Blood mercury levels of dental students and dentists at Dental School of Tehran University

Dentists are often considered at risk of mercury poisoning due to using amalgam. To investigate the plasma and whole blood mercury levels in dental students, residents and clinical teaching staff, who work with amalgam and have mercury exposure, we performed this study.

We conducted a historical cohort study on fifty persons of dental group by a census of dentists in restorative department of Tehran Dental School and fifty persons of control group at Des. 2006. Data collection was carried out using questionnaire. Following taking 4cc blood by standard venojects, all samples were sent to a lab by cold box and cold vapor atomic absorption method was performed for determining blood mercury level. Statistical analysis was performed by SPSS program by using t-test, chi square and logistic regression.

This study showed mercury blood and plasma levels were significantly more in dental group (P <0.001). Also this study demonstrated all of the persons in exposed group had mercury level under Threshold Level Value (5µg/dl) expect of 2 persons.

Although mercury hygiene is good in dental school at present, but close monitoring of environmental mercury and physical and laboratory examination of dental workers is recommended.