[The concept, clinical design and transfer application of target restoration space].

The target restoration space (TRS) is a required tooth space that should be occupied by an esthetically formed and optimally functioned crown, veneer, or other fixed restoration. It can be either internal of or external of a tooth. Since minimal invasive can't be achieved without a minimal TRS, a precise preparation of slightest damage should conform to the transfer guide based on TRS. This paper introduces the concept, design of TRS, explains how it can be applied in tooth preparation, and helps to better understand a precise and minimal invasive tooth preparation technique.