摘要
目的 以离体牙作对照，比较复合树脂、银汞作桩核材料对烤瓷熔附金属全冠瓷层耐压强度的影响。方法 选大小相近新拔除的左上第 １ 磨牙 １０ 枚，按常规作牙体制备并翻制银汞及复合树脂代型各 １０ 枚，依制备牙常规制作烤瓷熔附金属全冠共 ３０ 枚，以专用粘接剂将各冠粘接于牙、银汞及树脂代型上。用自凝塑料将牙及各代型根部包埋成方块。利用国产万能测试机，将标本置于平台中央，标本牙合面中央置 ６ ｍ ｍ 钢球，以 ０．１ ｍ ｍ ／ｍ ｉｎ速度加压至瓷崩裂。记录每标本瓷裂时的负载量（千牛顿），数据经方差分析。结果 ３ 组比较抗折裂强度无明显统计学差异。结论 两种桩核材料只要使用得当，对烤瓷熔附金属全冠瓷层抗折裂强度无明显影响。
Objective To determine the influence of two core materials on the porcelain strength of porcelain fused to metal crowns (PFMC).Methods Ten human upper molars of approximately equal sizes were chosen and prepared by routine methods and the occlusal surfaces were set on one plane.Twenty replicas (10 amalgan and 10 composite resin) were made.Then thirty PFMC were fabricated by routine methods and luted with 3M cement to the teeth and replicas.The teeth and replicas were mounted in acrylic resin blocks and then tested for fracture strength in an universal testing machine using a steel ball 6 mm in dsmeter in contact with the centre of the occlusal surface.A static pre load was applied and then increased at a rate of 0.1 mm/min until fracture occurred.The fracture loads were recorded and the data were analysed by using ANOVA.Results ANOVA analysis indicated no statistically significant difference in the porcelain fracture strength of PFMC for different core materials.Conclusion The two materials (amalgan and composite resin) have no obvious influence on the porcelain fracture strength of PFMCso long as thet are used properly.
基金
铁道部资助
