Optimizing esthetic contouring of presintered zirconia: An expanded cast technique

Zirconia restorations present challenges during esthetic contouring because of their sintering shrinkage and hardness after crystallization. This article introduces a technique that leverages digital workflows to enhance esthetic outcomes by performing contouring and internal staining in the green state. A 6-unit anterior zirconia prosthesis was designed and milled on an enlarged scale to account for the material's sintering shrinkage. Simultaneously, the digital cast was scaled using the same factor and additively manufactured. This enlarged cast allowed the presintered crowns to be seated accurately, enabling detailed anatomic contouring and internal staining while the zirconia was still soft (green state) and easily modifiable. Once sintered, the crowns were finalized on the original-sized cast with final polishing, external characterization, and glazing. This approach eliminated the guesswork of shaping enlarged restorations, ensured harmony with adjacent teeth, and minimized the risk of introducing cracks or phase transformation. Using an enlarged cast with presintered zirconia enhanced precision, efficiency, and esthetic predictability.