Assessment of the antibacterial activity of natural products containing mouthwashes and their effect on color stability of resin composite: in-vitro study

Abstract Aim Natural products have been reported to have an antibacterial effect on oral bacteria. The current work aims to assess their antibacterial effect against Streptococcus mutans and Lactobacillus acidophilus in comparison to commercially available two mouthwashes and their effect on the color stability of resin composite. Materials and methods Three solutions were made by dissolving powders of Stevia rebaudiana , Spirulina platensis , and Chlorella vulgaris extracts into distilled water to form a concentration of 0.5 for each solution. Two commercially available mouthwashes; one is an alcohol-containing mouthwash (Denton) and the other is chlorhexidine-containing mouthwash (Hexitol). The antibacterial effect of the mouthwashes against S. mutans and L. acidophilus was assessed by the agar well-diffusion method. The color stability of nanohybrid resin composite (Neo Spectra ST, Dentsply) was measured after immersion of 10 × 2 mm disks of nanohybrid resin composites for 1 month using a spectrophotometer (Vita Easyshade). The data were analyzed by dependent t test and one-way analysis of variance test followed by Tukey post-hoc test. Results The highest antibacterial effect against S. mutans was reported with Chlorella containing mouthwash 48 h and Denton after 72 h. Moreover, the highest antibacterial effect against L. acidophilus after 48 and 72 h was recorded with Denton. Regarding color stability, all mouthwashes reported unnoticeable color-changing (Δ E <3). Conclusion S. rebaudiana, S. platensis , and C. vulgaris can be used as safe and efficient mouthwashes.