There is never a suitable substitute for daily brushing and flossing
While some products, including water irrigation devices (or "water picks"), may be useful for specific applications, they may not be as effective as traditional flossing in the removal of plaque.
Water picks use powerful tiny bursts of water to blast away food particles and other debris in hard-to-reach areas of your mouth. Dentists use professional-grade water picks when preparing a tooth for restoration, or in general cleaning and exams.
People with painful gum disease or highly sensitive gums may find water picks useful for supplementing their brushing regimen. People with orthodontia, including braces, have found water picks quite useful because toothbrush bristles often get stuck.