[Clinical and microbiological study of factors determining effective scaling and root planing]

The aim of the present study was to monitor longitudinally the clinical and microbiological parameters after root debridement in order to determine the factors affecting successful and unsuccessful results. Nine patients with moderate and severe periodontitis participated. Four sites of single root with over 5-mm periodontal pockets in each quadrant were selected. The oral hygiene was controlled in all patients, then root debridement was performed without anesthesia at the three sites of the quadrants every two weeks during eight weeks. The clinical parameters consisted of plaque index, gingival index, probing depth, clinical attachment level, bleeding on probing, tooth mobility and the value of gingival crevicular fluid (GCF). The microbiological parameters such as percentages of cocci, motile rods, non-motile rods and spirochetes and the number of microorganisms were examined and the percentages of black pigmented Bacteroides (BPB) and Actinobacillus actinomycetemcomitans as well as the number of anaerobic colonies were counted. The results demonstrated that a reduction in the probing depth was observed in all sites except four. The successful sites clinically showed a decrease of the probing depth and GCF value and, microbiologically, reduced percentages of the spirochetes and BPB. The results indicated that the decrease of the probing depth and GCF under 50 Periotoron units in coincidence with the bacterial reduction can be used to determine the successful response of root debridement.