Pulmonary risk of intraoral surface conditioning using crystalline silica.
OBJECTIVE
This study evaluated the pulmonary risk caused by possible respirable dust of Al2O3 and SiO(x) resulting from chairside tribochemical sandblasting procedures in a dental office.


METHODS
Dust was collected using a trap near the working field, and quantitative morphologic determination and identification were performed with SEM and EDAX. Forty blasting processes (total time 20 minutes) were aimed at a dummy to obtain maximum pollution of the workplace. Respirable dust fraction was measured using personal air samplers with an 8-microm cellulose-nitrate filter and a volume flow rate of 2 L/min. Mass of the respirable dust fraction was determined, and respirable free crystalline silica was identified with the help of infrared spectroscopy.


RESULTS
Blasting of metal or ceramic surfaces with tribochemical agents produces respirable and potentially harmful SiO(x) and Al2O3 particles with a diameter of less than 5 microm, showing a total concentration in the air of less than 0.3 mg/m3. With and without dental suction, the concentration of the respirable free crystalline silica was smaller than 0.02 mg/m3.


CONCLUSIONS
Concern regarding the risk of chairside tribochemical methods and possible impairment of health of patients and dental staff is unfounded, even under extreme conditions or without protective measures, since the concentrations of SiO(x) found in the air of the workplace were far below the current threshold value of 0.15 mg/m3.
Department of Prosthetic Dentistry, School of Dental and Oral Medicine, University of Cologne, Germany. beate.mayer@medizin.uni-koeln.de
Beate
B
Mayer
Hans
H
Raithel
Dieter
D
Weltle
Wilhelm
W
Niedermeier
D000395:Air Pollutants, Occupational / Q000032:analysis*; D000537:Aluminum Oxide / Q000032:analysis*; D003764:Dental Materials / Q000032:analysis*; D003780:Denture Repair; D004391:Dust / Q000032:analysis; D004577:Electron Probe Microanalysis; D005374:Filtration / Q000295:instrumentation; D006801:Humans; D007754:Laboratories, Dental; D008171:Lung Diseases / Q000209:etiology*; D008452:Maximum Allowable Concentration; D008855:Microscopy, Electron, Scanning; D016273:Occupational Exposure / Q000032:analysis*; D010316:Particle Size; D012307:Risk Factors; D012822:Silicon Dioxide / Q000032:analysis*; D013055:Spectrophotometry, Infrared; D013499:Surface Properties
D000395:Air Pollutants, Occupational; D003764:Dental Materials; D004391:Dust; D012822:Silicon Dioxide; D000537:Aluminum Oxide