reimplantation:
    return to mouth of tooth/teeth lost through trauma
reline:
    plastic buildup of denture to compensate for bone loss (usually accomplished in conjunction with a dental laboratory)
restoration:
    the replacement part or portion restored on a damaged tooth
retainedroot:
    root remaining in jaw after tooth is extracted or broken off
root:
    tooth structure that connects the tooth to the jaw
root canal:
    common term for root canal therapy, also the interior space of the tooth root
root canal therapy:
    process of removing pulp of a tooth and filling it with an inert material
root resection:
    removal of root of a tooth while retaining the crown
rubber dam:
    soft latex sheet used to protect one or more teeth from moisture and to keep materials from falling to the back of the throat