Bench Mastery: Long-term temporary with CAD/CAM

As any technician can attest, technology is ever-changing and quickly rewriting the way we fabricate our dental restorations. This includes provisionals, which is what we will discuss in this particular case study.

I had been used to creating temporary restorations using an acrylic heat-cured method, which was both time-consuming and labor-intensive. But with the advantages we see with digital technology by CAD/CAM milling machines for implants, long-term temporary restorations are much more simple to create-even the All-on-4 type of implant restoration.  

This provisional stage is especially important for the technician and patient to determine comfort and fit level for the final prosthesis. Once the patient approves the fit of the provisional, the technician is able to duplicate it for the final restoration.

Check out this video with images from the restoration ...

Case Study01 In Fig. 1, the lab received an impression for an All-on-4 implant case, which is pictured here before pouring up the model.

02 In Fig. 2, the soft model was poured up using the temporary abutment. The CAD design was created by the Amann Girrbach Map 400 Scanner (Fig. 3).

03 In Fig. 4, we see the computer design created by the technician. We are able to use the library to verify access holes to navigate future prosthetic options. In the front view (Fig. 5), the size of teeth, shape and contour is all controlled through this design process. It is easy to work with the software and create a unique design for the patient’s particular situation. Premiotemp by Primotec is a multilayered PMMA material that is made with multiple layers-including translucency (Fig. 6). This leads to a very life-like provisional result for the patient.

Click here to see the final results of the restoration process.

04 I tried to fit the shape of the restoration to the cylinder of the abutment and screw it all the way down on the model (Fig. 7).  

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Check out this video with images from the restoration ...

05 Fig. 8 shows the die fit to the cast model. Next, I used GC Gradia Light Cure Dentin material for bonding (Fig. 9).  

06 The restoration is next fit to the model in this facial view image (Fig. 10). Using a medium pumice, I applied polish to the restoration (Fig. 11). After cleaning the polish off the restoration, I dried it and inspected it for an appearance check (Fig. 12).

07 Finally, I applied a high shine polish (Fig. 13) and checked the fit on the model (Fig. 14). In the mirrored image, we see the 10-unit provisional implant as a finished restoration (Fig. 15).

Conclusion
Prior to this technique being available for technicians, creating a temporary such as this one was much more of a struggle. Now, it’s possible to make a better temporary for patients, with excellent results in less time and maximum profit. It’s an amazing step in technology, and clinicians should be happier with the worry-free delivery of the patient’s restoration in a minimum amount of time.

ABOUT THE AUTHOR
An accomplished dental technician with more than 20 years of experience, Luke S. Kahng, CDT, is the founder and owner of LSK121 Oral Prosthetics, a dental laboratory in Naperville, Ill. He has published more than 85 articles in dental journals, and his lectures have taken him across the United States and internationally. He is the creator of the Chair Side Shade Guide Seasons of Life, 3.0, 4.0, 5.0, 6.0 and 7.0 ceramic shade tabs, which were invented to facilitate effective communication regarding color between doctors, patients and technicians.

This article originally appeared in the February 2014 issue of DLP. For information on other great techniques and lab products, subscribe to DLP's weekly newsletter: http://bit.ly/dentallabenews.