An endodontic system (10) is proposed comprising a handpiece (14) that includes a head operable to releasably hold a tool (18), and a motor operable to rotate the tool (18) while the head holds the tool (18)； and control circuitry operable to: instruct the motor to urge the tool (18) to rotate in a first direction, instruct the motor to quit urging the tool (18) to rotate at a predetermined moment to allow the tool (18) to coast in the first direction, determine a parameter that represents drag experienced by the tool (18) as the tool (18) coasts, if the determined parameter does not exceed a predetermined limit, then instruct the motor to urge the tool (18) to rotate in the first direction, and if the determined parameter does exceed the predetermined limit, then instruct the motor to urge the tool (18) to rotate in another direction opposite the first direction.
