Dental treatment apparatus and method of driving the same

A dental treatment apparatus comprising:

• a drive unit comprising a micromotor and a motor driver that drives a cutting tool held at a head of a handpiece;
• a microcomputer that controls the drive unit that drives the cutting tool;
• a position detector that detects a position of a tip end of the cutting tool within a root canal by electric root canal length measurement;
• and
• a load detector that detects a load applied to the cutting tool,
• wherein the microcomputer controls the cutting tool to be held at the head forward driven in a direction of cutting of an object to be cut,
• wherein the microcomputer controls the cutting tool to be reverse driven in a direction reverse to forward rotation drive when the cutting tool is forward driven and the load applied to the cutting tool and detected by the load detector is equal to or higher than a reference load,
• wherein the microcomputer controls the cutting tool to be reverse driven in a direction reverse to forward rotation drive when the cutting tool is forward driven and the position detector detects the tip end of the cutting tool reaching a reference position,
• wherein the microcomputer carries out a fail-safe control when the position detector detects movement of the tip of the cutting tool toward a root apex position while the cutting tool is reverse driven;
• wherein the microcomputer carries out fail-safe control when the cutting tool is reverse driven and the load applied to the cutting tool and detected by the load detector is equal to or higher than the reference load;
• wherein the cutting tool being controlled to be forward driven comprises the cutting tool being controlled to mainly be driven clockwise, and
• wherein the cutting tool being controlled to be reverse driven comprises the cutting tool being controlled to mainly be driven counterclockwise.

A method of driving a dental treatment apparatus, the dental treatment apparatus including a drive unit comprising a micromotor and a motor driver that drives a cutting tool held at a head of a handpiece, a microcomputer that controls the drive unit that drives the cutting tool, and a position detector that detects a position of a tip end of the cutting tool within a root canal by electric root canal length measurement, the method comprising:

• forward driving, under control by the microcomputer, the cutting tool held at the head in a direction of cutting of an object to be cut;
• reverse driving, under control by the microcomputer, the cutting tool in a direction reverse to forward rotation drive when the cutting tool is forward driven and the position detector detects the tip end of the cutting tool reaching a reference position;
• carrying out, by the microcomputer, a fail-safe control when the position detector detects movement of the tip of the cutting tool toward a root apex position while the cutting tool is reverse driven;
• wherein forward driving the cutting tool comprises controlling the cutting tool to mainly be driven clockwise, and
• wherein reverse driving the cutting tool comprises controlling the cutting tool to mainly be driven counterclockwise.