Digital light printing of zirconia/resin composite material with biomimetic graded design for dental application

Stress concentration and excessive wear on the opposite jaw teeth are the main problems that lead to the failure of all-ceramic crown restoration. The objectives of this study were to: (1) Synthesize the biomimetic gradient zirconia/resin composites. (2) Control the porosity and structure so that the mechanical properties of the biomimetic gradient zirconia/resin composites are close to enamel and dentin.

Biomimetic uniform zirconia scaffolds with different widths (1.6 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.2 mm) and Biomimetic gradient (1.6 mm-2.2 mm) zirconia scaffolds were designed using 3DMax and Magics, fabricated by digital light processing 3D printing, and then infiltrated into dental resin for mechanical testing, finite element simulation and cytotoxicity testing.

Results show that the ceramic-polymer composites exhibit a significant enhancement in strength (1.37-fold increase) and toughness (2.08-fold increase) compared to zirconia ceramic scaffold (P < 0.05), highlighting the effectiveness of our structural design. In addition, the gradient design further improves the mechanical strength of the composites. Notably, the gradient composite crown exhibits a bending strength of 138.3 (±16.7) MPa, a toughness of 9.0 (±0.5) MJ/m³, and a compressive strength of 113.7 (±2.6) MPa, values that are comparable to those of natural enamel and dentin, and shows good biosafety.

Biomimetic gradient zirconia/dental resin materials were precisely fabricated through a series of studies, which is expected to further improve the clinical treatment effect. At the same time, the strategic design also provides new ideas for the performance improvement of other dental materials.

Gradient zirconia/resin composite materials with mechanical properties matching natural teeth were precisely fabricated, and are expected to significantly improve clinical treatment outcomes. Additionally, the strategic design provides new insights for enhancing the performance of other dental materials.