Kanzow P, Rammert L-S, Rohland B, Barke S, Placzek M, Wiegand A. Effect of face masks on salivary parameters and halitosis: Randomised controlled crossover trial. J Oral Pathol Med 2023; 52: 56-62.

Wearing face masks does not seem to result in measurable side effects on salivary parameters such as a reduced salivary flow rate or VSC levels.

This study aimed to measure the effect of different face masks on salivary parameters and halitosis. The randomised controlled crossover clinical trial with four periods included 40 orally healthy participants using different face masks (cloth mask, surgical mask, filtering facepiece 2 [FFP2] mask) or no mask (control) for four hours in random order. Unstimulated salivary flow rate (primary outcome) and stimulated salivary flow rate, salivary pH and buffer capacity of stimulated and unstimulated saliva (secondary outcomes, blinded), and volatile sulphur compounds (secondary outcome) were measured before and after the four-hour periods. Of 40 randomised participants, 39 completed the study. Unstimulated salivary flow rate prior to face masking amounted to 0.6 ± 0.3 ml/min. Face masking had no significant effect on unstimulated salivary flow or the other salivary parameters. The concentration of volatile sulphur compounds (VSCs) prior to face masking amounted to 157.3 ± 59.7 ppb. Four hours of face masking did not change the salivary flow rate, pH, and buffer capacity, and had no significant effect on VSC levels.