<prompt> Saliva isHypeonicHypotonicIsotonicAt first hypeonic, then isotonic  <response>: Saliva has a pH normal range of 6.2-7.6 with 6.7 being the average pH. Resting pH of mouth does not fall below 6.3. In the oral cavity, the pH is maintained near neutrality 6.7-7.3 by saliva. The saliva contributes to maintenance of the pH by two mechanisms Ref: guyton and hall textbook of medical physiology 12 edition page number:400,401,402 