Tensile bond strength of acrylic resin teeth to denture base repair resin

The aim of this study is to evaluate the effect of different surface treatments of the artificial acrylic teeth on the bond strength to Denture Base Repair Resin. Fifty acrylic cylinders were milled from large size acrylic molars. The cylinders were then randomly assigned to five experimental groups, each containing ten cylinders. The flat surfaces were considered as bonding areas. The surface treatment regimens were: Group 1: polished (control group), Group 2: polished+methyl methacrylate, Group 3: sandblasting + methyl methacrylate, Group 4: sandblasting+universal repairing adhesive (Clearfil Repair-Kuraray), Group 5: polished+dichlormethane. All sandblasting procedures were realized using 50 µm alumina (30 seconds), from a distance of 10 mm. A self-cured denture base repair resin (Duracryl - Spofa Dental) was used for manufacturing the bonding test specimens, according to the ADA specification No. 15. After 30 days of water storage, each specimen was tested in tensile at a speed of 1 mm/min. Tensile bond strength mean values were statistically significant among groups, ranging from 13,5 MPa (group 4) to 35,9 MPa, the latter pertaining to group 5. Dichlormethane treatment leads to enhanced bond strength to the artificial teeth and may be considered as a laboratory and clinical procedure as well, in order to improve the quality of bonding.