title: Four year study will examine effectiveness of recall intervals.
mesh_terms: D001071:Appointments and Schedules; D017598:Efficiency, Organizational / Q000706:statistics & numerical data; D006801:Humans; D011313:Preventive Dentistry / Q000706:statistics & numerical data*; D016032:Randomized Controlled Trials as Topic; D013997:Time Factors; D006113:United Kingdom