Perpectual preservation of what is remaining is more important than meticulous replacement of what is lost . -M.M DE VAN DICTUM Teeth do not possess the regenerative ability found in most other tissues. Therefore, once enamel or dentin is lost as a result of caries, trauma, or wear, restorative materials must be used to reestablish form and function. Teeth require preparation to receive restorations, and these preparations must be based on fundamental principles from which basic criteria can be developed to help predict the success of prosthodontic treatment.Marginal fit and adaptation is...