Evaluation of the physico-mechanical properties of a new antimicrobial-modified glass ionomer cement

Abstract

<strong>Objective:</strong> The use of natural plant extracts for the control of dental and periodontal pathogens is considered a promising alternative to synthetic chemicals owing to their claimed minimal harmful effects and maximum efficacy. Therefore, this study aimed to prepare an extract mixture of three plants to enhance the antimicrobial activity of a conventional glass ionomer cement (GIC). <br /> <strong>Materials and methods:</strong> An alcoholic extract mixture of olive leaves (<em>Olea europaea</em>), fig leaves (<em>Ficus carica</em>) leaves and roots of miswak (<em>Salvadora persica</em>) was prepared using a glass Soxhlet extractor. The prepared extract mixture was proportioned to the water used for preparation of a freeze-dried glass ionomer cement at three different extracts: water mass ratios (groups; 1:2, 1:1, and 2:1). Chlorhexidine diacetate (0.5 %) modified glass ionomer cement was prepared for comparison. Gas chromatography-mass spectrometry was used to chemically analyse the extract mixture. The control and modified materials were evaluated with regard to: antimicrobial activity, compressive strength, flexural strength, water sorption, solubility, shear bond strength and film thickness. Statistical analysis was performed using Minitab 17.3.1 for Microsoft Windows. <br /> <strong>Results:</strong> The extract mixture was significantly effective against <em>Streptococcus mutans </em>and also against <em>Micrococcus luteus</em> but only with the highest concentration group (2:1). Compressive strength and flexural strength results revealed that the 2:1 group recorded the highest values among all the other tested groups. Furthermore, there were no statistically significant differences between all the groups with regard to the percentage of water sorption, however for water solubility the 2:1 plant-modified group was significantly different from all of the other groups. Shear bond strength results showed insignificant difference between the control group and each of the CHX-GIC and the three plant modified groups 1:2, 1:1, 2:1. Failure mode analysis revealed the predominance of mixed and cohesive failures. All the tested groups yielded a film thickness of less than 25 µm film thickness. <br /> <strong>Conclusion:</strong> Natural plant extracts can be a promising agent for enhancing the antimicrobial activity and other properties of GIC without adversely affecting its performance.