Lemongrass (Cymbopogon citratus) oil nanoparticle synthesis, characteristic, and evaluation of antibacterial and antifungal effects and the influence on hardness of acrylic resin

Context: Acrylic resin is used in dentistry as a removable denture base. It can cause various pathologies when not properly cleaned. One of the pathologies is denture stomatitis caused by Candida albicans and Streptococcus mutans accumulation on the acrylic resin surface. Therefore, microbial agents such as denture cleansers are needed. 

Aims: To evaluate the characteristics of lemongrass (Cymbopogon citratus) nanoparticles as a better antibacterial and antifungal herbal ingredient and their relationship with acrylic hardness. 

Methods: C. citratus oil nanoparticles (LON) were synthesized and analyzed by transmission electron microscopy (TEM). Electrospray ionization tandem mass spectrometry (ESI-MS) analysis was used to analyze the characteristics of LON bioactive components. Minimum inhibitory concentration (MIC) and minimum bacterial concentration (MBC) against C. albicans and S. mutans and mechanical hardness test of acrylic were performed. 

Results: The LON concentration of MIC and MBC against C. albicans and S. mutans was 25 and 100%, respectively. One-way ANOVA showed no significant difference between groups of LON with different concentrations (p=0.687). A paired t-test showed significant differences in acrylic resin hardness before and after treatment of LON with 100% (p=0.022) and 50% (p=0.021) concentration. There was no significant difference in hardness before and after treatment of other concentrations of LON and chlorhexidine as positive control. 

Conclusions: LON treatment on acrylic resin decreased the growth of C. albicans and S. mutans without altering the mechanical properties (hardness).