Gomes-Filho João Eduardo, Hopp Renato Nicolás, Bernabé Pedro Felício Estrada, Nery Mauro Juvenal, Otoboni Filho José Arlindo, Dezan Júnior Elói
Department of Endodontics, Dental School of Araçatuba, State University of São Paulo, Araçatuba, SP, Brazil.
J Appl Oral Sci. 2008 Sep-Oct;16(5):345-9. doi: 10.1590/s1678-77572008000500008.
The aim of this study was to evaluate two root canal filling techniques used in teeth that had their apical foramen disrupted and compare the apical infiltration with an ideal clinical situation. Twenty-seven freshly extracted single-rooted teeth were selected and radiographed to confirm the existence of a single and straight root canal. The crowns were removed at a mean distance of 11 mm from the apex. The teeth had the root canals instrumented and were randomly assigned to 3 groups (n=9): ND group - root canals were filled using the lateral compaction technique and no disruption was performed; DRF group - the apical constriction was disrupted by advancing a #40 K-file 1 mm beyond the original working length, the canals were reinstrumented to create an apical ledge at 1 mm from the apical foramen and were obturated with a master gutta-percha cone with same size as the last file used for reinstrumentation; DF group - the teeth had the apical constriction disrupted and the canals were obturated with a master gutta-percha cone that fit at 1 mm from the apex. The teeth were submitted to dye leakage test with Rhodamine B for 7 days, using vaccum on the initial 5 min. The teeth were sectioned longitudinally and the leakage was measured in a linear fashion from apex to crown. There was no statistically significant difference (p>0.05) between the groups that had the apical foramen disrupted (DF, DRF), but significant difference was found between the disrupted groups and the non-disrupted one (p<0.01). In conclusion, none of the evaluated techniques was able to prevent apical infiltration, so working length so the working length determination has to be established and maintained carefully.
本研究的目的是评估两种用于根尖孔已破坏牙齿的根管充填技术，并将根尖微渗漏情况与理想临床情况进行比较。选取27颗新鲜拔除的单根牙，进行X线摄片以确认单一直根管的存在。在距根尖平均11 mm处截除牙冠。对根管进行预备后，将牙齿随机分为3组（n = 9）：ND组——采用侧向加压技术充填根管，未进行根尖破坏处理；DRF组——用#40 K锉超出原工作长度1 mm以破坏根尖狭窄部，重新预备根管以在距根尖孔1 mm处形成根尖台阶，并用与最后用于重新预备根管的锉相同尺寸的主牙胶尖进行充填；DF组——破坏牙齿的根尖狭窄部，并用距根尖1 mm处适配的主牙胶尖充填根管。牙齿用罗丹明B进行7天的染料渗漏试验，最初5分钟施加真空。将牙齿纵向切开，从根尖到牙冠以线性方式测量渗漏情况。根尖孔已破坏的两组（DF、DRF）之间无统计学显著差异（p>0.05），但破坏组与未破坏组之间存在显著差异（p<0.01）。总之，所评估的技术均无法防止根尖微渗漏，因此必须谨慎确定并维持工作长度。
