Can digital dental xray machine malfunction and overexpose patients to radiation? are safety mechanisms in machine/software to limit radiation levels?

Same machine..: Most digital dental x-rays uses the same machine used to take regular x-rays , just the dental software on a laptop or a tablet uses sensors to receive that picture digitally instead of printing it on a hard copy( regular x-ray)..

Digital X-rays: Generally digital x-rays have a lower radiation exposure than conventional x-rays. There a re safety features built into the machines. You dentist would know if the machine was not functioning properly.