title: Guided tissue regeneration using a polylactic acid barrier. Part I: Environmental effects on bacterial colonization.
abstract: OBJECTIVE
  The purpose of this study was to assess the dynamics of bacterial colonization in intra-osseous defects following guided tissue regeneration (GTR) therapy using a resorbable barrier.
  
  
  METHODS
  In each of 30 patients, one intra-osseous defect was treated with GTR using a polylactic acid membrane (Guidor). Plaque samples were taken from the defect site, other teeth and mucous membranes following initial therapy (baseline), and at 3, 6 and 12 months after periodontal surgery. Additionally, samples were taken from the defect sites at 1, 2 and 4 weeks. Actinobacillus actinomycetemcomitans (A.a.), Porphyromonas gingivalis (P.g.), and Bacteroides forsythus (B.f.) were detected by polymerase chain reaction (PCR). Supportive periodontal therapy was performed at 3-month intervals.
  
  
  RESULTS
  In the 29 patients completing the study, the assessed microflora was detected in 3 (A.a.), 13 (P.g.) and 14 (B.f.) defect sites at baseline, in 2 (A.a.), 2 (P.g.) and 2 (B.f.) following surgical debridement, and in 6 (A.a.), 10 (P.g.) and 22 (B.f.) at 12 months. Defect site colonization following GTR therapy was significantly correlated with presurgical colonization at other assessed teeth (A.a. and P.g.: tau = 0.45 and 0.66, respectively; P < 0.001), or on mucous membranes (B.f.: tau = 0.44, P < 0.001).
  
  
  CONCLUSIONS
  The colonization of periodontal pathogens at sites treated by GTR may correlate with the intra-oral presence of these pathogens before surgery. If colonization of GTR sites by periodontal pathogens is to be prevented, intra-oral suppression/eradication of these pathogens may be required before surgery.
authors.affiliation: Clinic of Conservative Dentistry, University of Tübingen, Germany.
authors.forename: S G
authors.initials: SG
authors.lastname: Rüdiger
authors.forename: B
authors.initials: B
authors.lastname: Ehmke
authors.forename: A
authors.initials: A
authors.lastname: Hommens
authors.forename: H
authors.initials: H
authors.lastname: Karch
authors.forename: T F
authors.initials: TF
authors.lastname: Flemmig
mesh_terms: D020341:Absorbable Implants; D000293:Adolescent; D000328:Adult; D000368:Aged; D016976:Aggregatibacter actinomycetemcomitans / Q000254:growth & development; D016301:Alveolar Bone Loss / Q000382:microbiology / Q000601:surgery; D001439:Bacteroides / Q000254:growth & development; D001672:Biocompatible Materials; D002951:Citrates; D003773:Dental Plaque / Q000382:microbiology; D005260:Female; D005500:Follow-Up Studies; D006090:Gram-Negative Bacteria / Q000502:physiology*; D016557:Guided Tissue Regeneration, Periodontal / Q000295:instrumentation* / Q000379:methods; D006801:Humans; D019344:Lactic Acid; D008297:Male; D008567:Membranes, Artificial; D008875:Middle Aged; D009055:Mouth / Q000382:microbiology*; D009061:Mouth Mucosa / Q000382:microbiology; D010518:Periodontitis / Q000382:microbiology / Q000601:surgery; D011091:Polyesters; D011108:Polymers; D016966:Porphyromonas gingivalis / Q000254:growth & development; D013223:Statistics as Topic; D014070:Tooth / Q000382:microbiology
chemical_list: D001672:Biocompatible Materials; D002951:Citrates; C105021:Guidor; D008567:Membranes, Artificial; D011091:Polyesters; D011108:Polymers; D019344:Lactic Acid; C033616:poly(lactide)