My first dentist took full mouth bitwing xrays( a total of 10 images). a week later, went to another dentist for a 2nd opinion and they said xrays needed to be a min 18 to 20 images. which is true?

A full mouth series of X-rays consists of generally 18 images. But, there are instances where 10 images can be adequate. Are you missing any teeth. Have you had a significant amount of dental treatment. I always like to see full images of teeth, showing the full root of teeth before I can adequately make an assessment. By taking only bite wing X-rays, that can’t be done. Have combo.-PAs.&Bws

A second opinion for a specific area of concern needs a single x-ray and a bitewing for back teeth and at most two x-rays for a front tooth, but at different angles. No need for more exposure. A digital x-ray is instant and a panoramic is time saving. Make sure a lead apron is placed on you.

Either is acceptable, depending on what the Dentist is trying to visualize.