Effect of alloy type and surface conditioning on roughness and bond strength of metal brackets

摘要: The effect of 5 different surface conditioning methods on bonding metal brackets to cast dental alloys was examined. were fine (30-µm) or rough (125-µm) diamond bur, sandblasting (50-µm 110-µm aluminum oxide [Al2O3]), and silica coating (30-µm silica). Fifty disc-shaped specimens (gold-silver, palladium-silver, nickel-chromium, cobaltchromium, titanium) ground with 1200-grit silicone carbide abrasive polished before being reused for each method. Polished surfaces used as negative controls. After measuring roughness (RZ), bonded the conditioned a self-curing resin composite. Specimens thermocycled (5000 times, 5°–55°C, 30 seconds), shear bond tests performed. Significantly higher (P .001) roughnesses observed use bur (RZ ~33 µm), Al2 O3 ~14 ~10 compared controls ~1 µm). Silica ~4 µm) 50-µm demonstrated no significant difference > in when control group showed resistance forces (0 MPa). Bond values greater (19 MPa) used, Al2O3 (7 (8 all tested. However, interaction between exhibited differences .0001).