# Effect of different surface treatments on repair bond strength of alkasite based restorative material

## TL;DR

This study finds that using a 2-step etch and rinse adhesive improves the bond strength between old and new alkasite-based dental restorations.

## Contribution

The study identifies the most effective surface treatment for repairing alkasite-based restorative materials.

## Key findings

- A 2-step etch and rinse adhesive produced the highest repair bond strength.
- Surface roughening with burs resulted in the lowest repair bond strength.
- Laser preparation combined with adhesives showed intermediate bond strength.

## Abstract

This study investigates various surface treatment methods to assess shear bond strength between set Cention N (alkasite-based restorative material) and fresh alkasite based restorative material. Assessing different surface treatments provide insights in optimizing repair procedure that enables durability of the restoration, thus potentially benefitting clinical outcomes.

A total of 48 alkasite based restorative material blocks, measuring 4 mm in depth and 8 mm in diameter, were prepared. The samples were randomly divided into 8 groups (n = 6) according to the surface treatment done. Group I: Surface preparation by bur; Group II: Surface treatment by laser; Group III: Application of 2-step etch and rinse adhesive (Adper Single Bond 2 adhesive),Group IV: Application of single step self-etch adhesive (Scotchbond Universal adhesive); Group V: Bur preparation followed by application of 2-step etch and rinse adhesive; Group VI: Bur preparation followed by application of single step self-etch adhesive; Group VII: Laser preparation followed by application of 2-step etch and rinse adhesive; and Group VIII: Laser preparation followed by application of single step self-etch adhesive. Post-surface preparation, all the specimens were restored with freshly mixed alkasite material. All samples were then subjected to repair bond strength measurements using a universal testing machine. ANOVA with post-hoc Games-Howell test and two-way ANOVA with post-hoc Bonferroni test was performed to evaluate the influence of surface preparation on the repair bond strength.

Among the various surface treatments, use of a 2-step etch and rinse adhesive resulted in a higher repair bond strength compared to other surface treatments, whereas roughening of the surface using burs resulted in the lowest repair bond strength (P=0.02).

Application of 2-step etch and rinse adhesive to the existing alkasite based restorative material provides superior bonding with the freshly added alkasite based restorative material.