Evaluation of Shear Bond Strength of Various Chairside Reline Materials to 3D Printed Provisional Crown Resins Following Surface Treatment.

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.