Background and Objective: Dental caries is one of the most important diseases in all societies. Saliva and its pH plays an important role to keep mouth wet and control factors influencing dental caries. Furthermore, chemical control of microbial plaque by mouth washes is accepted as an adjunctive treatment option besides the standard treatment procedures. The aim of this study was to compare the effect of mouth wash consumption Irsha and Persica on salivary pH. Materials and Methods: In this experimental cross-over study, 38 patients with a mean age of 27 years who meet the study criteria were selected from students and patients referred to Shahed Dental School. The unstimulated salivary pH was calculated prior to mouth wash consumption. The patients used Irsha mouth wash according to manufacturer's directions and their salivary pH was calculated after 5, 10, 20 and 30 minutes. After 72 hours wash out period, they were recalled for Persica mouth wash usage while their salivary pH was assessed similarly as done for the Irsha mouth wash. Then, t test, paired t test and ANOVA test for repeated measurements were used for data analysis. Results: The study showed the mean salivary pH was not statistically significant prior to mouth wash consumption (a mean value of 7.180 before Irsha and 7.16 before Persica consumption). The mean value of salivary pH were 7.255, 7.245, 7.184 and 7.230 after 5, 10, 20 and 30 minutes respectively when patients received Irsha mouth wash these values were 7.406, 7.475, 7.421 and 7.347 when patients used Persica mouth wash and exhibit statistically significant differences at all time sequences (p < 0.004, p < 0.0001, p < 0.001 and p < 0.006). The mean salivary pH changes was statistically significant during times studied when patients used Persica mouth wash while these changes was not statistically significant after the use of Irsha although no significant difference was found between baseline and 30 minutes time sequence after the Persica usage. Conclusion: Based on the results of this study, it seems that Persica mouth wash usage is accompanied with higher values of salivary pH than Irsha mouth wash in different time consequences studied.
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