Related Experiment Video
Updated: Feb 11, 2026

Oral Biofilm Analysis of Palatal Expanders by Fluorescence In-Situ Hybridization and Confocal Laser Scanning Microscopy
Published on: October 20, 2011
Bactericidal Effect of Various Laser Irradiation Systems on Enterococcus faecalis Biofilms in Dentinal Tubules: A
Xiaoli Wang1, Xiaogang Cheng1, Xin Liu1
1State Key Laboratory of Military Stomatology and National Clinical Research Center for Oral Diseases and Shaanxi Key Laboratory of Stomatology, Department of Operative Dentistry and Endodontics, School of Stomatology, The Fourth Military Medical University , Shaanxi, P.R. China .
Objective:
The aim of this study was to compare the bactericidal effect of various laser irradiation systems on Enterococcus faecalis biofilms in dentinal tubules by using a novel dentin infection model and confocal laser scanning microscopy (CLSM).
Background Data:
Laser-activated irrigations have been proposed as an adjuvant to conventional protocols of root canal treatment to enhance the smear layer removal, which is a promising protocol for root canal disinfection.
Materials And Methods:
E. faecalis were centrifuged into the dentinal tubules, cultured for 3 weeks, and then received 1- and 3-min treatments as follows: (A) 5.25% sodium hypochlorite (NaOCl) irrigation, (B) Nd:YAG laser irradiation, (C) diode laser irradiation, (D) Nd:YAP laser irradiation, (E) Er,Cr:YSGG laser-activated NaOCl irrigation, and (F) Er:YAG laser-activated NaOCl irrigation. Bacterial reductions were assessed by CLSM using a LIVE/DEAD® bacterial viability stain method.
Results:
For each group, the bacterial reduction increased as the treatment time increased (p < 0.05). The Er,Cr:YSGG and Er:YAG laser significantly enhanced the bactericidal effect of NaOCl (p < 0.05). Under the conditions of the same treatment time, bacterial reductions were presented in the descending order of Er:YAG + NaOCl, Er,Cr:YSGG + NaOCl > Nd:YAP > Nd:YAG, diode > NaOCl.
Conclusions:
Under the conditions of present study, treatments of Er:YAG + NaOCl and Er,Cr:YSGG + NaOCl presented the strongest bactericidal effect among the tested protocols and are potential protocols for root canal disinfection.
Related Concept Videos
Confocal Fluorescence Microscopy
Scanning Electron Microscopy
Fundamental Principles
Accelerated...
Matrix-Assisted Laser Desorption Ionization (MALDI)
Leaky Scanning
Renal Tubule and Collecting Duct
Proximal Convoluted Tubule (PCT):
The PCT is the initial segment of the renal tubule, extending from the Bowman's capsule that encloses the glomerulus. Its convoluted structure and microvilli-lined cells increase the surface area for reabsorption. The PCT reabsorbs glucose, amino acids, sodium, and water from the filtrate, ensuring essential...
Biofilms

