Endotoxin levels in periodontally healthy and diseased sites: correlation with levels of gram-negative bacteria.
This study investigated the correlation between endotoxin levels and the percentage of Gram-negative bacteria in healthy sites and in periodontitis sites. Twelve healthy adults participated. Each subject provided 3 periodontitis sites with 5 to 8 mm probing depths that bled on gentle probing and 3 healthy sites with sulcus depths of 1 to 3 mm that did not bleed. Clinical examinations and sterile paper point sampling of all study sites were conducted on days 0, 7, and 14, and site-specific endotoxin levels and percentage of Gram-negative bacteria were determined. There were significant differences in both endotoxin levels and percentage Gram-negative bacteria between healthy and periodontitis sites across all 3 sampling periods, but no difference across sampling periods in the healthy sites and the periodontitis sites, respectively. Correlation coefficients revealed a high degree of correlation between site-specific endotoxin levels and percentage of Gram-negative organisms. Using a sample dilution of 1 x 10(4), endotoxin levels differentiated healthy from periodontitis sites with a specificity of approximately 91% and a sensitivity of approximately 90%.