Statistical analyses.

<div> Antiseptic mouthwash use is widespread due to its oral health benefits. However, its impact on systemic physiological processes, particularly nitric oxide (NO) bioavailability and muscle contractility, is not fully understood. We sought to determine the effects of cetylpyridinium (antibacterial) versus sodium chloride (control) mouthwashes on salivary and breath NO markers and muscle contractile function in healthy young adults. Thirty participants (n = 15/group) completed a randomized, parallel-arm, blinded trial, comparing the two mouthwashes before and after 7 d of treatment. NO bioavailability was inferred via measurement of salivary nitrate (NO₃⁻), nitrite (NO₂⁻), and cyclic guanyl monophosphate (cGMP) concentrations and breath NO level. Contractile function of the knee extensor muscles was determined via isokinetic dynamometry. No changes in salivary NO₃⁻, NO₂⁻, or cGMP or in breath NO were observed in response to either treatment. However, cetylpyridinium mouthwash reduced the percentage of NO₂⁻ in saliva (17 ± 10% vs. 25 ± 13%; p = 0.0036). Peak torque at velocities of 0–6.28 rad/s was unaffected by mouthwash use. Calculated maximal knee extensor velocity (Vmax) and power (Pmax) were therefore also unchanged. Cetylpyridinium mouthwash reduces the relative abundance of NO₂⁻ in the oral cavity but does not significantly diminish overall NO bioavailability or impair muscle contractile function in healthy young adults. </div>