The present randomised controlled study compared the 3-year outcome of local anaesthetics with anaesthetics and lavage in patients suffering from painful temporomandibular joint (TMJ) locking. The study included 45 patients referred for treatment of temporomandibular disorders (TMD) to the Department of Orofacial Pain and Jaw Function, Faculty of Odontology, Malmo University, Malmo, Sweden. All patients received a history questionnaire and clinical examination according to the Research Diagnostic Criteria for TMD, panoramic radiographs and magnetic resonance imaging at baseline. Twenty-five patients were randomised to anaesthetics alone and 20 patients to anaesthetics and lavage. Three years after treatment, we sent the 37 patients who were available for follow-up a questionnaire that evaluated pain intensity, physical and emotional functioning, and global improvement. Thirty-four patients responded. The primary outcome was defined as >= 30% pain relief. In an intention-to-treat analysis, 28 of 45 patients (62%) reported >= 30% pain relief at the follow-up. At 3 years, improvement in pain relief, physical functioning, emotional functioning and global improvement differed non-significantly between local anaesthetics and anaesthetics and lavage. Compared with baseline, significant improvements (P < 0.05) in pain intensity, physical functioning, emotional functioning and global changes had occurred in both groups after 3 years. Because outcome measurements in the local anaesthetics and lavage and the local anaesthetics groups differed non-significantly 3 years after treatment of painful TMJ disc displacement without reduction, use of lavage (50 mL saline) has an equivalent effect as local anaesthetics.