Antimicrobial comparison on effectiveness of endodontic therapy and endodontic therapy combined with photo-disinfection on patients with periapical lesion: a 6 month follow-up

This study compares the antimicrobial effect of photodynamic therapy (PDT) combined to endodontic treatment with conventional endodontic treatment alone in patients with necrotic pulp and has a 6-month radiographic follow up comparing the healing of periapical lesions. Fifteen patients with periapical lesion and requiring root canal treatment were selected. Microbiological samples were taken after accessing the root canal, conventional manual endodontic therapy (group 1 n=5) and after accessing the canal, endodontic therapy and PDT (group 2 n=10). All the root canals were filled with a calcium hydroxide paste for 1 week. Radiographs were taken after obturation and following 6 months. Endodontic therapy alone presented an 87% reduction in microorganisms while the combination with PDT had a 95% reduction. Radiographic follow up showed 32% higher reduction in the lesion area in PDT group. Results suggest that the use of PDT added to conventional endodontic treatment leads to a further major reduction of microbial load. PDT is an efficient alternative to chemical antimicrobial agents. It is a non-cumulative local treatment, which may be an appropriate approach for the treatment of infections in the oral cavity.