Clinical investigation of levels of lipopolysaccharides and lipoteichoic acid after antimicrobial photodynamic therapy in teeth with secondary endodontic infection: an observational study.

INTRODUCTION

This study aimed to evaluate the effectiveness of photodynamic therapy (PDT) in reducing lipopolysaccharides (LPS) and lipoteichoic acid (LTA) levels in secondary endodontic infections and assess their correlation with clinical symptoms.

MATERIALS & METHODS: Seventy patients requiring nonsurgical endodontic retreatment were selected for this study and divided into two groups: one group received photodynamic therapy (PDT), while the other was treated with sodium hypochlorite (NaOCl). Using ELISA and chromogenic assays, endodontic samples were collected to measure lipoteichoic acid (LTA) levels and lipopolysaccharides (LPS). Strict aseptic techniques and contamination prevention measures were adhered to throughout the procedures. The data were analyzed using SPSS version 26, applying descriptive statistics and significance tests with a p-value threshold of 0.05, a 95% confidence level, and 80% power.

RESULTS

The study found that photodynamic therapy significantly reduced lipoteichoic acid and lipopolysaccharides levels compared to sodium hypochlorite irrigation, with mean changes of 253.78 and 154.35 (p = 0.02). Additionally, a significant mean reduction in lipopolysaccharide levels favored PDT (p = 0.013). Symptomatic patients exhibited a higher mean level of lipoteichoic acid (507.48) than asymptomatic patients (210.14, p = 0.001). However, no significant correlation was found between lipopolysaccharide levels and symptoms (p = 0.606). Endodontic infections and to assess their correlation with clinical symptoms.

CONCLUSION

This study shows that photodynamic therapy (PDT) significantly reduces lipoteichoic acid and lipopolysaccharides levels, outperforming sodium hypochlorite irrigation in secondary apical periodontitis management. It also reveals a strong correlation between higher lipoteichoic acid levels and clinical symptoms, with no significant link found for lipopolysaccharide levels.