Development of whitening mouth rinses formulated with mushroom residues and their effect on enamel's physical properties.

Objectives: This study aimed to develop whitening mouth rinses formulated with industrial mushrooms and compare them with over-the-counter whitening mouth rinses.

Materials and methods: Formulations with black shimeji mushrooms, mushroom substrates, and mushroom stalks were developed. Bovine enamel/dentin samples were divided into 7 groups (n = 10): Colgate Luminous White, Listerine Whitening Extreme (LWE), Listerine Cool Mint (LC), mushroom extract rinse (MEC), mushroom substrate rinse (MSB), mushroom stalk rinse (MTC), and artificial saliva. Samples were stained with black tea for 6 days, and then were immersed in 100 mL of each mouth rinse twice daily for 14 days. Color parameters (CIELAB [ΔE*], CIEDE2000 [ΔE₀₀], whiteness index for dentistry [ΔWI_D]) and microhardness (Knoop hardness number [KHN]) were analyzed at T₁ (initial), T₂ (24 hours), and T₃ (7 days). Mouth rinse pH was measured, and enamel was examined using a scanning electron microscope. Data were analyzed using generalized linear models, and KHN with the generalized linear mixed model for repeated measures (p ≤ 0.05).

Results: ΔE* was higher in LW and MSB groups. No significant differences were found for ΔE₀₀ (p = 0.0982) and ΔWI_D (p = 0.2536). Experimental mouth rinses did not promote enamel whitening based on ΔE₀₀ and ΔWI_D. LWE and LC reduced KHN and had a more acidic pH, while MEC had higher KHN at T2. MEC, MSB, and MTC had alkaline pH, not altering the tooth surface.

Conclusions: Black shimeji mushrooms are promising for mouth rinse development due to their alkaline pH and non-altering effect on surface microhardness.