Author(s): Zhang, LD (Zhang, Ludan); Li, YM (Li, Yamin); Zhang, Q (Zhang, Qian); Du, N (Du, Ning); Li, XF (Li, Xuefen); Zhang, QY (Zhang, Qianyi); Yuan, LT (Yuan, Lintian); Dong, F (Dong, Fan); Jiang, YX (Jiang, Yuxi); Tang, J (Tang, Jun); Wang, YG (Wang, Yuguang)

Source: PHOTOBIOMODULATION PHOTOMEDICINE AND LASER SURGERY Volume: 38 Issue: 11 Pages: 694-702 DOI: 10.1089/photob.2020.4821 Early Access Date: OCT 2020 Published: NOV 1 2020

Abstract: Objective: We developed an implantable wireless blue micro light-emitting diode (micro-LED) device and evaluated the utility of continuous antimicrobial blue light (aBL) irradiation emitted from this micro-LED for root canal disinfection.

Methods: An implantable wireless blue micro-LED device (peak wavelength: 410 nm, maximum power: 15 mW) was developed to be placed in the root canal. Optical transmission of the device in human dentin tissue was simulated using Monte Carlo ray-tracing method. The bactericidal effect of low-level aBL on planktonic root canal infection-related bacteria [Enterococcus faecalis, methicillin-resistant Streptococcus aureus (MRSA), and Prevotella intermedia] was evaluated by colony counting. The biocompatibility of continuous low-level aBL exposure was evaluated by infrared thermal imaging and cell viability tests. Thirty extracted intact human single-rooted teeth were prepared and the root canals were infected with E. faecalis for 14 days to form biofilm. The infected root canals were randomly divided into three groups (n = 10), and treated with normal saline (group NS), calcium hydroxide (group CH), and micro-LED device (group aBL) for 3 and 7 days. The bactericidal effect of each group was evaluated by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM).

Results: Monte Carlo simulation showed that blue light irradiation of the micro-LED device decreased exponentially with the light transmission distance through human dentin tissue. Planktonic E. faecalis, MRSA, and P. intermedia were significantly eliminated after irradiation with 432, 36, and 1.35 J/cm(2) aBL, respectively (p < 0.05). Infrared thermal imaging and cell viability tests showed that continuous aBL exposure is biocompatible in vitro. CLSM and SEM analyses revealed that the micro-LED device had a greater antimicrobial effect than CH on E. faecalis biofilm in the root canal.

Conclusions: The wireless blue micro-LED device is a promising and user-friendly approach for root canal disinfection that will facilitate infection control in the root canal using aBL.

Accession Number: WOS:000586366200001

PubMed ID: 33103954

eISSN: 2578-5478

Full Text: https://www.liebertpub.com/doi/10.1089/photob.2020.4821