Dr. Anthony Ponzio.
In restorative dentistry, restoring form, function, and aesthetics efficiently is central to a positive patient experience.
This clinical case presents the full-coverage replacement of a fractured crown on a maxillary posterior tooth using Katana Zirconia One Speed, Clearfil Universal Bond Quick 2, and Panavia SA Cement Universal (Kuraray Noritake Dental).
The same-day CAD/CAM approach prioritized speed and predictability without compromising aesthetics or fit.
Case presentation
A 59-year-old female patient presented with a chief complaint of a broken tooth on the maxillary right side after biting into an olive pit. Her medical history was unremarkable.
The clinical evaluation revealed a fractured mesiolingual cusp on a full-coverage restoration on tooth #3.
The patient reported no discomfort other than the sharp edge of the fractured crown. The tooth had a history of root canal therapy (RCT) that appeared clinically acceptable, and periodontal probing revealed no concerns.
Figure 1: Tooth #3 previously had an existing full-coverage restoration with RCT.All images courtesy of Dr. Anthony Ponzio.
Figure 2: Fractured mesiolingual cusp on tooth #3.
Diagnosis and treatment planning
The diagnosis was a fractured full-coverage restoration on a RCT tooth, with the bonded restoration compromised at the mesiolingual cusp. After reviewing treatment options, the patient agreed to replacement of the existing restoration with a new full-coverage crown.
Anesthesia and restoration removal
Anesthesia was achieved with 1/2 carpule of 3% mepivacaine. Because the existing restoration appeared to be bonded to a root canal-treated tooth, it was removed in multiple small pieces rather than sectioned and lifted with a crown spreader, minimizing the risk of tooth fracture.
Tooth preparation and digital impression
Following removal of the restoration, the preparation was refined to ensure appropriate reduction, smooth contours, and clear margins. Gingival retraction was placed, the tooth was rinsed, and digital impressions were captured.
Restoration design and milling
Katana Zirconia One Speed was selected in shade A2 as the restorative material. The restoration was designed in CEREC software and milled using Primemill, with a milling time of four minutes and 10 seconds.
Figure 3: Katana Zirconia One Speed full-coverage crown was designed in CEREC software and milled with CEREC Primemill.
Figure 4: Intaglio view of the milled Katana Zirconia One Speed full-coverage crown.
Sintering and polishing
After milling, the sprue was removed and the restoration was prepolished before sintering in the CEREC SpeedFire furnace. Using the speed cycle, sintering was completed in less than 10 minutes, during which time a hygiene exam was performed. Once cooled, the restoration received a final polish, and the intaglio surface was sandblasted to prepare it for cementation.
Try-in and cementation
The crown was tried in to verify acceptable occlusion, contacts, and margins, then cleaned with Katana Cleaner. The restoration was delivered using CLEARFIL™ Universal Bond Quick 2 and Panavia SA Cement Universal.
The cement was tack-cured, excess was removed, and the restoration was allowed to fully cure for five minutes. Contacts and occlusion were reverified, and a final radiograph was taken before the patient was dismissed.
Figure 5: Post-op buccal view of Katana Zirconia One Speed restoration on tooth #3.
Figure 6: Post-op occlusal view of Katana Zirconia One Speed full-coverage crown on tooth #3.
Rationale for product selection
I chose Katana Zirconia One Speed for this restoration because of its combination of aesthetics and efficiency. The speed-cycle sintering let us complete this crown chairside in less than 10 minutes without sacrificing the natural, gradated appearance patients expect from a final restoration.
For cementation, I relied on Clearfil Universal Bond Quick 2 and Panavia SA Cement Universal because of their high bond strength and easy cleanup.
These two products work well together; there's a touch-cure chemistry between them that creates a stronger bond, which is especially valuable in cases like this one with a shorter preparation.
Outcome and patient satisfaction
The patient was amazed at how quick and easy the process was, and the restoration's shade matched expectations as soon as it was seated. My team and I continue to be impressed by how short furnace times can be achieved without compromising aesthetics or fit, an approach that has changed the game for single-visit dentistry.
Dr. Anthony Ponzio is a 2004 graduate of the University of Illinois College of Dentistry. He currently practices in Oak Park, IL, with a special focus on technology in dentistry. He is also the clinical director of P1 Dental Partners, a dental preferred organization. Ponzio has been a CEREC Basic and Advanced Trainer for over a decade. He is a member of the CDOCS Faculty at Spear Education and spent seven years on the clinical faculty at Midwestern University's College of Dental Medicine, where he helped integrate CEREC CAD/CAM technology into the curriculum.
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