Radicular – refers to tooth root

Radiograph – also known as an x-ray, image of bone and tooth structures produced through exposure to ionizing radiation

Reimplantation – reinsertion of tooth into its socket following trauma that partially or completely removed it

Reline – resurfacing of the tissue side of a removable denture to correct issue with fit

Resin – material used in dental restorations and other dental treatments

Resorption – loss of bone or structure

Retainer – appliance used to ensure teeth do not return to prior misaligned state following orthodontic treatment

Root – portion of the tooth that attaches the tooth to the gums and socket

Root Canal – pulp cavity inside the tooth root

Root Canal Therapy – treatment of disease or injury to the tooth pulp, generally involves the removal of part or all of the pulp and replacement with inert material

Root Planing – a procedure used in the treatment of periodontal disease, involves deep cleaning of teeth at the roots to remove calculus and other substances

Rubber Dam – latex sheet used to isolate part of the mouth from saliva and potential contaminants during surgery