Clinical and microbiological effects of root debridement in periodontal furcation pockets

The aim of the present study was to investigate longitudinally over 52 weeks the clinical and microbiological effects of plaque control and root debridement at molar furcation sites. The results were compared with changes at non-molar sites. 24 non-molar sites and 31 grade II molar furcation sites with probing depth greater than or equal to 5.0 mm were monitored in 11 patients. Clinical measurements consisted of plaque scores, probing depths, and changes in probing attachment level. Microbiological monitoring was carried out with phase-contrast microscopy and anaerobic culturing. The debridement resulted in improvement in probing measurements and microbiological counts for both groups of sites. A slightly less favorable clinical response was noted for molar furcation sites. Higher post-operative microbiological counts were found throughout the 52-week observation period for molar furcation sites. Sites with probing attachment loss showed higher microbial counts and higher proportions of spirochetes, black pigmented colony forming units (CFU), and Bacteroides gingivalis CFU than sites with probing attachment gain. Individual site analysis, however, demonstrated marked variations of the microbiological counts at the different postoperative time points. In the few available sites undergoing probing attachment loss, no apparent association between target micro-organisms and periodontal deterioration was observed.