Abstract: Traditional tooth preparation is limited by the resolution of the human eye and the inaccuracies of manual operation, making it difficult to meet the micrometric precision requirements of minimally invasive restorations. To address and advance the resolution of such issues, and in conjunction with the interpretation of relevant group standards, this article systematically outlines key technical points for achieving precise preparation. In preoperative design, both biological and mechanical factors are considered. In margin design, the microscopic supragingival 200μm margin concept uses the gingival margin line as a geometric reference, proposing that margins be placed 0-200 μm above the gingiva. This not only achieves aesthetically pleasing restorative outcomes with “invisible” margins under daily naked-eye observation but also minimizes impact on periodontal health. Intraoperatively, the use of surgical microscopic breaks through visual limitations, providing a visual support for refined operation. Furthermore, intraoperative digital guide assistance addresses the issues of poor controllability and non-uniqueness of the previous preparation quantity, which relied on empirical analogy to judge the shape. The adoption of rigid preparation guides and calibrated burs intraoperatively enables closed-loop, data-driven control of the preparation design, which is key to the practical implementation of precise preparation. Therefore, an integrated precise preparation system—combining accurate geometric contour positioning design of the preparation and restoration, microscopic visualization, and digital guide assistance—can elevate tooth preparation from a heavily experience-dependent procedure to a quantifiable, predictable digital and intelligent precision restorative technique.

Key words: tooth preparation, preparation guide, precise restoration, micro-prosthodontics, guided prosthodontics