title: Bacterial morphotypes and early cellular responses in clinically infected and non-infected sites after combination therapy of guided tissue regeneration and allograft.
abstract: OBJECTIVE
  To compare the bacterial morphotypes and early cellular responses in periodontally treated sites with and without pus formation after a combination of guided tissue regeneration (GTR) and allograft therapy.
  
  
  METHODS
  45 subjects with 80 sites having periodontal lesions with moderate to deep pockets and angular bone defects participated. 28 treated sites in 25 patients were included in the studies. 14 sites suffered from symptoms and signs of infection with pus formation during the healing period were assigned to the pus (P) group. Another 14 sites had asymptomatic healing and were assigned to the non-pus (NP) group. The GTR membranes were retrieved 4-6 weeks after surgery and processed for SEM examination. The bacterial morphotypes on the membranes were observed and photographed. Bacterial adhesion score (BAS, 0-5) and the presence of leukocytes and fibroblasts were estimated from photographs.
  
  
  RESULTS
  The results showed that large numbers of bacteria (high BAS) were present on both sides of the coronal 2/3 of the membrane in both groups, irrespective of clinical conditions. At the apical 1/3 of the membrane, moderate numbers of bacteria were still found on the outer side in the P group. The BAS of rod-shaped bacteria were significantly higher in the P group than that of the NP group on the outer coronal 2/3 of the membrane. The frequency of the presence of fibroblasts (18.5%) at the apical 1/3 of the inner (tooth facing) side of the P group was much lower than that of the same location (28.6-29.6%) in the NP group. The presence of leukocytes and fewer numbers of fibroblasts on the GTR membrane were associated with greater BAS for rod- and filament-shaped bacteria.
  
  
  CONCLUSIONS
  GTR membranes are commonly colonized by oral bacteria during retention, even on uncomplicated and tissue covered portions. The overt infection clinically (pus group) of the membrane-allograft treated sites is associated with a significantly elevated BAS of rod-shaped bacteria, and may be closely related to the occurrence of its adverse early healing responses (inflammation, pus formation, fewer fibroblasts and greater accumulation of leukocytes).
authors.affiliation: Department of Periodontology, School of Dentistry, College of Medicine, National Taiwan University Hospital, Taipei, Taiwan.
authors.forename: S J
authors.initials: SJ
authors.lastname: Lin
authors.forename: L T
authors.initials: LT
authors.lastname: Hou
authors.forename: C M
authors.initials: CM
authors.lastname: Liu
authors.forename: C S
authors.initials: CS
authors.lastname: Liao
authors.forename: M Y
authors.initials: MY
authors.lastname: Wong
authors.forename: J Y
authors.initials: JY
authors.lastname: Ho
authors.forename: W K
authors.initials: WK
authors.lastname: Chang
mesh_terms: D000328:Adult; D000368:Aged; D001419:Bacteria / Q000302:isolation & purification / Q000472:pathogenicity / Q000648:ultrastructure*; D001422:Bacterial Adhesion; D016025:Bone Transplantation; D003131:Combined Modality Therapy; D004866:Equipment Contamination; D005260:Female; D016557:Guided Tissue Regeneration, Periodontal; D006801:Humans; D008297:Male; D008567:Membranes, Artificial; D008855:Microscopy, Electron, Scanning; D008875:Middle Aged; D010518:Periodontitis / Q000382:microbiology / Q000473:pathology / Q000628:therapy; D014184:Transplantation, Homologous
chemical_list: D008567:Membranes, Artificial