纤维桩树脂粘接修复中不同根管封闭材料和粘接程序下粘接界面的扫描电镜观察

Scanning electron microscope analysis of the root dentin bonding interface filled with different pastes or bonded by different program in fiber post and resin bonded repair

目的观察不同根管封闭材料和不同粘接程序对纤维桩树脂粘接后牙本质粘接界面微观结构的影响，以期改进临床操作步骤，优化纤维桩的树脂粘接效果。方法选择15颗人下颌单根第一前磨牙，分为5组，每组3颗：A组：氧化锌丁香油糊剂根充，常规粘接纤维桩（RelyxUnicem）；B组：Vitapex封闭剂根充，常规粘接纤维桩；C～E组：AHPlus封闭剂根充，C组常规粘接纤维桩，D组35％磷酸酸蚀＋常规粘接纤维桩，E组酸蚀后涂布Singlebond2粘接剂＋常规粘接纤维桩。将牙根浸于生理盐水中1周后截为根冠1／3、根中1／3、根尖1／3段，每段厚3mm。扫描电镜观察。结果除D组外，A、B、C、E组牙本质粘接界面均出现树脂突。每种根管封闭剂根冠1／3段树脂突最多、最明显，其次是根中1／3段，根尖1／3段最不明显。不同组牙根中自粘接树脂形成树脂突的情况不同。A和B组仅根冠1／3段出现较少的树脂突，C～E组根中1／3段和根冠1／3段均出现较多的树脂突。与C组相比，增加酸蚀步骤的D组未见明显树脂突形成，而酸蚀后涂布粘接剂的E组牙根内树脂突增大伸长更加明显。结论对于使用纤维桩加强的残根残冠，建议使用C～E组根管封闭剂，无需在纤维桩粘接程序前进行酸蚀处理，而酸蚀后涂布粘接剂有可能增加纤维桩的粘固力。

Objective To observe the influence of different bonding process and three different root canal sealing materials on microstructure of root canal dentin bonding interface after fiber post and resin bonding, so as to improve clinical operation steps and to optimize fiber post resin bonding effect. Methods Fifteen human single mandibular first premolars were selected. Three were bonded with fiber posts through Relyx Unicem conventional bonding steps after filled with root canal sealing materials of zinc oxide eugenol paste（ Group A）, and another three were bonded through the same steps after filled with sealing materials of Vitapex（ Group B）. The other nine were filled with sealing materials of AH Plus, randomly divided into three groups and bonded through different steps as follows： conventional bonding steps only （Group C ）, etching with 35% phosphoric acid before conventional bonding steps （Group D）, and etching and coating with Singlebond 2 adhesive before conventional bonding steps （ Group E）. After immersed in saline solution for one week, all the roots were cut into three sections of 3 mm in thickness with emery chip and numbered as crown section, middle section and tip section respectively. The samples were observed the resin protrusion in mixed layer of dentin interface and dentinal tubules by scanning electron microscopy. Results We observed the resin protrusion in microstructures of the roots bonded through Relyx Unicem after filled with three different root canal sealing materials（Group A, B, C, E） ： most obvious in the root crown sections, middle in the root middle sections and least in the root tip sections. Differences were observed in roots filled with different sealing materials： little resin protrusion were observed in crown sections only in Group A and B, but large number of resin protrusion were found in crown and middle sections in Group C-E. Compared with Group C, no more resin protrusion were found in Group D. More and elongated resin protrusions were found in Group E. Conclusions We recommend using AH Plus as root canal sealing materials for residual crown and root needed to strengthen by fiber post. It is no need to etch before Relyx Unicem conventional bonding steps. However, coating Singlebond 2 adhesive after acid etching has the potential to increase fiber post cementation.