Determination of the presence of root-bound endotoxin using the local Shwartzman phenomenon (LSP)

The purpose of these studies was to determine, by attempting to elicit the local Shwartzman phenomenon (LSP), if the material extracted from periodontally involved root surfaces is actually endotoxin or only an endotoxin-like substance. A total of 719 periodontally involved teeth and 201 unerupted third molars yielded pooled samples of root surface grindings which were treated with the endotoxin extraction technique nonpyrogenic saline or pyrogen-free water. In the first study each of the reconstituted extracts was injected into the right palatal gingiva of New Zealand white rabbits which had demonstrated the ability to elicit an LSP. Commercial Salmonella enteritidis endotoxin was injected into the left (control) palatal gingiva. This was followed 18 hours later by a provoking injection of 200 to 300 microgram S enteritidis endotoxin in a marginal ear vein. In the second study, reconstituted extracts were injected into the right side of the abdomen of New Zealand white rabbits. The left (control) side received varying amounts of S enteritidis endotoxin. Twelve hours later each animal received a provoking injection of 400 microgram of S enteritidis endotoxin in a marginal ear vein. In both studies the animals were examined 6 hours later for visual signs of an LSP. After sacrifice, the tissues were prepared and histologic sections evaluated by two examiners who were unaware of how the specimens had been treated. The results indicated that a heat-stable, phenol-water extractable and highly irritating substance could be obtained from periodontally involved root surfaces. However, it is questionable if the substance extracted was actually endotoxin. If a true endotoxin, it was present only in extremely small amounts.