[UpAllNight]

--The Utah "Division of Radiation Control" claims that a "bite-wing" dental XRay requires 150-350mrem.
Don't want to get into a tif with you... I suspect that the "2mrem" you're recalling is "whole body exposure" that the subject gets in that procedure, not the amount of radiation that the Dental XRay uses to take a picture of that very localized area of the mouth. --

No. They say mR. There is a difference between mR and mrem. mrem is the effective dose.

[AFPhys]

You're right - there is a difference between a mRad and a mRem. However, in this case, they're equivalent:

There are several others places to cite, but for details see: http://www.radford.edu/~fac-man/Safety/Radiation/chp5.htm where they conclude:
"In summary, the roentgen is a unit of exposure, the rad is a unit of absorbed dose, and the rem is a unit of biological dose. The rem is the unit that is used to measure radiation doses to personnel. For practical purposes, however, the roentgen, rad, and rem are essentially equivalent for gamma and beta rays and can be used interchangeably. Commonly used subunits are milliroentgen, millirad, and millirem (mR), which are equal to 1/1000 of these units."