Micro-abrasion is a fine stream of air and tiny sand particles that gently removes decay. This will never completely eliminate the drill, but when it is appropriate to use micro-abrasion is far superior to drilling. The flutes of the bur hit the tooth and cause microscopic cracking, heat, and vibration. This all points to the need for numbing teeth. Micro-abrasion cleans the cavity like a small sandblaster with no cracking, heat, vibration, or, usually, numbing.
Some patients report a cold sensation but none ever ask to be numbed.
Now you should be able to see how a minimally invaded micro-abraded tooth filled with a composite bonded restoration is the best way to maintain the structural integrity of a tooth for the years ahead. The most ideal use of micro-abrasion is treating decay in children's teeth. When you look at back teeth you notice they are loaded with fissures and pits on the biting surface that tend to gather brown stain. This is where teeth are most susceptible as the fissures are too narrow to let in one toothbrush bristle, but plenty big for a stadium full of bacteria. These bacteria eat the foods we eat and excrete acids which cause the fissures to deepen and turn into true decay.