Particulate aerosolization during the drilling of amalgam restoration and teeth.
Kao EC; Yue PC; Chen BT
J Dent Res 2000 Apr; 79(Suppl):570
A potential hazard DC particulate inhalation by patients and health workers is associated with removal of amalgam restorations and excavation of carious teeth. The objectives of this study was to determine the mass of aerodynamically respirable particles collected during high-speed drilling under two conditions: dry cut and wet cut (with water spray and suction), and the distances of aerosol dispersion from the source. The drilling was performed in an operatory measuring 3.9 x 3.3 x 2.4m with an airflow of 5810L/min. Extracted teeth and those with amalgam restorations were plated in a mannequin typodont. Aerosol containing amalgam or teeth particles were created by drilling with cross-cut carbide burs for 30 minutes. Multiple: survey (n=3) of particulate exposures were evaluated at simulated breathing zones of patient, dentist, dental assistant and at various locations in the operatory using personal air samplers (IOM) and aerodynamic particle sizing Marple cascade impactors. The distances for sampler placement ranged from 0.24m-2.3m from the source of aerosol. For dry cut, total mass of amalgam particulate recovered from IOM's ranged from 2-30mg/m3 and that of teeth particulate ranged from 3-8.7mg/m3. They were significantly higher than wet cut which ranged from 0.9-11mg/m3 for amalgam and 0.8-7mg/m3 for teeth (p<0.05). The particulate recovery generally decreased with increasing distance for both materials. The dentist and assistant were exposed moderate amounts of aerosols while the patient exposure was the highest. 36% of teeth particulates and 41% of amalgam particulates recovered from the cascade impactors were found to be in respirable range of 0.5-5 microm in size. The use of efficient water spray and suction and the use of protective barriers for all dental personnel and patients are important to reduce the exposure of amalgam and teeth aerosols during, denial drilling.
Mine-workers; Mine-disasters; Safety-education; Safety-equipment; Safety-measures; Safety-practices; Equipment-design; Equipment-reliability; Ergonomics; Metals; Safety-personnel
Journal of Dental Research