Correlation Between LPS and LTA Levels With Clinical Features in Secondary Endodontic Infections

This study aimed to quantify LPS and LTA levels in root canals requiring endodontic retreatment due to secondary or persistent infection and evaluate the relationship between Gram-positive and Gram-negative virulence factors and clinical symptoms and signs. Samples were collected from the root canals of 40 patients who needed endodontic retreatment and had radiographic evidence of apical periodontitis. Lipopolysaccharides (LPS) and lipoteichoic acid (LTA) were quantified using Limulus amebocyte lysate and enzyme-linked immunosorbent assay tests, respectively. LPS and LTA were detected in all samples, with mean values being 5.1 EU/mL(±2.83) and 537.53 pg/mL(±134.14), respectively. Significant correlations were found between levels of LPS and LTA with clinical features. In conclusion, coronal restoration directly influences the load of LPS and LTA in root canals with secondary infection. Furthermore, higher concentrations of endotoxin (LPS) are associated with larger areas of periapical bone resorption, as well as with the presence of clinical signs and symptoms.