Influence of Time Elapsed After Alumina-Blasting on a CAD/CAM Resin-Block

Objectives: The aim of this study was to evaluate the influence of time elapsed after alumina-blasting on the bonding performance of a CAD/CAM resin block (CRB).
Methods: A CRB (KATANA AVENCIA Block, Kuraray Noritake Dental) was cut into 12 slices of approximately 2 mm thickness. Prior to cementation, the CRB slices were polished by (#600 SiC) and subjected to alumina-blasting using 0.1 MPa, 0.2 MPa with 50 µm alumina sand or untreated. The CRB slices were cleaned with 99 % ethanol for 3 min in an ultrasonic bath, followed immediately by the application of Clearfil Ceramic Primer Plus (Kuraray Noritake Dental) in case of same day curing groups. For 1 week groups, the slices were kept in room temperature for a week before applying the Ceramic Primer. The CRB slices were then cemented to bovine incisor crowns with exposed dentin surfaces (#600 SiC) using Panavia V5 (Kuraray Noritake Dental) in accordance with the manufacturer's instructions with or without light curing. All the specimens were then subjected to micro-tensile bond strength (µTBS) test, (n=13, 1×1 mm beam shape) and failure mode analysis was performed under the SEM observation. The µTBSs for results were subjected to a 3way-ANOVA, 2way ANOVA with Bonferroni’s correction (α=0.05).
Results: Three-way ANOVA reported a statistically significant effect for all the parameters. Pretreatment using alumina-blasting in the same day of cementation significantly enhanced the µTBS with both curing mode.
Conclusions: Time elapsed after alumina-blasting on a CRB affected the bonding performance.