Influence of Al2O3 and P2O5 contents in sol-gel ionomer glass system on the structure and their cement properties

Glass ionomer dental cement (GIC) is commonly used as a restorative material. The sol-gel synthesis of the ionomer glass is an alternative method, which can produce higher purity and homogeneous at low temperature compared with the traditional melt-quench method. This study synthesized the ionomer glass with the variation of Al 2 O 3 and P 2 O 5 contents in the glass formula by the sol-gel route. The term of Al/(Si+P) ratio was evaluated by XRD and XPS to understand the structural change in the sol-gel glasses. The relationship of the chemical structure of the sol-gel glass, the ions releasing behavior, setting time, and compressive strength of the sol-gel GIC were determined. This study demonstrated that the increase of Al 2 O 3 content in glass formula increased [AlO 6 ] octahedron and bridging oxygen (BO) in the glass structure, while the increase of P 2 O 5 content in glass formula led to the increasing of the [AlO 4 ] tetrahedron and BO. The sol-gel GIC composition met the maximum compressive strength at Al/(Si+P) = 1.57, whereas the general GIC composition required at Al/(Si+P) nearby 1. Moreover, in vitro cell viability of NIH/3T3 fibroblast cells also showed promising result after 2 days culture. This study provided the knowledge for adjusting the sol-gel glass composition for the appropriate properties of GIC. Highlights The variation of Al 2 O 3 and P 2 O 5 content in the ionomer glass formula prepared by the sol-gel route was studied. XRD and XPS results showed that the glass structural change for the sol-gel glass with the variation of Al 2 O 3 and P 2 O 5 contents, Al/(Si+P) ratio affected to the glass ionomer cement (GIC) properties. DOE analysis evaluated the interaction effect between Al 2 O 3 and P 2 O 5 contents resulting to Al/(Si+P) ratio of 1.57 for the sol-gel glass composition whereas the general GIC composition required at Al/(Si+P) nearby 1. This study recommended the adjustment of the sol-gel glass composition for GIC application.