Dental preparation uses a tooth preparation guide custom-made for fitting with teeth of a patient. The preparation guide includes one or more guide channels for guiding a cutting tool. The preparation guide enables modification of the teeth as planned with high level of precision. A dental prosthesis for installing onto prepared teeth of the patient is provided before preparation of the teeth. The prosthesis includes features that are complementary to the prepared teeth. The prosthesis can be installed immediately after preparing the teeth using the preparation guide. With the high level of accuracy and precision in the preparation of teeth, no modification of the prosthesis would be needed for installation.