Method:
17 volunteers received a prophylaxis 48 hours prior to study. Thereafter they were required to abstain from all oral hygiene procedures and plaque was allowed to accumulate for 48 hours. The Plaque Sampling method was used in this study. All subjects were required to rinse for 3 minutes with 15ml of 20% sucrose solution and 7 minutes after that, the supragingival buccal and interproximal dental plaque pH was measured. The subjects were then divided into 2 test groups and 1 control group and were asked to rinse with 15ml of one of the following rinses: distilled water, control (CO), 5% sodium bicarbonate (SB5), or 10% sodium bicarbonate (SB10) for 3 minutes. The dental plaque was sampled every 5 minutes thereafter for 30 minutes. Plaque pH was measured using the ISFET microelectrode (Model IQ125 Professional, MiniLab). Paired and Independent student’s t-tests, were performed with SPSS.
Result: There were statistically significant differences (P < 0.05) in the mean buccal plaque pH change compared to the 7-minutes post sucrose rinse up to 30 minutes between CO group and the SB10 group (the mean pH change is almost 3 pH unit for each time interval) but was not significant between the CO group and SB5 group. The mean interproximal plaque pH change compared to the 7-minutes post sucrose rinse pH up to 30 minutes were not significant between any groups. There were also no statistically significant differences between buccal and interproximal plaque pH at all time interval within each group.
Conclusion: Rinsing with sodium bicarbonate 10% solution was more effective in increasing the buccal plaque pH compared to a distilled water rinse up to 30 minutes post sucrose rinse.