go with a dine solution. lester a dine has decades of experience with dental
photo.

http://dinecorp.com/

i have had several digital cameras in the last 10 years and nothing compares
with the results i've had with what they sold me.

get a reflex cam.  consumer camera's shutter lag causes a lot of focus
problems in macro photography, and u dont notice it until u r sitting at
your desktop and the patient is gone.

I have a Konica-Minolta DIMAGE Z5, 5.0 megapixels (Z6 is already on the
market after only 6 months I bought my camera)
yes! a normal family camera but... macro up to 1 cm from the lens.
lights or flash?... the dental chair's light works right for me, also have a
pair or fine mirrors that help a lot.

Gabe