Antimicrobial photodynamic therapy: A promise candidate for caries lesions treatment

Author(s)

Alves Diniz, Ivana Marcia ^[1] ; Horta, Ivay Diniz ^[2] ; Azevedo, Cynthia Soares ^[1] ; Elmadjian, Thais Regina ^[1] ; Matos, Adriana Bona ^[1] ; Lorenzetti Simionato, Maria Regina ^[3] ; Marques, Marcia Martins ^[1]

Affiliation

^[1] Univ Sao Paulo, Dept Restorat Dent, Sch Dent, BR-05508000 Sao Paulo, SP - Brazil

^[2] Fed Univ Minas Gerais UFMG, Sch Engn, BR-31270901 Belo Horizonte, MG - Brazil

^[3] Univ Sao Paulo, Inst Biomed Sci ICB, Dept Microbiol, BR-05508000 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: Photodiagnosis and Photodynamic Therapy; v. 12, n. 3, p. 511-518, SEP 2015.
• Web of Science Citations: 18

Abstract

Background: Antibacterial photodynamic therapy (aPDT) is a promising adjunctive therapy to the treatment of caries lesions, mainly in the minimally invasive approach to preserve dental tissue and favor its repair. Here we analyzed both the efficacy of aPDT in reducing the bacterial load in cariogenic biofilms and the indirect effect of noxious components produced by aPDT on the viability of dental pulp cells. Methods: The aPDT protocol was established using 0.025 g/mL methylene blue (MB) and 5 min pre-irradiation time. A continuous-wave diode laser (660 nm, 0.04cm(2) spot size, 40 mW, 60s, 60 J/cm(2) and 2.4J) was used in punctual and distance modes to excite the MB. The protocol was first tested against Streptococcus mutans (U159) biofilms produced in 96-well microplates, and then evaluated on caries-like affected human dentin discs of three thicknesses. The number of colony forming units (CFU) was compared between groups. Discs were then assembled in metallic inserts to produce an artificial pulp chamber and allow investigation of the indirect effects of aPDT on dental pulp cells by the 3-(4,5-dimethylthiazol-2-yl)-diphenyltetrazolium bromide (MTT) assay. Data were analyzed using Student's t test or one-way analysis of variance (ANOVA) followed by the Tukey's test at a significance level of 5%. Results: Bacterial load reduction was observed in biofilms produced both in the microplates (p < 0.05) and on the caries-like affected dentin discs (81.01% or mean reduction of log(2) 1.010 +/- 0.1548; p = 0.0029). The cell viability of aPDT and control group was similar (p > 0.05). Conclusions: aPDT may be considered a promise adjunctive therapy for deep carious lesions. (C) 2015 Elsevier B.V. All rights reserved. (AU)

• FAPESP's process: 12/16552-0 - Effects of low level laser therapy associated to a BMP4 incorporated scaffold on dental pulp stem-cells differentiation and migration. An in vitro study.
• Grantee: Ivana Marcia Alves Diniz
• Support type: Scholarships in Brazil - Doctorate
• FAPESP's process: 13/03864-6 - Effects of low level laser phototherapy associated with scaffold with incorporation of BMP4 in adhesion, proliferation and differentiation of stem cells from human dental pulp: in vitro study
• Grantee: Marcia Martins Marques
• Support type: Regular Research Grants