Concentrations of many pharmaceutical preparations are expressed as a:

Which of the following statements regarding patient preparation for dental radiography is not correct?

A) The patient should be protected with a lead/lead-equivalent apron and thyroid collar. B) The patient's occipital protuberance should be against the headrest during exposure. C) The patient's eyeglasses may be left in place to protect the eyes. D) Objects in the mouth such as dentures, partials, and retainers should be removed prior to exposure.

The development of pseudomembranous colitis is associated with the growth of

A) Prevotella intermedia. B) Porphyromonas gingivalis. C) Clostridium difficle. D) Treponema denticola.