A surface of a posterior tooth or occlusion rim that is intended to make contact with an opposing occlusal surface. (The Journal of Prosthodontic Dentistry; The Glossary of Prosthodontic Terms; July 2005, page 57)
The anatomic portion of the tooth that is covered by cementum and is located in the alveolus (socket) where it is attached by the periodontal apparatus; radicular portion of tooth.