Related Experiment Video
Updated: Mar 8, 2026
Author Spotlight: Exploring Photodynamic Therapy with Curcumin in a Murine Model for Oral Candidiasis
Published on: October 27, 2023
Photodynamic Inactivation of Cariogenic Pathogens Using Curcumin as Photosensitizer
Natália Costa Araújo1, Rebeca Ferraz de Menezes2,3, Vanda Sanderana Macêdo Carneiro1,4
11 Department of Restorative Dentistry, Dental School of Pernambuco, University of Pernambuco (UPE) , Camaragibe, Brazil .
Objective:
This investigation assessed the susceptibility of Streptococcus mutans and Lactobacillus acidophilus to Photodynamic Therapy (PDT) when grown simultaneously in dentine carious lesions.
Background Data:
PDT is a technique that utilizes light to activate photosensitizers in the presence of oxygen to produce reactive radicals.
Materials And Methods:
A culture medium of 1% glucose, 2% sucrose, 1% young primary culture of L. acidophilus 108 CFU/mL, and S. mutans 108 CFU/mL was utilized to inoculate the bacterial induced caries on human dentine slabs. Different concentrations of the photosensitizer (0.75, 1.5, 3.0, 4.0, and 5.0 g/L) were activated through exposure to the light-emitting diode source with a central wavelength of 450 nm and a fluency of 5.7 J/cm2. Two light intensities (19 and 47.5 mW/cm2) were tested. Four different groups were analyzed: L-D- (control group), L-D+ (drug group), L+D+1 (PDT group 1, light intensity of 19 mW/cm2), and L+D+2 (PDT group 2, light intensity of 47.5 mW/cm2). ANOVA/Tukey tests were utilized to compare groups (α = 5%).
Results:
Both light intensities required 5.0 g/L of curcumin for significant bacterial reduction (p < 0.05). No significant effect was found for L-D+, thus proving the absence of a potential inherent toxicity.
Conclusions:
Curcumin has a toxic effect on microorganisms at appreciable concentrations upon photoactivation. However, it was required to use the maximum concentration of the drug for a successful procedure.
