No abstract

The aim of this work was to evaluate the occupational risks of exposure to mercury utilized in dentistry, to which dental auxiliaries from the public health system of the city of Araguaína, Tocantins, Brazil are exposed. The dentistry process from the city health system was rigorously studied based on an assessment, in the DATASUS database, of the number of amalgam restorations conducted in the period from January 2003 to December 2009. In this study, we evaluated the storage conditions of mercury residuals in the public dental offices in the studied municipality. Different barrier solutions for the storage of mercury residuals were studied regarding their efficacy in controlling the emission of mercury vapor in the environment. The solution containing ammonia presented the best time of storage of residuals (19 days at 37 °C), followed by the so lution containing photographic fixative (12 days) and the sodium bicarbonate solution (7 days). Based on these information, a profile of the dental auxiliaries actuating in the public dental offices of the city of Araguaína was characterized according to age, sex, level of exposure to mercury and conducted biosecurity procedures. The study allowed the elaboration of a database regarding handling and discard of amalgam residuals, with the purpose to assist public health policies to modify risk situations to which the professionals and/or their patients are exposed. A biological monitoring program was also carried out using as marker the presence of mercury in urine samples (HgU) from members of the dentistry team of the Araguaína public health system and from students from the Araguaína unit of the health care technical school who actuated as dental auxiliaries in other municipalities of the north region of the state (n=91). For comparison, a group of "not exposed" to mercury was evaluated (n=43), determining their HgU values. The research allowed to conclude that the HgU values from the dentistry team were within the limits set by Regulatory Norm nº 7 by the Brazilian Ministry of Labor (up to 35 µgHg.g-1 CR). Regarding mercury contamination, the average HgU concentration for the "exposed" group (5,61 µgHg.g-1 CR) was approximately 8 times higher when compared to the values from the "not exposed" group (0,65 µgHg.g-1 CR), making evident the need for a professional training and residuals management program, as well as for a more effective actuation in the realization of periodical biological monitoring in the professionals from the dentistry team.

Infiltração; Condicionamento ácido dentário.