Design for additive manufacturing using the contactless support strategy for the fabrication of ultrathin zirconia dental veneers.

Abstract

The rapid globalization, along with significant growth in the hospitality and aviation industries, has set a new standard for aesthetics. Nowadays, physical appearance has become an indicator of self-confidence, boosting the global aesthetics market. In this study, dental laminate veneers were fabricated in the laboratory-scale digital light processing technology using the zirconia material. Dental veneers are a widely used prosthodontic option that serves as a minimally invasive restorative option to enhance tooth appearance. The conventional fabrication of dental veneers requires extensive physical support during printing, which increases the post-processing challenges. Due to the thickness of the veneers (∼0.4 mm), support removal resulted in cracks and damage to the green bodies. Thus, this study employs a novel contactless support strategy that increases printing accuracy while eliminating post-processing steps. The novel strategy utilizes the slurry's viscosity as a contactless support, with the sample in a pseudo-floating state during fabrication. This strategy successfully fabricated samples with a thickness as low as 0.36 mm without pronounced striations/cracks. Further accuracy enhancement was achieved by optimizing the distance between the veneer and the contactless support to 0.5 mm. The precision analysis through 3D scanning showed that the fabricated samples deviated by an average RMS of 182 μm from the CAD model, which was within the acceptable error margin. The fabricated veneers also demonstrated satisfactory flexural strength, which exceeded the recommended value by ISO 6872 standards.