The effect of photodynamic therapy on Aggregatibacter actinomycetemcomitans attached to surface-modified titanium.
OBJECTIVE
The purpose of this study was to evaluate the effect of photodynamic therapy (PDT) using erythrosine and a green light emitting diode (LED) light source on biofilms of Aggregatibacter actinomycetemcomitans attached to resorbable blasted media (RBM) and sandblasted, large-grit, acid-etched (SLA) titanium surfaces in vitro.


METHODS
RBM and SLA disks were subdivided into four groups, including one control group and three test groups (referred to as E0, E30, E60), in order to evaluate the effect of PDT on each surface. The E0 group was put into 500 µL of 20 µM erythrosine for 60 seconds without irradiation, the E30 group was put into erythrosine for 60 seconds and was then irradiated with a LED for 30 seconds, and the E60 group was put into erythrosine for 60 seconds and then irradiated with a LED for 60 seconds. After PDT, sonication was performed in order to detach the bacteria, the plates were incubated under anaerobic conditions on brucella blood agar plates for 72 hours at 37℃, and the number of colony-forming units (CFUs) was determined.


RESULTS
Significant differences were found between the control group and the E30 and E60 groups (P<0.05). A significantly lower quantity of CFU/mL was found in the E30 and E60 groups on both titanium disk surfaces. In confocal scanning laser microscopy images, increased bacterial death was observed when disks were irradiated for a longer period of time.


CONCLUSIONS
These findings suggest that PDT using erythrosine and a green LED is effective in reducing the viability of A. actinomycetemcomitans attached to surface-modified titanium in vitro.
Department of Periodontology, Research Institute for Oral Sciences, College of Dentistry, Gangneung-Wonju National University, Gangneung, Korea.
Kyungwon
0000-0001-7236-4020
K
Cho
Department of Oral Microbiology, Research Institute for Oral Sciences, College of Dentistry, Gangneung-Wonju National University, Gangneung, Korea.
Si Young
0000-0001-8826-1413
SY
Lee
Department of Periodontology, Research Institute for Oral Sciences, College of Dentistry, Gangneung-Wonju National University, Gangneung, Korea.
Beom-Seok
0000-0002-5280-3249
BS
Chang
Department of Periodontology, Research Institute for Oral Sciences, College of Dentistry, Gangneung-Wonju National University, Gangneung, Korea.
Heung-Sik
0000-0002-7986-1019
HS
Um
Department of Periodontology, Research Institute for Oral Sciences, College of Dentistry, Gangneung-Wonju National University, Gangneung, Korea.
Jae-Kwan
0000-0003-1710-1580
JK
Lee
Bacterial viability; Erythrosine; Photodynamic therapy; Titanium