Coupling element for attaching a medical or dental instrument to a control or supply unit

A medical or dental treatment device, comprising:

• a first medical or dental instrument part comprising a first medical or dental instrument part controller operable with electrical power,
• a second medical or dental instrument part which is distinct from the first medical or dental instrument part and comprises a second medical or dental instrument part controller operable with electrical power,
• at least one sensor which is arranged in one of the first or second medical or dental instrument part and is configured to generate a sensor signal,
• two shared electrical lines comprising a first shared electric line and a second shared electric line, wherein
• the first medical or dental instrument part and the second medical or dental instrument part can be coupled to one another to connect via a shared supply tube to a shared electrical power source and to a shared control, regulating or supply unit, wherein the first shared electric line and the second shared electric line connect to the first and second medical or dental instrument part controllers and supply electrical power from the shared electrical power source to the first and second medical or dental instrument part controllers for operating the first and second medical or dental instrument part controllers, and wherein
• at least one of the first shared electric line or the second shared electric line connects to the at least one sensor to transmit the sensor signal of the at least one sensor over the first or second shared electric line to the shared control, regulating or supply unit.