One-Tooth One-Time (1T1T): A Straightforward Approach to Replace Missing Teeth in the Posterior Region

Figure 1. Patient 1 had a history of periodontitis controlled for more than 7 years. She presented with a missing tooth No. 30 that was never replaced because of a lack of time and financial issues. The second patient lost tooth No. 5 for cariologic reasons years before. In both cases, the quantity of keratinized tissue dimension was more than 5 mm. (a, b) Case 1. (c, d) Case 2. Figure 2. The initial radiologic situation displayed optimal hard-tissue quality and quantity in both cases. (a) The baseline cone-beam computerized tomography scan shows a type 2 bone quality and sufficient bone availability for the placement of a regular-diameter implant of at least 10 mm in length. (a, b) Case 1. (c) Case 2. Figure 3. Considering the optimal bone availability, in both cases minimally invasive surgery was applied. A buccal miniflap was performed to push the soft tissues outward to favor the peri-implant soft-tissue profile. (a, b) Case 1. (c–e) Case 2.

Figure 4. Case 2. Variobase abutment and Cerec plastic scanbody placed on the implant to perform the intraoral scanning. Figure 5. Chairside crown manufactured with the Cerec MCXL using a PICN block with a preshaped hole fitting the abutment. The crown design was performed with the Cerec 4 software. Special attention was given to the restoration's emergence profile. (a, b) Case 1. (c, d) Case 2.

The polymer-infiltrated ceramic network crown intaglio was etched with hydrofluoric acid for 60 seconds, subsequently cleaned in 90% ethanol ultrasonic bath for 5 minutes, and recovered by a silane layer, which was applied using a microbrush and left for 60 seconds, then air dried for 10 seconds. The Variobase abutment was screwed on an implant replica to facilitate handling. After neck protection with a silicone impression material, the abutment was sandblasted (50-μm alumina particles, 2 bar), cleaned, and recovered by a silane layer in the same way as the crown intaglio. After screw head protection with Teflon, the crown was cemented on the abutment with a resin composite cement, according to the manufacturer's recommendations. Finally, the restoration was stained with a light-cured nano-filled composite coating agent, according to the manufacturer's recommendation and after crown etching and silanization. The final crown was subsequently polished with dedicated instruments.

Figure 7. Final crowns. (a, b) Case 1. (c, d) Case 2. Figure 8. Clinical views just after crown placement, with occlusal contact points highlighted. (a, b) Case 1. (c, d), Case 2.

and 10. Figure 9. Clinical outcomes at 1-year and 6-month follow-up, respectively. Note the optimal soft-tissue integration. (a, b) Case 1. (c, d) Case 2. Figure 10. Radiologic outcomes at 1 year and 6 months, respectively. Note very stable peri-implant bone levels. (a) Case 1. (b) Case 2.