Digital Dental Impressions with Intra-Oral and Desktop Scanners
Imaging reflective surfaces like gold is often difficult with intra-oral scanners. In this video, you can see how the whole occlusal surface of the gold crown is captured with the Medit i500 and the contact area as well. It is certainly not flawless, but it works great. No powder or dusting was used here and no animals were harmed in the process either. Take a look at how nicely visible the margin is on the mesial of the second molar!
This is the triple tray technique used to image the prep, the opposing, and the bite with the Medit Desktop Scanner by Burbank Dental Lab. Not a single contact was adjusted and crown fit perfectly!
[videopress QRPhcJb9]Fit perfectly. Not a single adjustment to the contact area or the occlusion
Here’s a straight forward scan of a molar crown prep. You can see how angling the camera helps you capture the contact areas of adjacent teeth. You can spend a little more time capturing more data below the height of contour, but that is not necessary as you won’t be making contact to that area (otherwise you won’t be able to seat the crown).
You can see the rest of the process of imaging the opposing and capturing the buccal bite and articulating the models together in the video. With the color capture, more often than not, it is not necessary to retract the tissue to visualize the margins.
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Many intra-oral scanners struggle with “black triangles” where there is tissue recession. Another area that is difficult to capture is the distal of second molars. Here is a video that shows a live scan with the Medit i500 that starts from the mid-line and images all the way to the second molar, captures the distal of the second molar, crosses over to the palatal and scans from to the contra-lateral second molar.
Once the distal of the second molar is captured the camera is rolled to the buccal, and the imaging continues to the midline, on the facial. The second video shows the upper and lower arches articulated together
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In this video, you can see how easy it is to image both arches and capture all the margins and contacts. There are certain areas that are not necessary for you to capture. For example, in contact areas of adjacent teeth, you do not need to image anything below the height of contour of the adjacent teeth, since you won’t be making contacts to those areas.
This is an upper and lower case that is scanned with the Medit i500 intra-oral scanner. The lower arch was prepared first and imaged and saved. Then the upper molar was prepared and scanned as well. The bite was captured from the buccal while the patient was biting down in maximum intercuspation. Tissue retraction was not necessary in either case as we could discern the margins simply by the color difference between the tooth structure and the tissue.
The software allows you to export the file in STL, PLY, or OBJ formats. When just submitting an STL file to the lab, the color difference in the model is not transmitted. But with other formats, you can easily convey to the lab what you see clinically.
Image of case exported as STL
Image of case exported as OBJ
Delivery of the restorations, fabricated by Burbank Dental Lab. There were no adjustments made to the contacts or to the occlusion.
Scanning with the Medit i500 for full arches is relatively easy, as long as you keep a few important items in mind. Unlike most iOS (Intra-Oral Scanners), humidity and fogging of the lens is not an issue. Isolation helps a lot; in particular, lip retraction is essential. The optragate does a great job with keeping the cheeks out of the way.
The software is pretty intuitive and can remove tissue that moves during the scan. It assumes that tissue movement is not part of your model and it automatically removes it. Sometimes, the lip gets in the way too often, and the software starts to think it is part of the equation and leaves it around. This is an easy issue to resolve with a number of tools available to you.
There are free form tools and brush tools that can help you easily adjust and edit areas and re-image the areas by reactivating the camera and fill in the voids. In this video you can see how easily you can reverse some steps and make appropriate adjustments. The Undo and Redo feature also helps when you are in a bind that can take you back in stages. If you inadvertently overdue an edit, you can simply press forward and it will add those elements back.
Every intra-oral scanner struggles to some degree with imaging certain materials and has a focal length that makes it difficult to image deep margins. The difficult materials are the reflective ones; like eMax, metal abutments, and zirconia. Some machines even require you to mask or opaque these materials before imaging them.
Conversely, most scanners do well with imaging soft tissue. The depth of the vestibule and the focal length of the camera determine how well you can pick up these areas. The video below shows an initial test and more particularly a technique where you pick up soft tissue and natural dentition as your landmarks and start developing full arch scans around these “anchors”
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The video above produced this detailed image performed with the Medit i500 camera. Total time taken to image this arch was about 5 minutes, two to three times longer than normal because every single tooth in the arch was restored with eMax. Only the anterior lingual are natural teeth. It is just a preview of more things to come from CAD-Ray.
The laptop used had the following specs:
It’s always a good idea to take photos of everything you unpack whenever you purchase any equipment or technology.
It helps you keep track of all the items and where they belong, before you start installing it. Oh and reading the manual helps as well. As of July 14, 2018, you need software version 1.1.0.0 which you can download from meditlink.com
CAD-Ray Distribution LLC has a training facility located in downtown Los Angeles that also operates as a full service dental practice. We house and operate imaging machines for digital impression, we can take CT images on patients, and we can fabricate restorations in house.
We also have a close working relationship with Burbank Dental Lab which houses a variety of milling, printing, and fabricating machines.
Our programs are designated for CE credit by CAD-Ray Inc.
Introducing the CAD-Ray Obstructive Sleep Apnea Device, manufactured by Burbank Dental Lab. This appliance is printed with an FDA approved material by an FDA certified lab. They also happen to print thousands of surgical stents and models with a variety of printers.
You can submit your case digitally and the whole process is done without pouring up any models or suck-down stents. Printing vs. milling also has a lot of advantages with faster turn around time and less cost. Instead of delivering a device that has to meet minimum thickness requirements that inadvertently increase the patients vertical dimension, this oral appliance is ultra thin and durable.
In this video, you can see the required thickness of some materials that increase the vertical dimension to the pointy that they may cause discomfort. Moreover, we can customize the design to include small hooks and knobs, in which patients can even use orthodontic rubber bands, reducing the bulk of the material significantly.
These cases can be submitted through the CAD-Ray portal for design, sent to Burbank Dental for manufacturing (printing), and returned to you in a short period of time.
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If you are risk averse and want to take your first step into digital dentistry without altering a single thing you do in your practice, consider a desktop scanner, like the Medit T500. Combine the traditional H&H technique in a triple tray and then place the material on the scanner. In minutes you can capture the prep, the opposing, and the proper occlusion. It is incredibly accurate because you don’t pour up the impression with stone where you can introduce errors.
Here’s a video of how to take an H&H impression from YouTube by Dr. Marty Jablow:
In this video you can see the set up to scan a triple tray H&H impression. Just mount the tray on the table and insert into the imaging box. With a couple of clicks, the software automatically rotates the table so it can image everything captured by the PVS material:
[videopress jhycrnD0]Watch hour you can see how the table move so that the camera can pick up images well beyond the flash left by the PVS material
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Once the impression taking is finished, the models are rendered and you can proceed with the design. You can see in this video how readily visible the margins are and how properly the models are articulated together. The fact that you don’t have to pour up the impression material with stone, you are not likely to introduce errors in topography of the models.
[videopress LKxe6UtC]This is a very simple way to digitize alginate impressions and triple trays in your office and not waste time pouring them up. With a click of a button you can send the data to a lab or design and fabricate the restoration in your office.
Here’s is the stl from the scan that was imported into a software called meshmixer to visualize the three dimensional model and the the detail
[videopress TYse603p]click on this image to download the stl and see for yourself!
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