3D Printing Assisted Investment Casting of Dental Crowns for Recycling of DMLS Waste

Traditional lost wax-based investment casting (IC) is an established process to prepare dental crowns (DC), scaffolds, implants, etc. for both human and veterinary patients. But hitherto, little has been reported on the use of direct metal laser sintering (DMLS) waste (support material) for the fabrication of DC as functional prototypes. This study highlights the fabrication of DC for canine’s strategic teeth (ST) by IC of 17-4 precipitate hardened stainless steel and Ni-based alloys (collected support structure used in DMLS). The DC master pattern for ST with different geometries (volume (V)/surface area (A) ratios) was printed on fused deposition modeling by using acrylonitrile butadiene styrene filament with input parameters such as infill pattern (IP), infill density, layer height. The printed master patterns were post-processed (PP) before IC. The response parameters, namely microhardness (HV), peak load (PL), surface roughness (Ra), and dimensional deviation (Δt) were optimized by using Taguchi L₁₈ orthogonal array. Results outlined that for Ra of cast DC, material composition (MC), V/A ratio, and PP are significant parameters. For HV, PL, and Δt the significant parameters are MC, IP, and PP, respectively. The results are supported by photomicrographs, porosity, and thermal stability analysis.