Objective To study the concentration of endotoxin in debris and underlying dentin of deep caries with different rate of progression .Methods Forty-four clinically asymptomatic third molars with deep caries and 10 normal third molars were chosen. Samples were collected with pyrogen-free instruments and incubated in BET water,and the concentration of endotoxin was determined with LAL KTA. Results Endotoxin was found in all debris. Active deep caries had significantly higher amount of endotoxin in debris t...