Blog Author: Daniel Wilson
This isn't a novel post but for some of the new CEREC users, I thought I would share some bread and butter dentistry. I would rarely do crownlays during the BC (Before CEREC) days. As we all know the biggest challenge was provisionalization and you as the clinician had to be knowledgeable enough about materials to explain to the lab technician about material selection, color and translucency so you could get the results you desired.
Now with CEREC, there are a number of different materials at our disposal and no worries about provisionals. For this case, I had plenty of enamel to bond to and enough clearance so I could have used just about anything in this case. Typically my go-to for crownlays is IPS e.max HT (high translucency). I've used MT with success but I find blending the margins is a bit easier with HT.
Another thing I really try to focus on with these cases is smooth flowing margins. Unlike the days of gold inlays and onlays where sharp internal line angles and boxes were the norm, resistance and retention form are not my primary concern. With proper bonding, these do not come off.
For this case, I intentionally choose A2 HT because the cusp tips of the premolars where brighter. I selectively etched the enamel with 35% phosphoric acid, scrubbed the tooth with Adhese Universal for 20 seconds and bonded with Ivoclar Vivadent Variolink Esthetic Warm Plus.
Nothing earth shattering, but these are the types of cases where efficiency and predicatability are paramount for us each day.
CEREC gives us a ton of options and allows us to do treatment for patients without the frustration to us as clinicians or frustration to our patients. For me one of those treatments is Maryland Bridges. As we all know, if we attempt to do this with a lab, provisionalization is challenging and we are at the mercy of the lab for getting the shade and fit correct. CADCAM has made this a very efficient and predictable option for us chairside.
This patient has a lot of compromises but really wanted something fixed versus her removable partial to replace #23. As you can see from the radiograph, tooth #24 is not doing well. I had her get a consultation from an endodontist and took a CBCT. He thinks it looks fine and would be a candidate for an abutment but I still think the tooth is toast. I really wanted to avoid potentially opening a bag of worms with #24 and didn't want to prep #22 for full coverage to act as an abutment for a conventional 3 unit FPD.
So after some discussion, I felt a Maryland bridge was the best option. In this case, I did prep a little into the canine a little bit.
Here's the proposal:
Restoration at try-in:
I used a C14 block A2 LT. I did have to re-fire this case a second time for color.
Nothing earth shattering for this case, but I'm still amazed how we can do this in less than a two hour appointment and be ultra conservative and get a great result. I don't know how long this will last (I've been searching on PubMed for articles that Skramy refers to but couldn't find them), but with total etch and enamel bond, I think it will do well for quite some time.
So my patient coordinator says her step mom is in need of a second opinion about her front tooth. I tell her to send her over and sure enough, she has a old, loose PFM that is failing and there is inadequate ferrule and simply has a poor long term prognosis.
She is mortified about esthetics and how this implant will look (despite her many other dental concerns). I don't place implants yet, but walk her through the process and give her the recommendation for the surgeon I work with, etc., etc. Fast forward to about 16 months ago, she shows up at my office saying the surgeon says she is ready to go. I'm a bit lost now because I hadn't heard anything from my surgeon and our plan was to make her a custom healer at the time of surgery. Anyway, she ends up seeing a different surgeon in town, has extraction of #9 and immediate implant placement with a Straumann 4.8RC. Now fortunately, this isn't the end of the world in this case. Implant was placed pretty well, it is a tibase compatible system but there were some challenges that I had to deal with that took some extra time and extra cost (thankfully I have a CEREC otherwise the costs would have been even more). So here's a pic and radiograph of how she presented with the implant in place .
As you can see from the initial photo, I have some gingival asymmetry to address, so we discussed that I would be placing a provisional crown to help shape the tissue and make the final result more esthetic. She had a minor freak out moment until I explained that her provisional implant crown wasn't removable like her flipper :) So I choose to use Telio CAD as a provisional. For those of you that don't restore implants yet, I would highly recommend Level 3. This by itself has paid for my CEREC several times over. Plus, having full control of the outcome it nice too. I used to hate making an implant provisional chairside. It is time consuming and tedious. But with CEREC, this become quite easy and predictable. Yes, it cost me about $150 in parts for the variobase and for the TelioCAD block, but I'm still ahead even after the cement retained crown that will cost me a little less than $180.
As you can see from the radiograph, the implant is countersunk about 0.5-1.0mm. It may be a bit exaggerated from the angle of the PA. I was able to seat the scanpost completely, and then we designed Screw Retained Crown on the CEREC. Sorry I can't pull up my design right and show you a screenshot of it, but usually I make the facial emergence profile a little concave for everything touching the tissue with my anterior implant abutment or crown. In this case, I matched the shape of tooth #8 in my proposal at the gingival third so that I would get the tissue to move apically to my desired location. Everything above my depicted line was concave and not blanching the tissue. I will say I did have to make releasing incisions on the mesial and distal interproximally to get the tissue to release enough to seat provisional crown completely
One important step with using Telio CAD is that you need to use SR Connect on the intaglio surface of the implant crown. This is an methyl-methyacrylate(MMA) liquid that is light cured in order to optimize the bond of the Telio CAD to the tibase. Still sandblast the tibase, use your Monobond Plus and cement with the Hybrid Abutment HO cement by Ivoclar Vivadent. Sam has an excellent video showing the full process.
Here is the Telio CAD provisional seated about 1 month post. Not perfect but much better.
At this point, things are more predictable and easier to deal with. This wasn't an ideal case. The patient is in some serious need of soft tissue grafting in a number of areas. Wasn't interested in ortho and wouldn't let me recontour a few of her other teeth to help with some line angles, but overall given my restrictions, I was able to make her happy and deliver a nice result. This would have been a lot more unpredictable and expensive without CEREC.
Final restoration: (Photos are 15 months post op)
Utilized IPS e.max MO-2 abutment block (fired on P7)
IPS e.max B1 MT
I'm no expert on this so let's see what others say, but wow, great job and great photography. The lateral incisors are begging to lose that labial flare.. perhaps go after those next to make a difference
There was a thread last week when Sam kept asking why not Feldspathic Porcelain for a Veneer or an anterior crown. For me personally, a lot of my decisions for block was a matter of very my comfort was, and not being familiar with the properties of other blocks. After going to Level 4 a few years ago, it was the first time I really saw Sam and Mike's affinity for VITA blocks. As we can all attest to, Mike's case make us want to cry sometimes because they are so good and makes me wonder what type of "hack shop" I run :)
Everyday I get better and better with understanding block selection for certain cases, but as I use VITA Mark II or VITA Triluxe more, I really like the esthetic properities of the materials and obviously being able to see color straight out of the mill is a huge benefit too.
Here are a few cases that I have done to showcase the power of the block. Obviously, VITA isn't the strongest material we have so if strength is a major concern for a cause, I would revert back to blocks like Celtra Duo or eMax.
This patient hated the spaces at the gingival 1/3rd of her lower anteriors. She is post ortho and I inherited the case after the ortho was already finished. We discussed the challenges of closing the spaces completely, and I wanted to prep them as conservative as possible but essentially they are crown preps because I had to prep interproximally to the lingual aspect so far to help with the space closure gingivally, and was only able to preserve the lingual cingulum of the lower teeth. Funny how pics show all your flaws, but I swear I rounded all the preps with a 3M finishing disc and they still look to sharp in a lot of areas. Fortunately, the restorations all milled and seated beautifully. This was a case I did same day. I have 1 mill unit and used Biojaw to help with the design of the crowns, and the patient was in the chair for about 4 hours.
Day of Pics:
1 month Post op:
Ironically I didn't stain and glaze the case. I tried the crowns in and polished them slightly but when I tried them in, she was so happy that she didn't want me to do a thing. So I polished them completely and bonded them using a total etch technique with Variolink Esthetic Neutral. The blocks were VITA Triluxe 1M2. I still am pretty amazed that we have materials that can come out of the mill, be polished and bonded and look like this.
Patient needed veneers on #8 and 9. Again I used VITA Triluxe (A1C) and bonded used total etch technique with Variolink Esthetic Neutral. This was one of my first cases with using GC Lustre Paste. I hate the texture. Part of the learning curve of using Lustre Paste. It really is apparent in the photos but the patient loved them so much that she didn't want me to touch them. One of these days I will find an excuse to polish this veneers more :)
Day of pic:
1 week post op: Sorry about the articulating paper mark...ugh
This was a really frustrating case. Patient hated her crown because of the dark grey margins and asked if I could improve it. I tried and failed with emax LT. Ended up sending her home and milled out a few different blocks and the one that looked the best was VITA Mark II A1. I did bond this with a Variolink Esthetic Light. This was stained and glazed with Lustre Paste. The whole reason I chose to even mill the crown in Mark II was because I was reading about a veneer case that Mike had done where he was able to conservatively prep for a veneer and block out a reasonably dark prep. So I thought, what the heck, I'll try it. Not perfect but the patient was pretty happy.
Color of core after PFM removed:
I inherited this case and I know the patient was frustrated with the lack of communication, and this lead to him switching to me. I was a little worried that he wasn't going to be a good patient by some of his initial comments but I made it clear with pictures, waxups and just general discussion of what we could achieve. He was interested in CEREC and so paranoid about these looking big and bulky like his prior bridge, that he wanted to see my proposals before I milled them...
Tough case nonetheless. He was a bit brighter than B1 so I went with a BL2 MT block...geez...they are bright!
Tried it in and it didn't look too bad but definitely needed to be toned down. So I used L-A and L-3. The A stain to give a little more gingival color and the L-3 to lower the value of the crowns. As many discuss, there is a bit of a learning curve for Lustre Paste, but I do love it. The abutment block is a MO2 block...used an S-block for Biomet 3.4 implant
So I did this case about 9 months ago, but finally got some after photos. In hind sight, I am pretty happy with the case, but now I think I would have choose an A2 MT block. When I did the case, I had V1 and V3 Impulse blocks but felt like the value would have been too high, so I choose an A2 HT. #7 was darker and short pre-operatively so I was cautious about that and I did some recontouring of the mesial aspect of #10 in order to help keep the centrals the same size. I did a wax up of the teeth and did biocopy
One of the docs in my practice referred this younger woman to me to match her darker endo treated Central to the rest of her dentition
So the tooth wasn't that dark and she had previous attempts at some internal bleaching but obviously the previous dentist wasn't able to get it dark enough. I was pretty conservative with my prep and didn't reduce the facial more than I typically prep. My plan was to use an MT or Impulse block.
I ended up using a V3 Impulse block and used eMax stains for this case. I actually added a little bit of composite on the mesial of #8 & 9 in order to close her gingival embrasure a little more and then biocopied what I had done. I was pleased with this case and really happy that I didn't need to go with a lower translucency block. With the pics blown up I may have put a little too much translucency on #8 but the patient was thrilled and didn't want me to change anything. A few of these pics have some try in paste residue on the tissue. I ended up needing to tone down the value a touch so I cemented with Variolink Esthetic Warm.
My office manager's mom came in on Friday and #6 was fractured and needed a crown before we impressed for her new upper partial. I know from reading the boards, not everyone likes the HT blocks for full coverage. I use it a fair amount for full coverage crowns depending on the patient and what I'm trying to achieve. I really pay attention to the stump shades and what cement shade I use because I have had cases that ended up being a little grey. I also tend to choose one shade lighter for color (i.e. for A3 choose A2 HT block). I am excited to use some different blocks, and learning more at the Level 4 course in June.
#6 was an A2 HT bonded with Multilink Transparent . 1 shade was heavier for the gingival 1/3 and extended the color to the mid portion of the tooth. Used blue shade in a slight U shape to create some translucency for the 2-3mm of the incisal edge and used a slight bit of white to create some slight decalcifications and try to match the other teeth.
Other pic is of A2HT crowns on #2 & 3. I didn't want to drop margin on #3 to cover the root surfaces and the patient didn't have any sensitivity issues. I just spray glazed the tooth crowns and used Multilink Yellow cement to warm up the color and help blend the transition to the root surface.
To learn more about Mastering Multiple Anteriors With CEREC, visit https://www.cerecdoctors.com/campus-learning/hands-on-workshops/id/3
To learn more about this case visit https://www.cerecdoctors.com/discussion-boards/view/id/38283