Zare Jahromi Maryam, Barekatain Mehrdad, Ravanbod Shirin, Ranjbarian Parisa, Kousehlar Sara
Dept. of Endodontics, Dental School (Faculty), Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran.
Dept. of Operative Dentistry, Dental School (Faculty), Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran.
J Dent (Shiraz). 2017 Mar;18(1):56-60.
Endodontic irrigants and medicaments may affect the bond strength of intracanal posts to root dentin.
The aim of this study was to compare the effect of calcium hydroxide (Ca(OH)) and 2% chlorhexidine gel (CHX) on bond strength of fiber post cemented with resin cement to root dentin.
This in vitro experimental study was conducted on 36 mandibular premolars. Canals were prepared using the step back technique. After root canal irrigation, the teeth were divided into three groups of 12. Ca(OH) paste and CHX gel were used as intracanal medicaments in the first and second groups respectively. No intracanal medicament was used in the third group (control group). Access cavities were then sealed and the teeth were incubated for one week. The root canals were then filled using gutta percha and AH26 sealer and the teeth were incubated for 72 hours. Tooth crowns were then cut at the level of the cementoenamel junction and intracanal posts were placed. The teeth were mounted in auto-polymerizing acrylic resin, and incubated for one week .They were then sectioned into 1.5mm thick slices from their coronal surface using a fully automated cutting machine, and subjected to push-out test until failure. The load at debonding was recorded and data were analyzed using one-way ANOVA, post-hoc test and t-test. The coronal margin of the root was at the level of the surface of acrylic resin in the mold.
The mean bond strength was 4.45 MPa in the Ca(OH), 2.45 MPa in the CHX and 2.48 MPa in the control group. The difference in this regard was statistically significant among groups (= 0.04). The Ca(OH) group had significant differences with the CHX and control groups (= 0.03 and = 0.02, respectively). The difference between the CHX and control groups was not significant (= 0.974).
Based on the results, Ca(OH) increased the bond strength of fiber post to root dentin but 2% CHX had no effect on bond strength.
根管冲洗剂和药物可能会影响根管内桩与牙根牙本质之间的粘结强度。
本研究的目的是比较氢氧化钙（Ca(OH)₂）和2%氯己定凝胶（CHX）对用树脂水门汀粘结的纤维桩与牙根牙本质粘结强度的影响。
本体外实验研究选取36颗下颌前磨牙。采用逐步后退技术预备根管。根管冲洗后，将牙齿分为三组，每组12颗。第一组和第二组分别使用Ca(OH)₂糊剂和CHX凝胶作为根管内药物。第三组（对照组）不使用根管内药物。然后封闭髓腔，将牙齿孵育一周。接着用牙胶尖和AH26封闭剂充填根管，并将牙齿孵育72小时。然后在牙骨质牙釉质界水平处截去牙冠，放置根管内桩。将牙齿固定在自凝丙烯酸树脂中，孵育一周。然后使用全自动切割机从牙冠表面将其切成1.5毫米厚的切片，并进行推出试验直至失败。记录脱粘时的载荷，并使用单因素方差分析、事后检验和t检验对数据进行分析。牙根的冠方边缘位于模型中丙烯酸树脂表面的水平。
Ca(OH)₂组的平均粘结强度为4.45MPa，CHX组为2.45MPa，对照组为2.48MPa。各组之间在这方面的差异具有统计学意义（P = 0.04）。Ca(OH)₂组与CHX组和对照组有显著差异（分别为P = 0.03和P = 0.02）。CHX组和对照组之间的差异不显著（P = 0.974）。
基于结果，Ca(OH)₂提高了纤维桩与牙根牙本质的粘结强度，但2% CHX对粘结强度没有影响。
