Microscopic and chemical evaluation of the filling quality of five obturation techniques in oval-shaped root canals

Objectives The aim of this study was to assess the filling quality of five obturation techniques in oval-shaped root canals. Materials and methods A total of 212 mandibular first molars with one distal oval canal were selected. Distal canals, shaped with WaveOne Gold Primary, were randomly divided in five groups (n = 40) for obturation: continuous wave condensation, GuttaCore, Thermafil, single cone with AH plus, and single cone with BioRoot RCS. The proportions of gutta-percha-filled areas (GPFA), sealer-filled areas (SFA), void areas (VA), and the sealer/gutta tags into dentinal tubules at 4 mm and 2 mm from the apex were analyzed by an optical numeric microscope, SEM, and energy-dispersive X-ray (EDX). Data were then compared by Kruskal-Wallis one-way ANOVA on ranks (alpha = 0.05). Results At 4 mm, a statistically significant higher GPFA and lower SFA were observed in the GuttaCore and Thermafil groups compared with the 3 other groups. A statistically significant lower VA was observed in the continuous wave condensation, GuttaCore, and Thermafil groups than in the two single-cone groups. At 2 mm, there were a statistically significant higher GPFA and lower SFA and VA in GuttaCore and Thermafil groups than in the 3 other groups. At the two levels investigated, the presence of gutta-percha tags was clearly demonstrated for GuttaCore and Thermafil groups; no tags were observed in the 3 other groups. Conclusions Obturation quality was overall improved in GuttaCore and Thermafil groups.

Automated summary

GuttaCore and Thermafil groups showed significantly higher gutta-percha-filled areas and lower sealer-filled areas compared to the other groups at both 4 mm and 2 mm levels. There was also a significant improvement in obturation quality with the presence of gutta-percha tags in the GuttaCore and Thermafil groups compared to the other groups.