# Ultrafast sintering of dental zirconia: composition-processing-property relationships with high-throughput fail-fast screening

> **NIH NIH R01** · UNIVERSITY OF PENNSYLVANIA · 2024 · $449,557

## Abstract

Project Summary/Abstract
Conventional sintering (CS) protocols produce high quality zirconia restorations suitable for a wide range of
indications. However, CS requires a firing cycle of 4 – 10 h, a bottleneck in digital dental workflow precluding
zirconia from chairside applications. Current speed sintering (SS) protocols using fast heating (up to 6C/s) in
an induction furnace can reduce sintering times to 0.3 – 0.5 h. However, because of inefficiency of convective
heat transfer, leading to temperature inhomogeneity, SS produces microstructures with higher porosities, thus
compromising zirconia translucency and strength. In addition, non-uniform densification raises concerns about
chemical and dimensional stability, internal fit and marginal adaptation of restorations. As a result, SS is largely
limited to the fabrication of single-unit crowns from 4 mol% yttria stabilized zirconia (4YSZ). Accordingly, the
long-term goal is to drastically increase sintering speed (on the order of 60 s) while maximizing mechanical and
optical properties of dental zirconia (exceeding those of the SS- and CS-YSZ) by implementing novel UFS
technologies. The overall objectives of this proposal are to (1) establish composition and time-temperature-
transformation (TTT) relationships to guide material selections for various industries and sectors, with special
attention to the optimization of strength and translucency of YSZ for dental applications; and (2) demonstrate
improved dimensional, long-term chemical and structural stabilities pertaining to the quality and longevity of
UFS-YSZ restorations relative to SS and CS. The central hypothesis is that novel UFS methodology will
dramatically increase time efficiency of digital workflow while optimizing zirconia properties and expanding the
range of indications for single-visit treatments. This hypothesis follows directly from preliminary results and a
state-of-the-art material science knowledge base. To test this hypothesis, we will pursue 3 specific aims: (1) To
characterize the properties of yttria stabilized zirconia using ultrafast sintering technology in conjunction with
high-throughput fail-fast screening; (2) To determine the resistance to low temperature degradation and fatigue
fracture of ultrafast sintered zirconia relative to current speed and conventional sintering; and (3) To evaluate
the dimensional stability, internal fit, and marginal adaptation of ultrafast sintered 3-unit fixed dental prostheses
relative to current speed and conventional sintering. The approach is innovative because it departs completely
from the current furnace-sintering concept by using Joule heating elements with more effective radiation and
conduction heat transfer. The proposed research is significant because it addresses current challenges in poor
material properties associated with SS and the long sintering time of CS. Such an approach will improve the
efficiency and accuracy of restorative procedures to provide more treatment ...

## Key facts

- **NIH application ID:** 10922819
- **Project number:** 5R01DE033545-02
- **Recipient organization:** UNIVERSITY OF PENNSYLVANIA
- **Principal Investigator:** Liangbing Hu
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $449,557
- **Award type:** 5
- **Project period:** 2023-09-06 → 2028-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10922819

## Citation

> US National Institutes of Health, RePORTER application 10922819, Ultrafast sintering of dental zirconia: composition-processing-property relationships with high-throughput fail-fast screening (5R01DE033545-02). Retrieved via AI Analytics 2026-05-27 from https://api.ai-analytics.org/grant/nih/10922819. Licensed CC0.

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