# Compressive Strength of Glass Ionomers With Different Polymerization Mechanisms: A Comparative In Vitro Analysis

## TL;DR

This study compares the compressive strength of different types of glass ionomer cements used in dentistry to determine their performance based on polymerization methods.

## Contribution

The study introduces a classification framework for glass ionomer cements based on compressive strength and polymerization mechanisms.

## Key findings

- Riva Light Cure SDI showed the highest compressive and tensile strength among tested materials.
- GC Fuji IX GP Fast and GC Fuji II LC had statistically equivalent compressive strength despite different polymerization methods.
- Maxxion R FGM had the lowest compressive strength with less variability in results.

## Abstract

Aim: The aim of the study is to evaluate the compressive strength of different glass ionomer cements with distinct polymerization mechanisms through an in vitro experimental design.

Methods: Four materials were analyzed: GC Fuji IX GP Fast GIC (GC Corporation, Tokyo, Japan) and Maxxion R FGM (FGM, Joinville, Brazil) (self-curing) and GC Fuji II LC (GC Corporation) and Riva Light Cure SDI (SDI, Bayswater, Australia) (light-curing). One hundred cylindrical specimens (25 per material) were prepared following ISO 9917-1:2007 standards and stored in artificial saliva at 37°C for 15 days before undergoing compression tests.

Results: Statistically significant differences (p < 0.001) were found between materials, with Riva Light Cure SDI exhibiting the highest compressive strength (1,603.7 kN) and tensile strength (121.47 MPa), which were significantly superior to those of other materials. Surprisingly, no significant differences (p = 0.911) were found between GC Fuji IX GP Fast (self-curing, 911.2 kN) and GC Fuji II LC (light-curing, 965.8 kN), suggesting that the manufacturer's specific chemical composition had a greater influence than the polymerization mechanism. Maxxion R FGM presented the lowest values (613.0 kN), but with less variability.

Conclusion: Glass ionomer cements can be classified into three performance categories: high (Riva Light Cure SDI), intermediate (GC products), and basic (Maxxion R FGM), providing a framework for clinical selection based on specific requirements. The statistical equivalence between GC products with different polymerization mechanisms offers valuable flexibility for diverse clinical situations in pediatric dentistry.