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Special Issues
July/August 2016
Volume 37, Issue 3

Use of Zirconia-Reinforced Lithium Silicate (ZLS) to Restore Stained Teeth

Attaining desired esthetics and a strong final outcome

In this case involving a 41-year-old male patient, teeth Nos. 5 through 12 were restored using Celtra® Duo, a zirconia-reinforced lithium-silicate chairside millable block, and CEREC® Omnicam (Dentsply Sirona, www.dentsplysirona.com). The patient presented a unique challenge because of staining caused by exposure to antibiotics at a young age and specific esthetic wishes. The Celtra Duo (ZLS) restorations were definitively cemented with Calibra® Ceram Adhesive Resin Cement opaque shade (Dentsply Sirona Restorative) to achieve the desired bond strength and esthetics and maximize procedural convenience.

Key Takeaways

• Utilizing a new ZLS low-translucency chairside block with customized stain options can be successful in masking dark tooth shades. Minimum axial wall reduction is 1.0 mm to 1.5 mm for this material; however, an increased material thickness was used to better mask the dark tooth shade (preferably >2mm).

• Using an appropriate definitive cement that combines ease of use and shade choices (in this case opaque) can enhance the outcome for dentist and patient.

• When patients desire replication of existing tooth shape and/or position, the use of features in CAD/CAM software simplify workflow.

About the Author

Jason H. Goodchild, DMD
Associate Professor and Chairman
Department of Diagnostic Sciences
Creighton University School of Dentistry
Omaha, Nebraska
Clinical Education Manager
Focus North America
Dentsply Sirona Restorative
Milford, Delaware
Private Practice
Havertown, Pennsylvania

Fig 1. Preoperative view of 41-year-old male patient. He previously had porcelain veneers on teeth Nos. 5 through 8. The veneers for teeth Nos. 5 and 6 were missing, the veneer on tooth No. 7 was redone with direct composite, and the veneer on tooth No. 8 was cracked and repaired with direct composite. Veneers on teeth Nos. 9 and 10 were intact, the veneer on tooth No. 11 was missing but the opaque cement remained on the facial aspect of the tooth, and the veneer on tooth No. 12 was redone with direct composite.

Figure 1

Fig 2. Occlusal view of preoperative condition for teeth Nos. 5 through 12.

Figure 2

Fig 3. Preoperative anterior radiographs.

Figure 3

Fig 4. Completed full-coverage preparations on teeth Nos. 5 through 12. A chamfer finish line was used, where up to 2 mm of reduction was achieved. Note the dark, striated appearance of the prepared teeth.

Figure 4

Fig 5. Occlusal view of completed full-coverage preparations on teeth Nos. 5 through 12.

Figure 5

Fig 6. Extraoral view of patient’s provisional restorations for teeth Nos. 5 through 12. The one-piece provisional was fabricated using Integrity® Multi-Cure Crown and Bridge Material (Dentsply Sirona Restorative) and cemented with Integrity® TempGrip™ Temporary Crown & Bridge Cement (Dentsply Sirona Restorative).

Figure 6

Fig 7. Intraoral view of patient’s provisional restorations for teeth Nos. 5 through 12, after tissue healing.

Figure 7

Fig 8. The final crown restorations for teeth Nos. 5 through 12 were fabricated using Celtra® Duo (ZLS) low-translucency shade A2, CEREC Omnicam, and MC-XL Mill (Dentsply Sirona CAD/CAM).

Figure 8

Fig 9. Try-in stage of Celtra Duo (ZLS) crowns for teeth Nos. 5 through 12. At this visit, tooth shape and esthetics were adjusted to meet the patient’s esthetic requests. In addition, interproximal contacts and occlusion were adjusted. Celtra Duo (ZLS) can be milled, polished, and inserted for flexural strength of approximately 210 MPa, or fired to achieve a maximum strength of approximately 370 MPa. In this case, the restorations were stained using Celtra Duo Universal Stain LF Violet to help block the darkness of the stump coming through the bicuspids. After that, a universal stain was used for cervical third, the Celtra Duo Incisal Stain i1 for the incisal third, and Celtra Duo Light Violet and Celtra Duo White stains were used to characterize the crowns and further enhance final esthetics. The crowns were fired as per manufacturer’s recommendations in a Programat CS2 oven (Ivoclar Vivadent).

Figure 9

Fig 10. At delivery, the intaglio of the crown restorations were treated, according to the manufacturer’s directions, with 9.5% Porcelain Etchant (Bisco Inc.) and Calibra™ Silane Coupling Agent (Dentsply Sirona Restorative).

Figure 10

Fig 11. Final cementation was accomplished using Calibra Universal Self-Adhesive Resin Cement. This cement features a longer gel phase, which enables easier cleanup, especially for multiple-unit cases, and several shade options. For this situation, opaque shade was selected to further block out the dark tooth stumps. The protocol involved hydrofluoric acid etching of the intaglio of the crowns followed by application of silane coupling agent. The teeth were isolated and Prime & Bond elect® (Dentsply Sirona Restorative) was applied. The adhesive was air-thinned and light cured for 10 seconds. The crowns were then filled with a layer of Calibra Universal cement and gently seated; seating progressed from the midline backward. Note: The patient had specific esthetic requirements to mimic existing tooth shape, size, and contour. The final restorations did not follow basic design rules and proportions; this was in response to the patient’s wishes.

Figure 11

Fig 12. Postoperative view of completed Celtra Duo (ZLS) crowns on teeth Nos. 5 through 12.

Fig 12.

Fig 13. Postoperative occlusal view of completed Celtra Duo (ZLS) crowns on teeth Nos. 5 through 12.

Fig 13.

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