'm going to give you a basic introduction to CEREC. I want to make sure that you can have an understanding of what it is that CEREC is, how it can be beneficial in your practice if you're a dental assistant, if you're an office manager, if you're a dentist. Certainly there are different levels of training that you each of you may need or may need to be exposed to but the goal here is to create some information for you so that you can use it to make informed decisions and hopefully if you're a dental assistant be able to affect some change and provide some assistance for your doctor. So CEREC, the word you see right here, there are a couple of different ways you can you can read this but it is pronounced CEREC if you ask the people at Dental Supply Sirona. It's not CERAC or CEREC or CERIC. It's CEREC. Generally speaking, at least the way I was trained, is it's Chairside Aesthetic Restoration of Economical Ceramic or Chairside Economical Restoration of Aesthetic Ceramic but I usually tell my patients that it stands for Ceramic Reconstruction. That seems to be what works best. This technology is in use and I know it's less than 10 percent of dental offices across the country. I'm talking about in office. In labs, however, there's a lot more and there's a higher percentage of labs that use CAD CAM, CEREC, or a different version than dental offices but it's in a very small percentage of dental offices across the country. So let me give you a brief walkthrough of what you're seeing here on the screen. So this, of course, like I said, is the acquisition unit. You have a keyboard here on this particular version. This is your mouse ball or your track ball. This allows, of course, to control the mouse. Then you have three buttons. This basically is the left click button. This, of course, is the right click button. And this one is, if you can envision, if you had one of these, that is this. So this right here is your scroll. Which we use here as a zoom when we're designing. So the mouse itself is a little bit different. You've got your left click, which is your left click here on your mouse. Your right click, which is your right click here on the mouse. And, of course, this button is as if you were using the roll, the track, the roll ball here. What do you call this thing? We use it as a zoom when we're designing and, of course, this is how you move the mouse around. So, as I mentioned before, this is the camera. Do not ever drop this camera. Its cost is exceptional. There are little sleeves which can be changed and which should only be changed if necessary. Mine won't come off, which is fine. By an authorized trained personnel. And this sleeve comes off, which reveals the actual camera and some of the prism inside the unit. Occasionally these will get dinged up or scratched on the end, especially if you're dragging them across the tooth as you're imaging. So be careful you don't do that. But it's a lot cheaper to change this sleeve out than it is, of course, to change the camera. So don't ever drop this camera. Anytime you place it back in the cradle here, make sure you lock this. That will help to hold it in place. You'll notice here on the side, this is a heater. So you see the little wavy lines? That's supposed to tell you that there's heat. This is a heater and if you put your finger on it, it's pretty warm. The idea is where this lens sits, it keeps it warm. And so that minimizes the amount of fogging on the lens when you put it in the patient's mouth to take images. So like I said, make sure when you place that camera in the cradle that this is always locked. That lowers the risk of it falling out. Now you can still lift it up and pull it out, but make sure it's always locked when it's sitting there. I had a dental assistant drop one of these. I'm sure it was an accident. It wasn't intentional. Unfortunately, it was just the sleeve that needed to be replaced. That was about $1,200. The camera lens, I was told at the time, and it was a version that's different, excuse me, that's different than this, would have cost about $12,000 to replace the whole camera. So be very cautious. Okay, so what are we looking at here? We are looking at the start screen. I'm going to turn this so I can access it a little bit easier. We're looking at the start screen. So this is basically the landing page. Now for most of us, you'll come up with a screen that looks something like this. You may have an icon somewhere. But what I always do is I go over here to CEREC software. We're running version 4.5.2 as you can see there. And of course I'll double click on that. Now I don't need to double click on it because it's already open here. But then we'll come to this screen. Now the next step is to add a patient or to pull up an existing patient. So you can certainly search through the existing patient database. Now I won't do that here. I don't want to violate any HIPAA and show any patient information. But you can show patients or you can search through patients. And then you can just add a new patient. So we'll click there. We're going to click on the add new patient. So this particular version of the software, 4.5, starts with this particular screen. I'm going to add myself. You'll notice this light. Let's go back. The caps lock. This light is on here. So that's how you get a capital letter is by pushing the down arrow here or by pressing and holding the shift, right? So I'm going to type in my name, tab, or you can click down to the next one, and my first name. See it automatically defaults to have that first letter capitalized. And then you can if you want to go through and put in the date of birth and or the patient ID. I usually just leave that as today's date, the date of the crown date of birth. We don't normally take the time to put that in. You're certainly more than welcome to. And then the dentist, I would suggest you keep a system in your office and make sure that the assistants or whoever sets up your machine knows exactly how to do this. I usually put the last name of the dentist only. Now it can be capitalized, can be lowercase, whatever you want to do. So now we've got our patient profile set up. We're ready to move on to the next step. We're going to add a case. Good morning. Hi, just ignore me. I'm recording a video. So here's the next screen that comes up in software version 4.5.2. You can see on the left side it's asking for a restoration type. And we have all sorts of choices that we can choose from. For our intents today, we're going to talk about a single restoration. But let me click through the different options for you. There's a bridge, which is of course a multiple tooth restoration. And there's an implant restoration. So I would suggest to make sure that you know what you're doing, of course, and that you set it up appropriately before you move forward with the case. Meaning before you bring the patient back or before the doctor's in the room ready to go if you're a dental assistant. So single tooth restoration. This software version will automatically detect what restoration you're doing, which makes it a little bit easier. Before in earlier versions, we had to select either inlay, onlay, crown, veneer. So basically, when this is selected, I'm ready to select the tooth that we're going to be working on, whether that's an upper or lower tooth. One thing to bear in mind though is the options we have selected below, the design mode and the material, will be expressed for each tooth we click on that's showing here, if that makes any sense. So for instance, if I have biogeneric individual, which I'll explain in a moment, or Emax and Emax, when I click on a tooth, it's going to express these two as what that tooth will be. Whereas if I go in and I select biogeneric copy and select a tooth, now these two will express into the restoration, if that makes any sense. So whatever options you have selected over here will follow through with the tooth that you select. So let's talk about these options. Biogeneric individual is probably what you'll be using most when you design restoration, single crowns, bridges, veneers, inlays and onlays. The software is now very, very adept at creating a restoration that blends and matches the adjacent teeth, the anatomy and such. So generally we're going to be using this biogeneric individual choice. Now biogeneric copy is a great choice for you. If you have a tooth that's generally intact, if you have a patient who's a clincher and a grinder and you want to make sure that you maintain the occlusion as it stands now, or if you're designing a crown that goes underneath a partial denture, we can copy the restoration, the current shape of the tooth with the restoration so that the partial fits right over it. That way you don't have to send the partial to the lab. And this is one of the great benefits of CEREC here as well. Now biogeneric reference I don't normally use anymore. Early on in Red Cam and Blue Cam I used this a lot, but now the reference tool is not normally needed with the generic individual that we have. So recap here on design mode, biogeneric individual is the option you'll most of the time have selected. Copy is probably the next most frequently selected used option. This requires us to scan the teeth before we do any preparation, so bear that in mind. And then reference I rarely use, so I would suggest focusing on the biogeneric individual. So materials, you'll notice these little stars. These are my favorites, which you can change. It's just the favorites that automatically default, but I can go through and select any number of manufacturers and materials here by clicking on this drop down. So you can see the manufacturer name. Let's just say we wanted to do a Vita crown, Vita ceramic. So that's a Vita material. And then it asks us to select the material, which is a Mark II. So all sorts of other options as well. And I can certainly just select Emacs from my favorites list there. All right, now if I want to get to Emacs a different way, I can go to the Ivoclar, but you'll notice that Emacs is not listed in this menu because it's listed in the favorites. So you can go in through configuration and change what your favorites are, but generally we don't need to do that. So you just leave it here. If it's one of your more frequent ones, usually the software will automatically pick those out and put them in the top. So we've got Emacs, we've got SeraSmart, and we've got Empress, which are most frequently used materials. Okay, so let's just say we're going to use Emacs, which is probably the one we most often use. Now you can see all the teeth are white now, ready for us to select. So I have a model here, which was used to make a lab restoration, and it looks like we have tooth number 13, 14, and 15, which a bridge was prepared on by some other doctor at some point in the past. So we are just going to select tooth number 13 for an individual crown restoration. We're not going to do a bridge, we're doing an individual crown on tooth number 13, okay? And then I have the opposing also. So we've got a little mounted model here, and again we're focusing on a single restoration tooth number 13, okay? So we're going to use Emacs for tooth number 13 crown. So I've got auto-detect of course, I've got the bi-generic individual, and I've selected Emacs. Now we're going to go ahead and select tooth number 13. There it is, tooth number 13. So I'm going to click it with my left button, that's your left click on your mouse. This is this, okay, your left click. And now you'll notice we get the cursor details that come up, or I'm sorry, the case details. So it just basically is recapping everything that I just set up. So we have the auto-detect, which is here. We have the bi-generic individual, which is listed there. And then we have the IPS Emacs, which is listed there. You can see the manufacturer, Ivoclar, and the material Emacs. Now if I wanted to change this, if I'd made a mistake and I decided I'd rather do this in Serismart or some other material, it's easy enough just to click on this pencil. And now you can go in and edit any of these options, all right? But what I'm doing now, if I clicked on that edit button, is I'm only editing this restoration. I'm not editing anything that comes forward. So if I change this to Serismart, and then I click on another one, it's going to default to what's over here on this side, okay? So I'm going to hit cancel. We still have Emacs, we still have Ivoclar. So next step is to go ahead and move forward. Now you can, if you want to, we can do multiple restorations at a time, whether that's adding a bridge, or adding another single restoration, or changing a restoration, whether I wanted a different option or different material, I can change that and then click on whatever other teeth I want to do. Now I would suggest, when you're first starting, for your level of experience, probably I'd suggest doing a single tooth at a time for the design process. Now if you're doing a tooth that's opposing another tooth, you may want to do those concurrently, because it certainly is time consuming if you were to design one tooth, wait for the milling machine, wait for the firing process, bond it in, and then design another one, wait for the milling machine, wait for the firing process, if you're doing opposing teeth. So yes, you can definitely do those concurrently. I would suggest, if you're new to CEREC, if you're just starting out, start with very simple cases, avoid any anterior teeth, work from premolars back, and get those simple cases under your belt before you start doing anything more challenging or complicated. Next, we're going to move forward to our scanning screen, scanning protocol. So here now, the camera is active. You can see me moving it around. If I get close enough, you can see my smiling face. You can't really see it. Hello. Anyway, you can see all this. This is also smudging here. So a couple of things, you can see it flashing at this. This is the image rate. I'm going to go ahead and wipe off just on my shirt here, see if we can get that smudging off of there. There we go. That's a little better. Now, you can see some of these are little small scratches, and that's pretty normal. You can expect to have some scratches. But let's talk about what's on this screen first. I'm going to turn this camera off for a minute by just left clicking there. So this is our imaging screen. This is normally what populates what defaults. So the lower jaw, the upper jaw, and of course, the buckle scan, which we'll get to in a moment, and then the camera view. Now, you can, if you want to, you can grab this and make this bigger or smaller. I, a lot of times, like to make it really big. But what's going to happen when we turn the camera on, it's going to start imaging as soon as we get to the appropriate focal depth. Now, it doesn't matter what it's over, it's going to image it, whether it's my finger or whether it's the modeling or the restoration or the tooth that we've prepared. So the ideal focal depth, you know, is about eight to twelve millimeters from the tooth. And when we go in, I always have a fulcrum. I'd suggest you always hold the camera like a handpiece or a pencil. Some of the less experienced docs will hold it overhanded, and you can certainly do this temporarily if you need to. It's just so much easier and balances a little bit better, even though it's pretty bulky on the back end, if you hold it in this manner. So I like to use my ring finger as a fulcrum, and if the patient's laying back, you know, I'm going to end up having a fulcrum on their right side. So I'll just demonstrate this. When I scan, I'm going to have a fulcrum somewhere, whether it's anterior or the right side. And then, like I mentioned a minute ago, we're going to want to avoid dragging the lens over the teeth, because that'll scratch the lens and put those little scratch marks that you saw. The idea is, as soon as you get the appropriate focal length, it's going to start capturing images. So let's demonstrate that. I'm going to turn on the camera. I'm just going to mouse over the camera switch. I'm going to left-click there, and I'm going to bring it down into focal depth. You can hear all that popping. Let's turn that sound off. So you can see, as I'm moving around, it's making the popping noise, and that's telling me that it's capturing images. And as I go out of focus, it stops making the noise, or the same sound, I should say. Now that sound also tells you that you're not capturing any data that your computer recognizes. It's looking for common data between the images. So if I go back, and image just a little bit more, honestly, we've got plenty of image detail there. I'm going to set the camera back down. I'm going to lock it. I'm going to turn the camera off, so it stops clicking. And then let's just look at what we have. Now, granted, this model has been troughed for a bridge or for a restoration, so we're not going to be able to see the gingiva that would normally be in there. But the idea is, we want to make sure that we can capture all of the detail. So we have a little bit of incomplete detail there, so I'm going to fill that in. And as long as we have the adjacent surface, the interproximal contact, that's what's important. So let me go ahead and turn the camera back on. And you see, once it notices that common data, then it starts capturing. Let me turn this down. Let's try that. There we go. So now we have a full image set for that particular tooth. Now, one thing you need to notice is, where did those images go? They went in the upper jaw folder. If I would have accidentally put them in the lower jaw, or started scanning on the lower, or scanning in the buccal folder, it'll still allow us to take those images, but it'll put them in the wrong folder. So how do we move those? Well, you just left-click and you drag them. It's going to ask if I want to move them or copy them. So I would suggest, if you're doing a biocopy, there's one way we can work around and copy them. But just move it to the other image. So now it's in the lower jaw. Well, now obviously this is an upper tooth, so now we need to move it back. So I'm just going to select this data and we're going to move it. You don't need to drag it to the recycle bin and re-scan. All you need to do is move it to the correct location. Now, one thing that sometimes happens is if you get all three of these boxes filled and you've got these two in the wrong location. Well, how do we deal with that? Well, there's this button over here that will allow you to add a folder. And if you do need to move them around, and this is maybe going a little bit off the tracks, you can add any of these. So let's just say we want to add that one. And then if all three of these are filled, then I can move this one out of the way, move the lower to the upper, and then move that one back. Does that make sense? And then I can turn off that folder when I'm done with it. So basically you're using it as a holding folder temporarily while you're moving files around. So don't feel like you need to delete everything and redo it if you've moved them into the wrong folders. Okay, so let's notice this. It did get a little bit of my finger, or what would have been my glove. Not a big deal. Usually if there's floating data, the computer, the software, will filter that out. So let's add the lower jaw. Here's my lower jaw. Very lovely. We're going to go ahead and select. You can see the yellow is around the outside. That means that's the active folder. We're going to select the lower folder, and then I'm going to turn it on. All right, so now the camera is active. And remember we're working on tooth number 13, so I need to scan basically this little segment of the jaw. And we don't need to scan the whole thing. I just need the opposing teeth, and to make sure I have a clear image of the buckle. So again, remember your fulcrum. Then we're going to position in the focal depth, and we're going to just get a little bit of this data here. And always remember, try to avoid dragging the camera lens over the surface of teeth. So for the opposing model, that's plenty. Now I could go in and trim these off, but I don't really need to. It's just fine. So the next image set that I'm going to need is the buckle scan, and that tells the computer how the teeth are oriented next to each other, or opposing each other. So basically in the mouth, I'm going to have the patient bite down, and usually I tell them like this. I tell them, go ahead and bite together. I want to make sure both sides are together at the same time. Both of your molars are interdigitated or locked together, and I want you to squeeze really hard. And then you have to physically look and make sure they're biting all the way together. If the patient's already numb, it's not uncommon for them to bite incorrectly. So make sure that when you have them bite down, they're biting in their normal bite position, and that both sides are touching as much as they can be, given that we've reduced these out of occlusion, and that the teeth look like they're interdigitated correctly. Otherwise, you know, if they bite wonky because of, you know, they're numb and they can't tell, and you design a crown based on an incorrect bite, well then you'll spend either five hours adjusting the crown to fit in the bite, or they'll come back and need a root canal or have a giant toothache. So make sure that they bite correctly, and sometimes it's worthwhile to have the buckle scan done before they're numbed, so that you can make sure they're biting correctly. But you have to guide them and direct them a little bit. Make sure you bite in your normal bite position with both sides together at the same time. Anyway, so let's talk about this buckle scan image. So again, make sure they're biting normally, and the patient would be laying like this. I'll lean it over here so you can see a little better. Make sure your camera's active. And then again, you want to fulcrum. I'm going to position it. Oh, see, it's not collecting because I'm still on the lower jaw here. So I need to activate the buckle folder, and now we're going to go ahead and scan that. And then all you really need to do is walk up and down a little bit along that buckle side of those teeth, and that's plenty of data right there. Okay, so at this point, let's turn that camera off and kind of evaluate what we have. There's plenty of data here. Again, we're working on tooth number 13, just a single crown restoration. And this is, you know, this is pretty straightforward, pretty simple. At this point, we could hit the next button and move forward to the design process, or if we wanted to, we could edit these models or edit these images. So to edit them, you've got a couple of tools up here, or you can use this right click to get to that same tool, the cut tool. All right, so I'm going to use the cut tool, and let's just say we want to trim off some of this extra data. So you'll notice how I did that. Remember, we talked about the rotate, the zoom, and the pan. These three buttons are also rotate, zoom, and pan as we design. See how I'm holding that left button, or I'm sorry, the right button down and panning, and then zooming with the middle button, and then rotating with that left button. Zoom and pan. So if I want to cut, you can see I've got the cut activated, so you always double click to start, and then I'm going to outline, single clicking, you don't want to double click until you're at the very end, the detail that I'm going to cut out, and then double click to end, and you can see it ghosts out the area that I have selected, so now we can hit apply, or we can undo it. So we're going to hit apply, and it's going to shear off that little area of the model. Now that still should be plenty of data to bring these two images together in an appropriate occlusal scheme, but if you look at this, there's a little green check box. This check box is really critical at this step. If you don't have this check box highlighted, you either don't have enough common data in between these two image sets, or your buckle scan is not clear enough. So make sure when you're doing your imaging, you end up at this stage with a green check mark. Otherwise, you need to clarify your models, trim off some extra data, or go back and make sure that there's enough modeling, enough common data in between these two image sets, so that the computer can recognize that common data on the buckle side of here, and the buckle side of there, or vice versa. Okay, so at this point we have a green check. We like the way things look, we're going to go ahead and move forward, hit our next button. So the computer is going to take a little bit, and sometimes depending on how much time you've given it to think at the last step, it'll take a while at this step to calculate these models. But because after we scanned, we sat there and talked for a little bit, they're already pretty much done with the modeling. So now we're brought to this step, and this step is the model positioning step, where basically now I'm telling the software where in the mouth is this area, where are we working with this in the mouth basically. So usually I suggest positioning it here first, and then bringing these two into position. So we know this is the patient's upper left. So again, we've got our pan, rotate, and zoom. In this particular screen, the zoom button is inactive. So I'm going to drag this with my pan, and you'll notice we've got anterior teeth, we've got premolars, and we've got molars. That's kind of a general guideline. And I like to put the incisal edge of the upper anteriors right along that line, so that line's cutting right through the incisal edge. So I'm going to pan and rotate until I get those positioned where I want them to be roughly. So we're trying to get that canine in the anterior. Let's get this rotated just a little bit more. And some people's arch form is not this particular shape, so as long as you're generally in the vicinity, it's fine. So now we need to line up the occlusal plane. So we have, again, we have rotate and we have pan, I'm sorry, rotate and, yeah, rotate and pan, but not zoom in this particular screen. So if you do want to rotate, rather than grabbing right in the middle, I would grab off to the side. It gives you a lot more fine control. If I grab right in the middle, then it's more difficult, kind of like using a lever. The further away you get, the more fine control you have. So I'm going to position this where I think the occlusal plane is. And notice the posterior teeth are up off that occlusal plane. That's because it's rotated up a little bit. So let's rotate that down. Now we got to rotate this down, bring that back down, and that's pretty darn good. We've got the little ghosted lower jaw along the occlusal plane there. And because of this particular arch form, you know, it doesn't quite line up with this round Europa model arch. So we're going to just leave it right there. Tooth number 13 is clearly visible. I'm going to hit OK. Now, if you positioned it incorrectly, if I were to put it up here, you'd get a prompt that says, whoops, looks like you're on the wrong side or something, and then it gives you a chance to correct it. So next step is drawing the margin. Now, depending on your preparation or your doctor's preparation, sometimes the margins are really easy to see, and sometimes they're not really easy to see. So oftentimes it's worthwhile using a laser or using cord or some sort of a gingival retraction paste. So as far as the margins are concerned, I would encourage you to make sure, if you're the doctor, to make sure you have a very clear margin. These margins are really critical to maintaining an adequate restoration, a good marginal seal, and making sure that long term you end up with a good restoration. Yes, you can get by with some less than clear margins. And certainly, what is textbook perfect does not necessarily mean it's required in every clinical situation. There is, for some of us and many of us and almost all of us, a difference between what's clinically acceptable and what is textbook perfect. So we're looking for clinically acceptable to create a good long term outcome. Many of you, which are amazing dentists and incredibly skilled clinicians, can do the textbook perfect model prep. But for most of us, like me, that beautiful textbook perfect model prep only comes periodically. Now, I definitely look for high quality, well above the standard of care, but occasionally it doesn't look ideal. So don't beat yourself up if it's not ideal, as long as it's clinically acceptable, all the caries is removed, and you're going to yield a long term restoration for your patient. All right, so margin finding is actually very simple. So what we want to do, again, is position the tooth in a location where I can see it well. And now we have all three of these buttons active. We've got the rotate, we've got the zoom, and we've got the pan. So I'd suggest zooming in with the tooth you're working on centered in your screen. Zoom in so you can see it really clearly. And then you can, I want to make sure you understand this, you can move the model as you marginate. Many of us don't do that when we first start because we don't realize it can be done. But yes, you can move the model as you're marginating. So to marginate, it's going to automatically default to the auto margin finder, which if you have a very clear margin will find the margin for you. So I'm going to leave it on auto, and I'm going to double click on a margin. Double click. Okay, then I'm just going to start dragging, and you can see that green line follows the margin pretty darn well. Now notice I've done nothing but double click there and drag. I haven't clicked again. So I want to get a different angle on this model. So I'm going to press and hold that left button, and I'm going to rotate. And you'll notice it didn't apply the margin. It didn't click it at all. It just moved the model. So you can feel free to do that. I'm going to press and hold again and rotate. Now you see it's popping around a little bit. So I'm going to go ahead and single click, and you'll notice it applied that margin. Now I can always undo it. If I hit the right button, now it's back to green. Now I'm going to click the left button. It's blue, so it's applied it, but I can always undo it, and I can always edit it later. So don't feel like what you do now, you have to leave there. So I'm going to rotate the model again. Notice the margin is still trying to find the margin, and I can zoom, and I can pan during this margin step. I mean you can see the margins flipping all over the place. So as long as you don't click it, you're okay. I'm just pressing and holding for longer than a second. It's not going to look at that particular action as a click. So let's get back in here a little bit and zoom in. So we're still on auto margin, and I'm going to see if it'll take us all the way through there. Again, I'm rotating. See, now it's off the margin a little bit, which is okay. So a couple of things I can do here. I can either click to manual mode, or I can edit it later on. All right. So let me just go ahead and click to manual mode. So I can go over here, and I can click it to manual mode. So now you notice that margin is white, or that line is white. I can always go back to auto mode. I'm going to single click it, single click, single click. And again, we can move around and look at it. And then I'm going to turn back to auto mode. Now it's back on auto. It's green. Another way to get to that is to push the space bar. So if you click the space bar, notice what that margin line is doing. It's going from auto to manual, auto, manual, auto, manual. And yes, that doesn't look ideal, but I'm going to fix that in a minute. So let's go back to manual, because I think for most of us, the margin is going to be very visible. You'll be able to see what's going on and be able to create a high quality margin with auto. So notice I double clicked at the end. Now I'm going to review. And yes, I don't like some of these spots. And yes, this is not the most clear margin. So we're going to go ahead and double click where I want to repair it and double click to stop. Okay. Generally, I think that's okay. This is a little wonky. To be honest, since I didn't prep this tooth, I'm not exactly sure where the margin is, but I'm going to double click to start, double click to stop. And let's just say for our intents and purposes, that that's adequate, which some of you may want to do a little adjusting, a little tweaking to that margin. Well, let's just say for our intents and purposes, that that is a good margin. The next step is to move forward. Now you can look at the preparation, the actual reduction amount preparation analysis, and it'll tell you if you're reduced enough or not based on that buckle scan. So having a good buckle scan is really important. Let's go ahead and look at this step. This step is the undercut analysis or the insertion axis, which I would suggest leaving that alone. You can probably leave this alone, but let's evaluate it just in case. So what it's going to do, it's going to lay colors over the top of that tooth, telling us how much space there is between the tooth and another surface. Right. So over here is our little key, which tells us, you know, it looks like we're pretty good. This particular coloration is in roughly in that area. So we've got plenty of reduction. One other way to look at it is to turn on this lower jaw. And yeah, you've got plenty of reduction right here. We can actually measure that if you wanted to. But this step, the insert, the preparation analysis gives us a good feel for how well we're doing at reducing. So be cautious. You know, there's a difference between removing tooth structure and actually reducing the tooth to creating appropriate reduction. We don't want to just drill till there's a gap that we think is enough. Oftentimes you have to measure that. And sometimes you have to get real specific to make sure we have appropriate reduction off the occlusal in particular to facilitate a good long-term restoration. Okay. So we're going to go and go to the next step. Now this automatically, the computer is going to start throwing in a restoration. And what it's doing is it's using the adjacent teeth to calculate the anatomy and the proposed position and location and generally the contours. So you'll also notice we've got a bunch of tools that pop up here. Now in your particular situation, whatever tools you turn on or show will stay here. So if I want to leave the analyzing tools here, or if I want to hide them, I can minimize them when they go back over here. Now, if I want to turn them back on, I can click right there and now they're back. So generally we like to minimize those. I don't normally need this toolbar because I can get to all of these tools by using the right click over the restoration during the design phase. So that's a key takeaway here. Right click is the same as going over to here and clicking on one of these. So I'm going to disable this toolbar because I don't need it there. And I'm going to drag this up just so they're both together. All right. Now let's zoom out again with our center button, the zoom button, and let's look at this. Personally, I don't like the position of this tooth. It seems like it's a little bit too buckle, but let's turn on the lower arch right here by clicking that on. And you notice it's at 100% opacity. And I'm going to zoom in here and we'll take a look. So the first thing I like to do, I like to remind all my students and anyone that I work with mentoring and training that anytime we're doing a crown or a veneer or a bridge, we always want to focus on big to small. You always want to start with the large to small. Some of us will go in and start using our tools and do these real minute, you know, let's smooth this, let's round this, when in reality we should be positioning the whole tooth first before we do any of that finishing work. So I'm going to turn those tools back on. We're going to leave them on here because I want you to see what we're doing. Let's turn off the lower arch and you'll notice the minimal thickness button is clicked. And this is a discussion for another lecture. And I have a couple of videos that are out there where we talk about the minimal thickness and the settings and the parameter settings, which is important that you know. But the blue area indicates that those areas are below the threshold that I've set up in the parameters on the computer. So it's lower than the minimum. So you always want to bear that in mind when you're designing. You don't want to go too thin. Okay, so again, we start big to small, right? So I'm going to start with a position and rotate tool. So we're going to move here, all right, with a position and rotate tool. And the other way to get to it, like I said, is to right click, position, rotate. All right, so the first thing I'm going to do is get a little bigger picture by zooming out. And I'm going to rotate this crown. And I'm going to move it lingually so that it matches a little bit better that buckle corridor of the adjacent tooth. And see, you can look from all sorts of different angles. I find I generally like to look from the anterior going down that buckle corridor most of the time to ensure that we've got a good emergence profile there. So once I have it positioned generally where I want it, then I'm going to start working on all the other details. Now you'll notice the colors that you see, granted there's some, the red that you see is from the articulation paper, the blue, yellow, red, blue, green, yellow, and some red there, some red there. Those are indicative of calculated contacts or proximity. So if I turn on this lower jaw, you can see through it, that's where the teeth are touching, right? And when you look at the crown we're designing, there's no contact there. This dark blue indicates that we're less than one millimeter away from the surface. But you can see by positioning this, there's no contact on that tooth. So I don't personally like to deliver crowns that are not useful. So I always like to try to make sure the contact is appropriate. All right? So let's position that a little higher. I'm just going to bring that up until we have some contact. And that emergence profile should stay roughly the same. The colors look good. I'm going to turn off that lower jaw. Emergence profile still looks good. We got a minimal thickness violation or warning there. So I'm going to change tools. I'm going to right click here and I'm going to go to one of my shape tools. I like the circular shape tool. Many people use the anatomic shape tool, but I like the circular shape tool. And I'm just going to position where I want it. Notice I've got this on two directional. This is a little more complicated than we want to talk about today. I almost never use this four directional. This guy here, I always use the two directional. It's a little simpler for me in my simple mind. But I'm going to pull that out. Just click and drag down. I could push it in and make a real thin spot, but I'm going to drag it just to where that blue disappears. And then I want to verify that I didn't just create a huge lump sticking out of the side of that tooth. All right? So now we've generally got a position that we like. You'll notice the occlusion looks a little bit weird. This particular cusp arm is too tall. So I'm going to bring that down in that area. Let's make that too a little bigger. So you'll notice I have a tool size. I can change the size of this tool by clicking and dragging here. And it demonstrates here by how big that yellow circle is, how big the tool is. You can also over here, over the model, right click and go up and down to change the tool size. Do you see that? I'm just going up and down on the model. Pretty simple. And then I'm going to change these weird little spots so they look more cosmetic, more aesthetic, and hopefully more functional. So we've positioned it. We've got our occlusion basically right. All that's really left is to check our contact point and then do any final touch up with the polishing, the smooth tool rather. So I'm going to turn off the upper jaw. Now all we have is the restoration. And we're going to take a look at the contact. So personally for me, if I'm using Emacs, I want a little bit of yellow. So again, I'm using that circular shape tool. I'm going to press and hold and drag up or down. So you can see I can make that contact just giant if I wanted to. But I want a little bit of yellow right there. So if we look at that, you can see it's not jutting way out here. Like if I were to grab this here, I could actually drag that way out. See that? You can drag that way out, which I have no interest in doing. We want a nice contact that allows us to polish the tooth and still have some tightness that I'll have to fine tune when we deliver the crown. Okay? So all things considered, that's that. For me and my intents and purposes, I would hit next here and mill the restoration. But let me show you a couple other tools and then we'll end this lesson for today. So notice we used mainly the position and rotate tool and then the circular shape tool and that was it. Those are the only two tools I've used so far. So let me walk you through a couple of other tools. The anatomic shape tool, this one right here, many people use a lot. If I click on that, it allows me to select anatomic regions. So this is the whole, what's that, the mesial side of the tooth. If I go over here, it's the buckle and here's the incisal portion of the buckle. Here's the facial cusp, the lingual cusp, down on the buckle, distal. So basically this allows me to select regions of the tooth. Many people like to use this. It is very, very simple. Honestly, this tool is probably, for most of us, a little more useful and more often used than that circular shape tool. I've just fallen into that habit and used it forever. One other thing that I like about this tool is you can grab the entire occlusion. You can bring it up and down kind of like we did with a shape and rotate tool. You can also just grab the central groove and bring that down. But notice we've got some blue showing up, so I don't want to violate that minimal thickness width that we set up in parameters. So a couple of things to bear in mind, this prep is not ideal. You've got a really thin razor edge there, which could potentially create some risk for fracturing of that margin when it's milling. So make sure when you're doing your preparations, you never want knife edge margins with Emax. You always want to have a nice, you know, at least a millimeter chamfer shoulder or you can do a shoulder, a butt joint is what I'm trying to say. But I like to do a modified chamfer. So that is the design process. Like I said, I'd suggest whenever you're doing these restorations that you start out with the back teeth. They're easier, the computer does them really quickly. Front teeth, anterior teeth tend to take forever, especially for those of us that are just starting out. Start with posterior teeth, make it easy, keep it simple, and go from there. Usually we suggest spending some time with the machine when there's not a patient in the room staring at you wondering why it's taking so long. Make sure you get your practice out of the way first so that you can perform when you're with the patients. Anyway, the next step here is to go ahead and mill. And the milling is really, really simple. You hit the next button and sometimes it takes a little bit to communicate. All right, so you see it found our milling machine and these are all different. Put that over here too. Sizes of blocks, you've got a couple of little toolboxes that show up. Normally I would suggest you just leave it alone, just tell it what size. You can move the sprue if we need to, but generally the computer, the software is going to position that sprue in the most efficient way to mill the crown. Sometimes if you force the sprue to be in one particular location, this is the sprue by the way. If you force that little piece to be in one particular situation, it may not be an ideal situation for the milling machine. It may take longer, it may wear your burr out, it may break the crown as it's milling. So I would suggest leaving this alone. At this stage, just tell the computer what size of block you're using. We used almost exclusively 14 millimeter blocks at this practice. So when you click on 14, it's going to position it in a 14 millimeter block instead of the 12. And then you hit start. At this point, the machine is going to communicate with the milling machine and walk you through the process and it will start walking through the process of measuring the block and then starting to mill the restoration at a rate of 20 micron slices, which is pretty impressive. And here it's giving us an error that we need to change or clean the water filter. So we'll do that and we'll get it milling. So a couple of closing remarks here as we conclude this video. Honestly, the most important thing is that you spend some time practicing, get comfortable with it, get familiar with it. You want to make sure that you know what you're doing before, like I said, before you walk into a patient room and try to design six crowns with a patient staring at you, no temporaries, having all sorts of stress. I would suggest getting comfortable and getting familiar with how the machine works, how the process works before you spend any time using it on a patient. But when you're ready, this software version, 4.5.2, will do most of the work for you. So let's take a look at the MCXL milling unit. You can see this is the MCXL. This unit is about six years old. It's a good unit. If we pop it open, we can take a look at the burrs that are inside. These are diamond burrs. This is a medium grit diamond burr with a block chuck there, a manual block chuck. Over around the back side is where we'll find the network connection. Right now we're running a connection through the Wi-Fi. There's a serial port as well. And then there's the on-off switch in the back, which many of us don't know about until we have to force turn it off. When you turn on the unit, you can put it in demonstration mode, which is actually kind of fun for the patients. Hit the power button, and then click through these buttons that are on the front, and it'll put the unit in demonstration mode, and it will play songs. Now the songs that it plays are varied. There are four of them, I think. The first one here is Autumn Leaves, a jazz standard, one of my favorite jazz standards. And then it'll play Happy Birthday, and then the Star-Spangled Banner, and then there's one other march that I don't remember the name. Anyway, the machine itself is very versatile. Occasionally it'll need some TLC, some attention, but generally the machine works really, really well. With this particular unit, we can mill up to 55 millimeter temporary restorations without making any burr changes or any upgrades to the machine. Eventually I'd like to get a zirconia attachment add-on so we can mill dry with a little vacuum added to it so we can mill some zirconia. But for now, we use Emacs as our strongest material in office. Primarily use Emacs and CeraSmart and Vita.