三单位聚醚醚酮固定桥不同连接体面积抗折强度研究

The fracture resistance of three-unit polyetheretherketone fixed bridge with different connection areas

目的研究三单位聚醚醚酮固定桥不同连接体横截面积与抗折强度之间的关系,并探讨连接体的最小横截面积。方法选取下颌磨牙区新鲜离体牙30颗,制作成模型15副,随机分为A、B、C 3组,每组5个。运用CAD/CAM技术制作连接体横截面积分别为5.0 mm^2、7.0 mm^2和9.0 mm^2固定桥,游标卡尺测量连接体的实际横截面积,固定桥置于模型上,万能材料试验机加载直至固定桥完全破坏,计算机自动记录最大载荷,并观察固定桥破坏模式。单因素方差分析实验数据。结果 A、B、C三组的平均实际横截面积分别为5.40 mm^2、7.62 mm^2和9.73 mm^2,断裂载荷分别为(657.44±45.17) N、(877.94±71.11) N和(1 244.64±62.38) N。单因素方差分析3组断裂载荷差异有统计学意义(P<0.05),SNK两两相比抗折强度有显著差异(P<0.05),并观察到固定桥在连接体处发生完全断裂。结论连接体是固定桥的薄弱区域,增加连接体横截面积可增加固定桥抗折强度;临床推荐三单位聚醚醚酮固定桥连接体横截面积≥7.62 mm^2。

Objective To investigate the relationship between the cross-sectional area of different connectors and the fracture resistance of three-unit polyetheretherketone fixed bridge,and discuss the minimum cross-sectional area of the connectors.Methods 30 pieces of freshly isolated teeth in the mandibular molar area were selected to make 15 pairs of models,which were randomly divided into three groups(A、B and C)with 5 in each group.The cross-sectional areas were respectively 5.0 mm2,7.0 mm2 and 9.0 mm2 by CAD/CAM systems.The actual cross-sectional area of the connector was measured by vernier caliper.The fixed bridge was put on the model,fracture load was measured,the maximum load was recorded automatically by the computer,and the damage mode of the fixed bridge was observed.Results The average actual cross-sectional areas of three groups(A、B and C)were 5.40 mm2,7.62 mm2 and 9.73 mm2 respectively,the fracture resistances were(657.44+45.17)N,(877.94+71.11)N and(1 244.64+62.38)N.The oneway ANOVA and SNK revealed that there were statistically significant differences in fracture resistance between cross-sectional areas(P<0.05).The connectors of the fixed bridge was completely broken.Conclusion The connector is the weak area of the fixed bridge,and the fracture resistance of the fixed bridge can be increased by increasing the cross-sectional area of the connector.It is recommended that the cross-sectional area of three-unit polyetheretherketone fixed bridge be≥7.62 mm2.