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

Imam Akbar Sutejo; Jeehwan Kim; Sinuo Zhang; Chang Woo Gal; Yeong-Jin Choi; Honghyun Park; Hui-Suk Yun

doi:10.1016/j.dental.2023.03.021

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

Dent Mater. 2023 Jun;39(6):568-576. doi: 10.1016/j.dental.2023.03.021. Epub 2023 Apr 21.

Authors

Imam Akbar Sutejo¹, Jeehwan Kim², Sinuo Zhang¹, Chang Woo Gal³, Yeong-Jin Choi³, Honghyun Park³, Hui-Suk Yun⁴

Affiliations

¹ Korea Institute of Materials Science (KIMS), Changwon, Republic of Korea,; University of Science and Technology (UST), Daejeon, Republic of Korea.
² Korea Institute of Materials Science (KIMS), Changwon, Republic of Korea,; Pusan National University (PNU), Busan, Republic of Korea.
³ Korea Institute of Materials Science (KIMS), Changwon, Republic of Korea.
⁴ Korea Institute of Materials Science (KIMS), Changwon, Republic of Korea,; University of Science and Technology (UST), Daejeon, Republic of Korea. Electronic address: yuni@kims.re.kr.

PMID: 37088587
DOI: 10.1016/j.dental.2023.03.021

Abstract

Objective: 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 (Y₃Al₅O_12:Ce, YAG:Ce) as a promising esthetic restoration option.

Methods: 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.

Result: 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.

Significance: 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.

Keywords: Color-gradient; Dental crowns; Dental porcelain; Functionally graded additive manufacturing; Stereolithography.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Ceramics / chemistry
Color
Crowns
Dental Porcelain* / chemistry
Esthetics, Dental*
Materials Testing
Temperature

Substances

Dental Porcelain