摘要目的 探讨老化对4种水门汀材料与纤维桩粘接性能的影响,以期为临床选择适宜的纤维桩粘接材料提供实验依据.方法 选取216颗拔除1个月以内的单根管人下颌前磨牙,常规根管充填并预备桩道后,选用Fuji Ⅰ(A组)、Fuji Cem(B组)、RelyX Unicem(C组)和RelyX ARC(D组)4种水门汀材料分别粘接纤维桩(每组54颗牙);每组分为3个亚组,分别进行水储存24 h(粘接后即刻)、冷热循环和冷热循环-机械加载处理(每亚组18颗牙).每亚组8颗牙进行界面微渗漏评分,每亚组2颗牙使用扫描电镜观察界面微观形貌,每亚组8颗牙测试拉出强度.结果 粘接后即刻D组拉出强度[(278±26)N]最高,随后依次为C组[(219±12)N]、B组[(104±23)N]、A组[(73±8)N],组间差异均有统计学意义(P＜0.05).两种老化处理(冷热循环和冷热循环-机械加载)后A、B组拉出强度均比老化前(粘接后即刻)显著提高(P＜0.05),D组拉出强度显著下降(P＜0.05).扫描电镜示两种老化处理后D组粘接界面均出现狭窄的裂隙,A、B组粘接界面更致密、均一.两种老化处理后A、B组微渗漏减少,C、D组微渗漏增加.结论 应用树脂类水门汀粘接纤维桩可获得较高的即刻拉出强度,而玻璃离子类水门汀则表现出较好的粘接耐久性.

abstractsObjective To investigate the effect of four different cements on the bonding effectiveness of root canal dentine and fiber post before and after different treatments.Methods A total of 216 freshly extracted sound single-root-canal mandibular premolars were randomly divided into four groups.After root canal treatment and post space preparation being conducted on the premolars,Fuji Ⅰ,Fuji Cem,RelyX Unicem,RelyX ARC were used respectively to bond fiber posts and were marked with group A,B,C,and D.Microleakage,micromorphology of the bonded interfaces,and pull-out bond strength were evaluated in the immediate group,thermocycling group and thermomechanical loading group.Results In the immediate group,samples in group D showed the highest bond strength [(278 ± 26) N],followed by group C[(219 ±12) N],B[(104 ±23) N] and A[(73 ±8) N].Significant differences were found among all groups (P ＜ 0.05).A significant increase in bond strength was found in group A and B,whereas a decrease tendency was detected in group C and D after different treatments.Scanning electron microscope indicated that some little gaps were observed in group D after treatment,while a more intense bonding interface was found in group A and B.Microleakage scores in group A and B were lower than those in group C and D after aging treatments.Conclusions Resin cement can achieve a better immediate bond strength,while resinmodified resin cement may acquire a better long-term retention.