Percentage of Gutta-percha filled area in canals shaped with Nickel-Titanium instruments and obturated with GuttaCore and Conform Fit gutta-percha cones

Aim: The purpose of this study is to compare continuous wave with conform fit gutta-percha point and the core-carrier system with GuttaCore assessing the percentage of gutta-percha filled areas (PGFA), sealer filled areas (PSFA) and voids (PVA) in extracted teeth.   
Methodology: Seventy-five extracted single rooted premolars were assigned to 5 groups, groups A and C were shaped with WaveOne Gold medium, groups B and D with ProTaper Next X3, and group E with manual instruments #35 K-file. Obturations were managed with GuttaCore in groups A and C; with Conform fit gutta-percha points in groups B and D; and with ISO-sized 35 gutta-percha master cones and cold lateral compaction technique in group E. The teeth were sectioned at 2, 4, 6, and 8 mm from the apex and for every section the percentages of gutta-percha and sealer filled, and void areas with respect to the total area were calculated. Data obtained were analysed for each variable at each level by using a one-way ANOVA with group as dependent variable (α=0.05). Multiple comparisons between the five experimental groups were conducted by using the Student’s t-test with Šidák alpha correction.       
Results: At all levels group E produced significantly less PGFA and higher PSFA and PVA than all the other experimental groups. At 2 mm from the apex, group A showed significantly higher PGFA than group C and a significantly lower PSFA than C and D. At 4 mm from the apex groups A and B produced significantly better results in terms of PGFA than groups C and D. The PSFA and PVA were significantly lower in group D with respect to groups A and B. PVA were statistically significant lower in group C than in group B. At 8 mm from the apex group A showed significantly higher PGFA than groups B and D, a significantly lower PSFA and PVA than group B.

Conclusions: Independently of the instrument used for preparation (WaveOne gold versus ProTaper Next) Conform Fit point and GuttaCore produced very homogeneous obturations with high PGFA. The association of WaveOne Gold file system shaping and the GuttaCore obturation technique produced better results in terms of PGFA, PSFA and PVA than all the other techniques especially in the apical portion of the root canals. Manual instrumentation and the cold lateral obturation technique yield poor quality root canal obturations.