Please, take a seat, you should not be standing while you watch this.
Artificial intelligence by Medit i500 now identifies the location of your scanbody but it also automatically launches all that proper information into CAD software for instant abutment designs. Make sure to watch both videos. Enjoy.
A very common source of frustration for most dentists or those who are new to designing implant crowns is the emergence profile of the abutment or crown. Most of the time, the shape of the tissue dictates the digital design and this article showcases how we used the medit i500 for the intra-oral scan of the patient and then used exocad to design the restorations. Our advanced users can appreciate how we bring the arch model in twice- once as the maxillary model and once as the gingiva model. We then digital sculpt the tissue to create the proper profile yet we still have the original model to reflect back to asses the changes.
Download to ImplantCrownShaping.ZIP to design along
DESS Library Information for Nobe Active Compatible Components
NobelActiveCompatibleComponents-DESSUSA2019-2NobelActiveCompatibleComponents-DESSUSA2019-2
Few things in dentistry that can be as frustrating as seating a second molar restoration, whether you are doing same day dentistry or having a lab made prosthesis delivered. Here is a protocol we recommend that you follow to dramatically reduce surprises and post op adjustments. In this particular clinical case a zirconia crown debonded and we elected to fabricate an in-office emax restoration. The sequence is as follows:
Immediate post op x-rays were taken to verify seat and aid in resin cement removal. The excess cement was removed after the x-rays were taken
A common request when processing models is to create a plan that matches the occlusal plane of the arches. To keep it simple the algorithms of the Medit iScan will create a plane from the lowest data point on one side of the model to the highest point on the model on the contralateral side. You can control this plane by using the edit tool in the arches and crop out data so that you help the software to find this plane more easily. The more discrepancy there is between these data points will render drastically different planes than the occlusal scheme as seen in the attached photo. Besides, the less data you have to process, the faster the models will be rendered.
We got a bat signal from a group of doctors who were having trouble with ill fitting restorations to tibases. This can suck up a lot of time and energy to pinpoint the exact source of the issue, and you basically have to go through a pilot’s checklist before take off. Here’s a list you can use for yourself to determine what the cause of the issue, after you understand what the issue really is.
We took the case file from our users and directly imported their design case into a few of the CAM systems we have at CAD-Ray. We used Celtra Duo burner blocks to verify the fit. The screw-mentable restorations were binding on the walls of the tibase so it took a few adjustments to seat it completely. The good part is that the carbon on the titanium abutment leaves metal marks on the internal intaglio, so it is easy to know where to adjust
The restoration still needed some adjustments so we played around with some of the spacer settings, screw access holes, and other parameters to get it to seat all the way.
Even with these adjustments of the parameters a little analog milling helped get the restoration seated. The CAM software can give you plenty of hints on where it will bind. We recommend that you don’t change your spacer settings and understand that you will likely bind on the walls of the tibase and/or restorations as it is difficult for any machine to mill out all the detail you need to have NO adjustments. The good news is that the indexing and anti-rotation mechanism work properly.
In conclusion, it is physically impossible to mill the intaglio of a ceramic restoration to perfectly retrofit most tibases as they have too much detail that even 5 axis milling machines cannot reach. The choices are to increase the space between the walls of the tibase and the restoration providing enough relief to allow you to seat the restoration, but that comes at the risk of losing your antirotation mechanism. Alternatively you can mill them out knowing full well that they will bind and using the sophisticated CAM to pinpoint the areas that need adjustment.
Making sure that CAD software talks to the CAM software is critical for certain types of restorations. Simple crowns are fairly easy, but for crowns to fit to a milled abutment that needs to be indexed with the walls of an implant fixture, that is a much larger task. Here is an example of a simple error in code that resulted in lots of miss-mills and cost us hundreds of hours of trial and error to figure out. The incorrect nomenclature would prevent us from milling. Sometimes, it would actually make it to the milling machine but it would mill a completely different abutment than the one designed!
Once the abutment was milled out after correcting the line of code, it perfectly retrofitted the crown that was milled by CEREC MCXL (Celtra Duo material) and by the Imes Icore CORiTEC ONE (Vita Suprinity)
A custom titanium metal abutment is milled in such a manner where the drills DO NOT touch the connection. The type of connection is predetermined by the blank manufacturer and the cylindrical part of the abutment is milled out. This makes the symmetric geometry of the abutment a bit tricky for some to handle as indexing it properly to manage the timing of the connection is critical for easy delivery.
It is a good idea to know the exact dimension of the screw access hole. You want to set the diameter just outside the channel so that you don’t have to do a lot of post production adjustments. if it is made too thin however, you can have a mis-mill and have to repeat it. We’ve found 2.5 mm the perfect setting for the DESS titanium abutments.
Download this case to mill and see the results for yourself
With the Meditlink software you can design a case and then export the designs and take them to any milling machine of your choice. In this demonstration, we use the CORiTEC ONE to mill out the metal abutment in 45 minutes. This procedure is not intended to be a single appointment visit so timing is not critical and you don’t place undue wear and tear on the milling machine.
The crowns were milled with two different milling machines. A Celtra Duo block was used and milled with the CEREC MCXL and retrofitted to the abutment to verify the fit and accuracy. The same crown stl was milled out of Vita material in the imes icore machine. The whole point of the demonstration is that you can take scans from any intra-oral scan, take it to CAD software (in this case exocad) and then export the case and take it to any printer or milling machine of your choice. You must make sure critical information is accurately transferred from your CAD software to your CAM software, which is generally the construction / project file that accompanies the STL files of the prosthetic components
The same crown was milled out of Vita’s Suprinity material in 20 minutes with the imes-icore CORiTEC ONE. Take note of the internal adaptation of the metal abutment and the restoration and how when it is flipped upside down, the restoration does not fall out easily!
For our advanced users, we demonstrate how to plan and manage a two unit molar case so they can deliver multiple chairside restorations in a single visit. There are numerous short-cuts to this treatment protocol and we present them in great detail during our courses. The limiting factor for most doctors is that they have a single milling machine and we show our users how to balance prep and mill time so that they can complete 2 units in less than 90 minutes.
In this case however, we present two restorations that were prepared and delivered at the same time. The sequence of steps are:
As advanced users, you quickly recognize what areas in the model need to be closed either with imaging or with the “close hole” options during the processing step of the Meditlink software. If you are familiar with exocad or other CAD software programs you can just ignore these areas as they do not have any clinical significance whatsoever.
Once the case is designed you can mill them with your milling machine of choice. The testing of materials, fit, and milling machines are a constant at CAD-Ray.com so we milled the first molar with emax material and the MCXL and the second molar, a Celtra Duo material, was milled with the Imes Icore CORiTEC Once
An immediate post-op bitewing X-ray was taken to verify fit and to make sure that there was no excess resin cement left behind in the interproximal area. The premolar mesial to the working field also needs to be replaced and will be in the near future
At CAD-Ray, we are constantly looking for solutions that will satisfy a clinician’s needs in a dental practice. For the better part of a full year, we have been developing milling strategies that can speed up the manufacturing process and increase the longevity of the drills and the instruments used in fabrication.
In this video, we demonstrate a sample crown milling simulation where we try and place the restoration in the block to render the fastest crown in the shortest amount of time possible, with little wear on the drills.
Milling Simulation
When imaging and designing a restoration in exocad, with models captured by the Medit i500 intra-oral scanner, you will produce an stl file of the restoration along with the construction file.
The stl file alone carries enough information for most CAM software to instantly mill the restoration. The CEREC cam software gives you the ability to either import the project file or the stl file.
In this demonstration we showcase how you have to redraw the margins in the CEREC inlab software so you can mill the restoration when you only import the stl file.
Alternatively, if you imported the construction file, you could have skipped the margination step.
Our advanced users can appreciate “the lip” at the margin of the restoration. This is a function of the minimum parameter thickness in exocad.
Most people set this setting to 0.4 mm or less which adds material to the margins so they are protected during the milling process. This thickness is invisible to the naked eye and produce desirable results with lithium dissilicate
When we 3D scan the surface of an object, we plot geometric figures (usually triangles) on the surface of that object which is usually round or has some other geometric shape. A satellite beam hitting the surface of the earth is a good way to visualize the scanning process as the photo illustrates.
As you span across long distances, a meshwork of triangles are plotted together to accurately represent the topography of the object. You can start “veering off track” and forming models that are inaccurate representations of that object if you don’t properly form this framework. There are many variables that can introduce these errors including simple matters like speed of scanning.
Now, with this dental artificial intelligence program, the software can digitally plot and drop known shapes on top of attachments or devices we place in the mouth. Color mapping can let us know if we are staying accurate, on path, or introducing errors and deviations!
Now imagine if you have 6 objects sticking out of a flat plane that this AI program readily recognizes. Identifying these landmarks is the first step, but the bigger significance is that we can scan from object 1 > 2 > 3 > 4 > 6, and when we continuously to image backwards from object 6 to object 1, and our color coding remains the same, we are guaranteed scan accuracy.
People go to 2 extra years of schooling to do accurate work in complex cases, most of which will be replaced with software algorithms like this. This is a serious and significant advancement in dentistry, particularly in implant dentistry. Here’s a video that detail how we use it to restore dental implants.
In the following three videos we walk you through the steps of how the digital “scanbody drop” works to identify the location of an implant fixture. In the demonstration videos, we highlight this upcoming feature and how you an integrate the CAD software for implant designs and restorations. In the final video, we demonstrate how you can take the construction files to the milling machine of your choice and mill out the abutment and/or suprastructure.
In this case demonstration, we show how you can image in the Medit i500 and follow the most logical steps and sequences to produce a restoration. You capture the preparation, the opposing and bite and once the models are rendered, you can launch the CAD software of your choice. The lower right molar was endontically retreated and the porcelain fused to ceramic crown needed to be replaced as it was overcontoured and impinging on the soft tissue. After the crown was removed, the preparation was refined and impressions were taken. The remaining cotton / cavit / gutta percha was removed right before placement, a NX3 by Kerr was used, which is both build up material and a resin cement. The space between the intaglio of the crown and the pulp chamber was retrofilled at seating time and a final x-ray was taken to make sure there was no excess resin left behind.
Here, we utilize exocad. Once we click on the CAD software button, the software is launched and the models are imported automatically.
Once the case is designed, meditlink walks you through the next step which is to nest the restoration and to mill it with whatever milling machine you choose to utilize. Here, we used the CEREC MCXL, the Z4 from VHF, and the imes icore CORiTEC one.
Nest and mill with CEREC MCXL
Nest and mill in Zed 4 from VHF
Nest and mill in imes icore CORiTEC One.
Here, you can watch how all three machines come to a grinding halt as we pushed the amps on the surge protector and power to the units.
Immediate post op x-rays to verify seat and to make sure all excess resin cement was removed.
We’re so stoked to hear this podcast from Dr Alan Mead of Dental Hacks fame on CAD-Ray.com and the Medit i500
Here’s the link
When you start a case in exocad or in Meditlink, you have to define a project or define the job by entering a prescription. A dentalproject file is created that has all the pertinent data, like the type of restoration, the shade, the material, parameter settings,etc..
After the case is designed a dental cad project file is formed, along with the stl file of the restoration, accompanied by the construction information. Once the construction file is formed, the case can be import it into CAM software like cerec inlab. It carries a lot of information like the margin line.
Some CAM software can process simple redirections without the need for any other pertinent information from the construction file, while others require it. Some are so specific that a simple typo or wrong character will lead to mis-production.
In the case of cerec inlab, it’s best to have the construction file accompany the stl of the restorations, although there are numerous work-arounds in case you don’t. Once processed, the restoration is taken to the Mcxl milling machine.
Why are we so focused on teaching this concept ? Because it is critical for milling metal abutment where you have to keep track of an object that is cylindrical and symmetric in shape. The code in these files will dictate the indexing of the connections and how these abutments are milled.
This is the occlusal appliance that was milled and delivered from this patient’s scan approximately 7 days ago. The appliance did not need a single adjustment neither on the occlusal surface, nor in the intaglio.
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