Braga Neilor Mateus Antunes, Brito Manoel, da Silva Juliana Monteiro, Miranda Lilian Souto, de Carvalho Jacy Ribeiro, Faria-e-Silva Andre Luis
Department of Dentistry, State University of Montes Claros, Minas Gerais, Brazil.
Gen Dent. 2013 Aug;61(5):40-2.
This study evaluated the effect of different ultrasonic vibration protocols on custom cast post-and-cores' retention to the root canal. Post holes were placed in the root canals of human maxillary canines, and post-and-core sets were luted, using zinc phosphate cement. The samples were divided into 5 groups (n = 8). Group 1 (control) received no ultrasonic vibration. For the other samples, the tip of the ultrasonic device was positioned either over the incisal face of the core (Group 2), over the lateral core surfaces and close to the incisal edge (Group 3), over the lateral face of the core but close to the line of cementation (Group 4), or over the lateral face of the core but with the end of the mouth mirror handle positioned on the opposite surface of the core (Group 5). After a tensile test, data were submitted to 2-way ANOVA and Tukey's tests (P < 0.05). The control group showed higher values than all of the groups that were submitted to ultrasonic vibration. Bond strength was similar for Groups 2 and 3. Bond strength was lower in Groups 4 and 5; no statistical difference was observed between these 2 groups. Based on these results, both positioning the tip of the ultrasonic device near the cement line and placing a mouth mirror handle on the opposite surface of the core, are effective ways to reduce the retention of a cast post-and-core within a root canal.
本研究评估了不同超声振动方案对定制铸造桩核与根管固位力的影响。在上颌尖牙的根管中制备桩道，并用磷酸锌水门汀粘固桩核。将样本分为5组（n = 8）。第1组（对照组）未接受超声振动。对于其他样本，超声设备的尖端分别置于核的切端上方（第2组）、核的侧面靠近切缘处（第3组）、核的侧面靠近粘固线处（第4组）或核的侧面但口镜柄末端置于核的相对表面（第5组）。拉伸试验后，数据进行双向方差分析和Tukey检验（P < 0.05）。对照组的值高于所有接受超声振动的组。第2组和第3组的粘结强度相似。第4组和第5组的粘结强度较低；这两组之间未观察到统计学差异。基于这些结果，将超声设备的尖端置于靠近粘固线处以及在核的相对表面放置口镜柄，都是降低铸造桩核在根管内固位力的有效方法。
