不同微波热处理对树脂基托物理性能的影响

目的研究不同功率和时间微波热处理对义齿树脂基托物理性能的影响。方法采用同一模具制作40.0 mm×10.0 mm×2.0 mm大小的蜡型90个,随机分为Ⅰ、Ⅱ两组,Ⅰ、Ⅱ组各随机分成9组,每组试件数为5个。用常规水浴方式处理试件作为A组,用不同时间(6、8、101、2 min)和功率(5007、00 W)的微波热处理其他组的试件,用万能实验机测量Ⅰ组试件挠曲强度和弹性模量,用粗糙度测试仪测量Ⅱ组试件表面粗糙度。结果不同热处理试件的挠曲强度和表面粗糙度比较差异无显著性(P>0.05)。各微波组间弹性模量比较差异无显著性(P>0.05);各微波组与A组弹性模量比较差异均有显著性(F=2.29,q=3.76～5.09,P<0.05)。结论采用功率500 W或700 W,时间在6～12 min范围内微波热处理义齿树脂基托,对基托的物理性能没有明显影响。

INFLUENCE OF DIFFERENT MICROWAVE HEAT TREATMENT ON THE MECHANICAL PROPERTIES OF RESIN BASE

Objective To study the effect of different power and time of microwave heat treatment on physical properties of dentural resin base. Methods Using a same size tooting,90 wax forms(40.0 mm×10.0 mm×2.0 mm) were made,and divided into group Ⅰ and group Ⅱ,which were subdivided into nine groups,respectively,with five test pieces in each group.The test species managed with conventional water bath(group A) and microwave heat treatment at different time(6,8,10,and12 min) and different power(500 and 700 W).The flexural strength and elastic modulus of the species in groupⅠ were measured by a universal test machine;the surface roughness in groupⅡwas measured by a roughness tester. Results No statistical differences were found among different heat treatments in terms of flexural strength and surface roughness(P>0.05).The differences among microwave groups were not significant in terms of elastic modulus,but the differences were significant compared with that in group A(F=2.29,q=3.76-5.09,P<0.05). Conclusion Microwave heat treatment(500 or 700W;6-12 min) does not markedly influence the physical properties of dentural resin base.