Abstract:
This study evaluated the effect of ultrasonic treatment and surface treatments on transverse strength of denture bases which relined with auto-polymerizing acrylic resin. The study groups, ninety heat-polymerized acrylic resins (64×10×2 mm) were divided by three surface treatments: no surface treatment (N), applied MMA for 180 seconds (MM), applied MF-MA for 15 seconds (MF). They were relined with auto-polymerized acrylic resin to create 64×10×3.3 mm specimens. Then, they were divided further by ultrasonic which were no ultrasonic (X), ultrasonic in water (W), ultrasonic in 30% ethanol (E). As a result, all test groups were classified as NX, NW, NE, MMX, MMW, MME, MFX, MFW, MFE (n=10). All samples were performed three-point bending test. Two-way ANOVA presented that there was an interaction between ultrasonic and surface treatments. Then One-way ANOVA was analyzed. Ultrasonic could increase transverse strength of all relined specimens (p<0.05). Ultrasonic in ethanol increased strength superior to water (p<0.05) and presented the highest mean strength. In the same ultrasonic treatment, MMA and MF-MA increased the transverse strength of relined denture bases compared with no applying groups (N) (p<0.05). There was no difference between all MM and MF groups (p>0.05).
