Clearfil ceramic primer plus

The bonded specimens were kept in water at 37°C for 24 h. The top surface of the CAD/CAM resin slab was treated with 37% phosphoric acid (K-etchant) for 5 s, rinsed with water and air-dried. A silane coupling agent (Clearfil Ceramic Primer Plus, Kuraray Noritake Dental) was applied to the surface and gently air-dried. A bonding agent (Clearfil SE Bond, Kuraray Noritake Dental) was applied to the surface, gently air-dried, and light cured for 10 s. Then, a direct resin composite (Clearfil AP-X Shade A2, Kuraray Noritake Dental) was incrementally built up to a thickness approximately 2 mm high for the μTBS test. Each tooth was cross-sectioned longitudinally with a low-speed diamond saw (Isomet) to produce beam-shaped specimens with an approximate surface area of 1×1 mm 2 at the bonded interface. Before the μTBS test, the dimensions of each beam were determined with a digital caliper (Mitutoyo CD-15C). After this, each specimen was secured to a customized microtensile jig with a cyanoacrylate glue (Model Repair II Blue, Dentsply-Sankin, Tokyo, Japan) and placed in the testing apparatus (EZ-SX, Shimadzu, Kyoto, Japan) for the μTBS test at a 1 mm/min crosshead speed.

Impression with silicone rubber impression materials (EXAFINE putty type and EXAFINE injection type, GC, Tokyo, Japan) was performed after root canal preparation, and each tooth was temporarily sealed with temporary sealing material (Temporary Stopping, GC) after impression and stored in water for 24 h at 37 °C. Plaster models were made with plaster material (NEW FUJIROCK, GC), and resin cores were fabricated with resin core material (Clearfil DC Core Automix, Kuraray Noritake Dental) on the plaster models. Resin cores were alumina-blasted with Adabrader (Morita, Tokyo, Japan) for 10 s and dried with an air blow followed by silanization with Clearfil ceramic primer plus (Kuraray Noritake Dental) for 10 seconds and air blow-dried. The root canals were rinsed and dried in the same manner as in the Direct/DC group. Clearfil DC Bond was applied to the root canals for 10 s, and excess adhesive in the coronal side of the root canal was removed using paper points and light-cured for 10 s. Resin cores were cemented with Clearfil DC Core Automix, excess resin was removed, and then light-cured for 40 s. After light-curing, the specimens were stored in water for 24 h at 37 °C.

In this study, experiments were conducted on the assumption that a CAD/CAM resin block would be used for restorative treatment on the dentin surface after formation. For this purpose, the CAD/CAM resin block and the dentin surfaces were contaminated with immersion in artificial saliva for 60 s, and the microtensile bond strengths were measured and compared. CAD/CAM resin blocks (KATANA AVENCIA Block Universal, Kuraray Noritake Dental) was bonded to the dentin surface of a crown that had been polished with #600-grit silicon carbide paper using PANAVIA V5. The KATANA AVENCIA Block was cut to a thickness of 6 mm, and the flat surface was polished with #400-grit silicon carbide paper to form the standard roughness of adherend surface. After immersion in artificial saliva for 1 min, rinsing with water for 30 s, drying for 10 s, and treatment with each decontamination material as directed by the manufacturer, resin blocks were treated with silane coupling using primer (Clearfil Ceramic Primer Plus, Kuraray Noritake Dental). The dentin surface was treated with primer (PANAVIA V5 Tooth Primer, Kuraray Noritake Dental). The adhesive resin cement PANAVIA V5 was used as the luting cement, and was bonded by light irradiation from four directions for 10 s each using an LED light curing machine (PENCURE, J. Morita, Kyoto, Japan) with a mean output of 1,000 mW/cm