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24 Apr 2017

Posted by Andrew Hall on April 24th, 2017 at 10:21 am
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This is a case were we sometimes have to meet the patient at their primary need. He presented to me to" fix his front teeth."  There is a lot to deal with here, hygiene issues, assessment of diet as patient is high caries risk.  Yes we discussed a lot of options and the need for change in order for anything to be successful long term.  Ultimately we decided that we would crown the canines and the goal is to place two implant in the anterior segment and restore #7-10.

Here is initial presentation:

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Set the case up to mill the interim bridge with Telio Cad:

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My plan was to grind #7-10 down to the gum line, prep #6,11 and get a provisional bridge milling and then come back and extract the teeth.  Lesson learned here was that I should have taken the teeth down even more to allow for a better design of the interim bridge.  

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Next was to design the case - I did utilize biojaw in this case and the harmonic positioning.  This may not be the final restorative position, but you can see how it placed the proposals well in front of the extraction sites, given the position of the canines.  The case required a Telio Cad block B55.  I have attached the rst if anyone wants to play around and design the case.  

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While that was being milled it was time to extract the teeth, utilization of the Benex allowed for atraumatic extraction

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I did opt to place bone graft as well - curious how others would have handled this

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After grafting it was time to seat the bridge - I certainly needed to spend more time contouring and need to work on making the embrasures look better.  Many lessons learned, hope this helps someone out in the future with this type of case.  The patient was happy given the initial presentation and it's at least a start point for this case that is certainly a work in progress.....

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Thoughts and ideas welcomed.....

 

 

 


I was uploading photos last night when my husband was looking over my shoulder and said "Oh I can't wait for you to do that case! What a difference it will make for her." He was certainly surprised when I told him that this was my final photo, not my before picture...

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He thought I was kidding until I showed him the before picture. He asked my why I just didn't redo the centrals as well...

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I am always intrigued to discover what a patient sees about themselves when he/she smiles. In this case, she saw the lines on her laterals that were staining, but did not have any concerns with the esthetics of her two front teeth. Of course, as a dentist and someone who loves front teeth, my concern was the centrals. We talked about them, what could be improved, but again it just wasn't her priority. Will they need to be replaced someday- absolutely, but first I need to gain her trust. So I did some simple bonding on #7 and #10 using the same techniques that I do when I stain and glaze my Cerec crowns. I love using Cosmedent's Creative Color Tints and opaquers to mask any lines and help blend composites in nicely. Just like I would bevel to hide the margin on an onlay, I also bevel my margin on the facial to hide that dreaded line that composites tend to show. I know how to contour much better now, because I do them over and over on my anterior crowns trying to make them appear natural and this translates to my composite work. I also take time to really make my margins smooth and I polish heavily to help prevent staining. These techniques are simple and fast but can make a huge impact on the result. 

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There has not been a single day that I have regretted my journey in the Cerec world and this is why. Everyday I feel like I can apply the skills that I learn here on this board or from this community. Everyday I feel like I am becoming a better dentist and my journey is far from over. 

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19 Apr 2017

The esthetic bevel has been talked about numerous times on the forums from the stand point of being conservative and allowing restorations to blend in to the remaining structure.  But on of the benefits of this conservation of tooth structure is keeping the structural integrity of a compromised tooth.  This patient walked called in with an emergency of a fractured tooth.  The virgin tooth #13 fractured the lingual cusp below the gingiva.  

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The options were try and save the tooth or remove and implant.  There was still a lot of good tooth structure to work with as long as we didn't mow down the facial aspect.  In comes the esthetic bevel.  The lingual gingiva was removed with a diode laser to assess how deep the fracture was.  Upon exposure and probing it was found a margin could be placed without impinging on the biological width.  The root canal was accessed, instrumented and filled.  

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After this a build was placed and the tooth prepared for full coverage utilizing the esthetic bevel to keep as much of the buccal tooth structure as possible. 

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When doing a high and dry margin like this on the facial aspect make sure not to make the margin straight across.  There is a slight wave to the margin.  The eye notices sharp delineations and straight lines.  By making the margin smooth but uneven it tricks the eye.  To make the bevel either use a football diamond or a large chamfer bur.  

Fractures generally occur from working side interferances.  Thus buccal cusps on maxillary teeth and lingual cusps on mandibular teeth. By keeping the extra buccal tooth structure we reduce the risk of fracture from excursive movements. This danger to preparing the buccal aspect to the gingiva is weaking the tooth and leading it to fracturing at the gum line making the tooth unrestorable in the future.  The extra tooth structure acts as a buttress to fortify the tooth from future fracture. 

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The material of choice in this situation needs to have enough translucency to allow the bevel to blend in.  For this case an A2 MT Emax was used.  Care needs to be taken during cementation to prevent staining of the margin.  Make sure to etch the enamel for a full 20 seconds.  Lack of adequate time with etchant will cause premature break down of the margin.  Also allow the bonding agent to have time to penetrate well enough so follow the directions of the manufacturer for the proper length of time to allow it to work it's magic.  And finally seat the restoration clean off the excess with a greg 3/4 or similar instrument.  Press down firmly on the restoration, you should see a little more material express out.  Tack cure if that is your preference or allow it to gel.  Clean the interproximals but leave the facial alone.  Apply glycerin gel to the margin over the little bit of material left.  Do your final cure.  Now clean the excess with a fine diamond.  This will give you the most protection for the margin and prevent future staining.  

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Maintaining the extra tooth structure now gives the added strength to the tooth to allow it to have a much better prognosis than if the buccal tooth structure was removed for esthetics.  

 

12 Apr 2017

Posted by Mike Skramstad on April 12th, 2017 at 11:14 am
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I wanted to post a fairly difficult central incisor case that I just completed...

This patient came to me wanting to improve her smile.  She had some chipping and wear on tooth #8 and an old PFM on tooth #9 that had a previous RCT. 

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The tissue was extremely inflammed on #9 and the margin was quite subgingival.  I determined that she had a biologic width invasion here that was likely going to need osseous crown lengthening....

So first, I planned the case out using simple photoshop smile design...

Here is where she needed her gingival crest to be on 8 and 9:

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Here is where I planned where her teeth needed to be to have correct proportions.  Tooth #8 needed to be lengthened slightly and the incisal edge on #9 was correct based on her lip at rest photo:

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Then I quickly morphed the teeth into the correct position using photoshop:

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So... the plan was the following:

  1. Prep and provisionalize the teeth to the correct position using a diode laser to recontour the tissue based on the original plan
  2. Send her to the Periodontist to perform osseous crown lengthening (mostly on #9) to get the tissue to respond and eliminate the Biologic Width problem
  3. Allow the tissue to heal
  4. Fabricate the final restorations

After removing the crown on #9... I got another suprise... ouch:

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I opaqued the tooth to try the best I could to block it out and finalized the preparations on both 8 and 9:

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I made the provisionals on 8 and 9 and sent her to the periodontist:

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Two months later after healing, we did the final restorations out of e.max MT shade M1:

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There was still a little darkness coming from the root of #9, but overall I was very pleased (and the patient was thrilled).  If you look at the smile picture, it doesn't show :)

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This was a long and difficult case to do... but I feel because it was planned properly and the patient understood what was needed, it turned out pretty good!


Female patient with existing bridge from #7-10; 8 and 9 are the pontics.  She's not happy with the esthetics and won't even smile fully due to how bad it looks.  No worries...I have CEREC.  She's not interested in implants and I'm not comfortable using laterals as abutments.  So, we decide to do 2 bridges; #6-8 and #9-11 (cantilevers).  She was anxious to begin so  Mr Know-it-All here didn't feel a wax-up was needed b/c I could knock it out of the park.  Let the scanning begin!

Pre-Op "Smile"

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Pre-Op Retracted

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So CEREC images are taken.  In the ADMIN screen, I designate #6, 7 as crowns and #8 as a pontic.  I then designate #11, 10 as crowns as #9 as a pontic.  HERE'S WHERE I SCREWED UP.  I did not notice that the computer thought I was designing a 6-unit bridge and not 2, 3-unit bridges.  Notice how all 6 teeth are connected?  Yeah...I missed that. 

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I finish my design and finally notice the problem.  Oh crap.  I went back to the ADMIN screen and attempted to change it.  Nope...not permitted.  If I re-designated the teeth, I lost the design.  I solved my problem by creating a space/gap between the centrals.  How?  Dial in the contacts to where you want.  SAVE the case.  Use SHAPE ANATOMICAL tool to move one central and create a gap.  Mill that bridge.  Close the case WITHOUT saving it and you open it back up with the centrals/contact perfect again.  Use the shape tool on the other tooth and mill that bridge. 

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Yes, it wasn't fun adjusting the contacts and shaping the bridges but I made it work.  Here's the mistake I made and how to avoid it

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Note the arrow and how the computer has all the teeth connected.  Click on the chain and remove it to designate the case as 2 separate bridges. 

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Hope that helps someone avoid the fun I had milling these (each took an hour) and adjusting the contacts.  Yes, I could have redesigned the case but I also wanted to see if my work around worked.  Here are the immediate delivery pics. 

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11 Apr 2017

Posted by Arash Hosseini on April 11th, 2017 at 08:21 pm
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Hi Arash- thought I would follow up with a recent case that "might" address your respectable desire to be conservative, and and example of when I might cover a cusp or leave it... usually on molars, if there is an MOD present, I'm more likely to cover the cusps than leave them, but at least in a few recent cases made the decision to leave some intact..

30 existing MOD-A, recurrent caries apparent MB cusp

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31 O-A recurrent caries multiple fracture present, remarkable asymptomatic

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Removed amalgams initially with depth bur, just to establish fissure depth adequate for e.Max (1.5mm depth bur) on 30... 1.0 on 31 appropriate for Zirconia

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Was pretty committed to circumferential coverage of 31 just based on clinical appearance, and in a less esthetic area felt that zirconia would be my choice in a "conservative" mind to reduce less occlusally and axially... Extending only enough for proper resistance and retention form for a conventionally cemented restoration, to include fractures as much as possible. On 30, there was recurrent caries as anticipated undermining MB cusp, but the rest was clean.... at which point its a game time decision to reduce remaining cusps or not... in this case I didn't. Spefic reason? Complete vertical functioning patient, no fractures, dentin supported cusps, and esp not a lot of complexity that would complicate the seating... and because there are cavosurface margins, I felt a hybrid would wear and function better marginally (used Cerasmart). There was still some minor contact at DB margin, but the hybrid wears better, AND I adjusted opposing lightly to remove that area only...

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If I had decided I needed to cover the cusps which what was suggested above in one of your case examples...I would have taken what I had here in the design pic, and just reduce the remaining cusps sufficiently for the material (complete occlusal coverage would have been e.Max) and just smooth/blended the transitions from proximals to buccal and lingual surfaces... make sure there is at least a semi-functional cusp bevel buccally--- which is not a resistance/retention form issue as it is a sufficient thickness material for the case. More examples could be given, but was just trying to show that it's not dogmatic about not leaving cusps, it just depends on the case. Making your cases easier and more predictable, also makes you a better dentist.     :)

Not to beat a dead horse, but being conservative means different things to different people. But as far as how I think about it, I'd rather not leave things subject to predicable fracture, have restorations that are predictably delivered, and that means enough occlusal reduction---where there is plenty of enamel to bond to.... I am more concerned about reduction nearer the CEJ where you are closer to pulp space, cutting away enamel to bond to, expose pt to easier recurrent decay potential, etc. More could be said about all of that, but a good video series is available with better information.....

https://www.cerecdoctors.com/digital-learning/browse/category/tooth-preparation-for-chairside-cad-cam-restorations

Hope that helps!

Mark 


On 4/17/2017 at 9:33 am, Jonathan Ford said...

Call vita directly and you can buy individual stains and shades.

Do you know the per bottle cost?

04 Apr 2017

Posted by Ross Enfinger on April 4th, 2017 at 04:47 pm
View Comments (34)


If you've ever done a denture conversion to an implant-supported, screw-retained provisional prosthesis after the implant surgery, you know how messy and time-consuming it can be. So I was thinking: If we are capable of very accurate implant placement, then we should know exactly where our implants are going to be placed. And if we know that, then we should also know precisely where the prosthesis should attach, right? So what's stopping us from having a pre-made, implant-supported prosthesis instead of having to convert a windowed surgical denture? Well, as it turns out, the answer to that question is that nothing is stopping us except a little ingenuity and effort.

For the last few weeks, I've been working on an All-on-xxxx solution within the Sirona system. I must give a deserving shout-out to my lab partner on the following case, Brad Diver of Champion Ceramics Studio, for doing all the InLab design work and milling of the interim prosthesis. I also want to thank Jay Black from Winter Springs Dental Lab for all of his guidance through this process and for helping us create some clever work-arounds. Lastly, thank you to all my surgical mentors who encouraged me to take on my first All-on-xxxx surgery.

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04 Apr 2017

So I had this patient for initial exam last Friday with chief complaints of having a big hole with fractured filling on lower right side. I ended up doing # 30 onlay from GC Cerasmart. Everything went well and I asked some of my friends who are using CAD-CAM and their viewembedded imageembedded image on this particular case is that ML wall is way to thin and it will fracture and they would do full coverage crown on it. My argument to this is if it fails I will do crown for patient in short run but If I can buy out more time keeping more natural tooth why not do that. I want to get opinion about this case here and see if anyone would restore this tooth any differently in respect to material choice and/or preparing tooth for full coverage crown.