Computational Tracking of Dental Splatter: Comparison of High- Speed Drill and 9.3μm CO 2 Laser

Objective: The purpose of this study was to track and characterize visible oral splatter generated by a 9.3 μm CO2 laser compared to that of a traditional high-speed dental drill when performing a cavity preparation procedure. Methods: Extracted human second molars were placed in a dental-simulator mannequin head, which was positioned in a local dentist's operatory, along with a high-volume evacuation (HVE) system to simulate a typical clinical environment. A cavity preparation was performed using both a 9.3 μm CO 2 laser and high-speed drill, while maintaining identical cutting angle and location in the mouth. A high-speed camera was used to capture the splatter ejected from the mouth. The recordings were analyzed with both manual and computational-tracking methods using an image analysis software. A quantitative analysis of the tracked droplets was performed to determine splatter displacement, speed, and rate of droplet formation during the procedure for both the 9.3 μm CO2 laser and drill. Results: Over the visible tracking range during a time of maximal droplet generation, the 9.3 μm CO 2 laser, relative to the drill, generated 93.5% fewer droplets per second, reduced mean droplet speed by 35%, and reduced average maximum droplet speed by 50%. At a typical distance between the patient and the dentist, 0% of the laser-generated droplets, and 12% drill-generated droplets traveled a net displacement of >30 cm from the tooth. Mean splatter displacement rate, a weighted representation of the combined displacements of droplets over time, was 95% lower for the 9.3 μm CO2 laser than for the drill. Conclusion: Droplet tracking analysis showed that the use of a 9.3 μm CO2 laser reduced the amount, speed and displacement of splatter as compared to a conventional high-speed drill. Since splatter may harbor infectious pathogens, the laser reduces the risk of infection to dental practitioners.