Evolution of CEREC Technology

Celebrating 30 years of advanced restorations

Sameer Puri, DDS

This past September, almost 6,000 people participated in the 30th anniversary of the CEREC system (Sirona Dental, www.sirona.com). Clinicians, assistants, hygienists, office staff, and industry from all over the world engaged in presentations, breakouts, and hands-on workshops. As one of the keynote speakers of the event, it was interesting to see how much the technology has grown after being a CEREC user for almost 13 years and seeing the benefits of the technology firsthand.

At the Spear campus, participants learn how CEREC technology can impact a practice in a positive manner. This article provides an update as to what types of restorations and indications are possible with the CEREC system. The misconception is that CEREC is simply a crown-making machine that can only be used on select teeth. The truth is that the CEREC system can fabricate a number of different types of restorations and is a robust addition to any practice.

Early on in its introduction, the CEREC system was simple. Only rudimentary inlays were possible. These inlays were fabricated with the original version of the CEREC system as a two-dimensional design. Today, with the 4.4 software, clinicians have the ability to use the Omnicam powder-free camera and fabricate a multitude of restorations using 3-dimensional (3D) CAD software.

Crowns

Whether it’s a single-unit or a quadrant of restorations, the CEREC system is capable of handling virtually any type of restoration. From a single crown or a quadrant of restorations (Figure 1) to a few or a full complement of anterior restorations (Figure 2), the CEREC system has the tools to fabricate any type of restoration for the restorative dentist. Clinicians have a number of tools at their disposal that can change the size, shape, and anatomy of the restorations. Intuitive tools give the user feedback as to the thickness of the restoration, ensuring there is adequate thickness to avoid premature failure and fracture. Users can also slice through any restoration to see a cross section and ensure that they have adequately bulked out their restorations to prevent premature failure.

In addition to inlays, onlays, and crowns, users can fabricate restorations such as Maryland bridges. Whether the clinician decides to fabricate either a single- or dual-wing Maryland Bridge, and whether the restoration is intended as a provisional or a final restoration, all types of restorations are easily designed and fabricated with the software (Figure 3).

Materials

When clinicians are fabricating restorations, they are not limited to just a single type of material. When sending cases to a laboratory, clinicians will use a different material for anterior teeth vs posterior teeth. This is also possible when milling restorations with CEREC. At the time of publication, there were seven manufacturers with 30 different materials available for milling chairside with CEREC.

For example, IPS e.max® (Ivoclar Vivadent, www.ivoclarvivadent.us) has been a popular choice for clinicians to restore molars because of its tremendous strength. In the anterior, clinicians might be less concerned about strength and instead use a feldspathic ceramic, which is more translucent, esthetic, and available as a multilayered block to help with incisal translucency (Figure 4). Most importantly, clinicians are not limited to just a single material. In the workshops at Spear Education, there are 36 CEREC systems on site. All materials and their indications for use are reviewed thoroughly in the lecture portion of the workshops.

CEREC and Implant Dentistry

Implant dentistry has grown by leaps and bounds in the past few years. Previously, implants could not be integrated with the CEREC system, but today, implants are an integral part of CEREC technology. One might wonder how a chairside CAD/CAM system can help to restore implants, but CEREC offers a complete solution from planning to restorative.

Implant Planning

The implant planning protocol using CEREC follows the mantra of restoratively driven implant dentistry. Implants were formerly placed wherever the bone allowed. Today, that is well below the standard of care. Placing implants without regard for the final restoration can potentially compromise the procedure.

For example, a patient in his early 50s presented with a missing central incisor. He had been wearing a removable appliance to replace his central incisor. There was bone loss in the area and the incisive canal had enlarged, making implant placement difficult. Using the final restoration designed on the CEREC allowed the surgeon to place the implant in the necessary position (Figure 5).

Due to the enlarged canal and bone loss, the surgeon predicted that the proximity of the implant would be very close to the adjacent root. Without proper planning, this case would be extremely difficult, as there was an increased chance of violating the incisive canal as well as the adjacent root structure with the implant placement.

A surgical guide, based on the restoration plan designed by CEREC, was used to place the actual implant in exactly the spot that was planned in the software (Figure 6). A post-surgical radiograph showed the exact desired position of the implant and based on the surgical guide fabricated from CEREC, the surgeon was able to thread the needle and place the implant precisely where the implant could ideally support the final restoration.

Surgical Guides

There are two types of surgical guides that can be fabricated with CEREC. The first, fabricated by the Sirona laboratory, requires 5 to 7 days. The second type is the CEREC Guide, which can be milled on the same in-office milling units as the crowns and onlays.

After planning the final restoration and using that restoration to plan the implant position, the data is used to design the surgical guide. In less than 30 minutes, a surgical guide is fabricated out of an acrylic block and used to guide the placement of the implant. The fit and precision of the surgical guide is extremely accurate and it makes for a very predictable implant placement (Figure 7).

Implant Restorations

The final component of the implant paradigm is the ability to fabricate both cement- and screw-retained implant restorations. The restorations are fabricated using the CEREC chairside software, with a ScanBody (Sirona Dental) placed on top of the implant. When creating screw- or cement-retained restorations, users do not fabricate an abutment and seat it and rescan it to create the crown. Rather than requiring separate steps, the entire restoration, both abutment and crown, is designed together so the user can accurately determine the proper thickness of the restorations (Figure 8).

Sirona fabricates the TiBases for major implant systems. Once designed, the restorations (either the abutment or the final screw-retained crown) are milled from an IPS e.max abutment block (Ivoclar Vivadent). The abutment block has a hole inside that accurately corresponds to the Sirona TiBase, resulting in a precise fit of the IPS e.max to the TiBase so that the ceramic is properly supported.

Conclusion

CEREC is a robust system that allows for the fabrication of numerous types of restorations. The system is easy to use and can be made to work with a number of different types of practices. For additional information on the CEREC system or to see how the system works more specifically, visit www.cerecdoctors.com.

Disclosure

Dr. Sameer Puri is the director of CAD/CAM at Spear and the founder of www.cerecdoctors.com.

About the author

Sameer Puri, DDS
Director of CAD/CAM
Spear Education
Scottsdale, Arizona

For more information, contact:

Spear Education
866-781-0072
www.speareducation.com