The Mirror used by the Dentists to see the teeth of the patients is
The answer is Concave Mirror.
Reason – Concave mirrors are used as dental mirrors. this is because concave mirrors produce highly magnified images which is useful in obtaining larger view of teeth and gums. They produce magnified, upright images. It is useful to have a magnified image of a tooth when you’re looking for or repairing cavities, cracks, or other abnormalitie.
While Convex Mirror is used as a passenger side in a car , Some camera phones use convex mirrors to allow the user to correctly aim the camera while taking a self-portrait because a Convex Mirror also known as curved mirror in which the reflective surface bulges toward the light source. Convex mirrors reflect light outwards, therefore they are not used to focus light. Such mirrors always form a virtual image. Images formed by these mirrors cannot be projected on a screen, since the image is inside the mirror. The image is smaller than the object, but gets larger as the object approaches the mirror.
On the other hand A Plane Mirror is a Mirror with a flat (planar) reflective surface. For light rays striking a plane mirror, the angle of reflection equals the angle of incidence. The angle of incidence is the angle between the incident ray and the surface normal (an imaginary line perpendicular to the surface). Therefore the angle of reflection is the angle between the reflected ray and the normal and a collimated beam of light does not spread out after reflection from a plane mirror, except for diffraction effects.