BACTERIAL-COLONIZATION OF BARRIER MATERIAL AND PERIODONTAL REGENERATION

The objective of this study was to evaluate the relationship between t he presence of bacteria on the tooth-facing surface of ePTFE barriers and the clinical outcome of membrane supported reconstructive periodon tal surgery. 20 systemically healthy subjects affected by chronic peri odontitis were enrolled. One tooth site per patient, associated with a n angular bony defect and a probing attachment loss of >4 mm, was sele cted to be treated by means of a guided tissue regeneration procedure using an ePTFE barrier membrane. Antibiotics (Augmentin 1 g/day) for 2 weeks were prescribed. In addition to the use of chlorhexidine for po st-surgical plaque control, all patients were recalled once a week for professional tooth cleaning. The barrier material was harvested for S EM analysis after 4-6 weeks. Professional tooth cleaning and reinforce ment of sel-performed oral hygiene measures were given at 1 month inte rvals after membrane removal. For each treated site, the difference in probing attachment loss between baseline examination and a follow-up examination after 6 months of healing was calculated. The results of t he SEM-analysis revealed that bacterial colonization was evident in th e collar area of all the retrieved membranes. In the mid part of the m embranes 30 out of 60 microscopic fields (50%) demonstrated microbial colonization, and in the most apical part 9 out of 60 fiels (15%). Reg ression analysis indicated that gain in probing attachment level was p ositively correlated to initial attachment loss and negatively correla ted to microbial colonization of the mid part of the membranes. It was concluded that bacterial colonization in the mid part of the ePTFE me mbrane reduced the potential gain in probing attachment following GTR- therapy with almost 50%.