Methods: Particulate matter (PM) in air was measured using a custom made plexiglas cylinder. A high-speed handpiece was mounted on the side wall of the vessel and on the opposite side amalgam cylindrical specimens. The amalgam specimens (DMP Ltd, Greece) could move on a sliding mechanism and their position could be adjusted to the cutting bur. A new bur (SSW FG-559) was used for each specimen. The sensor of a particle size analyzer (Model Lasair II-310A, Particle Measuring Technologies, USA) was mounted on the top of the plexiglas cylinder and analyzed the generated particles. Measurements were conducted under the following conditions: a) empty cylinder b) empty cylinder with HEPA filter c) HEPA filter and the high-speed handpiece in operation d) HEPA filter and the high-speed handpiece grinding amalgam.
Results: When the high-speed handpiece was grinding the amalgam specimens the concentration of totally produced particles (number of particles/m3) ranged from 7.0x107 to 9.8x107. The particle size analysis of these particles showed the following mean percentage values: 3.12 % from 0.1 to 0.5 μm, 3.56 % from 0.5 to 0.7 μm, 34.32 % from 0.7 to1.0 μm, 26.42 % from 1.0 to 5.0 μm, 25.24 % from 5.0 to 10.0 μm and 7.32 % from 10.0 to 25.0 μm.
Conclusion: The results of this study showed that 92.66 percent of generated particles are smaller than 10 μm which are considered to be fully respirable.