Simplifying the Challenging: The One-tooth Restoration with CEREC by Paul Caselle, DDS


The quiet of my Sunday morning was broken when my cell phone rang. It was a patient, Susie, who had just fractured her front tooth when she slipped on ice the night before. Susie, a 21-year-old college student, was very upset because she had perfect teeth and was anxious to know how soon I could get her tooth fixed. After discussing the options with Susie and her dad the next morning, it was an easy decision for them to select a ceramic veneer. Some dentists in this case would advocate restoring the contralateral tooth to achieve a better aesthetic result; however, many patients find that unappealing and unacceptable, especially if the teeth are virgin.

Prior to using CEREC CAD/CAM in 2001 I struggled with these types of restorations not only due to the difficulty of trying to match tooth shade and morphology to existing teeth but also the difficulty in communicating to the lab exactly what I wanted for the patient. This often resulted in numerous appointments for the patient and a lot of chairtime for the office. Imagine the possibilities if you had the ability to just take an image of a prepared tooth that would allow you to better see the preparation and make corrections, if needed, to achieve a great fitting restoration. It would be ideal if you could actually make the crown in the office allowing total control of every aspect of design and manufacture. One way would be to have an in-house lab but for most general dentists, this is not feasible.

However, with CEREC technology and a stain and glaze oven, the single-tooth restoration is a routine procedure that is done every day in CEREC offices with predictable and satisfactory results.

Controlling outcome was the major reason I adopted CEREC technology, though a very important benefit is the patient experience. Although our patients like us on a personal level, coming to the office for multiple visits is not high on their lists. If I can minimize their time while providing great results, they are extremely happy and become missionaries for our office.

In Susie’s case, the challenge of matching tooth morphology could be easily achieved since CEREC software gives three possible ways to design a restoration: make copy of existing tooth (Biogeneric Copy), get a proposal of tooth morphology based on surrounding teeth (Biogeneric Individual) or copy a similar tooth such as the neighboring tooth 8 (Biogeneric Reference). In this case I selected Biogeneric Individual since the surrounding teeth were in excellent condition, allowing the software to render an acceptable proposal for tooth 8 that was fractured on the lingual, incisal and facial surfaces (Fig. 1).

The occlusal contact area was not prepared; therefore, the need for a bite registration was eliminated. Using Edit Tools (Fig. 2) the proposal was made slightly longer to provide flexibility in the final aesthetic result. The Scale Tool is used to add more material to the contact areas and the Form Tool is used to smooth the entire restoration prior to milling.

The case was milled using a shade 1m1c Vita block which was confirmed after taking a reading of tooth 8 with the Vita Easyshade. Once milled, the restoration was tried in and final adjustments were made. The crown was stained lightly using Vita Ochre Shading Paste in the gingival area and a slight amount of white shading paste was placed incisally to mimic the area of hypocalcification on tooth 8. After glazing the crown it was tried in with Variolink Try-In Paste to verify patient satisfaction prior to bonding. The bonding process started with the crown being etched and treated with Monobond. Next, the tooth was etched and Prime & Bond was placed on the preparation and crown and cured. The crown was bonded with Variolink II transparent base only. The final result immediately after bonding is seen in figure 3.

The patient was extremely pleased with the results and on a recent maintenance visit five years after the crown was placed; a photo (Fig. 4) illustrates the long-lasting results of CEREC restorations.

Another common case, which can be challenging, is the anterior tooth with old bonding. Paul is a 43-year-old utility worker with bonding on tooth 9 (Fig. 5), which had been fractured many years ago. Replacement options were discussed and he opted for a ceramic restoration which would provide for a longer-lasting solution.

Since the tooth was intact, I copied the existing morphology of the tooth (Biogeneric Copy). A pre-operative image of tooth 9 was taken; the tooth was prepped and images were taken with the CEREC AC Bluecam. The prepared tooth had the margin drawn and the next step in the design process was to copy the morphology of the tooth pre-operatively. To obtain an accurate copy of the pre-operative tooth, it is important to powder the entire buccal and lingual surface and capture those areas to duplicate the tooth’s morphology into the final design (Fig. 6).

The Scale Tool was used to slightly build out the proximal surfaces and the Form Tool was used to smooth out the facial surface. The restoration was ready to mill (Fig. 7).

Using the Vita Easyshade it was determined that Vita shade 1m1c was the best match to tooth 8. The restoration was milled out and tried in then slight adjustments were made to the contact area. The veneer was smoothed with a white silicone polishing wheel from Axis Dental. The restoration was glazed and bonded using the same material previously mentioned. The patient was extremely happy with the results (Fig. 8).

Another common challenge for dentists is the retrofitting of a crown to an existing partial. Tom is retired and on a limited income. He needed four crowns and a new partial and was financially unable to complete all the treatment at once. Typically a patient will be without his partial for a minimum of two weeks while the crown is fabricated and the lab tries to retrofit the crown to the old partial. Most dentists even warn the patient he might need to replace the cast clasps on his old partial to have it fit on the new crown resulting in added expense, no partial and another visit to our office. In Tom’s case, his partial replaced his upper incisors so being without his partial would be an aesthetic and functional hardship. With CEREC’s ability to copy existing morphology, I could restore the teeth that needed crowns one at a time as finances permitted without affecting the fit of his existing partial or the patient ever being without his partial.

Tooth 14 (Fig. 9) had deep decay and an old amalgam that was breaking down. Using Biogeneric Copy I was able to accurately copy the morphology and bond a crown (Fig. 10) on his tooth which enabled his old partial to fit.

Three months later Tom returned to have tooth 6 (Fig. 11) crowned. The new crown was bonded and his old partial fit perfectly (Fig. 12).

Patients are happy with CEREC restorations because of the convenience of a single visit, the aesthetics of life-like restorations and no multiple messy impressions or temporaries that can fall off. Dentists are pleased that office visits are reduced achieving increased production, a reduction in laboratory costs and, more importantly, patients are more than satisfied with the results.

Sirona Dental Company, the manufacturer of CEREC, has continued its research to develop innovative products such as Galileo’s cone beam technology that can integrate with CEREC. This integration allows the dentist to plan implant restorations from a top down approach resulting in precise placement of the implant by the surgeon. This significantly decreases the need for custom abutments and provides superior results because implants are placed appropriately within the arch.

Charlie was recently seen in my office with a fractured tooth (#4) which required extraction. Since his neighboring teeth were in excellent condition, an implant was the only viable option. Using CEREC I took an image of his upper right quadrant and designed a replacement tooth in CEREC (Fig. 13). I e-mailed the image file to my surgeon who imported the file into Galileo’s software (Fig. 14) to plan the placement of the implant in relation to the proposed restoration I designed. Once the implant type and size were determined (Fig. 15) a surgical guide was ordered to allow the surgeon to place the implant where the restoration was planned. After the implant is integrated, the implant can be easily restored with a CEREC crown using a stock abutment or a custom abutment can be fabricated using CEREC, if needed.

The restoration of a single tooth in dentistry can be very challenging but using CEREC technology can easily transform the complex into routine treatment. The ability of CEREC to meet the clinical needs of the dentist and the aesthetic needs of the patient has been well documented. Single-visit dentistry that patients truly appreciate and the predictability of results make this technology a valuable addition to any practice. The long-term results have been well proven to rival that of porcelain metal restorations. The updated CEREC 4.0 software allows for single to multiple units to be fabricated with ease. The technology continues to advance not only in software but also in hardware with the introduction of the Omnicam. This powderless camera with smaller head, allows easy access and video streaming of digital images, making this digital technology even more impressive. Many dentists acknowledge the benefits of this technology for multiple units but might not appreciate the fact that it is an extremely useful tool in the cases that are more clinically demanding, especially when only one or two units are involved in the anterior part of the mouth.

Author's Bio
As an early adopter of digital dentistry, Dr. Paul Caselle has embraced the benefits of digital dentistry and understands how it can help dentists transform their practices. Dr. Caselle has presented seminars to dentists on CEREC technology and Waterlase Laser Procedures. His article “Why You Should Really Consider CEREC Technology” was published in Dentaltown Magazine in February 2004.

Dr. Caselle is a graduate of the Sirona Speakers Academy and a member of the Mentor Group for CERECDoctors.com. He received Fellowship Certification in the World Clinical Institute of Laser Dentistry and is a member of the American Dental Association, Massachusetts Dental Society, Middlesex District Dental Society and Tri-County Dental Study Club.

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