Acrylic teeth ridge lap area chemical treatment trough tensile strength test investigations

The purpose of this study was associated to the surface treatments effect evaluation of three different organic solvents on the bond strength of artificial acrylic teeth to denture base repair resin. 40 large size acrylic molars were used to mille 40 acrylic cylinders. The cylinders were randomly assigned to four experimental groups, each containing ten cylinders. The cylinders flat surfaces were considered bonding areas. The surface treatment regimens were: Group 1: polishing (control group), Group 2: ethylene chloride treatment; Group 3: ethyl acetate treatment; Group 4: acetone treatment. 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. Each specimen was stored 30 days in distilled water and tested in tensile at a speed of 1 mm/min. The mean values of the tensile bond strength test registered were statistically significant among groups, ranging from 13,67 MPa (group 4, acetone) to 29,14 MPa ( group 2, ethylene chloride). The chemical treatment of acrylic teeth ridge lap area with ethylene chloride, leads to an enhanced bond strength of artificial teeth to the denture base resin compared to the control group, group 3 (ethyl acetate) and 4 (acetone), but reaches lower value levels compared to the ANSI/ADA Nr. 15 according to which tensile strength value must be, if statistically significant, 31 MPa.