Dawson Hall, a 72,000-square-foot Class-A office building in Chapel Hill 40 off Weaver Dairy Road, gained two new tenants last month. Joel M. Wagoner, DDS, purchased a 3,467-square-foot office condominium and Susanne P. Jackson, DDS, purchased a 2,913-square-foot office condominium. Both practices are relocating from other locations in town.