Efficacy of two instrument retrieval techniques in removing separated rotary and reciprocating nickel-titanium files in mandibular molars – An in vitro study

Abstract

Context: This in vitro study aimed to evaluate the efficacy of both the staging platform (SP) and burrow platform (BP) techniques in the retrieval of separated rotary and reciprocating files in mesiobuccal (MB) canals of mandibular molars. Materials and Methods: Forty extracted human mandibular molars with moderate curvature were used in this study. Anatomically, size-matched samples were equally distributed into two different retrieval techniques: Group SP and Group BP. Each group was further subdivided into two subgroups based on their motion kinematics: rotary and reciprocating subgroups. Four millimeters of ProTaper F1 20/07 (rotary) and WaveOne Gold 20/07 (reciprocating) instruments was separated at the apical third region of the MB canal in mandibular molars. Both techniques’ success in retrieving separated files was assessed and the canal volume loss was calculated using cone-beam computed tomography. The total time taken for retrieval was also analyzed. Results: The overall success rate for retrieval of separated instruments (SIs) was 92.5% (37/40). There was no significant difference in retrieval success rates between SP (95%) and BP technique (90%). BP technique (2.32 mm3 and 103 min) resulted in significantly lesser canal volume loss and longer time for retrieval when compared to SP technique (3.75 mm3 and 90 min). Conclusion: Within the limitations of the current study, in mandibular molars with moderate curvature, the BP technique showed a similar success rate to that of SP technique for retrieval of SI. The BP technique resulted in lesser canal volume loss but took more time for retrieval of SI when compared with SP technique.