An oral irrigator, also called a water pick, uses high PSI water to clean the teeth as a supplement to traditional oral hygiene. The device aims a stream of pressurised water at the teeth and gums to dislodge food particles and plaque build-up. According to Demetra Daskalos Logothetis, author of "Success in Dental Hygiene," while a water pick can help clean the teeth, it presents dangerous hazards if misused.

When you direct high PSI water at the gums to remove food particles, the water can in turn force the particles further beneath the gums. According to Michele Leonardi Darby, author of "Mosby's Comprehensive Review of Dental Hygiene," this can cause a severe infection that will require professional care to remedy. You can avoid forcing food particles further beneath the gums by brushing and flossing your teeth thoroughly before using a water pick.

The oral irrigator can damage the surface of inflamed gums if used incorrectly. When a pressurised stream of water encounters already tender flesh, you risk breaking the surface. This causes bleeding and tenderness of the mouth while increasing risk of further infection, says Darby. You should never apply high PSI water to severely infected gums. Treat the infection first by maintaining proper hygiene with regular brushing and flossing until the swelling subsides.

According to Esther M. Wilkins and Charlotte Wyche, author of "Clinical Practice of the Dental Hygienist," on rare occasions, high PSI water can damage and break the bonds on cavity fillings and braces. Though water picks make cleaning beneath braces convenient, if water pressure is too high it can break the bonding glue. When applied to a filling on the teeth, the water pressure can have the same damaging affect. This hazard is preventable by choosing a lower pressurised oral irrigator when cleaning an area with braces or cavity fillings.