# Comparing the Effects of Different Cleansing Agents on the Shear Bond Strength of Resin Cements on Surface-Contaminated Zirconia: An In Vitro Study

## TL;DR

This study compares how different cleaning agents affect the bond strength of resin cements to zirconia surfaces in dental applications.

## Contribution

The study introduces a novel comparison of sodium hydroxide as a surface treatment for zirconia, showing improved bond strength over traditional methods.

## Key findings

- Surface treatment with 5% NaOH significantly increased shear bond strength compared to HF acid and control groups.
- RelyX U200 resin cement showed better adhesion than Ivoclar SpeedCEM Plus in all treatment groups.

## Abstract

Background

The long-term success and durability of any dental ceramic material depends on how well they adhere to the resin cements. Though sandblasting of zirconia with abrasive particles is one of the most commonly used techniques to enhance the bond strength, surface damage and phase transition may affect the mechanical properties of zirconia. Hence alternative surface treatment methods using chemical agents, lasers, and silicone coatings can be employed.

Aim

To evaluate the shear bond strength (SBS) of two types of resin cement on surface-contaminated zirconia after using various cleaning agents.

Materials and methods

A total of 60 zirconia specimens were included in the study and divided into three groups, hydrofluoric (HF) acid, sodium hydroxide (NaOH), and a control, each containing 20 specimens. Within each group, the specimens were further subdivided into two subgroups based on the resin cement used: 10 specimens in the RelyX U200 subgroup (3M ESPE, St. Paul, MN) and 10 specimens in the Ivoclar SpeedCEM Plus subgroup (Ivoclar, Schaan, Liechtenstein). After surface treatment, the zirconia specimens were bonded to one of the two types of resin cement and subjected to a SBS test. A t-test was used to compare the resin cements, while an ANOVA test was conducted to compare the surface treatment groups.

Results

The NaOH group has shown significantly higher SBS in both RelyX U200 and Ivoclar SpeedCEM Plus subgroups than in the HF acid and control groups. RelyX U200 displayed superior adhesion to Ivoclar SpeedCEM Plus resin cement.

Conclusion

Surface treatment of zirconia with 5% NaOH exhibited increased SBS than HF acid-treated and non-surface-treated zirconia specimens. To strengthen the binding between zirconia and resin cements, NaOH may be used either on its own or in combination with other surface treatment methods.