Making the move to digital impressions with the CEREC AC Connect from Sirona Dental Systems

I guess one could say I was not instantly convinced. My introduction to digital impressions began in 2003 with a CEREC® 3 demonstration at a dental convention. From the beginning, I was fascinated with the digital imaging portion of the technology, but was resistant to change.

I had to weigh my intrigue with computers and new technology against the practicality of introducing this new technique into my practice. I had many questions about the learning curve and the training, the fit of the restorations and how patients would accept the procedure. 

While I loved the digital imaging part of the system and liked what people told me about their chairside experience with CEREC, for me, the milling was still an issue. I told my sales rep, “When Sirona comes up with a scanning unit that costs about $25,000 and a way to ‘zap’ a digital image over the Internet to my lab, and have THEM make the crown, then come and talk to me about Sirona Digital Impressions again!”

About a year went by. I was flipping through a dental journal and noticed an advertisement from a digital imaging competitor that used a digital imaging system. The technique required no powder, cost about $25,000, and the cases could be sent over the Internet for the lab to fabricate. After an in-office demonstration, I was excited and had the rep give me a contract to purchase the machine.

The day before I was to send the contract in, my Patterson sales rep came to my office and told me Sirona Dental Systems had just introduced the CEREC AC Connect system and it was worth investigating, because digital imaging without milling was what I wanted, and the purchase price was actually lower than my original intended purchase. Moreover, there are no additional scanning fees.I began my research, evaluating what others had to say and reading the research documents and evaluations that independent sources had provided. One researcher, whose opinion I value on most reviews, said, “If you are considering digital impressions, why would you consider anything else but Sirona?” That was a major factor in helping me make my final decision.

Why CEREC AC Connect

There are actually many reasons I chose Sirona’s CEREC AC Connect over other digital imaging systems. I quickly realized the extreme accuracy of Bluecam imaging and the technical support from Sirona simply afforded me the opportunity to do better dentistry. The Bluecam device is lightweight and ergonomically designed; it feels natural in my hand, not unlike holding a pen or pencil.

I also like that the image is instantaneously available for viewing and I can send my case directly to the lab. My CEREC AC Connect unit also allows me to mark my own margins directly on the digital impression. With other digital impressioning units, the image is sent to the manufacturer for prep margins, and is verified by the dental laboratory after the patient has left. I prefer having complete control of my impressions and margins from start to finish, and in real time.

In addition, the CEREC AC Connect’s small footprint is ideal for dental offices that are limited in space. It’s equipped with a convenient battery back-up so I am able to move the unit freely within my operatories, without the need to power down and then reboot the entire unit.

And while, in theory, I liked the idea of powder-free imaging, I noticed other systems that highlighted this feature were required to create many more images to “make up” for this lack of powder. With CEREC AC Connect, I typically take one-to-two images per tooth, and the job is complete.

My experience

I purchased the CEREC AC Connect in July 2010, followed by training with a digital impression instructor. After training, I began my first Sirona Connect case in mid-August. I then incorporated a soft tissue diode laser that October for gingival troughing, hemostasis and gingivoplasty. This has proven to be the most effective tissue management and digital impressioning combination for me.

In September 2011, I incorporated a second CEREC AC Connect unit into my practice. I use Sirona Connect for all of my restorative needs, including PFZ, IPS e.max® CAD, BruxZir®, PFM, PFT, all-metal crowns, onlays, inlays and veneers.

I am so happy I did my research and waited for the “right time” to incorporate this new technology into my practice. I am not against designing and milling, but for now in my practice, Sirona Connect meets my personal needs and practice requirements.

Using Sirona Connect has significantly increased the volume and quality of my restorations. My initial learning curve took about two months, without interruption in my daily schedule. Today, I can take a digital impression faster than a polyvinyl siloxane impression, and I have the option of a same-day turnaround on all of my cases. I average about 40 units of crown and bridge each month; one month I did 70 units with Sirona Connect.

Actual case

This case involves a 53-year-old female who had a fractured PFM on tooth No. 13 that was packing debris on the distal (Fig. 1). The plan was to remove the old PFM and replace it with a PFZ crown using Sirona Connect. Using an Isolite™ for retraction and isolation (Fig. 2), I removed the porcelain from the old PFM with a cross-cut diamond bur and grooved/sectioned the metal with a carbide bur.

After removing the old PFM, I placed a shoulder preparation to approximately the gingival height around the tooth (Figs. 3, 4). An Odyssey® 2.4 Laser by Ivoclar Vivadent was used for gingival troughing around the crown margin. I used the laser in the same manner that I used the “double cord” retraction technique.

I first troughed around the margins (“1st cord”), then scrubbed with a microbrush and a solution of 3% hydrogen peroxide to remove the tissue tags and any minor discoloration from the lasing. Following water spraying the prep for 10 seconds, I scrubbed for 20-30 seconds with ViscoStat® by Ultradent, which is a 25% solution of aluminum chloride, attached to an applicator brush. I left the ViscoStat solution on the gingiva for only 30-60 seconds, because of its low pH, followed by a thorough rinse of water spray.

After drying, I fine-tuned the final tooth margin to its desired position and the gingiva with the laser to the final desired height (“2nd cord”). In this case, I removed any remaining tissue tags from the troughing, scrubbed with hydrogen peroxide and ViscoStat for 30 seconds, followed by 10 seconds of water spray after each, then readied the prep by thoroughly air drying the tooth.

Next, I sprayed the tooth with CEREC Optispray®, identified the margins of the tooth preparation, and scanned the digital impression for tooth No. 13 (Figs. 5-7). An endodontic probe can be used to outline the powdered margins if there needs to be more delineation or contrast of the margins prior to scanning.
Advantages of the CEREC Bluecam camera include easy manipulation, easy placement in the mouth because of its small lens head and light weight, easy use on “gaggers” and other limited-opening patients, and minimal time needed to scan the teeth. After scanning the teeth, I have time to evaluate the digital impressioning image for detail and accuracy (Figs. 8, 9).

One of the beautiful aspects of digital impressioning with CEREC technology is the images are obtained in a controlled environment. There is a dry field and a dry tooth, with no moisture control issues either from oral humidity or hemorrhage, and there is time to take an accurate, distortionless digital image.

After the digital impression is taken, the next step involves mounting the case, drawing the margins and sending the case wirelessly to the laboratory via the Web portal. I send it back to my lab for evaluation, and then send it to infiniDent® for model fabrication using SLA technology. After fabrication of the model, infiniDent sends the model to my lab for fabrication of the final restoration, before being returned to my office for final cementation (Fig. 10). An overview of how Sirona Connect works is included (Fig. 11).

The possibilities

I’m often asked, “Don’t you have to be a computer ‘nerd’ to really enjoy using the CEREC system?” Absolutely not! Maneuvering through the CEREC Connect Software is simple, intuitive and easily learned. My dental team continues to be excited about the possibilities that

Sirona’s technology offers. Sirona Connect presents my dental team with not only excitement from a dental and technological standpoint, but also allows me the opportunity to educate the patient so he or she may experience a “wow” factor. Giving Sirona Connect brochures to patients encourages them to spread the word to their friends and market the technique for me. My restorations fit better than ever and the results have been a win-win situation for my patients, my staff and me.

I am excited about the future of Sirona Digital Impressions, and the possibilities and applications that can be incorporated into the general practice. Dentistry has lagged behind other medical fields in using digital technology, but this is rapidly changing. In 2011, there were about 33,000 CEREC users worldwide, with more than 12,000 users in the United States, and to date, more than 25 million restorations have been performed with CAD/CAM technology worldwide. CEREC by Sirona will allow you to “see more, do more, and do better dentistry.” The result is a win-win situation for you and your patients.