Improving glass Ionomer performance through plant extracts: a systematic review of in vitro studies

This systematic review aimed to systematically map and synthesize the available evidence from in vitro studies on the modification of Glass Ionomer Cements (GICs) with plant extracts, with a specific focus on evaluating their effects on the material's antibacterial, physicochemical, and mechanical properties.

The review was conducted in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. The search strategy, based on the Population Intervention, Comparison, and Outcome (PICO) framework, was applied to four major databases (PubMed, Embase, Scopus, and Web of Science), yielding 2,614 initial records. The Quality Assessment Tool for In Vitro Studies (QUINN Tool) was used to evaluate the risk of bias. Data regarding plant species, GIC types, modification methods, and outcome measures were extracted and synthesized narratively due to methodological heterogeneity.

The analysis of the 14 included studies revealed that Salvadora persica was the most frequently used plant species (6 studies). The primary outcome was a significant enhancement of the antibacterial activity of GICs against Streptococcus mutans without negatively affecting fluoride release. Most studies reported maintained or improved mechanical properties, such as compressive strength, at low extract concentrations (typically below 5%). However, the review identified significant limitations: a lack of methodological detail in extract incorporation, a near absence of cytotoxicity assessments, and insufficient investigation into ion release profiles beyond fluoride.

The incorporation of plant extracts presents a promising strategy for improving the antibacterial performance of GICs while preserving their beneficial properties. However, the current body of evidence is constrained by methodological inconsistencies and critical gaps in safety and long-term efficacy evaluation. Future research must prioritize standardized protocols, comprehensive biocompatibility testing, and analyses under conditions that better simulate the oral environment to ensure clinical translatability.