Chlorhexidine gluconate, a mouthwash commonly prescribed by dentists to treat the swelling, redness and bleeding gums of gingivitis, actually increases acidic levels in the mouth, leading to an increase in cavity-causing bacteria, reports a new study from the UK University of Plymouth, published in the journal Scientific Reports. The researchers analyzed saliva and blood samples of 36 healthy people that used the chlorhexidine twice a day for seven days and compared the results to using a placebo for the same amount of time. Other recent research has found that the germicidal mouthwash disrupted the ability of oral bacteria to turn nitrate into nitrite, a key molecule for reducing blood pressure, increasing the risk of higher systolic blood pressure. Chlorhexidine has been used increasingly as a pre-rinse before dental procedures due to COVID-19 concerns.