[The effect of water rinsing in removal of endotoxin from exposed root]

Previous studies have revealed that periodontally involved exposed roots show evidence of biologic toxicity possibly due to endotoxin from subgingival micro-organisms. Eleven periodontally involved teeth and five periodontally healthy teeth comprised the material. The teeth were rinsed in ultrasonic cleaner containing pyrogen-free water for one hour. The samples were taken from the solution after 1, 5, or 60 minutes. With the aim of removing residual endotoxin on the roots not eliminated by rinsing, each tooth was subjected to extraction of endotoxin with 45% phenol in water for 90 minutes at 65 degrees C. After extraction of endotoxin, the root surface of the involved teeth was further planned with a hand scaler. Endotoxin was extracted from the particles removed from the root surfaces. All samples were tested for endotoxin by limulus amoebocyte lysate assay. The amount of endotoxin from involved teeth was 4,500 +/- 2,000 ng per tooth and from healthy teeth it was 370 +/- 120 ng per tooth. The amount of residual endotoxin on roots from involved teeth was 32 +/- 20 ng per tooth and from healthy teeth it was 1.2 +/- 1.1 ng per tooth. The amount of endotoxin collected from particles removed from previously rinsed involved root surfaces was 1.5 ng per tooth. The rate of removal of endotoxin by water rinsing of a tooth was 64 +/- 25% in 1 minute, 85 +/- 16% in 5 minutes, 99 +/- 0.6% in 60 minutes.