PORPHYROMONAS-GINGIVALIS, PREVOTELLA-INTERMEDIA AND BACTEROIDES-FORSYTHUS IN PLAQUE SUBJACENT TO BRIDGE PONTICS

This study examined the distribution of P. gingivalis, P. intermedia a nd B. forsythus in plaque on metallic and porcelain pontics adjacent t o healthy and inflamed mucosa. Subpontic plaque was collected from 33 inflamed and 31 healthy sites. Plaque suspension was incubated with sp ecific rabbit antisera to P. gingivalis (FDC 381), P. intermedia (ATCC 25261) and B. forsythus (FDC 335), and the labelled cells disclosed w ith fluorescein-labelled goat-anti-rabbit IgG by indirect immunofluore scence microscopy. Mean proportions of P. gingivalis, P. intermedia, a nd B. forsythus at inflamed sites were 0.60+/-0.75, 2.48+/-2.28, and 0 .44+/-0.64% respectively and at healthy sites 0.21+/-0.43, 1.27+/-1.05 , and 0.15+/-0.18% respectively. These differences were statistically significant. Almost all sites were positive for P. intermedia, whereas only 12/31 healthy and 21/33 inflamed sites were positive for P. ging ivalis. 18/31 healthy and 28/33 inflamed sites were positive for B. fo rsythus, P. intermedia was recovered in higher proportions from metall ic pontics adjacent to inflamed sites (MI) than healthy sites (MH) or porcelain pontics next to inflamed (PI) or healthy sites (PH). P. ging ivalis is was recovered in higher proportions from MI than PH. We conc lude that both the nature of the pontic material and the health status of the mucosa affect the composition of the associated microbiota.