In vitro evaluation of methylene blue removal from root canal after Photodynamic Therapy

Karen Müller Ramalho*, Sandra Ribeiro Cunha, Eric Mayer-Santos, Carlos de Paula Eduardo, Patricia Moreira de Freitas, Ana Cecilia Correa Aranha, Cacio Moura-Netto

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)


In Endodontics, photosensitizers’ such as methylene blue and toluidine blue have been used in Photodynamic Therapy due to their positive results. However, they can stain the dentin from the root canal after Photodynamic Therapy (PDT). The present in vitro study aimed to evaluate different stain removal protocols from root canal after PDT using methylene blue (MB) dye. After mechanical preparation of the root canal of 40 uni-radicular human teeth, PDT was performed using 0,01% MB with parameters of 3 min of pre-irradiation and a diode laser irradiation emitting at 660 nm, 40 mW, 4 min, 9.6 J. After PDT, different protocols of MB removal were performed: Group 1 − control (0.9% saline solution); Group 2 − sodium hypochlorite (2.5% NaOCl); Group 3–17% ethylenediamine tetraacetic acid (EDTA); Group 4 − passive ultrasonic irrigation (PUI); The color of the dentin of the root canal was measured, before, immediately after the PDT and immediately after the cleaning using a spectrophotometer. The ΔE values found were statistically compared using the ANOVA and Tukey's tests (α=0.05). All the treatments lead to some cleaning of root canal after PDT, however, none of the treatments tested completely removed all staining caused by MB photosensitizer of the root canal. Among the treatments tested, PUI and Hypochlorite 2.5% promoted greater cleaning, with no statistically significant difference between them. In conclusion, within the protocols tested in the present study, no treatments were able to completely remove MB staining of the root canal after PDT.
Original languageEnglish
Pages (from-to)248-252
Number of pages5
JournalPhotodiagnosis and Photodynamic Therapy
Publication statusPublished - Dec 2017
Externally publishedYes


  • Endodontics
  • Methylene blue
  • Photodynamic therapy


Dive into the research topics of 'In vitro evaluation of methylene blue removal from root canal after Photodynamic Therapy'. Together they form a unique fingerprint.

Cite this