Filling Quality Evaluation of Calcium Silicate-based Sealer and Gutta Percha Cones using Two Obturation Techniques

Abstract

The purpose of this study was to assess the root filling quality of calcium silicate-based sealer and gutta percha cones by measuring, via micro-computed tomography (micro-CT), the percentage of voids when a single cone or continuous wave filling technique was used for filling artificial molar root canals. Additionally, sealer penetration, as measured by confocal laser scanning microscopy (CLSM), into the isthmus area in human extracted mandibular molars was compared between the two different filling techniques. Twenty artificial molar-shaped teeth were instrumented using rotary files. Three specimens were overlapped by micro-CT to confirm that the prepared canal space was consistent. Teeth were randomly divided into two groups; one group was obturated using the single cone (SC) technique, and the other group was obturated using the continuous wave (CW) technique. Additionally, six human mandibular molars were divided into two groups and prepared similarly. Obturated teeth were scanned by micro-CT, and the percentage of void volume between the filling materials and the root canal walls was calculated in both the apical and coronal areas. Human molars underwent CLSM. The percentage of voids between the filling materials and the root canal walls (%Vout) was not significantly different between the two obturation techniques (p > 0.05), except that, in the coronal area of the distal canal, the CW group showed a significantly higher void volume (p < 0.05). The percentage of voids inside the filling material (%Vin) was significantly higher in the CW groups for all comparisons (p < 0.05), except for the apical area of the distal canal (p > 0.05). In confocal microscopic images of human extracted molars, most of the isthmus area was obturated both in SC and CW groups, but in the SC group, the sealer penetrated the isthmus, while in the CW groups, gutta percha filled the isthmus.