Photodynamic Inactivation of Root Canal Bacteria by Light Activation through Human Dental Hard and Simulated Surrounding Tissue.

Cieplik, Fabian; Pummer, Andreas; Leibl, Christoph; Regensburger, Johannes; Schmalz, Gottfried Hans; Buchalla, Wolfgang; Hiller, Karl-Anton; Maisch, Tim (2016). Photodynamic Inactivation of Root Canal Bacteria by Light Activation through Human Dental Hard and Simulated Surrounding Tissue. Frontiers in Microbiology, 7, p. 929. Frontiers 10.3389/fmicb.2016.00929

[img]
Preview
Text
Photodynamic Inactivation of Root Canal Bacteria by Light Activation through Human Dental Hard and Simulated Surrounding Tissue.pdf - Published Version
Available under License Creative Commons: Attribution (CC-BY).

Download (1MB) | Preview

INTRODUCTION Photodynamic inactivation of bacteria (PIB) may be a supportive antimicrobial approach for use in endodontics, but sufficient activation of photosensitizers (PS) in root canals is a critical point. Therefore, aim of this study was to evaluate the ability of PS absorbing blue (TMPyP) or red light (Methylene Blue; MB) for light activation through human dental hard and simulated surrounding tissue to inactivate root canal bacteria. METHODS A tooth model was fabricated with a human premolar and two molars in an acrylic resin bloc simulating the optical properties of a porcine jaw. The distal root canal of the first molar was enlarged to insert a glass tube (external diameter 2 mm) containing PS and stationary-phase Enterococcus faecalis. Both PS (10 μM) were irradiated for 120 s with BlueV (20 mW/cm(2); λem = 400-460 nm) or PDT 1200L (37.8 mW/cm(2); λem = 570-680 nm; both: Waldmann Medizintechnik), respectively. Irradiation parameters ensured identical numbers of photons absorbed by each PS. Three setups were chosen: irradiating the glass pipette only (G), the glass pipette inside the single tooth without (GT) and with (GTM) simulated surrounding tissues. Colony forming units (CFU) were evaluated. Transmission measurements of the buccal halves of hemisected mandibular first molars were performed by means of a photospectrometer. RESULTS PIB with both PS led to reduction by ≥ 5 log10 of E. faecalis CFU for each setup. From transmission measurements, a threshold wavelength λth for allowing an amount of light transmission for sufficient activation of PS was determined to be 430 nm. CONCLUSION This study can be seen as proof of principle that light activation of given intra-canal PS from outside a tooth may be possible at wavelengths ≥ 430 nm, facilitating clinical application of PIB in endodontics.

Item Type:

Journal Article (Original Article)

Division/Institute:

04 Faculty of Medicine > School of Dental Medicine > Department of Preventive, Restorative and Pediatric Dentistry

UniBE Contributor:

Schmalz, Gottfried Hans

Subjects:

600 Technology > 610 Medicine & health

ISSN:

1664-302X

Publisher:

Frontiers

Language:

English

Submitter:

Eveline Carmen Schuler

Date Deposited:

22 Mar 2017 10:53

Last Modified:

02 Apr 2017 02:18

Publisher DOI:

10.3389/fmicb.2016.00929

PubMed ID:

27379059

Uncontrolled Keywords:

Enterococcus faecalis; endodontics; optical fiber; photodynamic; transmission

BORIS DOI:

10.7892/boris.93025

URI:

https://boris.unibe.ch/id/eprint/93025

Actions (login required)

Edit item Edit item
Provide Feedback