Esthetic Crowns: Not Just for the Anterior Teeth Anymore — Transcript
[00:00:17] Welcome and introduction
Hey everyone. Thanks for joining me tonight for our webinar on posterior zirconia crowns. My name is Andi Igowsky. Let me get this up and running. I am talking to you from Sheboygan, Wisconsin. It is sunny and warm, and we have a little bit of summer left to enjoy here in Wisconsin.
A little bit about who I am. I was born and raised in Green Bay, Wisconsin. Go, Pack, go. I graduated from the University of Minnesota Twin Cities with a Bachelor of Science in Medical Microbiology and Immunology. In 2008 I got my DDS at Marquette University in Milwaukee, Wisconsin, and went on to do my pedo residency at the Children’s Hospital in Denver, Colorado.
Shortly after, I joined my big sister at the practice she started in Sheboygan called Just Kids Dental. I think she’s on the webinar tonight supporting me, so hi, Jamie. In 2011 I got my board certification in pediatric dentistry. And we built our own office, which I’ll show you in the next couple of slides. Our office is Just Kids Dental. We built this standalone office, 9,000 square feet, just the two of us, Jamie and I, and we have 10 employees.
[00:01:49] Just Kids Dental: a tour of the office
A couple pictures. We have a coloring station, and our atrium is a really tall walk-in area with those paper lanterns. We call it our School of Smiles. That’s our theme. We’ve got a school bus movie theater in the waiting room, a coloring station, which you saw, and the iPad station for homework. We have a basketball court in the back in between our open bay chairs where the kids can hang out and shoot some hoops while they’re waiting for the doctor to do their checks. And we have a walking floor piano, just like the one from the movie Big. The red bell out front is what we call our no cavity bell. Kids love to ring it when they have no cavities. They get excited and look forward to ringing the bell at the end of their checkups.
This is a couple of snapshots of our clinical area. It’s 6,000 square feet, 10 chairs. Four of them are quiet rooms. We each have two of our own. I’m left-handed and my sister’s right-handed, so we do all of our ops and sedations in those quiet rooms. Then we have six semi-private open bays that are pretty spread apart: three on one side, then the basketball hoop in between, and the piano, and then three on the other, where we can separate smaller, younger kids from the older kids.
In our basement, I don’t have any pictures, but our staff area has a locker room, showers, laundry room, a conference room where we have our staff meetings and any presentations, a full kitchen, and a fitness center so that everyone can get their exercise and burn off some steam while they’re at work before, after, or during lunch.
[00:03:28] How Sprig began
Let’s talk a little bit about where Sprig comes in and why we are all here tonight listening and interested in pediatric zirconia crowns.
The story of how Sprig began: Dr. John Hansen was dealing with some frustrations of his own with his son, who kept fracturing his front teeth. He slipped in the shower, broke his front four teeth, and had strip crowns done. And as we all know, strip crowns on an active boy don’t tend to last. So he chipped them, chipped the facings, and that’s when Dr. Hansen got frustrated and wanted a better option. He met anesthesiologist Dr. Fisher, and together they created the first ever pediatric zirconia crown. And here we are 10 years later, so cheers to 10 years, Sprig.
In 2006, EZPEDO was founded. In 2009, the first zirconia crown was seated on a pediatric patient. In 2013, they introduced the zirconia preparation CE courses for all of us to learn and get better. In 2017, they rebranded as Sprig Oral Health Technologies. In 2019, MDSAP certified and continued in their international growth. And here we are, 2020, celebrating a decade of time-tested results and thousands and thousands of their crowns walking around, showing off their beautiful white teeth.
[00:04:59] My zirconia journey: the first posterior crown
A little bit about my zirconia journey, how I got started. In 2010, when I finished residency, I bought my first kit. I was not even done with residency yet. I went to the AAPD meeting in Chicago, stopped by the booth, was interested in the crowns and bought the anterior kit, sent it home to my sister and said, “Hey, you should do these.” She wasn’t all that thrilled with me and probably let them sit there till I got back and joined her. But shortly after, we taught ourselves how to do them and started on the anterior teeth.
In 2012, I did my first posterior crown. There’s a picture of it on your screen: tooth L. This was per patient request. He needed a crown. I recommended a pulp and stainless steel crown because that’s all I was doing, and the mom came to me and said, “Nope, I want a white crown. I know that they have them out there.” At first I had a pedo natural. I don’t know if anyone remembers what those are, but they were not long-lasting, and I offered to try. So I did the pedo natural. He came in about two days later because it cracked. I changed it out to a stainless steel crown against mom’s wishes.
Then at his six-month checkup, she came to me and said, “I went online and saw that you do EZPEDO crowns, and they make posterior ones. So I want you to take off the stainless steel crown and do the EZPEDO crown.” I hesitated, but called up EZPEDO, as Sprig was at the time, and they sent me one of every size for tooth L. I cut the stainless steel crown off and did my first zirconia crown. So this poor kid had that tooth cut into three different times, three different crowns.
And lo and behold, the zirconia crown lasted until he lost the tooth. That was 2012. He just lost the tooth this year. So eight years, my first zirconia posterior crown made it. At the time, I was not super happy with the mom for pushing me into doing them. But thanks to her, it got me going and starting on my posterior journey.
I was quickly interested in learning more about zirconia and wanting to make it a part of my practice. I attended the first EZPEDO symposium in 2014, quickly jumped in and started doing more and more of them, and by 2015, we were offering zirconia to everyone that needed a crown. We switched over so anything in the anterior got zirconia. Really very few composites, and no strip crowns, no NuSmile prefabricated crowns. It was all zirconia on the anterior.
In 2016, I started instructing at EZPEDO U, or Sprig U, and currently I have done or taught 10-plus Sprig Us. I have attended all four of the Sprig symposiums and presented cases, taught a few residency programs, the first ever European Sprig U in Amsterdam, and presented at the Australian New Zealand Society for Pediatric Dental meeting last year in Perth. And Sprig Live, if you missed it, was incredible last year. I got to present there as well and have become one of the lead instructors at Sprig University.
[00:08:27] Why we’re here, and tonight’s agenda
So why are we here? I think it’s a no-brainer. Why do we do what we do? It’s for those kids, those smiles. All three of those smiles are pretty unique.
The one on the left has the lone stainless steel in the anterior. It’s a canine. This is a friend of mine’s cousin’s son, and she didn’t know he was going to come out with a silver crown in the front. She immediately texted a picture crying, “Is there another option? Please tell me he doesn’t have to have a pirate tooth in the front.” I think we can all relate to that when the kids are really crowded and they need a canine crown, and there really hasn’t been a good option. Well, now there is. So she sent him to me to change that out. I think they came from St. Louis all the way to Wisconsin so that we could change that into a zirconia crown.
The middle picture is my last ever prefabricated NuSmile case, D through G. And the picture on the right is a full mouth of Sprig zirconia crowns from A to J, and on the bottom as well. So I think it’s clear to see what the most superior option is, and it’s pretty cool to see how it’s evolved in my practice in general.
So let’s get you all there. Obviously, you signed in in hopes to learn a little bit more about posterior zirconia. We’re all at a different place, I imagine, and we’ll hopefully find out a little bit more where everyone’s at.
Today, we’ll be talking about some of the scientific evidence; the pros and cons of zirconia; the EZCrown design, especially their V2 design, which is their more recent and fantastic design that has made it so much easier for us as clinicians to place these crowns, and I’ll talk a lot more about that. We’ll go through clinical technique and watch a video start to finish of their ASAP technique, or accelerated subgingival atraumatic preparation technique, and talk a little bit about tissue management and hemostasis, which is a critical part of having success with zirconia crowns.
A little bit about cementation. If we get to it, we can watch the video, but otherwise we can always go back to Sprig’s website to see those additional videos. And we’ll talk about the top three challenges. These are the questions that come up most often on social media groups or from people taking one of the Sprig U classes. They want to know about failures and how we can avoid them, and I think they’re the reason why people shy away from doing posterior crowns. So we’ll talk a lot about those top three challenges and how to avoid them.
Then we’ll end with a little bit of team training and how I think you can have your team help integrate zirconia crowns into your everyday clinical practice, and then some final remarks and some cases that I have done and that have lasted.
[00:11:21] The scientific evidence
We’ll start with a little bit of the scientific evidence. Some of the background here: this one’s from a study from 2016 looking at overall parental satisfaction with pediatric zirconia anterior crowns. They looked at 53 crowns on 18 kids between the ages of two and six. Here’s a photo just to show you D through G and what parents are looking at. They were treated at UT Memphis between 2010 and 2014, with a four-year follow-up.
These are some of the clinical outcomes they evaluated. Crown retention: as you can see, 96% of them stayed on; only two came off. Very good gingival response. Color match, excellent. Crown contour in terms of size, shape and aesthetics, excellent. No wear to the opposing dentition, marginal integrity was good, and no recurrent caries. What the findings show is that zirconia crowns are a clinically acceptable restoration in the anterior dentition, and parental satisfaction is high. Sprig’s commentary: it’s consistent with in-house data and follow-up from all the doctors that are using zirconia crowns.
Another study shows a 29-month follow-up of pediatric zirconia crowns. This one is out of France, looking at the attrition we assume to be happening when you’re opposing zirconia. But this study shows that really there’s no attrition to the opposing dentition. First photo, three months before, then four months after, a year after, 16 months, 20-plus months. Sorry. And no opposing attrition.
It also looked at gingival inflammation. I think this is one of my favorite things about using zirconia crowns: you rarely see the red, inflamed gingiva like you see around a stainless steel crown. This is showing 16 months, 20 months, and really excellent response. Twenty-nine months; I think at this point they’re starting to lose teeth as well.
Another thing that’s fun about seeing these zirconia crowns exfoliate is taking a look at the marginal adaptation. When you look at the adaptation, or the layer of cement between the crown and the tooth, it’s very similar to a stainless steel crown. What we might think has huge open margins when placing these crowns, really, that’s not the case. It’s similar to a stainless steel crown.
The findings: tooth preparation is more important than with a stainless steel crown. If you’ve ever done one, you’ll understand that. Subgingival reduction is the most crucial step, and we’ll talk about that when we get to preparation technique. They have good integration, no loss of retention, no fractures, no wear of the opposing dentition, and periodontal health was excellent. Marginal adaptation was similar to the stainless steel crown, and, as you can imagine, high parental satisfaction. I think it’s a no-brainer when you look at the aesthetics of those white crowns, truly lasting as long as a stainless steel crown would, or until the tooth exfoliates.
In conclusion, EZCrowns are a good restorative option for decayed posterior primary dentition. Sprig’s commentary: this is consistent with follow-up from their doctor database. Just a note that the study used glass ionomer cement, and we’ll talk a lot about cement and why I recommend glass ionomer when we get to that part.
[00:15:18] Zirconia pros: how strong do they need to be?
Zirconia pros and cons. It’s different than a stainless steel crown. You have to go in knowing that, completely understanding that your prep is going to be different. And that’s not necessarily a bad thing. There’s really no perfect restorative material yet, and they all have pros and cons. Zirconia is no different.
Some of the pros: high strength, like really high strength. They are hard. If you’ve ever tried to squeeze one in your hand, you’re not going to get it to budge. It is rock hard. Biocompatible, which is my favorite thing about them. The gingival healing around them is incredible and so neat to see when you see these kids at a one-week follow-up, two-week follow-up, six-month follow-up, and we’ll show a couple of pictures of that coming up. Aesthetics: patient satisfaction, for parents and kids, relates to the aesthetics. They want natural teeth. They don’t want a mouth full of silver, and they don’t want anyone to know that they had crowns or needed crowns. And plaque resistant. It’s pretty funny to see these kids at recall: if you disclose them, or take a look at their teeth before you clean them, there’s plaque everywhere but the beautiful white crowns.
We’ll start with the strength. The question really is, how strong do they need to be? In a research study, which I’ll show in the next slide, all of the zirconia crowns tested, every brand, far exceeded the mean maximum bite force of children in the primary dentition. Here’s that article. On a quick side note, if you look under the Handouts tab in the webinar, Sprig has included copies of some of the research. You can download them later or find them on their website.
This study looked at three available zirconia crowns on primary molars, and found a positive correlation between increased crown thickness and increased fracture resistance. Which makes sense: strength is primarily a function of thickness. Their version one crowns, from 2010 to 2013, were the ones used in this study, and they were thicker than the current crown.
If anyone dabbled in posterior crowns back in this version one phase, they were much harder to place, in my opinion. I think part of the frustration that we as dentists had with posteriors, and maybe why a lot of people avoid them, is that you felt like every time you placed one of these crowns, you needed to do a pulp. And I think that was honestly the case with version one. You had to reduce so much more to fit this thicker crown, and you ended up having to pulp the tooth pretty much every time. That is not the case with the V2s, which I’ll talk about in the coming sections.
Again, just showing how strong they are: this is a four-year-old who had an incident with a scooter and face-planted on the cement, and you can see pretty severe trauma in the anterior teeth. These are zirconia crowns on E, F, and G. There was trauma to the tissue and to the bone, and those crowns did not fracture. A palatal view of the same trauma: this photo is at the initial follow-up. I’m not quite sure if it was a week or two weeks, but you can see the healing’s already begun. The gingiva looks much better. Those crowns look fine. And here at six months, maybe it needs a little better hygiene, but those crowns are in the proper position, haven’t fractured, have lasted, and there’s no evidence of any damage on the X-ray either. So they can last through some pretty tough trauma. They are that strong.
Key point: the strength of zirconia is primarily a function of thickness. That’s where the thought process comes into the design of these crowns. You want a crown that’s robust enough to withstand the maximum bite force in kids, but you don’t want it so thick that you have to pulp the tooth every time or do a ton of reduction on the tooth. You want to keep the reduction to a minimum. All those things come into play when they’re designing their crowns.
[00:19:50] Biocompatibility, aesthetics and plaque resistance
Biocompatibility: this, again, is my favorite. This is a perfect picture to show that. It’s hard to tell where those crowns are. Perfect gingival healing response, pink stippling, no inflammation around those crowns, and that’s truly what they look like every single time. It’s incredible. You will not see that type of gingival healing around a stainless steel crown or around a prefabricated crown.
Another photo just showing the difference: preveneered crowns on F and G, which were replaced with EZCrowns D through G. Again, I think it’s a no-brainer when you look at the gingival response between the two photos and how much more natural and healthy that second photo looks. There was a study that showed this as well. They used four different types of implant abutments in a canine jaw and found that the healing and gingival response was far superior with the zirconia one, which is the second implant in the photo.
Then aesthetics. This is no question. I think we can all agree that these are by far the best-looking restoration we can put in children. It’s hard to tell in this photo which tooth is the crown. I like to show this one often in my presentations, or to other dentists, or even my hygienists or assistants: “Hey, which one’s the Sprig crown?” And it’s actually the molar. So pretty crazy. They’re beautiful. They’re natural looking. And that is all in part due to what Sprig does to their crowns, which we’ll talk a little bit about.
They blend better with natural teeth, and the more you offer them, the more they’re requested by parents and by kids. They want princess teeth. They want white teeth when they get to have that option. “It’s all white, front and back.” Those are the exact words I use when I’m trying to sell them to parents, or not even sell; we’re just talking about them. And there’s no need to worry about that white facing chipping off.
One of the questions we always get is, are they going to look like Chiclets? Are they going to be too white? And you can confidently answer no: they are going to blend in with the natural teeth and look, in size and shape, just like a natural tooth.
This is one of the fun cases that came to me as a second opinion from another pediatric dentist in town. They came to me with NuSmile preveneered crowns on the two front teeth. Those in the picture are actually E and F: two different size crowns, and you can see some of the chipping of the facing already. D was extracted, NuSmiles on E and F, and there was still decay on, as you can see, C, and then G and H. This photo is from the first visit in the office, with nitrous, where I put Sprig crowns on G and H. I said, “I’m sorry, I can’t match E and F. I don’t even have those crowns in my office anymore.” That’s a nice side-by-side comparison to show you the difference in aesthetics, and in the gingival margins and healing, and how much more aesthetic and non-inflammatory they are. Dad did not want me to cut the crowns off E and F, so I eventually did Sprig crowns on C, G, and H, which you see in the photo.
We talked a little bit about plaque resistance. Here’s a picture with disclosing agent showing you, like I mentioned, that plaque sticks to pretty much everything but the zirconia crown. You’ll even see it around the stainless steel crowns if you have stainless steel in the posterior. And the zirconia crowns really don’t have any plaque, which I think helps with that gingival healing and everything looking so much less inflammatory.
[00:23:45] The cons: no flex, no wear, more bleeding
Like we said, it’s not a perfect material. There are some cons. When we talk about strength, it’s hard. It’s diamond hard, it doesn’t flex, and it’s difficult to adjust. You can’t use your Howe pliers to crimp it. You can’t squish it. You can’t do anything to snap it over a margin. It’s that hard. It’s not going to flex over a ledge you leave. So it really requires more subgingival reduction. If you leave any little bit of ledge under the gingiva, when you try to seat that crown, it’s either not going to seat or you’re going to crack it. We’ll talk about that again in our prep technique.
Unlike natural teeth, zirconia doesn’t wear at all. Unlike stainless steel crowns, which we talked about can be adapted to fit the tooth, with zirconia the tooth has to be made to fit the crown. That’s why the prep is so much more difficult, or I guess more important and time-consuming: you have to get the tooth to fit the crown.
Just an opinion from Sprig: hyperocclusion might be more of an issue with zirconia than other materials, because it really isn’t going to wear down, and they recommend taking extra care to ensure the crown is not excessively high. You’ll get different opinions on this. I’m a pretty big stickler with occlusion when it comes to posterior, single tooth, full mouth, it doesn’t matter. I don’t like to leave the kids high in occlusion, and I check that when I’m seating the crown or trying the crown in. The more you do, you just know as it seats whether it’s high or not. I’ll talk a little bit about some of the things I do to check the occlusion.
When it comes to the design of their crown, they don’t want it to be in hyperocclusion. So for Sprig, the goal is a crown that, when seated, won’t be in hyperocclusion, in lateral function as well. That’s all taken into consideration when they’re designing their crowns.
We talked about it being so hard and strong that it’s not going to flex. So there’s a narrower window of acceptable preparation design for zirconia, and any adjustments can damage it. You don’t want to be seating it a little high and then taking your bur and trying to smooth it off. First of all, you’ll see sparks fly everywhere, but every time you do that, you can induce small microfractures that can then cause the crown to fracture later. The more undercut your crown, the more reduction that’s needed. Again, this comes into play with the design of their crown and the prep, which we’ll cover in the next section.
More subgingival preparation equals more bleeding, which equals hemostasis issues. Those are some of the cons. Your prep is going to be much more subgingival. It’s going to create a lot of bleeding, and you do have to get that under control, or you risk failure or the crown coming unbonded. That can obviously affect the clinical outcome negatively if you don’t have good hemostasis, and it’s a problem with any of the zirconia crown brands. Hemostasis becomes, I think, one of the biggest challenges for people in terms of long-term success with these crowns.
[00:27:11] The ideal crown and the EZCrown V2 FlatFit design
Again, when it comes to the design, what’s the ideal shape? You want to create a crown that requires a preparation design that, with practice, can be achieved rapidly, repeatedly, and without pulp exposure. That was a lot of the feedback from dentists who were using the posterior crowns before their V2 design: “Hey, I don’t like having to pulp these teeth if they don’t clinically need pulp therapy. What can we do to have a thinner crown that’s still strong enough that it’s not fracturing?” They took all that into consideration, tested it all, and came up with a crown that really requires no adjustment to seat if you do the right prep, even in a space loss situation. I don’t recommend starting your first posterior with a space loss scenario. You’ll just cause yourself extra stress. But they have created crowns that work every time in that situation.
Another con we talked about was that subgingival reduction. In order to fit the tooth to the crown, and we’ll see the design in some upcoming slides, you do have to prep a lot more subgingivally than for a stainless steel crown. What does that mean? Tissue trauma initially. You’ll see a lot of bleeding. You’ll see the tissue pretty torn up, but it heals fast. You’ll see these kids a day later, a week later, and it’s like you never did treatment on the tooth. So it does heal. I tell parents that as part of my post-op instructions. With that increase in bleeding, again, hemostasis is where the challenge can be.
So what does that mean for an ideal crown? You don’t want it to be too high. You don’t want it to need adjustments after you’ve cemented and seated it. You want minimal tooth reduction, prepping without pulp exposure, a crown that fits in areas of space loss and blends seamlessly with the surrounding natural teeth. That’s where their EZCrown Design V2 comes in. It is different than any other brand, and I’ll talk a lot about why. This is their 2010 to present.
The design is called a modified anatomic design. The pros: less tooth reduction, easier and faster seating, very aesthetic, it retains its natural look, and it allows natural gingival contours. There are four core features. The first is the FlatFit design, and we’ll talk about all of these. Their ZirLock retention. Space-Loss, where we’ll talk a little bit about the shape and why it’s different than the other crowns. And then the polychromatic finish.
So the FlatFit design: the crown is engineered to be easier to seat and require less tooth reduction. What you see is a flattened occlusal profile, so less occlusal reduction is needed. When you look at the original anatomic crown shape that they had, or even a competitor’s brand, you’ll see those deep cusp tip to fossa grooves, which look more like a natural tooth. But the problem is that you have to reduce so much more to get it to seat and not be high. This flattened occlusal profile allows for less reduction. I’ll show some more photos of that.
The second part of that FlatFit design: they broadened the buccolingual dimension, so there’s more room in the internal cavity. You can see in that visual it opened up so that you need less axial reduction to fit the crown. And they relaxed the interproximal undercuts, so there’s more space to fit back-to-back crowns. Most of the time, if there’s decay on L, there’s also decay on K, and you’re trying to do these back-to-back crowns, and it’s a little more challenging to seat them. But with the design of these crowns, you can confidently fit them back-to-back without the stress of having to change sizes and prep more, or pulp one of the teeth when you wouldn’t have needed to, and really have success with those cases. It also allows for faster seating, which saves chair time if you’re going to do these in your office, not under sedation or anesthesia.
Here’s another visual showing the tooth reduction needed. For Sprig’s occlusal reduction, like I said, it’s a flattened occlusal plane. From cusp tip to depth of fossa, it’s 1.3 millimeters on their largest, thickest crown. On the competitor, cusp tip to fossa is 1.8 millimeters, so much more occlusal reduction. You could potentially hit that pulp horn, especially if it’s a high pulp horn. So there’s less occlusal reduction with the Sprig crown, with that flattened occlusal plane.
This shows a side by side, so you can see how they have widened the opening of those crowns so that you have more room and less tooth prep. But at the same time, you can still use a smaller crown and have great marginal adaptation, as you saw in some of those photos of exfoliated crowns. While it looks like it would be a huge open margin, it’s really not, and I can attest to this because I have taken a peek at some of the exfoliated crowns, or had to extract a crown, and been able to look at the cement margin. It really is the same as a stainless steel crown.
It also saves more of the cingulum in the anterior, which is what gives your tooth strength. That’s part of the reason why, when you have trauma on those crowns in the front teeth, you’re not fracturing them right off at the gumline. You want to preserve as much of that cingulum as you can to save that tooth and keep it strong, even with a lot of tooth reduction.
Another photo illustrating cusp tip to central fossa, and how much you have to reduce at a minimum to get that crown to seat. With that flattened occlusal plane, much less occlusal reduction is needed, and it’s going to help with being able to seat and not be high in occlusion.
[00:33:59] ZirLock retention
The ZirLock feature is unique to Sprig. It’s the first in a zirconia crown, and also the most retentive. The patented retention grooves create mechanical retention. We have our chemical bonding with the cement, but we also want mechanical retention, so that you’ve got a bond from the tooth to the cement and from the cement to the crown.
If you ever lose a crown or have a crown come off, which truly, once you get your hemostasis technique down, does not happen often (I maybe have a handful, one or two a year that come off, and usually it’s around Halloween, eating sticky candy or something along those lines), when you take a look, you’ll see it’s always a failure of the bond between the tooth and the cement, not between the cement and the crown. Your cement will be in there in those retention grooves. It is always that failure, which usually means moisture or heme contamination, which is why hemostasis is that much more important.
That ZirLock feature, with those grooves, also creates twice the internal surface area, again maximizing that cement surface bond. You can see in the photo, if you look closely at the upper right one, the little waves of that ZirLock feature. And it locks the cement at the margin so that you’re not getting washout. When you’re rinsing after you’ve cemented, or cleaning up, that marginal cement is locking it in just below the gum tissue, where you need it to be the most retentive.
You can use any cement that you wish. For the most part, I would say most doctors are using glass ionomer or resin-modified glass ionomer. We’ll talk a little bit more about that. This just shows you a picture of the different internal structures of competitors’ crowns and that beautiful ZirLock feature that is unique to Sprig.
[00:36:14] Space-Loss crowns and the polychromatic finish
Then their modified Space-Loss crown. Think of these as your squished, or Howe-pliered, stainless steel crown. For me, most of the time if I ever have to squish my stainless steel crown, it’s an upper first primary molar. They have pre-squished crowns that are exactly the right design, start to finish. They’ve modeled them after that squished shape, so it’s done for you, because you obviously can’t squish that hard zirconia material. These are crucial when you have space loss: deep interproximal decay, or when you’re trying to seat back-to-back crowns.
There’s also space loss in their canines. First of all, a Space-Loss crown is going to have the red ink, or that prime mark, on there, depending on how long you’ve been using their crowns. I tell my assistants, “Oh, I need a C3 prime,” or “C3 red.” You can see that squished feature.
For the canines, if you look in Sprig’s kit, they don’t have a lower canine crown. You basically use the Space-Loss upper crown for the contralateral canine. So this C3 would fit on tooth M, and they work fantastic. That’s what you use for a lower canine. They’re narrower, it maximizes the cement surface bond, it has that margin lock feature again that we talked about, and you can use any cement you wish.
This is a picture of all three of those crowns in a row, where that space loss feature helps you fit them in that space. It saves about half a millimeter per surface along the span of those crowns. So it really does help when you’re trying to seat back-to-back, space loss or crowded cases.
This is an example. It’s not one I would recommend starting with when you’re trying your first posterior zirconia crowns, but it works. I would look at this ahead of time and probably say in my head, “Yep, these are going to need space loss.” If you look at a case and say, “Yeah, I’m going to have to squish my stainless steel crown,” anytime you think that, you would do the same with zirconia. It follows pretty much exactly in terms of sizing, which I’ll talk about in a little bit too. This is the finished product: two Space-Loss crowns were used on A and B.
One of the other features is that polychromatic natural finish. Each of the Sprig crowns is hand-finished with details that make them look incredibly realistic. They’re individually hand-finished, and they are unique, like a natural tooth. They also have a mirror-polished external surface, which allows for ultra-low wear on the opposing dentition.
The other thing that mirror finish allows is that you can bond or cement a space maintainer to them, and it will bond to the exterior of the crown. I have done multiple of them with a space maintainer, like doing a zirconia crown on T, extracting S and putting a band and loop over the crown, and I’ve rarely had them come off, maybe even less than when bonded to a stainless steel crown or a natural tooth.
With this polychromatic natural finish, you’ll see the gingival third is lightly stained, a little bit darker, and that matches the natural cervical color of a natural tooth. They’re glazed on the aesthetic surfaces, which reduces light reflectivity. And it’s one polychromatic shade, as I describe it. So one kit is all you need. You don’t need a light and a dark, or two kits, in terms of matching. Every one of these crowns is going to match and blend with the natural surrounding teeth.
This is a close-up showing the polychromatic natural finish: that smooth mirror finish, and truly ultra-low wear, where you’re not seeing any attrition to the opposing dentition. And here’s a close-up of a competitor crown with that rougher, more abrasive surface, where you may start to see some attrition.
[00:40:39] Poll: how many posterior crowns have you done?
Moving along to the clinical technique, which I imagine most people are here for. I did want to do a quick poll and see how many posterior crowns the people attending have done. I’m going to launch that. You’ll be able to click directly on your screen. Here are your options. I’ll give it a couple of seconds and see what the majority of people attending have done.
[…]
Awesome. I am going to close it and share that with everyone. For those of you listening, it looks like about half have done none, and a large percentage are in that one to 10. And we do have some 50-plusers in the group. Awesome.
I think most people who do any zirconia, when you ask, have maybe done none, are afraid to try them, or have tried one or two and have not been happy with the results and said, “Nope, this is too difficult. I’m much more comfortable with my stainless steel crown.” That’s from people that I’ve asked. So hopefully, after we go through the technique, you’ll be a little bit more comfortable. And if not, maybe you’ll be more interested in getting that hands-on by attending one of our Sprig Us, where you really get that one-on-one prep and truly leave confident in being able to place those posterior crowns.
[00:42:38] The ASAP prep technique, step by step
Let’s go back to the clinical technique, what we call, again, that ASAP, or Accelerated Subgingival Atraumatic Preparation, technique. There really is a systematic approach that’s critical, in my opinion, to having success. The benefits of a step-by-step approach are that you can improve your speed and efficiency, save chair time and money, and decrease your stress.
Sprig has really done this for you in the design of their bur system. They have created customized burs that make it a no-brainer: you can do this technique the same every single time and really ensure your clinical success. It helps to have a system in place so that you’re not panicking and going, “Oh, I have to go back and do more reduction,” when it’s built in, in relation to the design of their crown, to get it to seat every single time. With their burs, you’re able to do a depth-cutting technique and not hit the pulp. I say that because that’s probably the number one question I get. You really do not need to pulp the tooth unless the tooth needs a pulp. We’ll talk about that with their prep technique.
When you look at the crown, I guess the best way to figure out what your prep should look like is to see what the inside of a crown looks like. This is an impression of the inside of a crown, and you can see it’s a cylinder. I think the most critical thing to look at in this picture is that your interproximal is straight up and down. That’s something you have to be able to visualize in order to have success seating these crowns.
The first step in your prep is EZPrep Bur 1, which is the donut, or the cylinder. The depth of your cut is the full thickness of the bur, so they’ve already taken the guesswork out of it for you. The bur is 1.54 millimeters thick, and that’s how much reduction you need from the occlusal. If you remember from that picture, the thickest occlusal reduction from cusp tip to fossa was 1.3 millimeters. So if you go the depth of the bur, 1.54 millimeters, you’re in the clear in terms of reduction. You go all the way flat across the occlusal, full thickness of the bur, using the marginal ridges of the adjacent teeth for reference.
Then you move on to EZPrep Bur 2. This is measured in thickness for you, at 0.85 millimeters. Again, you go to the full thickness of that bur, making a depth cut and taking it all the way around, and you will have enough reduction and stay far away from the pulp.
This step, the supragingival reduction, basically creates a chamfer, or a margin at the gum line, that you are eventually going to remove. But going the full thickness of that bur is what gives you the right shape and amount of reduction to get your crown to seat. Think back to sim lab and creating a chamfer margin: you really do want to be able to see a margin around the tooth.
Critically, any time you’re doing axial reduction, don’t taper the bur. It’s incredibly difficult to avoid without thinking about it. It’s just natural for us, especially when we’re doing a stainless steel crown prep mindlessly. You just start prepping. You don’t have to worry about it, because you’re going to snap your stainless steel crown over, and it’s going to contour over any margin. That is not going to happen with zirconia, so you really do need to make sure you’re not tapering and not leaving subgingival ledges that will prevent your crown from seating. At this point, you want to make sure your bur is straight up and down and perpendicular to the tooth.
A couple of visuals there. This is an important checkpoint. Like I said, you want to create that margin at the gum line. You want this visible racetrack, or margin, around the entire tooth, and then you know you have the right amount of reduction. You’ll remove that margin next, but it’s about 0.8 millimeters, which is the thickness of the bur. So you can make a depth cut, take it all the way around, and look from the occlusal view down and see that racetrack, as we call it. If you can’t see it on one side (it’s sometimes hard to see that distolingual corner, especially on an upper molar in your mirror), you’ll want to go back and make sure you can see that racetrack. I think this is the most important step when we’re doing the hands-on at Sprig U, because we go around and check it for everybody, and you’ll find which part of the tooth is trickier for you, whether it’s the lingual or the mesial or something like that.
The third step is using EZPrep Bur 004 for your subgingival reduction. Like the photo depicts, you want to remove that racetrack, or that margin, drop down about two millimeters sub G, remove it all the way around and create that cylinder. You hug the bur axially along the root surface, making sure not to taper, and extend it about two millimeters sub G.
Just a couple of tips from clinicians who have done it for a long time. It’s always easier to go in at the thickest area of the sulcus. If you go in at the straight buccal or facial, that’s the thinnest gingiva, and you’ll see it tear up right away. It’ll heal; it’s not a big deal. But if you go in at the mesial or distal, or right at that line angle, you’ll find that you can drop your bur down and remove at the thickest area, and then slowly bring it around the rest of the tooth without causing nearly as much tissue trauma. Again, that’s the atraumatic prep technique. It takes some time, but it really does help with hemostasis afterwards, when you’re trying to cement your crown. And you need to remove that chamfer margin all the way, two millimeters sub G.
We’ll play this video for you. This is a posterior start to finish, so you can watch it being done, and you’ll see that it goes step by step with those burs, exactly every single time, like we talked about in that systematic approach.
[…]
[00:58:03] After the video: the most common prep errors
[The prep video played from 00:49:06 to 00:58:03 and was not transcribed.]
Hopefully, you enjoyed that video and got some tips in there. I often get the question whether I still do every bur and every step, and the answer is yes, every single time. I know what the preps look like now. I know if the crowns are going to fit or not. I usually know the sizes, know the crown that’s going to fit, and it seats every single time. I don’t have to go back and prep, but I still use those burs every single time and follow those steps. It truly makes your life easier. At this point, I can prep a posterior zirconia crown from start to finish as quickly as I can do a stainless steel crown. So with practice, it truly does get easier.
Some of the most common preparation errors we see: first, inadequate occlusal reduction. Remember to use the full thickness of the bur, and use the adjacent marginal ridge as your guide. I like to do that when I’m seating the crown as well. When I seat my crown, I seat it with my thumb, run it marginal ridge to marginal ridge, and make sure I’m not going up to the next tooth and that it’s flush all the way across, and then you’re guaranteed not to have high occlusion. So a little trick: the pad of your thumb truly helps make sure you’re not going to have high occlusion when seating it.
In back-to-back cases, sometimes you will need to prep a little bit more of the occlusal on the distal. Especially on uppers, if you’re doing opposing ones, so A, B, and S and T, sometimes you have to remove a little more of the distal occlusal of A just to guarantee that those are seated all the way down. That’s one of those things you learn from trial and error.
With anteriors in really young patients, like under two, who haven’t fully erupted their teeth and still have to get their molars or canines, maybe prep a little more subgingivally too, so that as they erupt a little more, you still don’t have crown margins showing. The same goes for really badly broken-down anteriors. You’ll see tons of cases out there of success with teeth broken to the gum line, doing what quickly showed in that video: almost a plug-and-pack technique, where you put your MTA or your pulp medicament in, then mix your cement, put cement into your pulp chamber over the medicament, like MTA, then fill your crown with cement and plug them together. You’ll have a super retentive crown. I also usually prep a little more sub G so I can seat that crown a little deeper with really no tooth structure left, and that cement will hold the crown on there. Very rarely do they break, fracture or come off. They are extremely successful.
The second error is not having adequate axial reduction, so make sure you use the full thickness of that number two bur. You want to see that racetrack. In the anterior, you can go a little less than the full thickness: about half to full thickness, depending on where your decay is or how much tooth structure you have left, and making sure you can see it 360 degrees.
And the biggest prep error is over-tapering your prep. When you over-taper and your bur is not straight up and down, you’ll leave a subgingival ledge that you can’t see. So you always, always need to upright your bur, go back, check and feel for ledges with your explorer, and make sure you’re not leaving any ledges. Otherwise, when you go to seat that crown, it won’t fully seat. As you can see in that upper molar, it looks like it’s canted to the side. There’s probably a ledge on the distal of that tooth not allowing that crown to fully seat.
What happens is, if you have a ledge and you try to seat it, you’ll hear or feel it crack, and you’ll go to take your crown off, and it’s always the distal. Just so you know, if that happens to you, which it will (it still happens to me about once a year), you can call Sprig and they will send you a replacement crown at no charge. The distolingual corner is usually the trickiest. One of the other instructors always said, whenever the crown doesn’t seat, “It’s always the lingual. Go back and do the lingual. Check the lingual. Do that ‘Ring Around the Rosie’ five times and check for ledges.” Make sure to upright your bur, almost putting even more undercut pressure on the tip of the bur, so that you do not leave ledges.
Remember, with these crowns you want a passive fit. You don’t want to have to snap it on, or if you do, you’ll see it snap. It’ll fracture. So make sure it’s a passive fit, not like a stainless steel crown. And never use a bite stick. You only want to seat it with finger pressure. Like I said, I use my thumb and gently seat it until the marginal ridges are touching, and I check, and it’s the right occlusion every single time. Here’s that finger pressure, using the thumb to run it along the tooth mesial and distal and making sure they’re fully seated.
Some of the things that can happen: the crown size is too large. If you have a crown that’s too large, it’s going to compromise the retention. That’s that much more cement you’re relying on to hold it. So always use the smallest size possible. I get that question a lot, too. To be honest, their crowns are sized, in my opinion, very, very similarly to a stainless steel crown. Ninety percent of the time I’m using a four, a D4, maybe a smaller one like an E3 in stainless steel sizes, and usually a two in the anteriors for E and F, and maybe a two or three on D and G. So it becomes very similar to what you would naturally guess for a stainless steel crown. And that’s important for back-to-back cases. You want to use the smallest size possible. If you don’t prep enough and you have to use a bigger crown, you’re never going to get those crowns to seat back to back.
The key to success is checking your work every single time and doing that “Ring Around the Rosie,” checking for ledges. When I first started doing them, my assistants used to laugh: “Is Dr. Andi’s bur dull? Because she keeps going, one, two, three.” And in my head, I’m counting one, two, three, four, five. I’m like, “No, that’s part of the steps.” And I still do it on every crown prep to this day. My assistants know now, though.
[01:04:20] Tissue management and hemostasis
In the next section, we’ll go into tissue management, or hemostasis. I’m going to run another quick poll just to see what everyone’s using for hemostasis. It’s interesting; there are so many different agents out there. Let’s see what everybody on here is using for hemostasis.
[…]
All right. I’m going to close it and share the results with everyone. A little bit of everything. By “time,” I mean sometimes, say you’re in a general anesthesia case, you prep the anteriors first for your crowns, then go on and do the rest of the mouth, the posteriors. By the time you go to cement the anteriors, it’s dry. Gauze pressure. There are a few people using the HemeRx Racellet pellets, and it looks like the hemostatic gels are the highest one, which is interesting to me. I myself use a combination of either HemeRx pellets or just gauze pressure, and I’ve found over time that it’s the quickest, easiest method for me. But we’ll talk a little bit about that.
Let’s quickly talk about the HemeRx pellets in particular, which Sprig offers, and which are a really quick, easy, great method, especially for zirconia crowns. The issue, if we don’t control hemostasis, is that you have compromised retention any time you get moisture under that crown or in that cement layer, which can cause microleakage. It’s pretty much, I would say, the number one cause of loss of retention. And you’ll sometimes see a gray appearance in the crown, which is blood that got into your cement, into your crown. So it makes for a not-so-aesthetic result. The top two reasons are movement of the crown during that initial set, which we’ll talk about, and lack of hemostasis.
The HemeRx pellets really are a fast way to deliver hemostasis where you need it, when you need it. And they really minimize the risk of contamination compared with other products. They’re tasteless and non-staining. There’s no ferric sulfate or aluminum chloride. They have no taste at all, so the kids aren’t cringing when they’re in there, and they really allow for a great result.
I, in particular, use them for my pulp therapy. When I’m doing my pulpotomy, I’ll put one HemeRx pellet in there while my assistant’s mixing the MTA, so it’s in there for less than a minute. I take the pellet out, rinse, dry, make sure there’s no bleeding or excessive bleeding, put my MTA in, and then I’m cementing the crown directly on top of that. No other medicament. So it’s a fantastic way, in my opinion, of handling that pulp therapy.
This is a spot where we usually show a video, but I’m going to skip over it. You saw a little of it in that posterior technique video, how they use them. You can always go on Sprig’s website as well.
[01:08:05] Cementation: why glass ionomer
A little bit about cementation. Everyone always asks, “What should we use?” Think about it in terms of the clinical situation. What type of cement has the longest track record and can be used in a moist environment? If you think about kids, there’s always saliva. There’s talking, crying, spitting, the blood that you’ve created, even if it’s a patient under anesthesia or sedation. You’re always dealing with moisture. So the biggest thing that comes to mind for me is glass ionomer or resin-modified glass ionomer.
Consider that multi-unit posterior cases are much more difficult to isolate than the anterior, which is right in front of you, or a single unit. It’s similar to placing a class two or a class five composite. Resin-containing cements require more, or better, isolation than a straight glass ionomer. Adhesion with these cements depends on the bond to the crown and the bond to the tooth, and loss of retention can occur at either. But with that ZirLock feature I talked about, you really don’t have to worry about that mechanical retention bond, and that means there’s no need for a try-in crown. No extra step, no extra autoclaving.
Other crowns can lack that mechanical retention when they’re relying solely on a chemical bond, which makes it even more crucial to have superior hemostasis, which none of us can do perfectly 100% of the time. A chemical bond, that cement bond, requires an isolated environment, and that’s where we’re prone to failure. It’s a more expensive cement, and there’s an additional cost for those try-in crowns. So the rationale, I think, points as a no-brainer to glass ionomer cement, but it really does come down to what you’re most comfortable with in your hands, and your ability to cause less trauma when prepping, as well as to keep it isolated.
Just a note: all the clinical studies to date use glass ionomer cements with zirconia, showing the success that glass ionomer has. It’s been used for decades in pedo for stainless steel crowns and almost 10 years for zirconia crowns. Glass ionomer is better suited to the clinical situation we’re in, with unpredictable isolation and hemostasis and a bloody environment from our prep. All Sprig U faculty, who have collectively placed 10,000-plus crowns, use glass ionomer cement.
It’s far less expensive than the others. Here’s a price comparison. I, in particular, use Ketac. It ends up being around $1.76 per crown when it’s the powder-liquid hand mix, which we use in our office. I don’t use that for my stainless steel crowns. I use resin-modified glass ionomer there, but I always use glass ionomer with zirconia.
Some extra pointers and tips on cementation. Always have your assistant load the crown full to the top. I like a thicker mix. The photo you see is me seating a canine and a molar, and I like my assistant to mix it thick enough that when I seat it, it literally displaces the gingiva a little, displaces the blood out of the sulcus, and it’s almost hard within a few seconds. It’s easy to peel away. I don’t have to hold the crown there as long. It takes about 30 seconds before I can start cleaning up the cement. Not everyone likes that thick a mix. It’s easier to play around with when you’re using a glass ionomer you can mix yourself, and decide what you’re comfortable with. But always have them load it full of cement, full to the top.
Once it’s seated, don’t take it off. Rotations are okay if you just need to rotate it a tiny bit, but you never, ever want to lift and pull back. If you do that, you’re going to lift blood up into the margins, and you’ll start to see those gray spots in the crown. Tack and wave is okay for those using a resin-modified glass ionomer cement in the anterior. In the posterior, it’s too thick. You’re not going to get any of that light through to get the initial tack of the cement.
When cleaning it up, there are a couple of different techniques: wet versus gel stage cleanup. If you’re in that wet or gel stage, you want to provide support. I’ll hold my thumb or finger over the crown, slowly start to peel the cement away, then let it sit for another 45 to 60 seconds to get that second, hard cure of the cement.
The biggest thing, I think, is that sometimes you deal with cement below the contact. It’s a challenge. To get rid of it, use an explorer to get underneath, or Superfloss works really well. It’s a tough thing to time, in terms of not wanting to remove it too soon and risk displacing your crown. But you do want to make sure you go in underneath that contact and get the cement.
Don’t go and blast. Think of when you’re doing your stainless steel crown: you hold the crown and your assistant does the air-water at the same time, and it blows all the cement away. Here, you’ll blast all that cement from the margin, and your crown will pop off or get moisture in it. Here’s a photo of a little bit of cement left underneath that contact, so make sure you go back and get under the interproximal. Whenever removing cement, don’t ever pull up on the crown or pull incisally. Always push apically. Push it into the gingiva and then remove it with your floss or your explorer.
[01:13:38] Top three challenges: loss of retention and “ghost teeth”
The top three challenges, or some of the biggest issues I think people have with posterior zirconia. First, loss of retention. Again, we talked about movement of the crown. A stainless steel crown is going to snap in there and hold through the initial set of your cement. That’s not going to happen with zirconia. It’s a passive fit. So you really do need that undisturbed environment for about 45 to 60 seconds, depending on how thick your mix is. Like I said, I can start to clean up at 30 to 45 seconds, but I still keep my thumb holding it in place. Then there’s lack of hemostasis: not controlling it can cause microleakage into the margin, and then your crown can come off. But really, when you have those things down and under control, or you’re using a thicker cement, I rarely see crowns come off.
One of the other challenges, which I think is all over iPedo and social media, is one of the hot topics of posterior zirconia: what’s going on with this atypical root resorption, or these ghost teeth? A lot of us are seeing these on our X-rays a year, two, three years later, but asymptomatic. Patients don’t have an abscess or a parulis or a bubble. No pain, tooth not mobile; we’re just starting to see early root resorption, or ghost teeth, as we’re calling them.
Really, there’s no known cause. I think it comes down to two things, in my opinion. One is traumatic occlusion. If you leave a crown a little bit high and the kids are grinding and biting down on it, as you remember, zirconia is so hard that something has to give. Is it the bone? That’s my question, I guess. The other: I personally think it’s a response to the pulp medicament, or to being close to the pulp and not actually needing a pulpotomy but maybe heating the pulp. What are you using for your pulp medicament?
There’s a great handout in the webinar from Dr. Hansen called Atypical Root Resorption, where he goes through his opinion on this from years of cases. He talks about the probable causes being occlusion, like I mentioned, overheating, microleakage, or over-preparation, and how to avoid those things.
Often, when I get this question, I ask people what they’re using for their pulps. So I’m going to run another quick poll and see what everyone’s using for their pulps, just to get an idea.
[…]
All right. I’ll share the results. It looks like, as I figured, about 50% MTA and 50%, I’m guessing, still on formocresol and IRM. I had to lump them into a couple of different groups because we only had the option to do five. I was just curious.
I’ll tell you my thoughts on it. Again, this is just from doing these over the years. I started with formocresol and IRM. That’s how I was trained, and that’s what my sister and I used for several years in our practice. And truly, I wasn’t seeing a lot of pulp failures. It was about an 85, 90% success rate. I mean, even better than that. I really wasn’t seeing a ton of failures. But we wanted to be ahead of the game a little and on board with the hospital protocol, so we switched to Biodentine for about a year. We had great success with it, no failures that I could think of or document. But it was a little more difficult to get a consistent mix every single time with our assistants. So we switched to MTA once we had an option, SmartMTA, and it’s a cheaper option, and it works phenomenally.
So we switched to MTA and really see very few failures. I’ll be honest: once in a while we’ll see these ghost teeth, with any pulp medicament. It just happens. Again, I don’t necessarily have an answer for why it happens. Over time maybe we’ll see a few more, but I don’t see abscesses or things like that as much with the MTA, and very few pulp failures at all. So I’m extremely happy with it, and we’ll pretty much stick with MTA.
[01:18:32] The third challenge: economics
The third challenge is economic. Again, it costs a little more to do these crowns. I always include this slide, or talk about this, in my Sprig U lectures. My top five can’t-live-without dental products are the STA (The Wand), Isolite, zirconia crowns, MTA, which I mentioned, and the HemeRx pellets. Now, I get it. These are all high-end, more expensive dental products. I use these on a daily basis, and when I’m doing a pulp and a zirconia crown, which in the office is all the time, almost as much as stainless steel crowns, I use those five things every single time.
So I broke down the cost of those specialty items and compared them with the less expensive alternatives, like your syringe, stainless steel crown, formocresol and IRM, what we were using before. The difference comes to about $30.24 per tooth. I think that amount can easily be built into your fees. Some people charge a local anesthetic fee, a behavior management fee, or just an increased fee for the cost of the crown. When we talk to our dental consultants every year, we take the fee survey, and they recommend that pediatric dentists, or specialists, set their fees at the 90th percentile. That’s something we use for certain things, especially our zirconia crowns and the specialty things other dentists can’t provide.
So you can build that into your fee, or you can just eat the cost. Is that $30.24 going to make or break it for you? I don’t think so. Is it worth it for the best experience and treatment for your patients? I absolutely think it is. The word-of-mouth referrals alone make up for that cost. I can’t tell you the number of other pediatric dentists that refer patients to us because the parents want white crowns, and those dentists aren’t willing to learn how, or aren’t willing to eat the cost or do them. So we get tons of patients who are referred in just for white crowns.
That’s my two cents on it. I do think it’s worth it. And it really becomes a huge part of your practice, and in my opinion it’s the standard of care, or where the standard of care is going.
[01:20:43] Team training: presenting, scheduling and sizing
The last little bit here is on team training, with some tips on how you can become successful at doing these in your office. We have a typodont like this, from Sprig, at every single chair, so my assistants can start talking about it in the treatment planning process. It shows parents a stainless steel crown versus a zirconia crown, anterior and posterior. That helps you upsell it, and what I mean by that is just giving them both options. When they hold it in their hand, they physically know what it looks like; they can feel it, touch it.
My assistants do the selling, or treatment planning, explaining the difference between the two and the benefits of each. They talk about the aesthetics. We can show before and after photos, and like I said, the parents can get an idea of what they look and feel like, and the assistants talk about the strength and biocompatibility in terms of the benefits.
They start to discuss cost a little, and we use taglines like “Only an $80 difference.” The number one question parents ask is how much does it cost, or how much more. We have it set so that it’s an $80 difference, so when you say it like that, “Oh, it’s only an $80 difference,” instead of saying, “Oh, it’s $423,” they instantly start to think, is that $80 worth it? And a lot of times they’re like, “Oh, if that’s it, $80 more, then absolutely I want the white one.”
Your assistants also need to be trained in how to schedule. They evaluate the behavior at the chair when they’re doing the cleaning. If it’s a super wiggly kid, can they sit still for 30 minutes to do these crowns? How many crowns? Is it one? Is it two? Is it eight? Is it better done under sedation or anesthesia, or can this patient tolerate it in the clinic?
And they watch the parents’ reactions, too. When you start to talk about crowns and their eyes get really big and they go, “Those silver ones?” or “Like the silver one the kid in the class has?” and they start bringing those things up, your assistants can start to feel the parents out on what they want and start talking about it. When I get to the chair, they’re like, “Oh, mom knows he’s got some big cavities in there. She’s leaning towards white crowns,” things like that.
Sizing the crowns: again, I have my assistants eyeball the tooth ahead of time. There are a couple of different ways you can size it. One is eyeballing it, like I said, and having it in your head: oh, it’s usually a two, or it’s a D4 in a stainless steel crown. Like I said, it’s usually a four, plus or minus one, so three or five, and the anterior is usually a two, same as a stainless steel crown. Always start with what your gut instinct would be for a stainless steel crown.
When you have that racetrack and you’re looking down occlusally at your prep, you’re basically looking at the inside of the crown and what the size is. So you can teach your assistants to look at that step too and say, “Oh, that looks like it’s going to be a three or four.” In the OR, I have my assistants over my shoulder looking at my preps, and they now have the crowns picked out in their heads. “Yep, do you think it’s a two?” They hand it to me, and nine times out of 10, they’re right.
You can hold the crown up ahead of time if you’re in there with nitrous; the assistant can take cotton pliers, grab a crown, compare it and have it out. It’s easier to have a starting point, I think, and it saves you time guessing the crown size. If you have perio probes, you can measure it. These are examples where an assistant eyeballed it, measured, and sure enough, it fit exactly the one she chose for me.
Tips for removing the ladders: you can use a spoon excavator to scrape off the majority of the ladder. You want to wait until after the cement is in; otherwise you’re going to wiggle and loosen that bond. What I do is have them partially remove the ladder before cementing. Do not fully remove it, or you may not know which side is buccal or lingual. They may hand it to you backwards. You always want to know which way you’re seating it. Toothbrush cleanup: at the very end, after my cement removal, I go around with a toothbrush and clean up all the extra cement around there, and you’ll be able to get the ladder off too. You can use a prophy cup as well, or you can leave it: leave the little blue marks in there as an oral hygiene check if you do a follow-up, because it really should brush off pretty easily.
[01:25:00] Ordering, restocking and post-op instructions
We got a lot of questions about ordering and restocking. My first bit of advice is to buy the kits. We have a kit in the office and one for the OR. Our OR kit is stocked a little more than our in-office kit because we’re doing multiple units at a time in the OR, versus one or two crowns at a time in the clinic. But we’ve had situations where one of us is in the OR and the other one’s in the office and needs the kit. So we have one for each. You really don’t ever want to be without the size you need. It’s not a fun situation to say, “Oh, I only buy fours, and it’s actually a three this time, and I don’t have one, so I have to stop and put a stainless steel crown on.” That’s not a happy parent when that happens.
So have enough of the crowns. We reorder when we’re down to two of any size, and we keep about six to nine of each in the anterior, nine on the higher end for the OR. At any point, if we have three or four cases in the OR, every one of them could need D through G, because that’s really what we’re doing for anterior decay, so you could use the same crown on every one of those patients. So you need enough. And two to four of each posterior. We have one person in charge of the ordering. A sticky note goes on her desk when one of the crown sizes is down to two, and she keeps track of the orders and orders in bulk when she can.
And have good post-op instructions for parents. Some of the wording we use: we use an all-white material that’s metal-free and biocompatible. Those are all tag words parents like to hear these days. They’ll come asking for anything metal-free, as you probably know. We also talk about our glass ionomer cement, stressing there’s no methacrylate, and that it’s fluoride-releasing underneath. Sometimes they’ll ask, can they get a cavity underneath? So we talk about the benefits of the glass ionomer cement.
We tell them their child’s bite may feel a little different for a day or two, and the gingiva might look a little bruised or red from bleeding but will heal quickly, usually within a day. You can encourage warm saltwater rinses, and Tylenol or Motrin if needed for discomfort. I usually tell them the discomfort is from having to go subgingival with a little more crown prep, or even from the anesthetic you give. Oral hygiene instructions: brushing and flossing just like a normal tooth. It is normal to bleed for a couple of days, so soft brushing, and avoid sticky foods, candy, gum and aggressive chewing. You can go to Sprig’s website and download the oral hygiene instructions that we use if you’d like a copy.
[01:27:39] Final remarks: the learning curve and some cases
A couple of final remarks, just to encourage you to give it a go if you haven’t done them, or if you have and stopped and want to start again. I encourage you to embrace the challenge. There is a learning curve, I get it. I’ve been on the learning curve. This is the general rule. The first three are going to be longer, harder, frustrating. But then all of a sudden you get to number 10, and it’s like, oh my gosh, I think I got this. It’s a little bit easier. And by the time you get to 30, you know this prep. You’ve got it. You can get the size, the seating. You don’t have to be frustrated with going back and prepping, and it really becomes as easy as a stainless steel crown. So like I mentioned: three to get started, 10 to get confident, 30 crowns, and then you’re a pro. You’ve got it. Once you’re there, it’s like that stainless steel crown.
Just a few of my before and after cases. This one is our eight-pack: back-to-back and opposing crowns. It’s a typical case you see in the office, not needing the anterior. This one is more of a full mouth case, the entire upper arch, so A through J. On the lower, I didn’t get a great picture, but K and L are crowns, S was extracted, and T was a zirconia crown with that spacer on it. That’s just a two-week follow-up, so you can see how great the gingiva already starts to look in that two-week photo.
And another one. I didn’t grab a before on this one, but this was my first case, I’ll say in quotes, out of quarantine. The day I got to go back into the OR after not working for about seven weeks was a roundhouse zirconia crown case. I think this is the largest case I’ve done: 16 zirconia crowns. We weren’t allowed to have cameras in the OR, with everything so new with the quarantine and coronavirus restrictions. So crowns on A through J, and then K, L, M, R, S and T. The only teeth I didn’t do were the lower incisors. That’s immediately after cementing. I don’t have follow-up on this patient yet, because now I just see them at their six-month recall for follow-up instead of having them come in a week or two after.
And just to show you, you can do these crowns in the office, too. It doesn’t all have to be under anesthesia to be successful. This little girl has, over time, had zirconia crowns on D, E, F, G, B, I, L and S, all done in the office with nitrous. And she loves her crowns. You can maybe see it in her attitude and her posing on our piano. Every time she comes in, she’s like, “Dr. Andi, can you take a picture of my princess teeth again?” Because I do, every time she comes in, because I’m always blown away. And my hygienist always forgets that she has zirconia crowns.
Really, they are beautiful and natural. I don’t think there’s any question about it, and you can become very successful at doing them. Practice is key. I love this quote from Malcolm Gladwell; I love his books: “Practice isn’t the thing you do once you’re good. It’s the thing you do that makes you good.” And I truly believe it. With practice, you can become great, and these crowns can become an integral part of your practice and truly make you the pediatric dentist that people want to come see and seek out, because you offer something the guy down the street doesn’t.
[…]
[01:31:10] Q&A: lost crowns, fractures and back-to-back seating
[Question not captured; appears to ask how she handles a zirconia crown that comes off, and whether she charges.]
Normally, just like with our stainless steel crowns, we ask them to bring the crown in with them. Most of the time, you can’t clean the cement out of it. I just like having it so that, if I didn’t write down the crown size I used, my assistants can compare and cement the crown themselves. I don’t charge for a new crown. Sometimes we’ll charge a re-cement fee, something like 30 bucks. Most of the time, if it’s within a year, I don’t charge anything. If it’s multiple times, I might consider charging for it, but really, most of the time I’m charging nothing or a re-cement fee, and definitely nothing within a year.
[Question not captured; appears to ask about crowns fracturing, and seating back-to-back crowns.]
Yes, I have had them fracture. Again, the fracturing is usually because of a ledge. It’s not necessarily because you can’t get them seated. I’m a creature of habit. I like having a system, so I do things similarly with my stainless steel crowns. I always prep them and seat the larger crown first. So I’ll always seat the E and then the D, but sometimes, as you know, it has to be seated a little bit canted or tilted. So I always try them in and try to seat them the exact same way. There’s really no rhyme or reason, but if I can’t get them seated back to back, or there’s a fracture, I’ll then go to the squished size, the Space-Loss crowns, and try that.
My first instinct is always to try the regular crowns first and seat those. I don’t use the Space-Loss crowns unless I have to, and if I have to, I’m usually going to use one on the D rather than the E, just personal opinion. I rarely use Space-Loss crowns, but if I ever had an issue with seating back-to-backs, or fracturing, I would go to a Space-Loss crown next.
[01:33:08] Q&A: broken-down anteriors, occlusal reduction and ghost teeth
[Question not captured; appears to ask whether badly broken-down anterior teeth need a lot of prep, or fail.]
It’s really not. You don’t have to do a whole lot of prep. If you remember, I mentioned that you can actually do half the thickness of the bur in the anterior. So if the tooth is badly broken down, you really don’t have to do as much prep. And like I said, these are sometimes the most retentive crowns we have. I’ll do what I described and go a little further subgingival so I can seat that crown and maybe get a little more tooth structure to cement to, but I don’t have issues with them falling off or fracturing at all.
Again, if I’m doing a badly broken-down anterior tooth, it usually needs a pulpectomy or a pulpotomy. I do both. Sometimes I’ll do an MTA pulpotomy, leave room to pack cement over the MTA, then fill the crown full of cement and jam it on there, and it almost creates a post and core with cement. It’s really super retentive. And knock on wood, I have had 100% success with MTA pulpotomies in the anterior. I have not had a single one abscess. Hopefully that stays true, because people look at me like I’m crazy that I’m not doing pulpectomies, but now with MTA I’ve switched over to just doing pulpotomies.
[Question not captured; appears to ask where she starts the occlusal reduction.]
I go from the marginal ridge. I start on the mesial or distal, drop it down from the adjacent marginal ridge, and basically, zoop, take it all the way across. So really it’s from the marginal ridge or the cusp tip. You can actually leave a little bit of that central fossa. You don’t have to prep all of the central fossa away. You actually want to be able to see a tiny bit of that central groove, because you don’t need any more occlusal reduction than that.
[Question not captured; appears to ask whether she warns parents in advance about atypical root resorption.]
Great question. I do not warn ahead of time. I really don’t see it that often, I’ll be honest. When I was looking through my cases from the past 10 years, I was able to find one case on X-ray where I had a good visual of this.
Sometimes I’ll talk about crown success in general. For me, I truly am just as successful long term with stainless steel as I am with zirconia. I’ll say that crown success, or pulpotomy and crown success, in the literature is 85%, but in my hands, in our practice, we see much greater success than that, and I am confident that these crowns are going to last until the tooth falls out.
When I will explain external root resorption, or a potential issue, to them is if I get in there and it’s a questionable pulpotomy, whether it’s semi-dry, just a spot of bleeding, or there’s a ton of bleeding. I’ll still often do the pulpotomy, because I think MTA is incredible, a miracle worker in itself. I’ve had success with MTA pulpotomies even in situations where I’m like, “I probably should have extracted the tooth.” So in that situation I’ll tell them there’s a chance this tooth may abscess or need to come out, or we may start to see some radiographic changes.
When I do see radiographic changes, I just describe it as that: changes in the bone, likely due to the large cavity that was there. The nerve inside the tooth was probably irritated by the decay sitting on top of it, and in turn, the treatment we had to do causes the body to have a reaction, and this is what it looks like on an X-ray. I’ll say that as long as the patient isn’t having any pain, swelling or an abscess, we will monitor it on our X-rays, and most of the time that’s a reasonable explanation for parents. Hopefully that answers your question.
[01:37:00] Q&A: insurance, MTA products and oral hygiene
[Question not captured; appears to ask about insurance coverage and fees.]
We find that insurers are pretty much covering it across the board now. When we first started, they definitely weren’t, and that’s when we were seeing the $80 difference. But insurers are covering it more than a stainless steel crown, including medical assistance, or Medicaid, in our state, and that’s in large part due to doing them and submitting them to insurance. If you don’t submit them, if you don’t do them, insurance companies don’t see that you’re doing them, and they don’t cover them. So the more you do, and the more people that are doing them and submitting them, the more they start to say, “Oh, this is a procedure that dentists want covered and are doing more often.”
That was the case for us with Medicaid, medical assistance, in Wisconsin. We were able to get them covered, and they cover the exact same amount for a stainless steel crown as they do for a zirconia crown. And they actually cover a little more if it’s done under anesthesia. Weird, but it benefits us, I guess, because we do accept it. You can make your fee whatever you want. We wanted to upcharge it, or upsell it, because it is a little more technique sensitive, and I tell parents that’s the main difference. It may take me a little longer to prep them. They’re a little more expensive to purchase, and we want to cover that $30.24 and still have a window of profit. So that’s up to you in terms of what you charge.
[Question not captured; appears to compare SmartMTA, NeoMTA and NeoPutty.]
I have used both SmartMTA and NeoMTA, and NeoPutty now. To be exact on your question about NeoPutty: you squirt it right out of the tube, no mixing. In my opinion, that would be more for a direct pulp cap or indirect pulp cap type of thing. It’s really expensive, in my opinion, to fill an entire pulp chamber in a pulpotomy with NeoPutty. That’s a lot of material at a pretty increased cost.
NeoMTA and SmartMTA differ just in how you mix them and how they come. SmartMTA comes in individual liquid and powder, so there really is no waste and you’re not cross-contaminating. It’s slick. I’ve got to the point with SmartMTA where I can get about four pulps out of one container, and not everybody uses the same amount. But if I’m doing A, B, S and T pulps, I’ll have my assistants mix it, and then I literally just cover the pulp orifices with the MTA, and the rest gets loaded with my glass ionomer cement. Nothing over the top. So I’m getting quite a bit of usage out of my MTA. It makes it very cost-effective.
[Question not captured; appears to suggest requiring good oral hygiene before offering zirconia crowns.]
Yeah, I agree. I’ll be honest: when we were first starting with zirconia, and it was more difficult for me to do them, or I wasn’t as confident or as quick, I used oral hygiene as my selling point. I’d say to the parents, “You want white crowns, then you need to prove to me you’re going to take care of them.” It’s a great way to train your patients and get them to want to take care of their teeth.
I’m at the point now where it really doesn’t matter to me, because I can do them as quickly, so that’s not a huge determining factor for me. Because as you saw, plaque doesn’t stick to these crowns. So you’re seeing less gingivitis and fewer problems afterwards than you are with stainless steel crowns.
A great example: I’ve done them on patients with special healthcare needs, where parents can barely get in there and brush, but they are desperate to have white crowns and want their child to be normal and have the same beautiful smile as their other child or the child down the street. I’ve done a couple of special needs cases where I did stainless steel in the back and zirconia in the front, and I am kicking myself that I didn’t do zirconia full mouth, because the gingiva on the anterior looks so much better and so much healthier. Even their medical doctors have commented on it: “Oh my gosh, you can tell which ones are better for overall oral health.” So I really think it’s a better option, in my opinion. But like I said, it’s a great tool if you want to use it as a way to get parents or kids on board.
I do talk about brushing your princess teeth. And you’ll be surprised: kids’ confidence really is affected by this. They love that beautiful smile, and they will take care of them. I have a lot who have changed. That patient I showed you with the full mouth (not the one with the 16 crowns, but the one with the spacer) came in, in that first picture I showed you, with plaque everywhere on the lower incisors, decalcified. Over the years, and I’ve got a six-year follow-up on him, his hygiene got better and better, and all of a sudden, there are these beautiful lower anteriors. It’s crazy. They start to take care of them because they love them. They want them.
[01:42:05] Closing
My email is on the screen, and you can reach me through Sprig as well. They’re fantastic customer service at answering questions. Pick up the phone, email; you will always get an answer back. They helped me tremendously when I was starting out. Always available if you need us.
And again, I encourage you to attend a Sprig U if you want even more in-depth information. I think the highlight for most people who go to a Sprig U is the hands-on portion. You’ll get a ton of experience prepping crowns. You’ll prep every tooth you want: posteriors, canines, which are my favorite, anteriors. One-on-one, you get a lot of that. So hopefully I’ll see a few of you at Marina del Rey in September. That’s the only Sprig U this year, and I will be there instructing it. So I hope to see a few of you there.
