# An In Vitro Evaluation of the Effect of Ceramic Material, Surface Treatment, and Adhesive Cement on Shear Bond Strength in Prosthodontics

## TL;DR

This study tested how different ceramics, surface treatments, and cements affect the strength of dental restorations in a lab setting.

## Contribution

The study introduces a regression model to quantify the combined effects of ceramic type, surface treatment, and cement on shear bond strength in prosthodontics.

## Key findings

- The total-etch technique and 5% hydrofluoric acid treatment significantly increased shear bond strength.
- Feldspathic ceramic and lithium disilicate performed better than alumina in terms of bond strength.
- Light-cured and self-cured cements had a negative impact on bond strength compared to dual-cured cement.

## Abstract

Background and Objectives: Ensuring the optimal shear bond strength (SBS) is essential for the long-term success of prosthodontic restorations. Our in vitro study aimed to evaluate the SBS of three types of ceramics (feldspathic, alumina, and lithium disilicates) using three adhesive cements (Variolink Esthetic LC, Variolink Esthetic DC, and Maxcem Elite). Materials and Methods: Healthy molars were prepared, and ceramic blocks were cemented following universally accepted luting protocols. SBS tests were performed using a custom-made testing machine. A multiple linear regression model assessed the effects of ceramic type, surface treatment, and luting agent on SBS. Results: The regression model explained 61.3% of the variation in SBS values (R2 = 0.613); the adjusted R2 = 0.605 confirmed the model’s robustness. The global F-test was statistically significant (F = 78.96, p < 0.001). The total-etch technique (+4.47), the use of feldspathic ceramic, and 5% hydrofluoric acid treatment (+3.28) significantly affected SBS. Feldspathic ceramic and lithium disilicate showed superior performance against alumina. Light-cured and self-cured cement showed negative effects. Conclusions: Ceramic material and cement type have combined effects on SBS. Optimal results were obtained with the total-etch technique, feldspathic ceramic, 5% hydrofluoric acid treatment, and dual-cured cement.