Meeting the Single Central Incisor Challenge in Implant Dentistry

Julián Conejo, DDS, MSc

A 35-year-old woman presented for restoration of a recently placed bone-level implant (BLT 4.1 mm RC, Straumann, straumann.com) in site No. 8. After clinical and radiographical evaluation, a digital impression was made (CEREC^® Omnicam, Dentsply Sirona, dentsplysirona.com), and a PMMA screw-retained provisional was designed and milled to correct the soft-tissue position and create an ideal emergence profile. The Ti-base (RC Variobase^® C, Straumann) was air-particle abraded with 50-µm aluminum-oxide particles at a pressure of 2.0 bars and fixated to the provisional with a self-curing acrylic resin. After 4 weeks, with the soft-tissue architecture around the implant now corrected, a new scan of the emergence profile was made. The scan file was sent to the laboratory for elaboration of the final monolithic restoration with a translucent zirconia material (KATANA^™ Zirconia STML, Kuraray, kuraraydental.com). A stain and glaze technique was used, as this zirconia material is multi-layered, providing intrinsic color degradation, desirable when restoring single central incisors. After try-in, the restoration was cemented extraorally to a new ti-base with an adhesive resin cement system (Panavia^™ V5, Kuraray) following the APC concept. After removal of excess cement and final polishing (Dialite^® ZR Extra-Oral, Brasseler USA, brasselerusadental.com), the screw-retained crown was delivered and torqued per manufacturer's recommendations. The screw-access hole was covered with gutta-percha and a composite resin.

Important factors for successful, natural-looking restoration of a single maxillary central incisor include soft-tissue architecture, restorative space, restoration contours, texture, color, and translucency.

The APC zirconia-bonding concept, aimed at achieving durable, long-term bond strengths to high-strength ceramics, includes three practical steps: (A) air-particle abrasion, (P) zirconia primer, and (C) adhesive composite resin.

The combination of digital technologies for better data acquisition with updated concepts on soft-tissue management and multilayered zirconia materials facilitates the challenge of restoring a single central incisor in implant dentistry.

Julián Conejo, DDS, MSc
Assistant Professor, Clinical Restorative Dentistry, and Director, Chairside CAD/CAM Dentistry, Department of Preventive and Restorative Sciences, University of Pennsylvania School of Dental Medicine, Philadelphia, Pennsylvania

Figures and Images

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Figure 1

Fig 1. Initial intraoral photograph of implant with healing abutment.

Figure 2

Fig 2. Initial intraoral soft-tissue scan after removal of the healing abutment.

Figure 3

Fig 3. Design of the provisional restoration with ideal contours.

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Fig 4. Intraoral photograph of implant site with ideal soft-tissue architecture after 4 weeks with the provisional restoration.

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Fig 5. Katana Zirconia Super Translucent Multi Layered disc for 5-axis milling units and block for compact chairside milling units.

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Fig 6. Panavia V5 resin cement system, Universal (A2), used to cement the restoration to a new ti-base extraorally.

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Fig 7. Final restoration after adhesive cementation to the ti-base following the APC concept.

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Fig 8. Intraoral photograph of monolithic zirconia screw-retained implant crown at insertion.

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Fig 9. Final intraoral photograph of implant crown with natural surface texture, color, and translucency demonstrating successful restoration of a single maxillary central incisor.

Figure 10

Fig 10. Final intraoral photograph from a lateral view showing ideal contours and soft-tissue architecture surrounding the restoration.