Compressive and Flexural Strengths of High-strength Glass Ionomer Cements: A Systematic Review

Objective: To perform a systematic review of test methodologies of high-strength restorative glass ionomer cement (GIC) materials for compressive (CS) and flexural strengths (FS) to compare the results between different GICs. Materials and methods: Screening of titles and abstracts, data extraction, and quality assessment was conducted in search for in vitro studies, which reported on CS and/or FS properties of high-strength GIC. PubMed/Medline (US National Library of Medicine-National Institutes of Health), EBSCO, and ProQuest databases were searched for the relevant literature. Results: A total of 123 studies were found. These were then assessed based on preestablished inclusion and exclusion criteria. Of the selected studies, two studies of fair quality tested CS, while none tested FS. The CS of experimental groups in both studies was less than their respective control groups. Discussion: It was observed that many studies reported following the International Standards Organization (ISO) recommendations for testing but with modifications. Additionally, in absence of guidelines for testing other parameters that may be potentially advantageous, authors have used differing experimental techniques. These disparities make it difficult to draw comparisons between different studies.