FDW Concept Implementation in everyday practice

intra oral facial scanners cad

Dental News Magazine June 2019

From the desire to find a 100% predictable workflow in morpho-functional rehabilitation of patients through 100% digital procedures that require shorter prosthetic time, we put together a digital puzzle about which we will speak in the next few lines.

First of all we need the right equipment, tested and approved, to meet these high demands and here we speak of speed, precision and predictability in the work process.

After about 3 years of research and work to get these results we can confirm that we can easily achieve these cases with the help of advanced technology.

List of necessary equipment

1. Facial Scanner

Why facial scanner? The documentary protocol will no longer have the photo included, because now the 3D face capture technology is advanced enough to be used in planning our cases.

Some scanners are quite inaccessible due to their higher price or difficult use, although we can identify some apps that are sold on the market that can turn the mobile phone into a facial scanner. Be aware that when choosing your facial scanner you have to make sure it has a integrated workflow in order to be able to use it in everyday practice. For example, phone apps for 3D face capture have distortions and are not accurate due to algorithms that are meant to smooth the face skin, which can distort the final results. 

You need a dedicated facial scanner with integrated workflow and especially the ability to do multiple body scanning in order to transfer vital information into the 3D design of the future smile.

So far it’s simple, but what are body scans and how can they help us? For the AFT scanner we have two such accessories:

  • a leading body scan
  • a body scan for your mouth

They are positioned according to the training that you benefit from when purchasing the product, namely the leading one is positioned on the front of the patient and is fixed well because it’s being used throughout the scanning period. The mouth accessory is fixed intra orally with the fingerprint material in the intra oral component of this accessory, and the extra oral accessory remains out to be scanned. 

After that we save the data into the EXOCAD CAD design software, where we can see the exact position of the jaw in the patient’s head, the same position as the patient’s jaw position. Thus, we no longer need a jaw guidance, which makes it easier to simplify the workflow by acquiring highly accurate data.

The design software allows us to place the patient’s head and intra oral stl file with great precision in the virtual articulator, and then we can begin designing the new smile with respect to the patient’s face. Until now, this was completely lacking and all protocols relied heavily on a 2D picture which was not enough.

With the help of the virtual articulator, once we finish the new design, we can create a prosthetic piece, both aesthetic and functional. The most important thing is that we can now communicate more easily and precisely with your physician allowing us to connect computers or apps in real time, thus actively participating in the design and confirmation of the final design.

2. Intra oral Scanner

The multitude of intra oral scanners and prices can give you headaches in choosing them. Before purchasing, you should know how accurate the data acquisition is, how reliable it is and how much it is appreciated in the work protocol. Our choice was the MEDIT i500 new Korean scanner of high precision and speed.

WHY MEDIT? Simple:

• Accuracy and speed

• Color scanning

• Easy to use interface

• Free updates

• Very good purchase price

• Exports STL and PLY files

• Zero annual fee

These reasons are almost enough, but it’s always a good idea to read the reviews of other experts and real feedback of real users who already have this scanner. We use it successfully in courses already and in patient cases, of course in combination with the facial scanner for higher predictability.

One of the best advantages of this scanner is the
reduced weight and the smaller head than the next one on the market, so the acquisition of the data, ie the intra oral impression in hard-to-reach areas, is much easier. Imprint time is much lower than the classic version, which of course implies lower costs.

The impression does not suffer from contractions and the printed model is 100% faithful, which helps us eliminate the two major causes of errors in the prosthetic parts. As with analog impression we still need to use the retraction cord as it’s not possible for any scanner to access the sub gingival area.

Intra oral scanners can also be of use in cases where no photos are needed. You can store .stl files on your computer before and after the end of the case. This way you can have the patient’s three-dimensional real situation at any time. 

3. CAD design – EXOCAD

Once you’ve acquired the .stl files from the facial and intra oral scanners, you can integrate them into Exocad and you can accurately plan the new design for the prosthetic piece. The project will be part of the facial and intra oral scanner file superimposed by the two types of scan bodies, the result being one of great precision when compared to cheap scanners without working protocols. Both the front of the patient and the intra oral situation will be visible on the screen, so we will be able to use the virtual articulator and we can function the prosthetic piece.

When finished, we can show in real-time to the physician the new design for confirmation and/ or on request, we can make small adjustments of shape or size. Now there are dozens of teeth libraries, from which we can choose a morphology/ shape that best suits the situation, especially as planning is being done on a simulator, identical to the patient. The new smile will be made taking into account the interaction between the teeth, lip and face of the patient.

We can also add the CBCT of the patient if we need the hard and soft tissues for a more accurate planning if implants, bone remodelling for coronary elongation, etc. are required.

4. 3DPrinter, SHERA print30

Once the design has been completed and we have the physician’s/ patient’s consent,

we can go to the last stage of planning, namely the printing of the new design. Here are three possibilities:

• Printing a block model and making a silicone key – the classic method

• Printing a silicone key and making a mock-up after this key

• Printing the initial situation without preparation and printing the mock-up veneers, the full-digital, fastest and most accurate method. 

If we are to implement the latest method, namely the direct printing of veneers, you need to know that it is the fastest and most accurate. The greatest advantage is that it can be “customised” by the physician directly into the patient’s mouth and can be rescanned to serve as the ultimate design. The patient can thus benefit from a real “testdrive” of the new smile. 

After final acceptance, this design can overlap on the final digital impression with preparations and can replicate 1 on 1, so the patient and the doctor will not have unpleasant surprises to receive restorations that do not resemble the initial stage teeth.

As a variety of materials we can mention:

• hard resins for creating working patterns or surgical guides

• resilient resins for making the gum or silicone-type keys for mock-up

• aesthetic hard resins for veneers used for mock-up

• total burning resins for pressing technique

This printer uses DLP technology and is very fast, being able to print two Geller arcades in less than an hour, or 30 crown veneers in less than 45 minutes being net superior to the quality and speed of any milling machines. 

We can be highly predictable from the planning phase, with the new design, and we can accurately measure the length or width and even the thickness of the future prosthetic piece. Moreover, we can measure the distance between the lip and the teeth and we can influence the thickness of future veneers to create an ideal support for the lips.

Following the design we are ready to print the veneers, as you can see the result in the following pictures. The patient has confirmed and accepted the treatment plan and we will proceed to the next stage, namely the completion of the case with minimally invasive veneers with Dr. Dan Patroi. 

MATERIAL used for milling

After everything is properly planned and we have already approved the final shape of the veneers/ crowns, we can use a wide range of materials for an optimal aesthetic result:

• IPS e.max CAD in colors A1 – D3

• IPS empress CAD multi in colors A1 – D3

• IPS e.max zirCAD LT & MULTI

• Telio CAD

Miladinov Milos (dentalphotography@yahoo.com) – dental technician

Arnold Forray – dental technician

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