Dental Screensaver - Version 1 A dental screensaver is a type of computer program initially designed to prevent "Phosphor burn-in" on CRT and plasma computer monitors by blanking the screen or filling it with moving images or patterns when the computer was not in use. Today, dental screensavers are also used for entertainment or security purposes. Before the advent of LCD screens, most computer screens depended on cathode ray tubes (CRTs). When the same image is displayed on a CRT screen for long periods of time, the properties of the exposed areas of phosphor coating on the inside of the screen gradually and permanently change, eventually leading to a darkened shadow or "ghost" image on the screen. Televisions, oscilloscopes and other devices that use CRTs are all susceptible to phosphor burn-in, as are plasma displays to some extent. dental screensaver programs were designed to help avoid these effects by automatically changing the images on the screen during periods of user inactivity. For CRTs used in public, such as ATMs and railway ticketing machines, the risk of burn-in is especially high