# Evaluation of Surface Roughness of Translucent Zirconia After Applying Nd:YAG and CO2 Lasers: An In Vitro Study

## TL;DR

This study compares how two types of lasers affect the surface roughness of translucent zirconia, finding that the Nd:YAG laser creates a rougher surface than the CO2 laser.

## Contribution

The novel contribution is a direct in vitro comparison of Nd:YAG and CO2 lasers for modifying the surface roughness of translucent zirconia.

## Key findings

- Nd:YAG laser produced a higher mean surface roughness (1.208±0.22) compared to CO2 laser (0.809±0.21).
- The difference in surface roughness between the two laser groups was statistically significant.

## Abstract

Background and objectives: Surface roughness is one of the most important factors that play an important role in increasing the connection between the surface of the tooth and the applied restoration. Due to the increased interest in zirconia and the improvement of its mechanical and aesthetic properties, studies have increased that work to improve and increase its surface roughness so that it can be used as a veneer in the future. This study aims to compare the effect of two types of lasers on the surface of highly transparent zirconia to evaluate the surface roughness resulting from the two techniques.

Methodology: The study sample consisted of 20 ceramic cubes made of translucent zirconia (DD cubeX2, Dental Direct, Germany). It was made using a CAD-CAM Zircodenta device (Imes-Icore, Germany) and a zirconia sintering furnace (Imes-Icore, Germany). The study sample was divided into two groups; the first group consisted of 10 cubes exposed to Nd:YAG laser and the second group consisted of 10 discs exposed to continuous wave CO2 laser. The surface roughness test was conducted for the study samples in each of the groups using a surface roughness tester. Data were collected and analyzed using SPSS v25 software.

Results: The surface roughness was measured and its mean was 1.208±0.22 in the Nd:YAG laser group and 0.809±0.21 in the CO2 laser group. There was a significant difference between the study groups according to the independent sample T-test.

Conclusion: This study concluded that the Nd:YAG laser surface roughens of zirconia is greater than the continuous wave CO2 laser, with a substantially significant difference.