Wilson's disease (WD), also known as hepatolenticular degeneration, was first described in 1912 by Kinnear Wilson. It is an autosomal recessive disorder caused by mutations in the ATP7B gene, a membrane-bound copper transporting ATPase. The disorder is caused by impairment of the copper transporting ATPase, ATP7B, in the liver, which disturbs copper transport, excretion into the bile, and incorporation into apoceruloplasmin. WD is an inherited copper metabolism disorder with pathological copper accumulation in many tissues, but especially in brain and liver. We conducted this study because copper accumulation in oral tissues in patients with WD have not been studied before. We think that copper accumulation and differences of oxidative events in oral tissues can cause tendency to periodontal diseases.