An oral irrigator includes a main body and a water tank connected to the main body. At least one first magnetic piece is disposed on the main body. The water tank defines a water storage space or the water tank and the main body jointly define the water storage space. At least one second magnetic piece is disposed on the water tank. The at least one first magnetic piece is magnetically connected to the at least one second magnetic piece to generate a magnetic attraction force. A sum of a gravity of the water tank and a gravity of a liquid fully filled in the water storage space is less than the magnetic attraction force. The water tank and the main body are not separated from each other under an action of gravity through the magnetic attraction force.

An ergonomic ultrasonic dental scaling device includes an acoustic assembly including an acoustic transformer configured to detachably receive a tip and a transducer coupled to the acoustic transformer. The transducer includes at least two first contacts coupled thereto. A resilient grip is coupled to the acoustic assembly and configured to dampen ultrasonic vibrational acceleration produced by the transducer. At least two rotational conductors are configured to electrically couple the at least two first contacts with at least two second contacts configured to connect to an ultrasonic drive system. A fluid connection is rotatably coupled to the acoustic assembly. The resilient grip is configured to rotate the acoustic assembly relative to the fluid connection, the at least two second contacts, and a handpiece housing. A rotational interface of the rotation is located forward of a longitudinal center of the ergonomic ultrasonic dental scaling device.