Fabrication of color-graded feldspathic dental prosthetics for aesthetic and restorative dentistry

• Published in: Dental materials Vol. 39; no. 6; pp. 568 - 576
• Main Authors: Sutejo, Imam Akbar, Kim, Jeehwan, Zhang, Sinuo, Gal, Chang Woo, Choi, Yeong-Jin, Park, Honghyun, Yun, Hui-suk
• Format: Journal Article
• Language: English
• Published: England Elsevier Inc 01.06.2023
• Subjects: Color-gradient; Dental crowns; Dental porcelain; Functionally graded additive manufacturing; Stereolithography; Functionally graded additive manufacturing; Color-gradient; Stereolithography; Dental crowns; Dental porcelain
• ISSN: 0109-5641; 1879-0097
• DOI: 10.1016/j.dental.2023.03.021

Feasibility investigation of natural teeth shades replication on dental prosthetics fabricated via functionally graded additive manufacturing (FGAM) using combination of feldspathic porcelain (FP) and yttrium aluminum garnet cerium (Y3Al5O12:Ce, YAG:Ce) as a promising esthetic restoration option. Color-graded feldspathic crown fabrication parameter through FGAM method was comprehensively examined from the slurry rheology, cure depth, debinding to sintering temperature. Effect of light absorbent also checked towards overcuring reaction during UV exposure by the shape comparison. Lastly, the flexural bending strength measured following ISO 6872:2015 to assure the applicability. Applying the studied parameter, natural teeth shades then imitated and investigated by alteration of FP and FP + 0.1 wt% YAG:Ce (Y-FP). Generated color across the structure captured through mobile camera, interpreted through the CIELAB coordinate and the gradation confirmed by the color differences (ΔE00) calculated using CIEDE2000 formula. Parameter study indicated that 70 wt% of FP slurry with 3 wt% dispersant and 0.2 wt% light absorbent is favored. It produces excellent flowability in our FGAM system with less overcuring justified by edge margin reduction from 95.65° to 90.00° after UV exposure on rectangle shapes masking. The obtain structure also offers adequate flexural bending strength of 106.26 MPa (FP) and 101.36 MPa (Y-FP) after sintering at 780 °C. This validated the materials as class 2 dental prosthetics citing ISO 6872:2015. Color gradation was verified by the yellow b* value reduction (14.8 to −3.33) as it shifted from cervical to incisal area while ΔE00 further affirmed the differences from each segment in comparison with the FP and Y-FP. Color gradation was successfully replicated by FP and YAG:Ce composition shift via FGAM technique. This result highlights the potential of FGAM as an alternative for fabricating dental prosthetics with high efficiency and improved esthetic appeal. [Display omitted]