Objectives: The purpose of this study was to evaluate the systemic mercury levels in urine of patients and dental school students caused by exposure to silver amalgam. It is currently believed that occupational exposure shows the highest rate of potential for poisoning by mercury. Dental professionals are part of that quota, introducing concerns regarding the handling of dental amalgam.
Materials and methods: The study comprised 40 urine samples from 20 subjects, which were divided into four sampling groups: G1A (n = 10) composed of students before their first occupational contact; G1B (n = 10) composed of the same G1 students after their first contact; G2A (n = 10) composed of patients who needed to have dental restorations before amalgam removal; and G2B (n = 10) composed of patients who needed to have dental restoration after amalgam removal. Cold-vapor atomic absorption spectrophotometry (CVAAS) was used as the evaluation method.
Results: A statistically significant difference was found among dependent groups 1 and 2 (p = 0.0038), whereas mercury levels increased considerably after the first occupational contact of all subjects.
Conclusions: Occupational exposure to dental amalgam poses a potential risk of increasing systemic mercury levels, although urine mercury levels in all the sample participants were below the limits of biologic tolerance.