Effect of surface preparation using ethyl acetate on the repair strength of denture base resin

Objective. The objective of this study was to evaluate the effect of surface preparation using ethyl acetate on the repair strength of a denture base resin. Material and Methods. Bar specimens were fabricated with a heat-processed denture base resin and cut in half. The repair surfaces of the specimens were treated with ethyl acetate for varying amounts of time before the autopolymerizing repair resin was applied. The specimens were then immersed in 37 degrees C distilled water for 2 days. A three-point bending test was used to determine the transverse strength of the test specimens. Ten specimens prepared using a 120-s application of ethyl acetate and 10 specimens prepared using a 5-s application of dichloromethane were thermocycled at 10,000 cycles ( at 5 degrees C and 55 degrees C) with a 60-s dwell time. The morphological changes in the repair surfaces after preparation were observed by scanning electron microscopy. Results. The repair strength of the denture base resin prepared using ethyl acetate for 120 s (30.6 MPa) was the highest among the results for the various amounts of time tested (p < 0.05). There were no significant differences between the repair bond strength both before and after thermocycling of the denture base resin prepared using ethyl acetate for 120 s and that of the denture base resin prepared with dichloromethane for 5 s (p > 0.05). Conclusion. Within the limitations of the current study, a 120-s application of ethyl acetate was as effective as a 5-s application of dichloromethane at preparing the surfaces of a denture base resin.