The influence of salivary pH and calcium/phosphate ions concentration on salivary gland stones' formation

ABSTRACT

Sialolithiasis is a multi-factorial pathology that accounts for more than 50% of salivary gland disease. However,the exact impact of salivary pH and calcium (Ca2+) and phosphate (PO43−) on the sialoliths' formation stillremains unknown. Materials and Methods: Seven removed sialoliths were put into flasks with artificial salivasolution that differed in concentrations of Ca2+ and PO43−. The changes in weights of sialoliths and alterations inpH had been measured for 13 weeks. Concentrations of Ca2+ and PO43− in the artificial saliva solution wereestimated at the beginning and at the end of the experiment. Results: Sialoliths' weight decrease was observedfrom the 2nd to 7th week. It occurred parallel with natural pH decrease (from 7 to 6.5 pH). Sialoliths’ weightsstarted increasing after pH was adjusted with NaOH. Analyzing the concentration changes of Ca2+ in everyflask, it was determined that from natural or double Ca2+ concentration, it decreased till similar amount (7–14times). Analyzing the concentration changes of PO43−, it was determined that from natural or doublePO43− concentration it decreased 24 times. Conclusions: Sialoliths' weights decreased parallel with natural pHdecrease and sialoliths grew when pH was adjusted. PO43− ions concentration decreased relatively more thanCa2+ ions concentration.