Quantification of the tug-back by measuring the pulling force and micro computed tomographic evaluation

Abstract

ObjectivesThe aims of this study were to quantify tug-back by measuring the pulling force and investigate the correlation of clinical tug-back pulling force with in vitro gutta-percha (GP) cone adaptation score using micro-computed tomography (µCT).Materials and MethodsTwenty-eight roots from human single-rooted teeth were divided into 2 groups. In the ProTaper Next (PTN) group, root canals were prepared with PTN, and in the ProFile (PF) group, root canals were prepared using PF (n = 14). The degree of tug-back was scored after selecting taper-matched GP cones. A novel method using a spring balance was designed to quantify the tug-back by measuring the pulling force. The correlation between tug-back scores, pulling force, and percentage of the gutta-percha occupied area (pGPOA) within apical 3 mm was investigated using µCT. The data were analyzed using Pearson's correlation analysis, one-way analysis of variance (ANOVA) and Tukey's test.ResultsSpecimens with a strong tug-back had a mean pulling force of 1.24 N (range, 0.15–1.70 N). This study showed a positive correlation between tug-back score, pulling force, and pGPOA. However, there was no significant difference in these factors between the PTN and PF groups. Regardless of the groups, pGPOA and pulling force were significantly higher in the specimens with a higher tug-back score (p < 0.05).ConclusionsThe degree of subjective tug-back was a definitive determinant for master cone adaptation in the root canal. The use of the tug-back scoring system and pulling force allows the interpretation of subjective tug-back in a more objective and quantitative manner.

Influência da patência apical na adaptação do cone principal de obturação. Análise por tomografia computadorizada de feixe cônico

“…Para obter uma adequada adaptação do cone principal de guta-percha no canal radicular instrumentado, devem-se ter em conta alguns critérios que podem ser avaliados por métodos visuais, táteis e radiográficos (Batista et al, 2003;Cagol et al, 2009, Jeon et al, 2017, mas o conhecimento da anatomia também é muito importante para a realização dessa etapa (Ricucci;Langelan, 1998).…”