Inhalation of aerosols produced during the removal of fixed orthodontic appliances: A comparison of 4 enamel cleanup methods

Introduction: During enamel cleanup after the removal of fixed appliances, aerosols, splatter, and dust are produced that can be inhaled. Although most inhaled particles are harmless, some might be associated with chronic diseases. Modern laboratory methods can now accurately simulate the human lung and predict the site of deposition of these inhaled particles. Methods: Orthodontic brackets and bands were attached to extracted teeth to simulate complete dental arches. Four variations of enamel cleanup were used: the variables were hand-piece speed and presence or absence of water. Air sampling was conducted by using a cascade impactor, and the filter media collected from each experiment were viewed under a scanning electron microscope to locate the particulate matter. X-ray microanalysis was used to identify particle composition. Results: The amount of debris deposited on the filter media was highly variable. The combination of fast hand piece with water irrigation demonstrated the highest concentration of debris deposited at the greatest depth in the (artificial) lung. Although the particles are most likely to be deposited in the conducting airways and terminal bronchi, some might be deposited in the terminal alveoli of the lungs and cleared only after weeks or months. The most common elements identified were calcium, phosphorus, silica, and aluminum. Other elements included iron and lanthanum. Conclusions: Aerosol particulates produced during enamel cleanup might be inhaled irrespective of hand-piece speed or the presence or absence of water coolant.