A cognitive systematic approach to analyzing preparation design for a difficult space management case.

There are at least two different techniques for preparing teeth prior to bonded porcelain restorations. The first involves using depth cutters guided by the existing tooth structure. A more recently developed approach integrates an additive wax-up that represents the final volume of the teeth, with indices used to guide the preparation design. This article illustrates in detail a clinical case that was prepared by combining the earlier simplified depth cutter approach with recontouring and preparation design principles determined clinically by the dentist. The same case was prepared in the laboratory on plastic models, using labial and incisal reduction preparation guides fabricated from a diagnostic wax-up. This combination of techniques will simplify preparation design for difficult space management cases and facilitate predictable and repeatable results that meet current esthetic standards while staying conservative and preserving tooth structure.