Introduction of 5-aminolevulinic acid as a theranostics agent in dentistry

• Published in: Photodiagnosis and photodynamic therapy 2019-03, Vol.25, p.336-343
• Main Authors: Lashkari, Sahar Mohammadpour, Kariminezhad, Hasan, Amani, Hossein, Mataji, Parisa, Rahimnejad, Mostafa
• Format: Article
• Language: English
• Subjects: 5-Aminolevulinic acid; Antimicrobial photodynamic therapy; Dentistry; Laser induced fluorescence; Photodynamic inactivation; Theranostics agent
• ISSN: 1572-1000; 1873-1597
• DOI: 10.1016/j.pdpdt.2019.01.021

[Display omitted] •5-ALA is toxic on Streptococcus sanguis for concentrations above 20 μM.•PDI of Streptococcus sanguis was demonstrated using 5-ALA and an LED light source.•5-ALA incubation in Streptococcus sanguis causes growth in fluorescence intensity.•5-ALA incubation in dental caries increases the LIF intensity just in decayed parts. The aim of this paper is to study the theranostic potential of 5-Aminolevulinic Acid (5-ALA)in dentistry. Photodynamic inactivation (PDI) and fluorescence spectroscopy of Streptococcus sanguis, and laser induced fluorescence (LIF) of several decayed teeth were performed using 5-ALA. In the absence of 5-ALA, 15 min illumination of the bacteria by the means of an LED light source led to only 1.16% viability reduction. On the other hand, 5-ALA revealed remarkable dark toxicity at concentrations above 20 μM. Furthermore, the synergistic effects of 10 μM 5-ALA and illumination by the light source for 5 and 15 min intervals led respectivelyto0.74log10 and 1.69log10 reduction of viability. Also, fluorescence spectroscopy of the bacteria showed a direct relationship between emission line intensity at 620 nm and the concentration of 5-ALA. In dental experiments, following exposing tooth with 40 mM 5-ALA, a significant autofluorescence growth was observed just in the decayed parts. Based on the strong dual modality of 5-ALA to annihilate cariogenic bacteria through photodynamic inactivation and enhancing LIF intensity for identification of dental caries, 5-ALA is proposed as a theranostic agent in dentistry.