Preventive planning against mercury over-exposure among Moroccan dentists using multidimensional statistical methods.

BACKGROUND Mercury used in dental amalgams constitutes a significant source of chronic exposure to this heavy metal among dentists. Thus, the safety of dental amalgam remains a controversial issue despite its long history of use. In Morocco, most studies about dental mercury were mainly focused on the environmental risk related to the management of mercury-contaminated waste. OBJECTIVE In order to evaluate the occupational exposure to mercury among liberal dentists practicing in two Moroccan regions, a multidimensional statistical approach was used to analyze the collected data. The main objective was to help establishing a targeted prevention plan aiming to reduce the mercury exposure among Moroccan dentists. METHODS Fifteen variables from 146 dentists were elected for a three-step classification procedure: a multiple correspondence analysis followed by a hierarchical ascendant clustering consolidated by the k-Means algorithm. RESULTS Three homogenous clusters were identified. The most important one includes 57.5% of the population as well as the majority of the risky factors. The characterization of these clusters allows proposing concise guidelines for a targeted preventive plan. CONCLUSIONS A real mercurial risk has been observed in the studied population. However, its impact on health as well as the efficiency of simple preventive recommendations remains to be unveiled.