방사선 조사후 아크릴릭 레진의 물성변화 = Change of Mechanical Properties of Acrylic Resins after High Dose Irradiation

다국어 초록 (Multilingual Abstract)

To investigate the effect of high dose irradiation on the mechanical properties. dental acrylic resin specimens were irradiated and the Vickers hardness number(VHN) and the 3-point flexure strength(FS) were measured before and after irradiation. Five kinds of acrylic resins were studied. Two(VRS. PS2) were heat cured denture base resins. one(VSC) was chemically cured denture base resin and the other two(ORJ, VOP) were orthodontic resins. The acrylic resin specimens were made according to the manufacturer's instructions and were finally polished with Microcloth (Buehler). Among ten specimens of each material. five specimens were irraditated with 100 Gy using a linear accelerator (Mitsubishi 6 MV), and the others were not. The specimens were immersed in 37℃ D.W. for 48 hours before testing. Each specimens the VHN was measured 10 times. Their FS was measured with an universal testing machine (Instron 4302, England), with a cross-head speed of 5 mm/min. The VHNs of heat cured resins were 21.52∼25.55 kg/㎟ before irradiation and 19.93∼26.58 kg/㎟ after irradiation. Those of chemically cured resins were 11.28∼16.6kg/㎟ before irradiation and 11.3∼14.3 kg/㎟ after irradiation. The VHNs of heat cured acrylic resins were significantly higher than those of chemically cured resins were significantly higher than those of chemically cured resins before and after irradiation(p<0.05). VHN of VRS was significantly increased after irradiation, and those of VOP and PS2 were significantly decreased after irradiation (p<0.05). The FS of resins studied were 6.7∼8.0 kg/㎟ before irradiation and 6.5∼8.4 kg/㎟ after irradiation. The FS of VSC and VRS increased after irradiation and those of VOP, ORJ and PS2 decreased after irradiation, but the results were not statistically significant. Before irradiation, the FS of heat cured resins were somewhat higher than those of chemically cured resin, but not statistically significant, and after irradiation the FS of heat cured resins were significantly higher than those of orthodontic resins. In conclusion. high dose irradiation did not result in consistent changes in mechanical properties.