title: Influence of a mandibular fixed orthodontic retainer on periodontal health.
abstract: OBJECTIVE
  To investigate the impact of bonded mandibular orthodontic retainers on local periodontal health.
  
  
  METHODS
  Two groups of subjects were recruited and designated Group F+, individuals who were provided with a fixed wire lingual retainer in the mandibular anterior area following orthodontic treatment and Group F-, individuals with no fixed wire and no clear sign of mandibular anterior malalignment. A clinical examination, a biochemical analysis, and a bacteriological analysis were performed at commencement baseline (BL) and at 1 week (T1), 4 weeks (T2), and at 8 weeks (T3) following retainer placement. The vertical position of the fixed wire relative to the clinical crown height in Group F+ was recorded and the subjects assigned to Subgroups Wi or Wg (the wire nearer or farther from the incisal edge, respectively).
  
  
  RESULTS
  Significant increases were found in gingival crevicular fluid (GCF) quantity, elastase activity, and protein content between T1 and T3 for both Group F+ and Group F-. A significant increase in F-Hb concentration was also found in Group F+. A comparison of the two groups identified significant differences for T3-BL in elastase activity and protein content. A Group Wi and Wg comparison showed significant baseline changes only in the F-Hb concentration at T2 and T3.
  
  
  CONCLUSIONS
  There was no difference in the status of the periodontal tissue between individuals with and without fixed retainers. In addition, the vertical position of the fixed retainer wire did not appear to influence periodontal health. The result, however, was obtained in subjects who possessed good oral hygiene. Attention should be paid to a patient's oral hygiene when employing the fixed retainer.
authors.affiliation: Department of Periodontology, The Nippon Dental University, School of Life Dentistry at Tokyo, Chiyoda-ku, Tokyo, Japan cookfroga@yahoo.co.jp
authors.forename: Akihiko
authors.initials: A
authors.lastname: Kaji
authors.forename: Satoshi
authors.initials: S
authors.lastname: Sekino
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ito
authors.forename: Yukihiro
authors.initials: Y
authors.lastname: Numabe
mesh_terms: D000328:Adult; D001439:Bacteroides / Q000302:isolation & purification; D001840:Dental Bonding; D003728:Dental Calculus / Q000145:classification; D003774:Dental Plaque Index; D015232:Dinoprostone / Q000032:analysis; D005260:Female; D005500:Follow-Up Studies; D005883:Gingival Crevicular Fluid / Q000737:chemistry; D005884:Gingival Hemorrhage / Q000145:classification; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D053583:Interleukin-1beta / Q000032:analysis; D007770:L-Lactate Dehydrogenase / Q000032:analysis; D019272:Leukocyte Elastase / Q000032:analysis; D008297:Male; D008334:Mandible; D018704:Orthodontic Retainers; D009969:Orthodontic Wires; D010512:Periodontal Index; D010514:Periodontal Pocket / Q000145:classification; D016966:Porphyromonas gingivalis / Q000302:isolation & purification; D011506:Proteins / Q000032:analysis; D012463:Saliva / Q000737:chemistry
chemical_list: D006454:Hemoglobins; D053583:Interleukin-1beta; D011506:Proteins; D007770:L-Lactate Dehydrogenase; D019272:Leukocyte Elastase; D015232:Dinoprostone