A dental treatment instrument includes a bridge unit, and a first tip and a second tip unit each configured to be replaceable with respect to the bridge unit, where the bridge unit includes a first lengthwise groove formed in a lengthwise direction at one end of the bridge unit, a first circumferential groove extending from the first lengthwise groove in a first circumferential direction, a second lengthwise groove formed in the lengthwise direction at the other end of the bridge unit, and a second circumferential groove extending from the second lengthwise groove in a second circumferential direction different from the first circumferential direction, and the first tip unit includes a first coupling protrusion extending in a direction vertical to the lengthwise direction of the bridge unit, and the second tip unit includes a second coupling protrusion extending in a direction vertical to the lengthwise direction of the bridge unit.