What is the best resolution your monitor is capable of? If it is new and fairly high end it may go as high as 1600 x 1200. Do the math; 1600 x 1200 = 1,920,000. That is just less than 2 megapixels (A megapixel equals one million pixels).
That means if you pay the big bucks for a high resolution camera and then take images at the highest resolution most of it is wasted. For example if you display an 8 Megapixel image on a 1200 x 1600 monitor then over 75% of the image is tossed out.
Get a good camera for the quality optics and features but don’t waste bandwidth on high resolution images. For most dental uses a 2–3 Megapixel image is great.