中文摘要：

目的评价复合树脂高强纤维（glass fiber reinforced composite resin，GFRCR）间隙保持器的抗疲劳强度，比较两种树脂材料制作的GFRCR间隙保持器的抗疲劳强度。方法收集离体磨牙40颗，随机分为A、B两组，每组20颗，分别用树脂Z350和Grengloo制作间隙保持器试件，试件经过温度循环后加载疲劳循环，记录循环次数，分别与标准抗疲劳强度比较，对结果进行统计学分析。结果两组循环次数分别与标准抗疲劳强度比较，差异有统计学意义（P＜0.001）；A、B组间抗疲劳强度差异无统计学意义（P=0.886）。结论GFRCR制作间隙保持器可获得良好的抗疲劳性能，推荐临床使用；树脂材料Z350和Grengloo制作的高强纤维间隙保持抗疲劳性能无明显差异。

英文摘要：

Objective To evaluate the fatigue resistances of glass fiber reinforced composite resin (GFRCR) space maintainers and to compare the fatigue resistance of GFRCR space maintainers made of two different kinds of composite resins. Methods 40 extracted human molars were selected. Samples were randomly divided into two groups (n = 20).Space maintainers in group A were made of Z350 composite resin, while space maintainers in group B were made of Grengloo composite resin. All the specimens were exposed to temperature alternating between 5～55 ℃. Then they were placed on the cyclic loading machine to bear cyclic loading and the number of loading times were recorded. The results were compared with standard fatigue strength. Results The fatigue resistances of two groups were higher than standard fatigue resistances (P < 0.001). The fatigue resistances of two kinds of space maintainers showed no difference (P = 0.886). Conclusion According to the fatigue resistances, GFRCR space maintainers can be clinically used.There were on differences between two kinds of materials in making GFRCR maintainers.