Effect of Cleaning temporary cement on Ni-Cr alloy's surface

Objective: To evaluate the effect of 5 methods (air abrasion with 1.Aluminum oxide, 2.glass bead, immersing in cement removal solution 3.RemovalonI, 4.L&R and 5.liquid of autopolymerized acrylic resin) for removing temporary cement(TempBondNE) on Ni-Cr alloy's surface to resin cement's bond strength. Methods: Casting Ni-Cr alloy cylinders (a pair of 7 and 9 mm diameter, 3 mm height) were prepared 120 pairs each and divided to 6 groups (control and 5 methods). The 20 pairs of each group of 5 methods were bonded with temporary cement excluding control group. After temporary cement were removed ,all pairs of casting were cemented with resin cement(Superbond C&B) and stored in water bath at 37°C for 24 hours. Shear bond strength were determined with a universal testing machine using a cross-head speed of 0.5 mm/minute. A 1-way ANOVA was performed, and multiple pairwise comparisons were completed with post hoc Tamhane test (alpha = 0.05).Results: Mean shear bond strength after using air abrasion with Aluminum oxide and control group were significantly higher than after using cement removal solution RemovalonI,but were not significantly different higher than mean shear bond strengths for the other 3 methods. Conclusion: In applications, air abrasion with 50 microns Aluminum oxide offers a simple, consistant, and effective methods to clean TempBondNE from Ni-Cr alloy, not effect to resin cement ‘s bond strength.