In vitro evaluation of root canal filling performance of combined warm vertical compaction, single cone, lateral compaction, soft-core methods

The aim of this study was to compare different obturation techniques in curved canals in terms of the percentage of gutta-percha filled area and voids. The obturation times and the incidence of extrusion of filling material were also compared. Slightly curved root canals (curvature, 20–30°) of 80 extracted human teeth were enlarged with twisted file adaptive rotary NiTi instruments and obturated as follows: Group A: cold lateral compaction with 35/.02 gutta-percha master cone; Group B: carrier based Soft Core obturators; Group C: modified continuous wave compaction; Group D: 35/.04 matched-single-cone. In all groups MM Seal was used as sealer. The teeth were sectioned horizontally at 2, 4, 6 and 8 mm from the apex. The total area of each canal segment was measured and the areas of gutta-percha, sealer and voids were converted to percentages of the total area. Data were subjected to the Kruskal–Wallis and post hoc dunn test. Obturation times were compared using ANOVA and post hoc Student– Newman–Keuls test.The The matched-single-cone obturation (group D) was significantly the fastest method while modified continuous wave compaction (group C) required significantly more time than all other techniques (p<0.05). No significant differences were obtained between the groups in terms of percentage of voids at any level (p>0.05). At all levels, groups B, C, and A produced significantly higher guttapercha filled areas (p<0.05) and lower sealer-filled areas (p<0.05) than group D. No significant differences were found between groups B, C, and A (p>0.05) regarding gutta-percha and sealer-filled areas. Within the limitations of the in vitro study, it can be concluded that lateral compaction of standardized gutta-percha cones is a good method for obturation of curved canals, but modified continuous wave compaction is more efficient than the other techniques.