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Digital prosthesis in implantology #1

Bellatek Encode technology (Zimmer Biomet) enables the prosthodontist to conduct his dental impression without the use of impression coping and to get a shaped abutment by CAD/CAM.

All surgery and prosthesis steps using Bellatek Encode technology for a treatment employing an impression technique with classical impression materials were detailed previously (posts « Adieu les transferts d’empreinte »).

In the continuity of the Bellatek Encode technology and thanks to the advent of digital tools available in the dental office, we are going to see in this post the direct CAD/CAM and semi-direct CAD/CAM’s contribution in implant prosthesis.

Three categories of CAD/CAM exist : direct CAD/CAM, semi-direct CAD/CAM and indirect CAD/CAM. In the context of this post, we will focus to the two first ones.

Direct CAD/CAM set is composed of 4 links : intra-oral cam, CAD/CAM software (CAD software and CAM software) and a milling unit. In this production environment, all procedures are performed in the office. The prosthodontist accomplishes digital tasks (optical impression of the patient’s dentition) and prosthesis CAD. CAM tasks and milling are achieved automatically, so prosthodontist task is limited to introducing cerec blocks and to check the proper functioning of the milling unit. The advantage of this technology is the complete realization of the prosthesis in the office with only one appointment.

As for semi-direct CAD/CAM, it allows to share the digital tasks.
The prosthodontist always performs an optical impression to achieve a virtual master cast. Then the latter is sent to a prosthesis laboratory which realizes CAD/CAM tasks and prosthesis milling. Two appointments are necessary in this case, one for the optical impression and another for the assembly of the prosthesis.

Alternatives of this two productions chains can be found. The subcontracting of CAD/CAM tasks to a laboratory is possible. In certain clinical situations, the prosthodontist who is equipped for doing direct CAD/CAM can be led to subcontract certain tasks either if they can’t be achieved with the links of his CAD/CAM chain or if it’s preferable to subcontrat achievable tasks for various reasons (like for the Bellatek abutments). The prosthodontist is going to do direct CAD/CAM and semi-direct CAD/CAM as part of a prosthetic treatment realization.

Through a clinical case, we are going to detail all the steps allowing the realization of an implant prosthetic rehabilitation due to the use of direct CAD/CAM and semi-direct CAD/CAM. Bellatek Encode technology used for this treatment is connected to the Sirona Connect system.

This is a 45-year-old woman in good health needing a prosthetic rehabilitation of the left maxillary posterior sector.
The treatment plan is the following :

  1. Left maxillary sinus rehabilitation
  2. 3 implants placement
  3. Production of an implant bridge sealed onto 3 implants abutments

First, a sinus-lift of the left side is performed with an allograft in the form of bone chips (Biobank) (figures 1 to 6).

Six months after the sinus graft, 3 implants Biomet-3I are inserted in one surgical step with specific healing abutments : the Bellatek Encode (BE) healing abutment (figure 7). The caracteristic of this healing abutment is the occlusal side which is encoded (figures 8 and 9) and is going to allow not to use impression coping during the implant impression. The BE healing abutment is connected to the implant during the implant surgery and it’s as if the patient had the equivalent of an impression coping inside the mouth. The number of screwing/loosening of the healing abutment is reduced to one cycle. The latter will occur during the insertion of the bridge.

Three months after the insertion of the implants and the confirmation of the osseointegration by the surgeon, the prosthodontist conducts the prosthetic part of the treatment in two stages :

  • Fig. 10 : Cerec Omnicam unit ( computer and cam)
    Fig. 10 : Cerec Omnicam unit ( computer and cam)
    The first session (semi-direct CAD/CAM) consists in taking of an optical impression of the patient dentition with the BE healing abutment connected into the implants with the CEREC software (CEREC Omnicam unity, computer and camera (figure 10)) for the purpose of the making of the CAD/CAM custom-made implant abutments (Bellatek abutments). It’s mandatory to respect the current protocol as for an impression taken with classical impression materials (BE healing abutment perfectly cleanded up, X-ray inspection of the abutment adaptation,etc…) However, an additional handling is necessary because of the very smooth metallic surface of the BE healing abutment, which is very hard to record without contrast product : it’s the powdering of the BE healing abutment. Once the digitization is finished, the prosthodontist goes online to create a Bellatek Encode order form (« connect stage »). Patient data are automatically uploaded and sent to the laboratory « Biomet 3I PSP ». An order confirmation from Biomet 3I is sent by e-mail within 24 hours to the prosthodontist. Then, 48 hours after the order confirmation reception, a design proposal is sent from Biomet 3I by e-mail to the prosthodontist. This latter must validate this design proposal. Once the proposal is validated, Biomet 3I produces and sends the custom-made abutments to the prosthodontist.
  • The second session (direct CAD/CAM) is about the Bellatek abutments installation and screwing, then the taking of an optical impression with Omnicam. The powdering is not necessary any more because of the sanding or any other preliminary treatment of the abutments. A virtual master cast is obtained. The prosthesis CAD can begin : the design enables to create a truly custom-made prosthesis (contact points, occlusion, embrasures). Then, the prosthesis is prefigured in a block (IPS Emax B32 by IVOCLAR VIVADENT (figure 11)). Once this step is validated, the machining begins (CEREC MCXL premium milling unit by SIRONA (figure 12)). Once the machining is finished (between 30 and 45 minutes), the prosthesis is tested and rectified in the mooth. Then the prosthesis is put in the oven (Programat CS2 by IVOCLAR VIVADENT (figure 13)) for crystallization and glazing during 25 minutes at 840-850 degrees Celsius (for the E.MAX). The prosthesis is taken out from the oven, and then prepared for placing in the mouth.

For the next three posts, all steps will be detailed and iconographied for the production of an implant bridge sealed onto 3 implants abutments.

All surgeries (sinus-lift and implants placement) were performed by Charles-Henry Sénéchaut.
Prothesis was performed by Steve Dohan
Did you integrate in your daily practice the digital technology ?
If yes, for which applications ?

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