Abstract
Titanium and its alloys have been the material of choice for dental implants since decades. Although, titanium is considered a biocompatible element reports of allergic reactions to titanium and its alloys have emerged over time. Whether dental implants can potentially induce hypersensitivity reactions or not is still debatable. The present paper discusses available literature on metal hypersensitivity including that induced by titanium and its alloys. It also discusses available tests for detection of metal hypersensitivity and the mechanisms through which titanium and its alloys may trigger hypersensitivity reactions in tissues, including that in the oral environment.