From Dr. Bicuspid (Registration Required). The article notes that the research confirms the safety of Nomad (one of my favorite products) and that there are 6000 handheld devices in use in the US.
January 16, 2012 — Dental care providers and their patients need not worry about radiation exposure when using the Nomad handheld intraoral xray device (Aribex), according to a new study in Health Physics (February 2012, Vol. 102:2, pp. 137-142).
via DrBicuspid Imaging.