Adhesive luting of new CAD/CAM materials

Objective: To evaluate the adhesive bonding performance of recently introduced tooth-colored CAD/CAM materials after different pretreatment protocols and using different luting materials. Materials and methods: The CAD/CAM materials under investigation were e.max CAD (lithium disilicate glass ceramic; Ivoclar Vivadent, Schaan, Liechtenstein), Celtra Duo (zirconia-reinforced lithium disilicate ceramic; Dentsply DeTrey, Konstanz, Germany), Lava Ultimate (resin nano ceramic; 3M ESPE, Neuss, Germany), and Enamic (resin infiltrated ceramic; Vita, Bad Säckingen, Germany). A total of 240 blocks (n = 5) received various pretreatments (no pretreatment, silane, sandblasting, sandblasting + silane, hydrofluoric acid, hydrofluoric acid + silane), and then different classes of adhesive luting composites were applied (adhesive: Prime&Bond XP + SCA + Calibra; Dentsply DeTrey; self adhesive: RelyX Unicem; 3M ESPE). After 24 h water storage and 10,000 thermocycles (5°C/55°C), specimens were cut into beams and microtensile bond strengths were recorded. Results: Bonding performance of recent CAD/CAM materials was clearly influenced by the pretreatment method (P 0.05). In general, significantly higher μ-TBS values were recorded for the ceramic materials compared to the hybrid materials (P 0.05). Among the hybrid materials, Enamic exhibited higher bond strengths than Lava Ultimate (P 0.05). However, despite the differences found, all materials showed a high level of bonding performance, being sufficient to withstand intraoral chewing forces during mastication. Conclusion: When pretreated as recommended by the manufacturers, recent tooth-colored CAD/CAM materials show an encouraging bonding performance for adhesive luting. Parole chiave: adhesive luting, CAD/CAM, ceramics, enamel, dentin, hybrid materials, resin composite