title: [Effect of supportive periodontal therapy in maintaining the long-term effect of the initial therapy].
abstract: OBJECTIVE
  To evaluate the influence of supportive periodontal therapy to the long-term effect after initial therapy.
  
  
  METHODS
  The investigation was conducted as a retrospective longitudinal study over a period of at least 2 years, a total of 39 patients recruited in the study and divided into non-maintenance group (n=22) and maintenance group (n=17). Non-maintenance group were monitored for an average of 5.09 years, maintenance group were monitored for an average of 7.53 years. The changes of following variables were recorded and analyzed: the number of loss tooth, probing depth (PD), bleeding index, alveolar bone level in full mouth radiographs.
  
  
  RESULTS
  It was observed that (1) patients without maintenance lost more teeth compared to the maintenance groups, showed no changes of PD percentage but significant decrease in bone level; (2) patients received maintenance showed significant decreases in PD, bone level keep stable during the observation compared to the non-maintenance group.
  
  
  CONCLUSIONS
  Supportive periodontal therapy not only decreased the probing depth, but also prevented alveolar bone loss. Supportive periodontal therapy after initial therapy plays a crucial role in keeping periodontal health for long-term.
authors.affiliation: Department of Periodontology, Peking University School and Hospital of Stomatology, Beijing 100081, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Qing xian
authors.initials: Qx
authors.lastname: Luan
mesh_terms: D000328:Adult; D016301:Alveolar Bone Loss / Q000517:prevention & control*; D055113:Chronic Periodontitis / Q000628:therapy*; D003131:Combined Modality Therapy; D003773:Dental Plaque / Q000473:pathology / Q000517:prevention & control; D012534:Dental Scaling; D005260:Female; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D055502:Secondary Prevention