Today i was in my dentist for a tooth filling procedure. After he had worked extensively on my tooth with a dental drill, the dentist accidentally scratched the back of his forearm quite hard on the tip of a drill/bur that had been used on me. The bur was resting in the vertical holder of the dental chair instrument’s tray. The injury was not bled immediately, although the abrasion was visible. He then continued using the same drill on my tooth. About 5 min later i noticed the wound had started to bleed on his forearm. 

After the procedure, i raised the issue of safety and asked whether this posed any risk of disease transmission. He reassured me that such incidents happen frequently and do not present risk of infection. I don’t know his health status. Im concerned that i might exposed to HIV or HepC through his wound and the instrument that was used on me. Am i in risk?