SILANE TO ENHANCE THE BOND BETWEEN POLYMETHYL METHACRYLATE AND TITANIUM

The machined surface of wrought titanium frameworks used in implant-su pported, fixed prostheses does not bond well with acrylic resin. Surfa ce pretreatment has been suggested to enhance the retention of polymet hyl methacrylate to machined titanium surfaces. This study evaluated a new bonding material (Rocatec) to determine its effect on the bond st rength between titanium and polymethyl methacrylate. Twenty rod-shaped specimens of grade 2 titanium (7.6 X 0.3 cm in diameter) were divided into two groups of 10 samples. Group A received no pretreatment and g roup B was pretreated with 110 mu m alumina air abrasive and the Rocat ec material. Heat-cured denture base resin was processed around each t itanium sample in a cylindrical shape approximately 0.9 X 1.5 cm. A Sh ell-Nielsen shear test was performed with a universal testing machine at a crosshead speed of 0.5 mm/minute to determine the bond strength i n megapascals (MPa). Group B specimens (23.8 +/- 1.78 MPa) had a shear strength 68% greater than group A (16.1 +/- 1.61 MPa) (p 0.0001). The results of this study indicated that surface pretreatment of grade 2 titanium with 110 mu m alumina air abrasive plus Rocatec bonding mater ial significantly enhances the shear bond strength to PMMA.