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Sin JH, Walsh LJ, Ranjit E, George R. Water-soluble vitamin-E for enhancing fluorescence diagnosis in infected human dentine treated with NaOCl. Photodiagnosis Photodyn Ther 2024; 47:104208. [PMID: 38729231 DOI: 10.1016/j.pdpdt.2024.104208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2023] [Revised: 05/07/2024] [Accepted: 05/08/2024] [Indexed: 05/12/2024]
Abstract
INTRODUCTION Bacterial fluorescence methods are of interest in endodontics for informing endpoints for debridement. This study explored potential fluorescence quenching reversal effects of a water-soluble vitamin E conjugate (d-α-Tocopherol polyethylene glycol 1000 succinate, TPGS) when applied to polymicrobial biofilms grown on dentine that had been exposed to sodium hypochlorite (NaOCl) to cause quenching. METHOD Extracted human teeth were debrided, embedded in transparent acrylic resin and sectioned. After smear layer removal, tooth dentine sections were inoculated with a polymicrobial inoculum, and cultured for 7 days to create biofilms. Samples (n = 8 per group) were exposed to 1 % or 4 % NaOCl for 2 or 4 min, and then treated with TPGS. Bacterial fluorescence readings under laser excitation at 655 nm were assessed over 10 min using a calibrated DIAGNOdent device. All data were assessed for normality (Kolmogorov-Smirnov test) and analysed with ANOVA followed by Bonferroni post-hoc tests. RESULTS NaOCl at both concentrations quenched fluorescence readings of biofilms grown on dentine samples, with a maximal reduction of 40.4 % at 5 min after 4 % NaOCl. Treatment with TPGS gave faster recovery of fluorescence readings compared to the control at 5 and 10 min. CONCLUSION The water-soluble antioxidant TPGS partially reversed fluorescence quenching caused by NaOCl. This agent may have value clinically for reducing the time needed for fluorescence readings to recover when NaOCl is used as an irrigant. This will facilitate more accurate assessment of endpoints for canal debridement.
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Affiliation(s)
- Jonathan H Sin
- School of Medicine and Dentistry, Griffith University, Gold Coast, Queensland, Australia
| | - Laurence J Walsh
- School of Dentistry, The University of Queensland, Queensland, Australia
| | - Eliza Ranjit
- School of Medicine and Dentistry, Griffith University, Gold Coast, Queensland, Australia
| | - Roy George
- School of Medicine and Dentistry, Griffith University, Gold Coast, Queensland, Australia.
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Tsai AC, George R, Teoh YY, Walsh LJ. Laser-fluorescence assessment of sodium hypochlorite quenching reversal agents on human dentine. Photodiagnosis Photodyn Ther 2022; 38:102791. [PMID: 35245671 DOI: 10.1016/j.pdpdt.2022.102791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 01/20/2022] [Accepted: 02/28/2022] [Indexed: 10/19/2022]
Abstract
BACKGROUND Laser-fluorescence diagnostic technology for real-time clinical assessment of residual bacteria could help assist in determining the endpoints for root canal debridement. Sodium hypochlorite (NaOCl) can however quench fluorescence and lead to false low reading. This study aims to evaluate various antioxidant for their ability to recover quenched fluorescence in dentine treated with NaOCl. METHODS Human dentine fluorescence was measured using 655 nm laser at baseline and again after a 2 min application of 4% NaOCl. The putative recovery agents were then applied, and the fluorescence measured after 5, 10, 20, 30 and 60 min. Recovery from quenching was also assessed using laser confocal scanning microscopy (CLSM) with a bound tetracycline fluorophore using 488 nm excitation. RESULTS A 5 min application of vitamin E oil or buffered 2% lignocaine solution (1:80,000 adrenaline) was effective in regaining quenched fluorescence within the following 5 mins. Distilled water, sodium thiosulfate, unbuffered 2% lignocaine with 1:80000 adrenaline and phosphate buffered saline were less effective, and of equal performance. Ascorbic acid and butylated hydroxyanisole were not effective and had deleterious effects on the levels of dentine fluorescence. CLSM provided confirmation of recovery from quenched fluorescence using vitamin E oil. CONCLUSION Based on these findings, reversal agents should be employed when assessing the fluorescence of dentine that has been exposed to NaOCl or other quenching agents.
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Affiliation(s)
- Andy C Tsai
- School of Dentistry, The University of Queensland, Herston, Queensland, Australia
| | - Roy George
- School of Dentistry and Oral Health, Griffith University, Southport, Queensland, Australia.
| | - Yu-Yao Teoh
- School of Dentistry, The University of Queensland, Herston, Queensland, Australia
| | - Laurence J Walsh
- School of Dentistry, The University of Queensland, Herston, Queensland, Australia
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Tsai AC, George R, Walsh LJ. Evaluation of the effect of various endodontic irrigants and medicaments on dentine fluorescence. Photodiagnosis Photodyn Ther 2021; 37:102651. [PMID: 34838696 DOI: 10.1016/j.pdpdt.2021.102651] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Revised: 09/30/2021] [Accepted: 11/22/2021] [Indexed: 12/18/2022]
Abstract
This study examined the effect of various root canal irrigants and medicaments on dentin fluorescence elicited by 655 nm visible red laser light. To replicate clinical use, irrigants were applied onto dentin samples for 2 min, while medicaments were applied for 2 weeks. Fluorescence values tracked from baseline across the following to 24 h, starting 5 min after exposure. Sodium hypochlorite, hydrogen peroxide, and articaine local anaesthetic (4% articaine with 1:1000,000 adrenaline) all significantly quenched fluorescence (p < 0.0001), which then returned to baseline levels after 20 min. Conversely, elevated fluorescence readings were recorded after 3% mepivacaine (p < 0.05), 0.2% chlorhexidine (p < 0.01) and chloroform (p <0.05). A 2 week application of Ledermix™ paste containing 3% demeclocycline caused an irreversible increase in fluorescence (p < 0.0001). Other tested endodontic materials (15% EDTA, eucalyptus oil, calcium hydroxide, Odontopaste™ clindamycin paste, and distilled water) had no impact on dentine fluorescence. The influences of endodontic materials on dentin fluorescence need to considered when using fluorescence endpoints to guide the progress of root canal treatment.
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Affiliation(s)
- Andy C Tsai
- School of Dentistry, University of Queensland, Herston, QLD, Australia
| | - Roy George
- School of Medcine and Dentistry, Griffith University, Southport, Queensland, Australia.
| | - Laurence J Walsh
- School of Dentistry, University of Queensland, Herston, QLD, Australia.
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Fluorescence characteristics of E. faecalis in dentine following treatment with oxidizing endodontic irrigants. Photodiagnosis Photodyn Ther 2021; 35:102344. [PMID: 34033937 DOI: 10.1016/j.pdpdt.2021.102344] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 04/08/2021] [Accepted: 05/17/2021] [Indexed: 11/21/2022]
Abstract
INTRODUCTION This study aimed to assess changes in the fluorescence characteristics of Enterococcus faecalis in human dentine over a period of 24 h following treatment with endodontic irrigants. METHOD Sterilised, non-functional extracted third molars were embedded in acrylic resin and uniformly sectioned into 2 mm thick dentine sections. After the removal of smear layer, the dentine sections were inoculated with E. faecalis and cultured for 7 days. The infected dentine sections were subsequently treated with different concentrations of sodium hypochlorite (NaOCl) and hydrogen peroxide (H2O2). Bacterial fluorescence readings were assessed at different time points using a calibrated laser device. All data were assessed for normality (Kolmogorov Smirnoff test) and analysed using ANOVA with Bonferroni post-hoc tests. RESULTS Fluorescence readings were quenched when E. faecalis infected human dentine sections were treated with oxidizing irrigants in vitro. Throughout a 24-hour period, fluorescence recovered in part but did not return to baseline level. CONCLUSION The fluorescence quenching effect of these oxidizing agents needs to be considered when using laser fluorescence in assessing the quality of root canal debridement or disinfection.
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Sin JHM, Hamlet S, Walsh LJ, Love RM, George R. Oxidising agents and its effect on human dentine fluorescence diagnostic measurements. Photodiagnosis Photodyn Ther 2020; 31:101950. [DOI: 10.1016/j.pdpdt.2020.101950] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2020] [Revised: 07/16/2020] [Accepted: 08/03/2020] [Indexed: 11/28/2022]
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Novel Approaches to Detect and Treat Biofilms within the Root Canals of Teeth: A Review. Antibiotics (Basel) 2020; 9:antibiotics9030129. [PMID: 32244927 PMCID: PMC7148501 DOI: 10.3390/antibiotics9030129] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 03/11/2020] [Accepted: 03/19/2020] [Indexed: 01/31/2023] Open
Abstract
Biofilms located within the root canals of teeth are a unique and pressing concern in dentistry and in medical microbiology. These multispecies biofilms, which include fungi as well as bacteria, form in a protected site with low shear stress and low oxygen tension. Systemic antibiotics are of limited value because of the lack of blood flow of the site, and issues with innate and acquired resistance. Physical disruption using hand or rotary powered instruments does not reach all locations in the root canal system where biofilms are present. Alternative strategies including agitated irrigation fluids, continuous chelation, materials with highly alkaline pH, and antimicrobial nanoparticles are being explored to meet the challenge. Detection and quantification of biofilms using fluorescence-based optical methods could provide an indication of successful biofilm removal and an endpoint for physical and chemical treatments.
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Agusman Aris A, Maupa H, Muis M, Idrus Tabba M. Effects of government policy, quality of human resources and professional institutions on workforce competitiveness using welding technology as mediating variable. JOURNAL OF SCIENCE AND TECHNOLOGY POLICY MANAGEMENT 2019. [DOI: 10.1108/jstpm-12-2017-0068] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Purpose
This paper aims to examine and analyze the effects of government policy, quality of human resources and professional institutions on workforce competitiveness using welding technology variable as a mediating variable.
Design/methodology/approach
This study used quantitative research by using partial least square – structural equation modeling (PLS-SEM) to analyze the collected data.
Findings
Based on the results of the analysis, it was noted that there was a significant influence between government policy, quality of human resources and professional institutions on welding technology. The coefficients are characterized by a positive direct relationship, which means that the higher the quality of government policy and human resources professionals variables, the higher the value of the institute of welding technology.
Social implications
This study recommends that government should create policies that have benefits to competitiveness of Indonesian workforce. Implications from this study support government to use the model to determine and initiate policies in the field of welding as well as establish clear and standardized operating standards and recruitment process (government apparatus) that can accommodate the competitiveness of welding workers in Indonesia.
Originality/value
The originality of this paper is that the participatory approach was adopted in this study using PLS-SEM. In addition, this study was one of the first studies to carry out research at the BNSP office, BLK-Bandung-Jakarta, Makassar, B4T and dismiss the Ministry of Manpower and the Ministry of Industry in Jakarta, Indonesia, where there was no research in this location. Previous studies conducted research in various case studies.
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Dispersion of near-infrared laser energy through radicular dentine when using plain or conical tips. Lasers Med Sci 2017; 33:251-255. [PMID: 29063474 DOI: 10.1007/s10103-017-2352-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 10/02/2017] [Indexed: 10/18/2022]
Abstract
The aim of this study was to investigate the influence of tip design on patterns of laser energy dispersion through the dentine of tooth roots when using near-infrared diode lasers. Diode laser emissions of 810 or 940 nm were used in combination with optical fiber tips with either conventional plain ends or conical ends, to irradiate tooth roots of oval or round cross-sectional shapes. The lasers were operated in continuous wave mode at 0.5 W for 5 s with the distal end of the fiber tip placed in the apical or coronal third of the root canal at preset positions. Laser light exiting through the roots and apical foramen was imaged, and the extent of lateral spread calculated. There was a significant difference in infrared light exiting the root canal apex between plain and conical fiber tips for both laser wavelengths, with more forward transmission of laser energy through the apex for plain tips. For both laser wavelengths, there were no significant differences in emission patterns when the variable of canal shape was used and all other variables were kept the same (plain vs conical tip, tip position). To ensure optimal treatment effect and to prevent the risks of inadvertent laser effects on the adjacent periapical tissues, it is important to have a good understanding of laser transmission characteristics of the root canal and root dentine. Importantly, it is also essential to understand transmission characteristics of plain and conical fibers tips.
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Walsh LJ, George R. Activation of Alkaline Irrigation Fluids in Endodontics. MATERIALS 2017; 10:ma10101214. [PMID: 29065540 PMCID: PMC5667020 DOI: 10.3390/ma10101214] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 10/04/2017] [Accepted: 10/20/2017] [Indexed: 11/16/2022]
Abstract
In conventional endodontic treatment, alkaline solutions of sodium hypochlorite (NaOCl) and ethylenediaminetetraacetic acid (EDTA) are used in combination to disinfect the root canal system and to eliminate debris and smear layers. An important concept that has emerged over recent years is the use of active physical methods for agitating these fluids to improve their penetration within areas that are not reached by endodontic instruments and to accelerate the chemical actions of these alkaline fluids against planktonic microorganisms, biofilms, soft tissue remnants and smear layers. Ultrasonic agitation and more recently pulsed lasers have emerged as two promising methods for activating endodontic irrigation fluids. Ultrasonic agitation with piezoelectric devices employs a moving tip, while laser agitation uses a stationary tip. Both methods cause cavitation, followed by implosions and shear forces which assist with debridement. Fluid streaming further enhances the activity of the fluids. While agitation enhances performance of irrigants, extrusion of fluids from the root canal during activation is a hazard that must be controlled.
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Affiliation(s)
- Laurence J Walsh
- The University of Queensland School of Dentistry, Herston, Brisbane QLD 4006, Australia.
| | - Roy George
- Griffith University School of Dentistry and Oral Health, Southport QLD 4215, Australia.
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Herzog D, Hosny N, Niazi S, Koller G, Cook R, Foschi F, Watson T, Mannocci F, Festy F. Rapid Bacterial Detection during Endodontic Treatment. J Dent Res 2017; 96:626-632. [DOI: 10.1177/0022034517691723] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Bacteria present in the root canal (RC) space following an RC treatment (RCT) can lead to persistent infections, resulting in treatment failure and the need for reintervention or extraction. Currently, there are no standardized methods in use to clinically detect bacterial presence within RC spaces. The use of paper point sampling and fluorescence staining was shown to be a rapid method, able to detect residual bacteria following treatment. The study demonstrated that Calcein acetoxymethyl (AM) proved to be a suitable dye for detecting vital bacteria within mature endodontic biofilms, with an improved sensitivity over colony-forming unit counting in a stressed biofilm model. Furthermore, in a clinical trial with primary RCTs, 53 infected teeth were sampled in vivo, and increased detection of vital cells was found when compared with colony-forming unit counting, highlighting the sensitivity of the technique in detecting low cell numbers. By combining fluorescent staining and microspectroscopy with software-based spectral analysis, successful detection of vital cells from RCs was possible after 5 min of Calcein AM incubation. Application of this technology during RCT has the potential to reduce persistent infections through vital cell detection and additional treatment. Furthermore, this technique could be applied to antimicrobial research and disinfection control in clinical settings ( ClinicalTrials.gov NCT03055975).
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Affiliation(s)
- D.B. Herzog
- Tissue Engineering and Biophotonics, Dental Institute, King’s College London, London, UK
| | - N.A. Hosny
- Tissue Engineering and Biophotonics, Dental Institute, King’s College London, London, UK
| | - S.A. Niazi
- Department of Restorative Dentistry, Dental Institute, King’s College London, London, UK
| | - G. Koller
- Tissue Engineering and Biophotonics, Dental Institute, King’s College London, London, UK
| | - R.J. Cook
- Tissue Engineering and Biophotonics, Dental Institute, King’s College London, London, UK
| | - F. Foschi
- Department of Restorative Dentistry, Dental Institute, King’s College London, London, UK
| | - T.F. Watson
- Tissue Engineering and Biophotonics, Dental Institute, King’s College London, London, UK
| | - F. Mannocci
- Department of Restorative Dentistry, Dental Institute, King’s College London, London, UK
| | - F. Festy
- Tissue Engineering and Biophotonics, Dental Institute, King’s College London, London, UK
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Laser-induced agitation and cavitation from proprietary honeycomb tips for endodontic applications. Lasers Med Sci 2014; 30:1203-8. [PMID: 24647465 DOI: 10.1007/s10103-014-1539-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Accepted: 02/03/2014] [Indexed: 10/25/2022]
Abstract
Cavitation and agitation generated by lasers in fluid-filled root canals create fluid movement and shear stresses along the root canals walls, enhancing removal of the smear layer and biofilm. When used with sodium hypochlorite and EDTA, laser activation of aqueous fluids can increase the efficiency of debridement and disinfection of root canals. However, the use of forward-firing laser fibers with such solutions poses a risk of driving fluid past the root apex, which could cause postoperative complications. The purpose of this study was to evaluate the mechanism of fluid agitation caused by a novel honeycomb tip. Glass capillary tubes filled with distilled water were used to replicate single-tooth root canals. A 980 nm pulsed diode laser was used with 200 μm diameter plain tips, tube-etched conical tips, and honeycomb tips. To record fluid movements, the tubes were backlit and imaged using a digital camera attached to a microscope. The honeycomb tips generated agitation with fluid movement directed onto the walls, while both the conventional plain fibers and the conical tips created fluid movement largely in a forward direction. The use of honeycomb tips alters the pattern of fluid agitation, and this laterally directed effect might lower the risk of fluid extrusion beyond the apex.
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