periodontal maintenance therapy
periodental maintenance threatment
engineering district；maintenance of way section；track division；track district；track maintenance division
abutment periodontal tissues
Acatalasia-periodontal destroy syndrome
apical periodontal cyst
Areas of periodontal ligament
balanced factorial ex-perimental design
Chronic periodontal disease
clinical periodontal index
combined periodontal-endodontic lesions
Combined periodontal-orthodontic treatment
Combined pulp and periodontal disease
distraction of the periodontal ligament
endodontic-periodontal combined lesion
Ex- perimental observation
graduated periodontal probe