Background: Needlestick and sharps injuries (NSIs) are serious problems for dental health care workers (DHCWs) because they are at risk for occupational blood-borne infections. In this study, risk factors for NSIs in DHCWs at Tohoku University Hospital (TUH) in Japan over 19 years were analysed. Methods: NSI data of DHCWs at TUH from April 2002 to March 2020 were collected from the Exposure Prevention Information Network (EPINet) and statistically analysed. Results: A total of 195 NSIs occurred during the 19-year study period. Approximately 58.5% of NSIs occurred in DHCWs with less than 5 years of experience. Injection needles were the most frequent cause of NSIs (19.0%) followed by suture needles (13.3%) and ultrasonic scaler chips (12.8%). Needle injuries occurred mainly on the left hand, whereas ultrasonic scaler chip and bur injuries occurred on the right hand and other body parts whilst DHCWs were placing the instruments back on the dental unit hanging holder without removing the sharps. NSIs from other instruments primarily occurred on both hands and foot insteps during cleanup. No case of occupational blood-borne infection caused by NSIs was observed during the study period at TUH. Conclusions: NSIs occurred in DHCWs with less experience, and there were associations between the instruments, timing of use, and NSI site. EPINet was considered a valuable tool for monitoring NSIs in order to develop future strategies for minimising NSIs.