We would like to address the comments made by Dr Guzzi and Dr Pigatto, in their letter regarding our paper “Occupational exposure in dentistry and miscarriage”.1 They were concerned about our exposure assessment and policy implications, and pointed out that no monitoring data were used in the assessment of exposure to mercury. In a retrospective case-control study such as ours, it is next to impossible to find environmental or biological monitoring data to cover relevant time windows for all the study subjects and for all the exposures. Therefore we assessed exposure to mercury based on the self-reported number of amalgam fillings made over a one-week time period. We also took into account exposure …