Antimicrobial effect of photodynamic therapy in carious lesions in vivo, using culture and real-time PCR methods.

Abstract

BACKGROUND:

The aim of this study was to evaluate the antimicrobial effect of photodynamic therapy (PDT) in carious lesions in vivo by culture and real-time PCR methods.

METHODS:

Ten teeth with deep active carious lesions were selected and five portions of carious dentin were removed for each tooth. Two increments were used as control, to represent the superficial and deep dentin, respectively. Methylene blue at 100mg/L was placed in contact with the cavity for 5min, before being irradiated with a halogen light source for 1min. Then, after PDT, other three portions were removed. The samples were processed in laboratory and the number of viable cfu was obtained. The real-time PCR analyses were performed in two increments of carious dentin, removed before and after PDT. The Streptococcus mutans DNA was isolated from carious dentin samples and amplification and detection of DNA were performed with real-time PCR. The cavities were then restored with glass-ionomer cement.

RESULTS:

Using conventional culture methods, the results demonstrated that viable bacteria were significantly reduced in all of the agar plates following photosensitization. No difference was found between both groups regarding S. mutans DNA quantification by real-time PCR.

CONCLUSION:

Although PDT may not affect the number of S. mutans DNA copies immediately after the treatment, clear reduction of the number of cfu was found. Despite its promising use for eliminating bacteria in dental caries treatment, further studies are necessary to establish an effective clinical protocol for the PDT.

• Authors: Patricia Valente Araújo, Jeane de Fátima Correia-Silva, Ricardo Santiago Gomez, Maria de Lourdes de Andrade Massara, Maria Esperanza Cortes, Luiz Thadeu de Abreu Poletto
• Journal: Photodiagnosis and photodynamic therapy (Photodiagnosis Photodyn Ther) Vol. 12 Issue 3 Pg. 401-7 (Sep 2015) ISSN: 1873-1597 [Electronic] Netherlands
• PMID: 26093167 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2015 Elsevier B.V. All rights reserved.

Chemical References

• DNA, Bacterial
• Photosensitizing Agents
• Methylene Blue

Topics

• Child
• Child, Preschool
• DNA, Bacterial
• Dental Caries (drug therapy)
• Dentin
• Female
• Humans
• Male
• Methylene Blue (therapeutic use)
• Microbial Viability
• Photochemotherapy (methods)
• Photosensitizing Agents (therapeutic use)
• Real-Time Polymerase Chain Reaction
• Streptococcus mutans (drug effects)