BOND CHARACTERISTICS OF PORCELAIN FUSED TO MILLED TITANIUM

Objectives. A bonding agent has recently been introduced that prepares the surface of milled titanium copings for bonding to low fusing dent al porcelains. This study evaluated the effectiveness of the bonding a gent by comparing the shear and three-point bending strength of specim ens made with three combinations of materials: 1) milled titanium/porc elain with bonding agent, 2) the same milled titanium/porcelain withou t bonding agent, and 3) cast high palladium/conventional porcelain. Me thods. Shear specimens consisting of porcelain cylinders 6 mm in diame ter and 8 mm in length were fired to the ends of metal cylinders 6 mm in diameter and 13 mm in length. Three-point bend specimens made of 25 x 3 x 0.5 mm metal bars were veneered with 8 x 3 x 1 mm of porcelain in the bar's center. Specimens were tested in shear and bending in a u niversal testing machine. The data were analyzed using one-way ANOVA a nd Newman-Kuels post hoc tests (p = 0.05). Results. When a titanium bo nding agent was used, porcelain to titanium bond strength was slightly but statistically significantly greater than the porcelain to high pa lladium bond strength. The result was the same when measured by both s hear and three-point bending tests. Without the bonding agent, the she ar strength of porcelain to titanium was significantly lower than that of the bonding agent and high palladium groups. Significance. The use of a bonding agent improves the bond strength of porcelain-fused-to-m illed titanium.