The highest AQP5 positive area% in Group 3 is in agreement with (Hu et al. 2023), who found that treatment with dental pulp stem cell exosomes up-regulated AQP5 expression and increased salivary flow rate in Sjogren’s Syndrome-related inflammation, while the high AQP5 positive area% in Group 4 could be related to the modulatory effect of i-PRF against the inflammatory process (Aydinyurt et al. 2021). Here, AQP5 is linked to Sjogren syndrome.