	After nine years of medical service in Liberia, Boone was granted a furlough in 1919 to the United States. Having recognized the need for a dentist, because the only dentist in Liberia died from the international Spanish flu epidemic, Boone studied mechanical dentistry at the Bodee Dental School in New York City. He was supported in his studies by the Lott Carey Foreign Mission Convention. He and his second wife returned to Liberia for some time.