Antimicrobial Effect of Silver Ionised Water Prepared with the Sintering Coating Method—Effect on Acid Production in Plaque

Abstract

Purpose: To investigate the effect of silver ionised water on acid production in plaque. Methods: After injecting 0.5 mL of silver ionised water (concentration: 5 ppm) produced with the sintering coating method in the sensor part of the pH metre, plaque collected from the oral cavity by one platinum loop was mixed in. Immediately after that, a 5% sucrose solution (1 g/20 mL) was added and the pH was continuously measured for 30 minutes at 1-minute intervals (A). Similarly, silver ionised water was mixed with 5% sucrose solution in the same way as in (A) at 3 (B), 5 (C), 10 (D) and 15 minutes (E) after plaque contamination. The pH was measured at 1-minute intervals. The pH of the purified water containing no silver ionised water mixed with plaque and sugar solution at the same time was measured and used as a control. Each experiment was conducted three times, and the pH measured every minute was compared as a percentage of the pH at the beginning of the measurement (100%). Results: Analysis of variance of the repeated measurements to determine the effect of silver ionised water on the decrease in pH revealed a main effect of silver ionised water and an interaction between time and group [F (1.302,20.826) = 39.145, p < 0.01]. Multiple comparisons using Dunnett’s method showed a significant decline in the rate of decrease in pH from B to E as compared with that in the control (p < 0.01). Conclusion: Silver ionised water was found to inhibit the acid production in plaque.