Many dentists use air-driven “hand-pieces” (the dental term for “drills”). While acceptable for many procedures, these “whiney sounding” air-powered hand pieces all have a degree of non-concentricity; they do not rotate perfectly smoothly.
For the most precise aspects of restorative procedures, we use electric hand-pieces. This results in extraordinarily precise interfaces between your tooth and your new restoration (dental crown, tooth veneer, or tooth filling). This will bring more comfort to you as well. With a more precise tool, there is less vibration and less noise.
Digital X-rays offer more precision since we view the image on a computer monitor, instead of holding up a 35mm film up to the light. Digital X-rays results in 1/6th the radiation exposure to you.