Purpose: To compare the shear bond strength (SBS) values of resin cement to zirconia treated with a new activating method. Materials and Methods: Forty-five zirconia specimens were divided into three groups: no treatment (group 1), plasma of argon cleaning for 375 seconds (group 2), and plasma of argon cleaning for 750 seconds (group 3). Composite cylinders were bonded with a self-adhesive cement. After 40 days of water storage, specimens were subjected to the SBS test. Data were analyzed with one-way analysis of variance and the Neuman-Keuls multiple comparison test. Results: Test groups obtained SBS values significantly higher (101% for group 2 and 81% for group 3) than controls. Conclusion: Plasma of argon appeared to improve bonding between zirconia and resin cement.