Effect of solvents on apically extruded debris and irrigant during root canal retreatment using reciprocating instruments

Aim To evaluate the effect of several solvents on the weight of apically extruded debris and irrigant during retreatment using a novel agar gel model. Methods Orange oil, turpentine oil and chloroform were used as solvents. Eighty single straight-rooted extracted human mandibular premolar teeth with a single root canal were divided into four groups (n = 20). All specimens were root canal-filled and weighed prior to their insertion into a prepared 1.5% agar gel model. The mean initial weights were measured by subtracting the weight of the specimen from the weight of the test apparatus and recorded. Following the removal of the coronal 4 mm of root filling, the test solvent was applied onto the root filling. No solvent was used in the control group. A Reciproc R25 instrument was used to remove the root filling in all groups. Apically extruded debris and test solvent were collected during retreatment procedures. The mean weights of apically extruded debris and irrigant were calculated by subtracting the mean initial weights from the weights of test apparatus without the Teflon tape and the specimen following the retreatment procedures. Data were statistically analysed using one-way analysis of variance. Results Use of solvents resulted in significantly less extruded debris and irrigant compared to the control group (P < 0.05). Chloroform extruded significantly more debris than orange oil and turpentine oil (P < 0.05). Conclusion Use of solvents during root filling removal was associated with less apically extruded debris and irrigant when compared to no solvent.