Antimicrobial Effect on <italic>Streptococcus mutans</italic> in Photodynamic Therapy using Different Light Source

Abstract

In a photodynamic therapy, the difference of antibacterial capacity was compared according to the type of source of light when the same quantity of energy is irradiated. After S. mutans is formed in planktonic state and biofilm state, erythrosine diluted to 40 μM was treated for 3 minutes, and as the type of light source, Halogen, LED, and Plasma arc were used, which were irradiated for 30 seconds, 15 seconds and 9.5 seconds, respectively. After the completion of the experiment, CFU of each experiment arm was measured to compare the photodynamic therapeutic effects according to each condition. The CFU of each experiment arm had no statistically significant difference. Under the same quantity of energy, the photodynamic therapeutic effect can be said to be the same regardless of types of light source, which is a useful result in the clinical field with various light irradiators.

Application of Teeth Whitening LED for Prevention of Dental Caries : Antimicrobial Photodynamic Therapy Approach

“…Since the output of the home whitening In our study, aPDT groups showed 95% reduction in planktonic states, whereas in dynamic biofilm state, the reduction rate ranged from 53% to 61%. It is well known that bacteria are considerably more resistant in biofilms than in planktonic cultures [11,21,22]. Although aPDT was less effective in the treatment of bacteria with dense biofilms than in planktonic culture, the difference was less than twofold.…”

“…In this study, erythrosine (Sigma-Aldrich, St. Louis, MO, USA) was chosen as a photosensitizer. The erythrosine concentration was 20 μM/L and it was prepared in phosphate buffered saline (PBS, pH 7.4), sterilized by filtration, covered in an aluminum foil, and stored at -20°C [11][12][13].…”

“…Previous studies have verified the effectiveness of aPDT by studying various light sources such as laser, halogen light, and light emitting diodes (LED). Although the light sources used in previous studies were all effective at reducing the microbial load [10,11], they cannot cover the entire oral cavity and dental arch due to the limited range of area covered by light radiation. Hence, there is the need for a light delivery system that can compensate for the disadvantages of the light sources previously used.…”

“…Various light sources and their energy level have been tested for aPDT effects. Kim et al [11]. showed effective aPDT effects on S. mutans regardless of the light sources (halogen light, LED, laser) with same energy of 18000 mW/cm 2 applied.However these conventional light delivery systems have limitation's of not being able to cover the entire oral cavity.…”

Recovery of Streptococcus Mutans Biofilm after Photodynamic Therapy with Erythrosine and LED Light Source

“…Erythrosine (Sigma-Aldrich, St Louis, MO, USA) was used as the photosensitizer, and the concentration of erythrosine was set as 40 μM, according to previous studies [11]. Erythrosine (molecular weight, 879.86 g/mol) powder was mixed with phosphate-buffered saline (PBS), followed by filter sterilization, to prepare a 1 mM erythrosine stock solution.…”