Effect of surface treatments to remove temporary cement remnants on the bond strength between the core composite and resin cement

Background: There was no enough data about the appropriate surface cleaning of core composite material after temporary cementation.

Aim: To evaluate the effects of surface cleaning techniques on initial shear bond strength (SBS) between core composite material and resin nanoceramic crown materials after temporary cementation.

Material and methods: Cubic specimens were prepared from prosthetic materials, including Lava Ultimate. Cylinder-shaped composites were cemented to glass slides with eugenol-free temporary cement, resulting in a total of 44 cylinders (n = 11). The surfaces of composite cylinders were then cleaned with an Er, Cr:YSGG laser, 37% orthophosphoric acid, yellow tape diamond bur, or dental explorer. Cleaned cylinders were bonded to cubic specimens with resin cement. Initial SBS tests were performed with a universal testing machine at 0.5 mm/min crosshead speed. One-way ANOVA and post hoc Tukey tests were used to analyze the obtained data (P =0.05).

Results: Initial SBS values were significantly affected by the different surface cleaning methods (P <.05). The highest SBS value was obtained with the laser group (SBS = 17.14), while the lowest was obtained with dental explorer group (SBS = 5.95). There was no significant difference between the diamond bur group and the laser group (P =0.982).

Conclusions: Laser irradiation or yellow tape diamond bur cleaning of the core composite surface could be recommended to strengthen bond strength between the resin luting cement and the core composite. Before adhesive or conventional cementation of prosthetic restoration, the core composite surface should be cleaned.