WordNet (r) 3.0 (2006):

periodontic
    adj 1: of or relating to or involving or practicing
           periodontics; "periodontal disease" [syn: periodontic,
           periodontal]

Moby Thesaurus II by Grady Ward, 1.0:

19 Moby Thesaurus words for "periodontic":
   allopathic, chiropodic, chiropractic, clinical, dental, exodontic,
   homeopathic, hydropathic, iatric, medical, naturopathic,
   neurological, obstetric, orthodontic, orthopedic, osteopathic,
   pediatric, prosthodontic, surgical