Do it all or not at all

The path to functional and aesthetic front teeth restorations by Dietmar Schaan, MDT and Knut Miller, DT – part one.

From the implementation of a precision model and the transfer of patient data into the Ceramill CAD/CAM system. To the construction and production of the final result. Dietmar Schaan and Knut Miller present a five-part article to explain an ideal step-by-step procedure to achieve functional and aesthetic front teeth restorations.

All or nothing

This is how the Amann Girrbach motto could be circumscribed. With Artex articulators, the company also set new functional standards and became a global player with the Ceramill CAD/CAM system.

From the very beginning, the dental specialist focused on the complete chain of dental technology processes to be able to ensure both utmost functionality and precision. The objective and purpose of the Ceramill system has therefore always been a functional framework based on state-of-the-art technology, which, if possible, will satisfy all the user’s wishes.

Continuous research and development has led to a refinement of software, products and process steps, which are, today, perfected in the ‘digital-function prosthetics’ (DFP), a holistic method to produce a functionally flawless dental restoration – with high precision and maximum profitability for the laboratory.

The first part of our article series deals with the acquisition of patient information using dynamic data, model production, articulator programming and preparation for virtual implementation.

  • front teeth restoration
    Figure 1: The patient’s situation prior to the grinding of the anterior teeth

Individual patient data

Today, an increasing number of restorations are produced using a digital workflow. With materials that are consequently suitable for use by a CAM system.

To produce dynamically functional dental restorations, the transfer of individual patient data into the CAD software is indispensable. Since the dental technician still needs various impressions of the patient situation. (Figure 8) It would be an advantage for every restoration, if further patient information would be available.

The dentist can then transfer these individual, static and dynamic registrations to the dental technician at a relatively low expenditure.

An indispensable element of the patient data is therefore the face-bow registration (Figure 2).

  • Figure 4 and 5: Left and right laterotrusion registration for determination of Benett angle on the left and on the right in the Artex CR

This is used to transfer and integrate the maxilla into the articulator in relation to the cranial axes. (Figures 15 and 16).

If the dental technician can find the centric occlusion by way of centric relation. (Figure 7) And, if he can thereby eliminate troublesome early contacts, there is nearly no hindrance left to a functional dental restoration.

  • gingival masks
    Figure 12: The master model with its individual segments, stumps and gingival masks

Using dynamic bite registration (Figures 3 to 6), the individual values of condylar path inclination (Figure 19) and Bennett angle (Figure 20 and 21) can be programmed individually on the articulator.

With these parameters, a functioning articulator in the CAD software enables the user to include all functional processes into the restoration, as early as during construction.

From analog to digital

The dental technician already lays the foundation for a well-fitting and functional restoration when producing the model. With the segmented models and the resulting expansion control (Figures 12 to 14), he is in the position to make precise statements on which parameters we have to include in the construction.

Besides the supplied patient parameters, the dental technician is able to determine the anterior and cuspid situation. They do this using the individual anterior tooth-guidance unit. (Figures 23 to 30) And it’s possible to reproduce it, subsequently, using the virtual articulator during construction.

  • Maxilla and mandibular situation
    Figure 18: Maxilla and mandibular situation in the Artex CR with the individual front teeth guidance unit

Figures 24-29

  • Front teeth
    Figure 24: The displayed front teeth guidance angle: 46 degrees

The pictures clearly show which differences occur in the design of functional surfaces. If the anterior tooth guidance is lost due to front teeth preparation and, if the technician uses the posterior teeth guidance by mistake. (Figures 31 to 33).

  • front teeth guidance unit
    Figure 30: Laterotrusion left with the maxilla master model under guidance of the individual front teeth guidance unit

When the analogue world meets the prerequisites for a functioning restoration, the path to a successful restoration in the digital world is open. The next article will deal with various Artex articulators, their calibration, the individual anterior-teeth guidance positioner, as well as their individual programmings and 1:1 transfer of patient data into the Ceramill CAD/CAM system.

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