Antimicrobial Photodynamic Therapy Associated With Systemic Treatment in Osteoradionecrosis: An In Vivo Study

Area of Science:

• Oral and Maxillofacial Surgery
• Regenerative Medicine
• Oncology Supportive Care

Background:

• Osteoradionecrosis (ORN) is a severe complication following radiotherapy for head and neck cancers, often affecting the mandible.
• Current treatments for ORN are limited, highlighting the need for novel therapeutic strategies.
• Irradiated mandibular bone exhibits impaired healing capacity, increasing susceptibility to complications like ORN after dental procedures.

Purpose of the Study:

• To investigate the efficacy of antimicrobial photodynamic therapy (aPDT), systemic pharmacological therapy, and their combination in promoting bone repair after tooth extraction in an irradiated rat mandible.
• To evaluate the potential of these therapies in mitigating ORN development.

Main Methods:

• A rat model was established involving focal irradiation of the mandible followed by molar extraction.
• Animals were divided into five groups: control, irradiated extraction, irradiated extraction with systemic therapy, irradiated extraction with aPDT, and irradiated extraction with combined therapy.
• Bone repair was assessed using micro-computed tomography, radiography, histopathology, and hepatic steatosis evaluation.

Main Results:

• Irradiated, untreated mandibles showed significant structural and histopathological damage.
• All tested treatment protocols demonstrated improved bone repair compared to the untreated irradiated group.
• The combination of aPDT and systemic therapy yielded the most favorable outcomes, enhancing bone architecture and osteogenesis.

Conclusions:

• Combined antimicrobial photodynamic therapy and systemic pharmacological therapy show significant potential as a multimodal approach for managing irradiated mandibular bone defects.
• This combined strategy may offer a promising therapeutic avenue for preventing or treating osteoradionecrosis.