The influence of sulfate-reducing bacteria colonization of 2 different bioresorbable barrier membranes for GTR. An 18-month case-controlled microbiologic and clinical study

The purpose of the present microbiologic and case-controlled clinical study was to examine the colonization of 2 different resorbable barrier membrane s by sulfate-reducing bacteria (SRB). The barrier membranes tested were Gui der matrix barrier and Resolut regenerative material. Ten patients exhibiti ng 3 Class II furcation defects and 7 intrabony defects were included in th e study. The probing depth and the clinical attachment level at 4 surfaces per tooth were taken at the beginning of the study. Microbiologic samples w ere taken from the experimental sites and from the approximal sites of the adjacent teeth. Both types of resorbable membranes were positive for SRB co lonization. The detection of SRB in 2 of 7 intrabony defects and in ail def ects with furcation involvement before the membrane placement indicated tha t these organisms are a common inhabitant of sites showing periodontal dest ruction and are associated with guided tissue regeneration (GTR). According to the clinical criteria for healing tendencies used in this study, the GT R procedures were less successful in the presence of SRB. There were no sig nificant clinical effects of different resorbable membrane materials or mem brane layout on attachment level changes for either the intrabony defect or furcation groups after 18 months. There were no statistical differences fo r sites that became exposed to SRB when compared to sites that remained une xposed after 18 months. The numeric significance of SRB in relation to the total microbial count needs to be determined to gain insight into the ecolo gic role of membrane resorption rates.