Abstract
BACKGROUND: The reline material and interim base should bond well in provisional restorations. Few research examined 3D-printed restoration-relining bonding. To test the shear bond strength (SBS) of chairside crown reline materials to microfilled hybrid 3D-printed resin (PR) utilizing different surface treatments and materials. METHODS AND MATERIALS: Three-dimensionally printed 360 provisional samples were divided into six groups based on surface treatment (monomer, 5% hydrofluoric acid, monomer and 5% hydrofluoric acid, monomer and 110 μm aluminum oxide, and control groups) and subgroups based on relining material (flowable composite resin, bis-acrylic, and poly methyl methacrylate). A universal testing device determined the bonded samples' SBS. RESULTS: The group that received hydrofluoric acid and air abrasion surface treatment and was relined with flowable composite had a significantly higher SBS value than the other groups. On the other hand, the group that received hydrofluoric acid and was relined with flowable composite had a significantly lower SBS value. CONCLUSION: Bis-acryl resin outperforms 3D-PR in SBS. Surface preparation for 3D-printed provisional restorations should include hydrofluoric acid and air abrasion.