One of the most important lessons a digital dentist has to learn quickly is how to not introduce errors when scanning dentition. The most likely area when s/he can introduce errors is in the anterior area where the incisor are not only narrower than molars but can also have translucent enamel. Add just a little spacing between teeth with diastemas and you can quickly distort the accuracy of the model. This is true of ALL intra-oral scanners in the market
There are a few ways you can overcome these issues and the second video highlights some of our preferred methods. The concept is easy- block the light from travelling through the tooth structure and you are set! Watch the videos to learn how to do it
Here are some examples of how light shinning through the enamel and /or ceramic instead of bouncing back resulting in errors in model accuracy. Lesson #1 for every ios user is to know when and where they are likely to introduce error. in dentate cases, it usually is right that the transition from premolar to canine to lateral. The surface area decreases dramatically and if you have translucent enamel and / or material and / or highly reflective surfaces you can “derail” the model building. Here is an exaggerated demonstration
Translucent enamel can also play a role in distorting the cavosurface margins of a inlay or onlay restoration. When imaging from the occlusal, the gingiva below the margins acts as a barrier to block light transmission through the enamel, but as soon as you start to roll the camera to the buccal or lingual, and you have enamel with no substrate behind it to block light transmission, you can introduce errors in the equation with any scanner.
There are many ways to combat this which include powdering the tooth structure, using a rubber dam, or in Medit’s case, you can use the color subtraction filter. You selectively tell the scanner to ignore certain colors and you use that exact color (here, it is the color of the glove) to block light transmission through the enamel. So the software just ignores the blue, but the light is prevented from shining through reducing the errors you would introduce.
At CAD-Ray, we have now designed over 20,000 implant cases since 2013. One of the most common requests we get is from doctors doing full arches and their desires to reduce the conversion time. A simple thought to keep in mind is that A LOT can be derived from the actual implant plan, even if you don’t do the surgery guided. You can extract the digital implant positions and fabricate temps and based on your level of experience, your conversion / temporary time can drastically reduce.
Another very helpful matter to keep in mind is a concept we preach a lot at our courses. It deals with relating models to each other, both automatically and manually. This can be a CT scan to an intra-oral scan, or a pre-op to a post op. You just have to find redundant landmarks for the software to merge the models together. One thing to keep in mind, particularly with the Medit i500 is that when you merge models to each other and process it, their relationship to each other is preserved.
There is a lot of benefit that can be derived from that. For example, in this video, we have the dicoms converted to surface STL’s which is very easy to do. We also have the intra-oral scan merged to that stl file. You can digitally extract the teeth and do bone reductions, and if you are ever in a bind where you lost track of the vertical dimension, you can use the jaws as the means to related the preop to post-op. Or you can even use the nose if you are really desperate.
in this case we import multiple models, videos, CT scans, and Face Scans so that our users can utilize all of these features. Click here to enter the member’s section to download the whole case and design along
here is a list of why the Medit Artificial Intelligent Implant Suprastructure Identification System is significantly more advantageous over all other cadcam systems.
- It s technically a crown and bridge case and the implant location or timing does not matter
- You can find margins outside the mouth! See the first video to appreciate the significance of this
- You don’t have to deal with retraction or hemostatis at all
- You don’t have to worry about sprue position. Many other systems force the placement of the sprue to a specific location often making the case more difficult to manage than necessary
- you are not limited to just a few implant lines
- you don’t have to worry about location of anti rotational notch
- you can digitally alter the prep and get a virtual reduction coping in cad
- Use any restorative block you want. There is no need to order special blocks with pre-fabricated access channels and keep a large inventory of many colors. Your regular block inventory will suffice. Just make sure the top of the tibase is wider than the diameter of the drill used to mill out the intaglio. Also, the CAM and the milling machine determine the exact product and different settings maybe utilized to give you relief off the walls. Some will even remove the antirotational notch because the adaptation is so tight, the restoration will not rotate due to the tall walls of the tibase
- You can check the fit outside the mouth on the same tibase or a one you keep chairside for every case to let you know that if you are not seating, it is clearly a contact or contour issue as opposed to an intaglio issue.
With Medit’s Crown Fit function, you can see exactly how much cement is required to seat the restoration and how well it is adapted to the tibase.
The following pictures depict the sequence of burs we recommend that you use to finish a preparation quickly. While patient is getting numb, take a quick look at the clearance you will need to reach proper material thickness. Once the quadrant is isolated with isolite and optragate, take an occlusal router bur and create a trough to gain the proper depth. Follow that with a flat disk, and you can quickly reduce the occlusal height.
A shoulder bur of .8 mm thickness can help you reduce the interproximal areas as well as the buccal and lingual margin lines. Before finishing the prep, place hemostatic agent like expasyl in the sulcus and place retraction cord. while it is setting, check your reduction. If you need more space, now is the time to reduce some more.
Once you have adequate clearance, retraction, and hemostatis, you can readily image and find your margins in the CAD software
Shining3d has a projector and a single camera that takes photos of the surfaces it is scanning. at first, you may think this is a shortcoming, but in many ways, it dramatically reduces errors a new user can introduce.
in the early days of cerec, all you needed to do was capture the margins and the area above the height of contours of the adjacent teeth. This made the try-in and the contacts really easy as the design software just dropped straight a straight wall down to make contacts to. same concept here!
also, after you image and place margins, A SINGLE CLICK takes you to design software where you can finish the case and mill it right away.
One of the big limitations of CEREC (a registered trademark of denstply sirona) with tibases and implant crowns is that it is limited to very few implant lines and the antirotational notch can just ruin your day as it needs to go into a specific location. You also have to deal with making sure the tibase is seated all the way and the scanbody is properly indexed. The one benefit is that you are dealing with just crown and bridge and you do not need to know implant position or timing at all when doing the design.
In this case, we demonstrate how we utilize the Medit i500 to capture a Tibase from Blueskybio, Biomax NP Conical Connection. Once the tibase is seated, we simply start scanning and then use the artificial intelligent implant suprastructure identification system to identify the location of the tibase. This in essence allows you to capture your margins OUTSIDE the mouth and you don’t have to bother with imaging the tibase, which is highly reflective in the patient’s mouth.
Once processed, you can then modify the tissue digitally and gain access to the tibase margins. You can print the model if you want and manufacture the restoration. In this particular case, we took the design to the CEREC mcxl inlab cam, nested it, and milled it out to demonstrate how we can image with one device from one manufacturer and fabricate a restoration by another company’s manufacturing machine. But the single greatest benefit is that you can place the sprue wherever you want.
IMPORTANT NOTE: The Tibase that you use MUST be wider than the drill milling the intaglio and the sprue must be thick enough to handle the milling process.
Once you understand how the digital workflow goes, you can image with one device, design in another, and then either print or manufacture with yet another device. Here we mill a sectional stent with the cerec that was designed in Blueskybio plan, although printing makes more sense because it is less wear and tear on your drills
PRODUCTS USED IN THIS CASE:
If you place enough implants, you may find yourself in need of a prosthetic part that just isn’t manufactured by anyone. For example, you may have a hybrid case on Bicons and for some reason you wanted to restored them with Multi Unit Abutments (MUA) and photogrammetry, yet there are no parts manufactured for such an endeavor. The problem is complex because a manufacturer needs to mass produce these parts and get them past regulatory matters.
Some have found a simple solution, which is to have the parts custom made specifically for the implant. If they need the MUA part before the procedure, they just send a digital or physical model into a lab that can custom make the part. The lab itself needs a prescription form on the lab analog. Since it is custom made, you have direct input on how tall you want the height of the margin, how much you want to displace the tissue, how much would want the restorative head angled, etc..
Most people will order a variety of them to address any situation on the same model and keep it in stock. What’s important to realize is that from the restorative standpoint, all your CAD software needs to know is the location of your abutment margins. It doesn’t care where fixture is and how the timing is lined up in the arch form. As long as it knows where the margins are, you can proceed with the design of the prosthesis.
Contact Andrew Seddler to send a digital or physical model and an Rx to get your custom made MUA’s
A dentist from Australia named demonstrates in this video how you can scan with the Medit i500 and import the stl file into CEREC Inlab18, design a restoration, and fabricate a restoration.
This is a great option for CEREC users who want a second intraoral scanner or want to upgrade from bluecam to a color scanner, even though you can’t design in color
DISTINCT ADVANTAGES OF DIGITAL IMPRESSIONS
Here are two very simple examples of clinical advantages of digital impressions over analog ones. You can edit or add to your models and you can work independent of time and sequence.
You can also know immediately if you have captured your margins correctly. Once you understand these concepts, there are dozens of ways you can apply these principles to make some of the most challenging clinical cases very easy to manage
FIND OUT HOW RESTORING IMPLANTS CAN BE THE MOST PREDICTABLE PROCEDURE YOU CAN DO
For decades, placing and restoring implants was a very stressful and unpredictable procedure. Digital dentistry has reversed that trend, making it now the most predictable procedure you can perform. You can easily capture contacts, opposing dentition, and the location of the implant. More importantly, you can design the emergence profile to your liking.
SEE HOW EASY IT IS TO ADD A CONTACT TO A RESTORATION WITH AN OVEN
Emax restorations are milled in a pre-crystalized state (blue phase) as it is more gentle on the drills than the final crystallized form. A big advantage of emax lithium dissilicate material is that you can easily add contacts with addition powder in the same cycle as glazing. This reduces the stress of try-ins and allows you to recover without wasting precious time. Other materials on the other hand may require extensive oven times or a re-mill (or send the restoration back to the lab)
upper denture duplicated with shining 3d. only needed the occlusal and buccal surfaces as the case is for a lower overdenture over immediate extractions, on healed implants. went ahead and just duped the whole denture with the ios. very good results
took off lower temps and scanned lower jaw. remaining teeth were used for long term temp abutments while implants healed. digital extractions performed and right vertical dimension for digital prosthesis design
Full arch imaging of mandible in preparation of overdenture
buccal bite taken intra-orally to mount arches at proper vertical dimension. you can see how the camera performs in this challenging case
Digital extractions performed in preparation for overdentures
Overdenture Design and Fabrication
If you’re experienced with CAD/CAM technologies in dentistry, you probably already know how important file types and system integrations can be for the outcome of a project.
In this video, we briefly preview a workflow that is 100% digital and allows the user to freely select which products and programs they want to use within the phases of production.
Practicing with open system technologies puts the user in the driver seat allowing them to maintain control & freedom.
Furthermore, as time goes on these users can freely replace and upgrade components according to their treatment plans and the rate of innovation.
In conclusion, once doctors decide to upgrade their practice into digital workflows, they should invest in open system technology. When they make this decision they will experience several advantages such as cost savings, flexibility, more product options, and future proof set ups.