The performance of a local exhaust hood ventilation system was evaluated during medical drilling applications into teeth and bone with respect to biological nano-particle emissions. The study tested several characteristics of a commercial exhaust hood ventilation system to determine the effects of the ventilation system location on medical worker exposure to nano-partical emissions in the general area and specifically in the breathing zone. The ventilation design considerations and ventilation hood positioning will be discussed with respect to nano-partical emissions determined from sensors in the drilling zone, the working zone, the breathing zone, and the general vicinity.