The disclosure is directed to systems and methods for treatment of periimplantitis using ultraviolet light. In some embodiments, the ultraviolet light is ultraviolet c light with a wavelength between 100 and 280 nanometers. In some embodiments, the ultraviolet c light makes the surface of the implant hydrophilic and more receptive to cell protein attachment. In some embodiments, an apparatus for treating periimplantitis using ultraviolet light includes a handpiece with a flexible neck and a rotatable tip at the end of the flexible neck. In some embodiments, the handpiece includes a contra angle dental handpiece or a straight dental handpiece which can couple to and direct ultraviolet light from either an end firing tip or a side firing tip. In some embodiments, the handpiece is sized to enable UVC light to be directed to an exposed area of an implant facing toward one or more posterior portions of the oral cavity.