The first antimicrobial substance to be discovered was penicillin, and this marked the beginning of the “golden age of antibiotics.” Recently, a severe lack of control in the use of antibiotics, great abuse in areas such as livestock feed, and unnecessary prescriptions for viral infections have led to growing global rates of antibiotic resistance in microorganisms. The discovery of new antibiotics cannot keep up with the speed of resistance developed by microorganisms. The rise in antibiotic resistance worldwide has driven research into the development of new antibacterial strategies. However, overall, 74.2% of the patients with chronic periodontitis have been revealed subgingival periodontal pathogens resistant to at least one of the test antibiotics. Additionally, some of the periodontitis bacteria forming red complex included P. gingivalis have been reported to acquire resistance to the antibiotic such as amoxicillin. Amoxicillin resistance was present in 43.3% of the study patient which β-lactamase enzymes capable of hydrolyzing β-lactam antibiotics11. Many antibiotics for periodontal disease treatment was not indicated to be associated with the interacellular energy metabolism inhibition of oral bacteria. Therefore, it is very important to intracellularly target molecules and/or microorgans not related to antibiotic resistance mechanisms. For example, antimicrobial photodynamic therapy (aPDT) has the potential to be an alternative to antibiotics, especially for the treatment of localized skin infections12.