title: Topical and systemic antimicrobial therapy in guided tissue regeneration.
abstract: BACKGROUND
  Bacterial contamination of membrane material negatively affects healing after guided tissue regeneration (GTR) procedures; conversely, flap connective tissue integration on barrier material improves the clinical outcomes. The objective of this study was to evaluate the effect of topical application of antibiotics on: 1) clinical outcomes of GTR surgical procedures using titanium reinforced expanded polytetrafluoroethylene (ePTFE) periodontal membrane; 2) bacterial colonization of membrane material; and 3) flap connective tissue-membrane integration.
  
  
  METHODS
  Fifty-six deep interproximal bony defects were treated with GTR surgical procedures using titanium reinforced ePTFE periodontal membranes. Patients were randomly assigned to 1 of the 2 antimicrobial treatment groups: the test group received weekly topical application of 25% metronidazole gel and the control group received systemic antibiotics (amoxicillin plus clavulanic acid 1 g/day for 14 days). Clinical outcomes were assessed at 1 year; the amount of bacterial contamination and connective tissue integration on membrane material was evaluated at time of membrane removal by means of a morphological (SEM) method.
  
  
  RESULTS
  No statistically significant difference was found between test and control groups in terms of clinical attachment (CAL) gain (baseline CAL - 12 months CAL; P = 0.2) and probing depth (PD) reduction (baseline PD - 12 months PD; P = 0.6). A greater increase in gingival recession (REC) (12 months REC - baseline REC) was found in the test group compared to the control group (P = 0.003). The SEM analysis revealed no statistically significant (t test) difference between test and control groups in the number of fields positive to integrated connective tissue (P = 0.82), while the number of fields positive to bacteria was statistically higher (P < 0.001) in the control group.
  
  
  CONCLUSIONS
  Local antibiotic administration is more effective than systemic use in preventing membrane contamination, but it does not improve clinical outcomes due to an interference of the vehicle (gel) with gingival tissues which may reduce the potential benefits derived from better control of the bacterial load.
authors.affiliation: Department of Periodontology, Faculty of Odontology, Bologna University, Italy. giovanzu@tin.it
authors.forename: G
authors.initials: G
authors.lastname: Zucchelli
authors.forename: N M
authors.initials: NM
authors.lastname: Sforza
authors.forename: C
authors.initials: C
authors.lastname: Clauser
authors.forename: C
authors.initials: C
authors.lastname: Cesari
authors.forename: M
authors.initials: M
authors.lastname: De Sanctis
mesh_terms: D000287:Administration, Topical; D000328:Adult; D000368:Aged; D016301:Alveolar Bone Loss / Q000601:surgery; D019980:Amoxicillin-Potassium Clavulanate Combination / Q000008:administration & dosage / Q000627:therapeutic use*; D000900:Anti-Bacterial Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D001419:Bacteria / Q000254:growth & development; D003238:Connective Tissue / Q000382:microbiology / Q000473:pathology; D004359:Drug Therapy, Combination / Q000008:administration & dosage / Q000627:therapeutic use*; D004866:Equipment Contamination / Q000517:prevention & control; D005260:Female; D005500:Follow-Up Studies; D016557:Guided Tissue Regeneration, Periodontal / Q000295:instrumentation / Q000379:methods*; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008567:Membranes, Artificial; D008795:Metronidazole / Q000008:administration & dosage / Q000627:therapeutic use*; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D017622:Periodontal Attachment Loss / Q000473:pathology / Q000601:surgery; D010519:Periodontium / Q000382:microbiology / Q000473:pathology; D011138:Polytetrafluoroethylene; D013499:Surface Properties; D014025:Titanium; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents; D008567:Membranes, Artificial; D008795:Metronidazole; D019980:Amoxicillin-Potassium Clavulanate Combination; D011138:Polytetrafluoroethylene; D014025:Titanium