[Episodic progression of periodontitis--histologic associations]

Periodontal lesions are primarily diagnosed using the periodontal probe. Using site-specific probing attachment level measurements in defined time intervals, dentists can identify patients and dentition segments that suffer temporarily from a high periodontitis progression rate. The present article describes whether sites where clinical measurements suggested a high progression rate had tissue characteristics different from nonprogressing sites. Ten patients with untreated advanced adult periodontitis were monitored for 10 months by measuring clinical parameters every 30 days. These parameters were gingival index, plaque index, bleeding index, bleeding on probing, probing depth and probing attachment levels. Every month pairs of contralateral sites were sought where one site had lost 2 mm (P-2) or more (P greater than 2) probing attachment (P-sites) and the other site had not (C-site). From these sites supracrestal soft tissue biopsies were taken. After histological processing, a first analysis determined the number of inflammatory cells in 9 standard areas in P- and C-biopsies. A second analysis evaluated cell populations at the apical end of the junctional epithelium. The results showed that bleeding on probing, probing depth and probing attachment loss were statistically significantly greater at P-sites. At C-sites there were only few inflammatory cells. At P-2-sites there were numerous inflammatory cells, and in P greater than 2-sites the number of these cells was statistically significantly greater than in corresponding control sites. The cell populations at the apical end of the junctional epithelium were different between P- and C-sites. At P-sites, the percentage of mast cells, monocytes/macrophages and plasma cells was statistically significantly greater than at C-sites. At C-sites, the percentage of fibroblasts was statistically significantly greater than at P-sites. These results demonstrate that clinical probing identifies episodes of periodontitis progression, which are associated with pronounced changes in tissue characteristics, namely greater numbers of inflammatory cells.