Mechanisms of tissue damage resulting from the use of oral water irrigation devices

Oral water irrigation devices (WIDs) are widely used for oral physiotherapy in homes and dental clinics throughout the world. A major area of concern in the use of WIDs has been the possibility of injury to the sulcular epithelium and underlying tissue. There are several documented clinical cases of tissue injury with the use of WIDs. The existing WIDs exert excessive pressures on the sulcular epithelium. Although it is known that the high jet impact pressures exerted by the WIDs cause the tissue damage, the underlying damage mechanisms are poorly understood. The damage to the sulcular epithelium and underlying tissue is mediated through several physiological and micromechanical processes and includes, among others, the following damage mechanisms: pressure-induced, diffusion-mediated, deposition of bacteria and toxins into the underlying tissue, damage to the collagen network integrity in the tissue, damage to the blood and lymphatic microcirculation, especially damage to the anchoring filaments attached to the terminal lymphatic wall, and direct mechanical damage due to abnormal shear forces induced by the jet. All these damage processes could lead to tissue necrosis.