Resistência de união entre cimentos e liga de níquel-cromo, em função da ciclagem térmica e variações no procedimento de união

We evaluated tensile bond strengths between a nickel-chromium alloy and cements at different times (one and 90 days) using or not thermocycling. Alloy used was Litecast B, and luting cements were Ketac-Cem, Vitremer, and Fluoride Enforce with three variations: a) only primer; b) with primer and bond; c) only with bond. Metallic discs with 6 mm diameter were cemented together and immersed in distilled water. Half specimens were thermocycled and half one not. Conclusions were: Ketac-Cem presented low bonding strength, being that of Vitremer very higher; the material Enforce when used only with primer increased adhesion with time but yet remained relatively low after 90 days; Enforce used with bond only achieved superior adhesion, still present specially with termocycling after 90 days; influence of thermocycling depends on adhesive system.