【作者】 吴友农； 葛兵； 黄娟； 韩新焕；

【Author】 WU You-nong~*,GE Bing,HUANG Juan,HAN Xin-huan.(*Dental Research Institute,Nanjing Medical University,210025,China)

【机构】 南京医科大学口腔研究所； 南京医科大学口腔内科学教研室； 南京医科大学基础医学院数学教研室；

【摘要】 目的:对根管治疗过程中根管预备结束和充填完成两个阶段牙齿的抗折力和折裂模式进行研究。方法:离体的上颌前磨牙根据形态先分成区组,每组3个牙齿,再抽签将区组内的牙齿等分入处理组。15个牙齿分入3个处理组。1组(对照组),不作任何处理;2组(预备组),开髓和根管预备:3组(完成组),与2组相同的处理之后,进行根管充填和复合树脂修复。全部牙齿制成试件后,采用万能测试仪测试牙齿的抗折力,即将直径3mm的钢制加载头对准牙齿合面的正中,以1800N为最大负荷,以1.0mm/min的速度下移,直至牙齿折裂;将折裂模式分为"轻度"和"重度"两级,由2名专家盲法评价。结果:各组的抗折力分别为:(1171.2±140.10)N,(514.8±219.23)N和(911.0±86.77)N。对照组最高,预备组最低。方差分析显示组间差别显著(F=26.50,P=0.0003)。各组折裂牙属于"重度"者分别有1、3、2个,预备组和完成组有"重度"者较多的趋势。结论:根管治疗术会削弱牙齿的抗折力,尤其是根管预备完成后的阶段。更多还原

【Abstract】 OBJECTIVE:To determine quantitatively of fracture resistance and fracture model as well at two stages of root canal therapy.METHODS:Every 3 upper premolars would be put together based on their shapes as a block,then were divided into 3 groups by drawing lots.Group 1,not any interventions was given as control;group 2,access cavity and root canal preparation were made;roup 3,offer procedure as group 2,then,obturate canals and restoration access cavity with composite resin. Universal testing machine was used for testing fracture resistance.Specimens were subsequently submitted to the steel head 3mm in diameter,an axial compression test with the speed of 1.0mm per minute and a maximum limit of 1800N,until fracture.Total values were analyses by Two-way ANOVA(α=0.05).The model of fracture of teeth was divided into"moderate"or"severe"and decided blindly by two dentists.RESULTS:The compression force resistance in groups were(1171.2±140.10)N,(514.8±219.23)N and (911.0±86.77)N respectively.Significantly differences were found between groups(F=26.50,P=0.0003) with the lowest of group 2.The numbers of tooth with"severe fracture"were 1,3 and 2 respectively in the group of 1,2 and 3.CONCLUSION:Root canal therapy process can weaken the fracture resistance of teeth at any stages,especially at the stage of after root canal preparation.更多还原