Cleanliness of dentinal tubules following gutta-percha removal with and without solvents: a scanning electron microscopic study

P>Aim To determine the influence of solvents on gutta-percha and sealer remaining on root canal walls and in dentinal tubules. Methodology The root canals of 70 teeth were prepared chemomechanically to apical size 40. In group 1 (n = 10; control group), the canals remained unfilled. In groups 2-4 (n = 20 each), the canals were filled using lateral compaction with gutta-percha and sealer. Removal of root fillings was undertaken after 2 weeks using Gates Glidden burs and hand files without solvent (group 2), with eucalyptol (60 mu L; group 3) and with chloroform (60 mu L; group 4) to size 50. After further irrigation using sodium hypochlorite and ethylenediaminetetraacetic acid, the roots were split, photographed and scanning electron microscopy (SEM) was performed. The number of filled dentinal tubules (SEM) and the surface covered by root filling remnants (photographs) were evaluated for the coronal, middle and apical third of each root half. Statistical analysis was performed via mixed model for clustered data followed by Tukey's test. Results After pooling the results of all thirds of the canal, open tubules were more prevalent in the control group, followed by the nonsolvent group, the eucalyptol group and the chloroform group (P < 0.05 between all groups). Less surface was covered by root filling remnants in the nonsolvent group than in the eucalyptol group and the chloroform group (P < 0.05); again, fewer remnants were found in the control group than in all other groups (P < 0.05). Conclusions Solvents led to more gutta-percha and sealer remnants on root canal walls and inside dentinal tubules.