Abstract
Enamel is the hardest tissue in the human body and is considered to be valuable because it cannot be regenerated if damaged. Therefore， the benefits and risks of removal of sound tooth structures should be carefully examined before prosthetic treatment. Over 20 years have passed since the introduction of prostheses using bonding bases for retention following orthodontic treatment. These can be applied in bounded edentulous spaces to replace a small number of teeth， and may prevent secondary occlusal trauma in teeth with moderate to severe periodontitis. Given that the metal is exposed， which confers an unaesthetic appearance even for a prosthesis applied on the lingual side， it is surprising that these prostheses have remained in use for such a long time. Connected crowns and bridges should be considered only if necessary. If cutting the teeth and not cutting the teeth at all are compared， which method should be selected if there is no major difference in effects? The answer is clear in light of the concept of minimal intervention（ MI）.
