# Influence of Different Surface Treatments on the Low-Temperature Degradation of Three Commercial Yttria-Stabilized Tetragonal Zirconia Polycrystal

## TL;DR

This study examines how different surface treatments affect the degradation of zirconia materials used in dental applications under wet conditions.

## Contribution

The study introduces a comparative analysis of surface treatments' effects on low-temperature degradation in three commercial zirconia brands.

## Key findings

- Sandblasting and polishing suppressed phase transformation in Y-TZP materials.
- Cercon® blocks showed minimal phase transformation and degradation after immersion.
- All three brands exhibited increased monoclinic phase with immersion time.

## Abstract

Aging of yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) under wet conditions is known as low-temperature degradation (LTD), which is associated with phase change and decreasing mechanical strength. Herein, we studied the effects of different surface treatments on the LTD of three different commercial Y-TZP blocks utilizing CAD/CAM technology, namely, Cercon®, e.max® ZirCAD, and Vita In-ceram® YZ. The blocks were immersed in 4% acetic acid at 80 °C for 0, 7, 14, and 28 days. The effects of surface treatments such as sandblasting and polishing were also examined. The results showed that the monoclinic phase increased with immersion time in all three brands. In Cercon® blocks, a minimal amount of phase transformation was observed, with the smallest amount of degradation after immersion. Sandblasting and polishing both suppressed phase transformation. After immersion, the mechanical strength exhibited a small decrease with time. Accelerating the evaluation of the LTD of zirconia may effectively help with clinical applications.