George, Saji; Kishen, Anil
Influence of photosensitizer solvent on the mechanisms of photoactivated killing of Enterococcus faecalis Journal Article
In: Photochemistry and Photobiology, vol. 84, no. 3, pp. 734 – 740, 2008, ISSN: 00318655, (Cited by: 58).
@article{George2008734,
title = {Influence of photosensitizer solvent on the mechanisms of photoactivated killing of Enterococcus faecalis},
author = {Saji George and Anil Kishen},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-42549139650&doi=10.1111%2fj.1751-1097.2007.00244.x&partnerID=40&md5=1c7f10ef8b53a75ee7d511322716c378},
doi = {10.1111/j.1751-1097.2007.00244.x},
issn = {00318655},
year = {2008},
date = {2008-01-01},
journal = {Photochemistry and Photobiology},
volume = {84},
number = {3},
pages = {734 – 740},
abstract = {This study evaluated the mechanisms involved and the influence of photosensitizer solvent in the killing of Enterococcus faecalis using photodynamic therapy (PDT). Enterococcus faecalis cells incubated with 100 μm methylene blue dissolved in water and in MIX (a mixture of glycerol:ethanol: water) were irradiated with 664 nm diode laser (63.69 J cm-2). The effect of PDT on the viability of bacteria, and the functional integrity of cell wall, chromosomal DNA and membrane proteins were analyzed. The bactericidal action of PDT was significantly higher when a MIX-based photosensitizer solvent was used (P < 0.001). Fluorimetric and fluorescence microscopy-based analysis showed the functional impairment of E. faecalis cell wall which was significantly higher when a MIX-based photosensitizer solvent was used (P < 0.001). PDT with MIX-based photosensitizer solvent showed extensive damage to chromosomal DNA. However, both PDT conditions showed similar trend in the degradation of membrane proteins, although cross-linked proteins were evident only in PDT conducted with MIX-based photosensitizer solvent. The findings from our study showed that PDT destroyed the functional integrity of cell wall, DNA and membrane proteins of E. faecalis. The degrees of damage on these targets were influenced by the photosensitizer solvent used during PDT. © 2008 The Authors.},
note = {Cited by: 58},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This study evaluated the mechanisms involved and the influence of photosensitizer solvent in the killing of Enterococcus faecalis using photodynamic therapy (PDT). Enterococcus faecalis cells incubated with 100 μm methylene blue dissolved in water and in MIX (a mixture of glycerol:ethanol: water) were irradiated with 664 nm diode laser (63.69 J cm-2). The effect of PDT on the viability of bacteria, and the functional integrity of cell wall, chromosomal DNA and membrane proteins were analyzed. The bactericidal action of PDT was significantly higher when a MIX-based photosensitizer solvent was used (P < 0.001). Fluorimetric and fluorescence microscopy-based analysis showed the functional impairment of E. faecalis cell wall which was significantly higher when a MIX-based photosensitizer solvent was used (P < 0.001). PDT with MIX-based photosensitizer solvent showed extensive damage to chromosomal DNA. However, both PDT conditions showed similar trend in the degradation of membrane proteins, although cross-linked proteins were evident only in PDT conducted with MIX-based photosensitizer solvent. The findings from our study showed that PDT destroyed the functional integrity of cell wall, DNA and membrane proteins of E. faecalis. The degrees of damage on these targets were influenced by the photosensitizer solvent used during PDT. © 2008 The Authors.
Kishen, Anil; Shi, Zhilong; Shrestha, Annie; Neoh, Koon Gee
An Investigation on the Antibacterial and Antibiofilm Efficacy of Cationic Nanoparticulates for Root Canal Disinfection Journal Article
In: Journal of Endodontics, vol. 34, no. 12, pp. 1515 – 1520, 2008, ISSN: 00992399, (Cited by: 235).
@article{Kishen20081515,
title = {An Investigation on the Antibacterial and Antibiofilm Efficacy of Cationic Nanoparticulates for Root Canal Disinfection},
author = {Anil Kishen and Zhilong Shi and Annie Shrestha and Koon Gee Neoh},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-56249084608&doi=10.1016%2fj.joen.2008.08.035&partnerID=40&md5=329d2af5ab4cb730d8fc47b3b78ea60d},
doi = {10.1016/j.joen.2008.08.035},
issn = {00992399},
year = {2008},
date = {2008-01-01},
journal = {Journal of Endodontics},
volume = {34},
number = {12},
pages = {1515 – 1520},
abstract = {This study aimed to investigate the antibacterial and antibiofilm efficacy of cationic nanoparticulates for root canal disinfection. Experiments were performed in two stages. In stage 1, experiments were conducted to examine the physical properties of three types of nanoparticulates. The antibacterial properties of nanoparticulates alone and nanoparticulates mixed with zinc oxide-eugenol-based sealer were studied. In stage 2, the ability of nanoparticulates-treated dentin to prevent bacterial adherence was examined. Zinc oxide nanoparticulates, chitosan nanoparticulates, a mixture of zinc oxide and chitosan nanoparticulates, and zinc oxide nanoparticulates with multilayered coating of chitosan were tested. This study showed that the incorporation of nanoparticulates did not alter the flow characteristics of sealer but improved the direct antibacterial property and the ability to leach out antibacterial components. There was a significant reduction in the adherence of Enterococcus faecalis to nanoparticulates-treated dentin (p < 0.05). These experiments highlighted the potential advantage of nanoparticulates in root canal disinfection. © 2008 American Association of Endodontists.},
note = {Cited by: 235},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This study aimed to investigate the antibacterial and antibiofilm efficacy of cationic nanoparticulates for root canal disinfection. Experiments were performed in two stages. In stage 1, experiments were conducted to examine the physical properties of three types of nanoparticulates. The antibacterial properties of nanoparticulates alone and nanoparticulates mixed with zinc oxide-eugenol-based sealer were studied. In stage 2, the ability of nanoparticulates-treated dentin to prevent bacterial adherence was examined. Zinc oxide nanoparticulates, chitosan nanoparticulates, a mixture of zinc oxide and chitosan nanoparticulates, and zinc oxide nanoparticulates with multilayered coating of chitosan were tested. This study showed that the incorporation of nanoparticulates did not alter the flow characteristics of sealer but improved the direct antibacterial property and the ability to leach out antibacterial components. There was a significant reduction in the adherence of Enterococcus faecalis to nanoparticulates-treated dentin (p < 0.05). These experiments highlighted the potential advantage of nanoparticulates in root canal disinfection. © 2008 American Association of Endodontists.
Xu, Zhang; Neoh, Koon Gee; Kishen, Anil
Monitoring acid-demineralization of human dentine by electrochemical impedance spectroscopy (EIS) Journal Article
In: Journal of Dentistry, vol. 36, no. 12, pp. 1005 – 1012, 2008, ISSN: 03005712, (Cited by: 33).
@article{Xu20081005,
title = {Monitoring acid-demineralization of human dentine by electrochemical impedance spectroscopy (EIS)},
author = {Zhang Xu and Koon Gee Neoh and Anil Kishen},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-55549127148&doi=10.1016%2fj.jdent.2008.08.007&partnerID=40&md5=9f331356ad50ad313c1db3d520fc7f6d},
doi = {10.1016/j.jdent.2008.08.007},
issn = {03005712},
year = {2008},
date = {2008-01-01},
journal = {Journal of Dentistry},
volume = {36},
number = {12},
pages = {1005 – 1012},
abstract = {Objective: The purpose of this study was to monitor in situ acid-induced demineralization of dentine by using electrochemical impedance spectroscopy (EIS) and correlate the EIS findings with changes in the chemical composition and ultrastructure of dentine. Method: EIS was used to monitor the process of demineralization of dentine induced by an acid model. Scanning electron microscopy (SEM) was used to examine the ultrastructure, while energy dispersive X-ray (EDX) and X-ray diffraction (XRD) analysis were employed to investigate the changes in the chemical composition of surface dentine with demineralization. Results: Two kinds of equivalent circuits that matched the histological structure of dentine were used to fit the EIS data. The parameters Rd, which is the resistance of the bulk of dentine layer and Rct, which is the charge transfer associated with the penetration of electrolyte into the dentinal tubules, decreased with increasing duration of demineralization. SEM images showed that the smear layer on the dentine and peritubular dentine disappeared with demineralization. The EDX results showed that the content of calcium and phosphorus decreased consistently with the decreasing content of HAP as shown by the XRD results. The findings from this study suggested that the changes in Rd and Rct determined by the EIS corresponded well with the variation in structure and composition of dentine. Conclusions: EIS could be employed to monitor structural and chemical compositional changes induced by acid-demineralization on dentine surface. © 2008 Elsevier Ltd. All rights reserved.},
note = {Cited by: 33},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Objective: The purpose of this study was to monitor in situ acid-induced demineralization of dentine by using electrochemical impedance spectroscopy (EIS) and correlate the EIS findings with changes in the chemical composition and ultrastructure of dentine. Method: EIS was used to monitor the process of demineralization of dentine induced by an acid model. Scanning electron microscopy (SEM) was used to examine the ultrastructure, while energy dispersive X-ray (EDX) and X-ray diffraction (XRD) analysis were employed to investigate the changes in the chemical composition of surface dentine with demineralization. Results: Two kinds of equivalent circuits that matched the histological structure of dentine were used to fit the EIS data. The parameters Rd, which is the resistance of the bulk of dentine layer and Rct, which is the charge transfer associated with the penetration of electrolyte into the dentinal tubules, decreased with increasing duration of demineralization. SEM images showed that the smear layer on the dentine and peritubular dentine disappeared with demineralization. The EDX results showed that the content of calcium and phosphorus decreased consistently with the decreasing content of HAP as shown by the XRD results. The findings from this study suggested that the changes in Rd and Rct determined by the EIS corresponded well with the variation in structure and composition of dentine. Conclusions: EIS could be employed to monitor structural and chemical compositional changes induced by acid-demineralization on dentine surface. © 2008 Elsevier Ltd. All rights reserved.
George, Saji; Kishen, Anil
Augmenting the Antibiofilm Efficacy of Advanced Noninvasive Light Activated Disinfection with Emulsified Oxidizer and Oxygen Carrier Journal Article
In: Journal of Endodontics, vol. 34, no. 9, pp. 1119 – 1123, 2008, ISSN: 00992399, (Cited by: 61).
@article{George20081119,
title = {Augmenting the Antibiofilm Efficacy of Advanced Noninvasive Light Activated Disinfection with Emulsified Oxidizer and Oxygen Carrier},
author = {Saji George and Anil Kishen},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-49349089404&doi=10.1016%2fj.joen.2008.06.019&partnerID=40&md5=ffcaf836370c00f19610e4d2508a5ea2},
doi = {10.1016/j.joen.2008.06.019},
issn = {00992399},
year = {2008},
date = {2008-01-01},
journal = {Journal of Endodontics},
volume = {34},
number = {9},
pages = {1119 – 1123},
abstract = {In this study, we tested the hypothesis that the inclusion of an oxidizer and oxygen carrier in the photosensitization formulation would facilitate comprehensive disinfection of matured endodontic biofilm by light-activated disinfection (LAD). Photosensitizing formulations containing methylene blue (MB) and an oxygen carrier alone (perfluorodecahydronaphthalene) (PF1) or in combination with oxidizer (H2O2) (PF2) or their emulsions formed with triton-X100 (Bio-Rad Laboratories, Hercules, CA) in different proportions (PF3 and PF4) were tested for photochemical properties and damage to the biofilm structure using confocal laser scanning microscopy. Conventional chemomechanical preparation, LAD using MB in water, and LAD using MB in emulsion (PF4) were also conducted on 10-week-old Enterococcus faecalis biofilm within root canals. MB in emulsion (PF4) was overall the most effective photosensitizer formulation for photooxidation, generation of singlet oxygen (p = 0.001), and in disinfecting biofilm bacteria. Advanced noninvasive LAD using a photosensitizer formulation containing oxidizer and oxygen carrier disrupted the biofilm matrix and facilitated comprehensive inactivation of biofilm bacteria. This modified photosensitizer formulation will have potential advantages in endodontic disinfection. © 2008 American Association of Endodontists.},
note = {Cited by: 61},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
In this study, we tested the hypothesis that the inclusion of an oxidizer and oxygen carrier in the photosensitization formulation would facilitate comprehensive disinfection of matured endodontic biofilm by light-activated disinfection (LAD). Photosensitizing formulations containing methylene blue (MB) and an oxygen carrier alone (perfluorodecahydronaphthalene) (PF1) or in combination with oxidizer (H2O2) (PF2) or their emulsions formed with triton-X100 (Bio-Rad Laboratories, Hercules, CA) in different proportions (PF3 and PF4) were tested for photochemical properties and damage to the biofilm structure using confocal laser scanning microscopy. Conventional chemomechanical preparation, LAD using MB in water, and LAD using MB in emulsion (PF4) were also conducted on 10-week-old Enterococcus faecalis biofilm within root canals. MB in emulsion (PF4) was overall the most effective photosensitizer formulation for photooxidation, generation of singlet oxygen (p = 0.001), and in disinfecting biofilm bacteria. Advanced noninvasive LAD using a photosensitizer formulation containing oxidizer and oxygen carrier disrupted the biofilm matrix and facilitated comprehensive inactivation of biofilm bacteria. This modified photosensitizer formulation will have potential advantages in endodontic disinfection. © 2008 American Association of Endodontists.
George, Saji; Kishen, Anil
In: Journal of Endodontics, vol. 33, no. 5, pp. 599 – 602, 2007, ISSN: 00992399, (Cited by: 71).
@article{George2007599,
title = {Advanced Noninvasive Light-activated Disinfection: Assessment of Cytotoxicity on Fibroblast Versus Antimicrobial Activity Against Enterococcus faecalis},
author = {Saji George and Anil Kishen},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-34147141451&doi=10.1016%2fj.joen.2007.01.018&partnerID=40&md5=26ff5798b7d03674f5f63fd7b85af612},
doi = {10.1016/j.joen.2007.01.018},
issn = {00992399},
year = {2007},
date = {2007-01-01},
journal = {Journal of Endodontics},
volume = {33},
number = {5},
pages = {599 – 602},
abstract = {Recent interest in light-activated disinfection demands insight on the selectivity towards bacterial cells compared with mammalian cells. This study was aimed to evaluate the cytotoxicity and selectivity of an advanced noninvasive light-activated disinfection (ANILAD) developed in our laboratory. The extent of cytotoxic effect of methylene blue activated by visible light of wavelength 664 nm was tested and compared with sodium hypochlorite (NaOCl) under in vitro and ex vivo conditions on fibroblast L929 cells. Simultaneous evaluation of cytotoxicity and antibacterial effect was also conducted to study the specificity of light-activated therapy (LAT) toward prokaryotic cells (Enterococcus faecalis). The cytotoxicity was evaluated by 3-(4, 5-dimethylthiazol-2- yl)-2, 5-diphenyltetrazolium bromide assay and trypan blue viability test, whereas colony-forming units were determined to evaluate bacterial viability. Data from both in vitro and ex vivo experiments showed that cytotoxicity was significantly less in LAT compared with NaOCl (p < 0.001). E faecalis cells were killed at a faster rate than fibroblasts. An irradiation dose producing 97.7% bacterial killing showed only 30% fibroblast dysfunction. This study indicated that ANILAD produced an insignificant effect on mammalian cells. © 2007 American Association of Endodontists.},
note = {Cited by: 71},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Recent interest in light-activated disinfection demands insight on the selectivity towards bacterial cells compared with mammalian cells. This study was aimed to evaluate the cytotoxicity and selectivity of an advanced noninvasive light-activated disinfection (ANILAD) developed in our laboratory. The extent of cytotoxic effect of methylene blue activated by visible light of wavelength 664 nm was tested and compared with sodium hypochlorite (NaOCl) under in vitro and ex vivo conditions on fibroblast L929 cells. Simultaneous evaluation of cytotoxicity and antibacterial effect was also conducted to study the specificity of light-activated therapy (LAT) toward prokaryotic cells (Enterococcus faecalis). The cytotoxicity was evaluated by 3-(4, 5-dimethylthiazol-2- yl)-2, 5-diphenyltetrazolium bromide assay and trypan blue viability test, whereas colony-forming units were determined to evaluate bacterial viability. Data from both in vitro and ex vivo experiments showed that cytotoxicity was significantly less in LAT compared with NaOCl (p < 0.001). E faecalis cells were killed at a faster rate than fibroblasts. An irradiation dose producing 97.7% bacterial killing showed only 30% fibroblast dysfunction. This study indicated that ANILAD produced an insignificant effect on mammalian cells. © 2007 American Association of Endodontists.
Kishen, A.; George, S.
Uptake of photosensitizers by bacteria is influenced by the presence of cations Conference
vol. 6535, 2007, ISSN: 16057422, (Cited by: 0; Conference name: Saratov Fall Meeting 2006: Optical Technologies in Biophysics and Medicine VIII; Conference date: 26 September 2006 through 29 September 2006; Conference code: 70487).
@conference{Kishen2007,
title = {Uptake of photosensitizers by bacteria is influenced by the presence of cations},
author = {A. Kishen and S. George},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-35648964611&doi=10.1117%2f12.740812&partnerID=40&md5=5350b952c15dadf5524260d76344163b},
doi = {10.1117/12.740812},
issn = {16057422},
year = {2007},
date = {2007-01-01},
journal = {Progress in Biomedical Optics and Imaging - Proceedings of SPIE},
volume = {6535},
abstract = {This investigation studies the influence of cations on photosensitizer uptake by Enterococcus faecalis (gram positive) and Actinobacillus actinomycetemcomitans (gram negative). Methods- The uptake of Methylene blue (MB) and Indocyanine Green (ICG), by bacteria were studied under the influence of divalent cations (CaCl2 & MgCl2) and EDTA. Further, E. faecalis cells subjected to trypsinisation and calcium channel blocker (verapamil) were also analysed for MB and ICG uptake inorder to understand the mechanism of photosensitizer uptake. Results- Uptake of ICG was enhanced in the presence of divalent cations in E. faecalis and A. actinomycetemcomitans. Treating cells with EDTA had no significant effect on the photosensitizer uptake, although the highest concentration tested showed an enhancement of uptake. In contrast to ICG, MB showed a decreased uptake by bacterial cells on subjecting them to divalent cations and EDTA. Calcium channel blocker had no significant inhibitory effect on photosensitizers uptake. However, trypsin treatment resulted in significant reduction of ICG uptake. The result suggested that ICG uptake by bacteria is mediated through specific transporter protein while MB is associated with the outer surface structures of bacterial cells.},
note = {Cited by: 0; Conference name: Saratov Fall Meeting 2006: Optical Technologies in Biophysics and Medicine VIII; Conference date: 26 September 2006 through 29 September 2006; Conference code: 70487},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
This investigation studies the influence of cations on photosensitizer uptake by Enterococcus faecalis (gram positive) and Actinobacillus actinomycetemcomitans (gram negative). Methods- The uptake of Methylene blue (MB) and Indocyanine Green (ICG), by bacteria were studied under the influence of divalent cations (CaCl2 & MgCl2) and EDTA. Further, E. faecalis cells subjected to trypsinisation and calcium channel blocker (verapamil) were also analysed for MB and ICG uptake inorder to understand the mechanism of photosensitizer uptake. Results- Uptake of ICG was enhanced in the presence of divalent cations in E. faecalis and A. actinomycetemcomitans. Treating cells with EDTA had no significant effect on the photosensitizer uptake, although the highest concentration tested showed an enhancement of uptake. In contrast to ICG, MB showed a decreased uptake by bacterial cells on subjecting them to divalent cations and EDTA. Calcium channel blocker had no significant inhibitory effect on photosensitizers uptake. However, trypsin treatment resulted in significant reduction of ICG uptake. The result suggested that ICG uptake by bacteria is mediated through specific transporter protein while MB is associated with the outer surface structures of bacterial cells.
Shrestha, A.; Tahir, R.; Kishen, A.
Optical sensor based system to monitor caries activity Conference
vol. 6633, 2007, ISSN: 16057422, (Cited by: 1; Conference name: Biophotonics 2007: Optics in Life Science; Conference date: 18 June 2007 through 20 June 2007; Conference code: 70608).
@conference{Shrestha2007,
title = {Optical sensor based system to monitor caries activity},
author = {A. Shrestha and R. Tahir and A. Kishen},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-36248973745&partnerID=40&md5=1ac1f87accd13f2377a19cc2e34f058b},
issn = {16057422},
year = {2007},
date = {2007-01-01},
journal = {Progress in Biomedical Optics and Imaging - Proceedings of SPIE},
volume = {6633},
abstract = {The aim of the study is to evaluate the ability of a visible light based spectroscopic sensor system to monitor caries activity in saliva. In this study an optical sensor is utilized to monitor the bacterial-mediated acidogenic profile of stimulated saliva using a photosensitive pH indicator. Microbiological assessment of the saliva samples were carried out using the conventional culture methods. In addition, the shifts in the pH of saliva-sucrose samples were recorded using a pH meter. The absorption spectra obtained from the optical sensor showed peak maxima at 595nm, which decreased as a function of time. The microbiological assessment showed increase in the bacterial count as a function of time. A strong positive correlation was also observed between the rates of decrease in the absorption intensity measured using the optical sensor and the decrease in pH measured using the pH meter. This study highlights the potential advantages of using the optical sensor as a sensitive and rapid chairside system for monitoring caries activity by quantification of the acidogenic profile of saliva. © 2007 SPIE-OSA.},
note = {Cited by: 1; Conference name: Biophotonics 2007: Optics in Life Science; Conference date: 18 June 2007 through 20 June 2007; Conference code: 70608},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
The aim of the study is to evaluate the ability of a visible light based spectroscopic sensor system to monitor caries activity in saliva. In this study an optical sensor is utilized to monitor the bacterial-mediated acidogenic profile of stimulated saliva using a photosensitive pH indicator. Microbiological assessment of the saliva samples were carried out using the conventional culture methods. In addition, the shifts in the pH of saliva-sucrose samples were recorded using a pH meter. The absorption spectra obtained from the optical sensor showed peak maxima at 595nm, which decreased as a function of time. The microbiological assessment showed increase in the bacterial count as a function of time. A strong positive correlation was also observed between the rates of decrease in the absorption intensity measured using the optical sensor and the decrease in pH measured using the pH meter. This study highlights the potential advantages of using the optical sensor as a sensitive and rapid chairside system for monitoring caries activity by quantification of the acidogenic profile of saliva. © 2007 SPIE-OSA.
George, Saji; Kishen, Anil
Photophysical, photochemical, and photobiological characterization of methylene blue formulations for light-activated root canal disinfection Journal Article
In: Journal of Biomedical Optics, vol. 12, no. 3, 2007, ISSN: 15602281, (Cited by: 111; All Open Access, Bronze Open Access).
@article{George2007,
title = {Photophysical, photochemical, and photobiological characterization of methylene blue formulations for light-activated root canal disinfection},
author = {Saji George and Anil Kishen},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-34547923122&doi=10.1117%2f1.2745982&partnerID=40&md5=947033aa4a74732647ebd627d94d8d2b},
doi = {10.1117/1.2745982},
issn = {15602281},
year = {2007},
date = {2007-01-01},
journal = {Journal of Biomedical Optics},
volume = {12},
number = {3},
abstract = {Tissue-specific modification of treatment strategy is proposed to increase the antimicrobial activity of light-activated therapy (LAT) for root canal disinfection. Methylene blue (MB) dissolved in different formulations: water, 70% glycerol, 70% poly ethylene glycol (PEG), and a mixture of glycerol:ethanol:water (30:20:50)(MIX),is analyzed for photophysical, photochemical, and photobiological characteristics. Aggregation of MB molecules, as evident from monomer to dimer ratio, depends on the molar concentrations of MB, which is significantly higher in water compared to other formulations. MIX-based MB formulation effectively penetrates the dentinal tubules. Although, the affinity of MB for Enterococcus faecalis (gram positive) and Actinomycetes actinomycetemcomitans (gram negative) was found to be high in the water-based formulation, followed by MIX, the MIX-based formulation significantly enhanced the model substrate photooxidation and singlet oxygen generation compared to MB dissolved in other formulations. Finally, the efficacy of LAT is evaluated on biofilms produced by both organisms under in vitro and ex vivo conditions. A dual-stage approach that applies a photosensitization medium and an irradiation medium separately is tested. The MIX-based photosensitization medium in combination with dual-stage approach demonstrates thorough disinfection of the root canal with bacterial biofilms. This method will have potential application for root canal disinfection. © 2007 Society of Photo-Optical Instrumentation Engineers.},
note = {Cited by: 111; All Open Access, Bronze Open Access},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Tissue-specific modification of treatment strategy is proposed to increase the antimicrobial activity of light-activated therapy (LAT) for root canal disinfection. Methylene blue (MB) dissolved in different formulations: water, 70% glycerol, 70% poly ethylene glycol (PEG), and a mixture of glycerol:ethanol:water (30:20:50)(MIX),is analyzed for photophysical, photochemical, and photobiological characteristics. Aggregation of MB molecules, as evident from monomer to dimer ratio, depends on the molar concentrations of MB, which is significantly higher in water compared to other formulations. MIX-based MB formulation effectively penetrates the dentinal tubules. Although, the affinity of MB for Enterococcus faecalis (gram positive) and Actinomycetes actinomycetemcomitans (gram negative) was found to be high in the water-based formulation, followed by MIX, the MIX-based formulation significantly enhanced the model substrate photooxidation and singlet oxygen generation compared to MB dissolved in other formulations. Finally, the efficacy of LAT is evaluated on biofilms produced by both organisms under in vitro and ex vivo conditions. A dual-stage approach that applies a photosensitization medium and an irradiation medium separately is tested. The MIX-based photosensitization medium in combination with dual-stage approach demonstrates thorough disinfection of the root canal with bacterial biofilms. This method will have potential application for root canal disinfection. © 2007 Society of Photo-Optical Instrumentation Engineers.
George, S.; Kishen, A.
Optimization of an advanced non-invasive light activated disinfection strategy Conference
Optical Society of America (OSA), 2007, ISSN: 21622701, (Cited by: 0; Conference name: European Conference on Biomedical Optics, ECBO 2007; Conference date: 17 June 2007 through 17 June 2007; Conference code: 104705).
@conference{George2007b,
title = {Optimization of an advanced non-invasive light activated disinfection strategy},
author = {S. George and A. Kishen},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85087598932&doi=10.1117%2f12.729439&partnerID=40&md5=3031b81cd6ce58fc5daaef93428f2f63},
doi = {10.1117/12.729439},
issn = {21622701},
year = {2007},
date = {2007-01-01},
journal = {Optics InfoBase Conference Papers},
publisher = {Optical Society of America (OSA)},
abstract = {A photosensitizer formulation and strategy was developed based on the photophysical, photochemical and photobiological characteristics of methylene blue (MB) for the disinfection of root canal using light activated therapy. Disinfection of matured E. faecalis biofilms on root canal dentine was tried with the newly developed 'Advanced Non- Invasive Light Activated Disinfection' (ANILAD), conventional photodynamic therapy, and conventional root canal therapy alone or in combination with ANILAD. The results showed that, although complete disinfection of nonmatured biofilm is possible by ANILAD alone, a combination of conventional root canal treatment (RCT) with ANILAD could achieve significantly higher bacterial killing (6log10-7log10 bacterial reduction) compared to any other tested treatment in matured biofilm (p<0.001). © 2007 SPIE-OSA.},
note = {Cited by: 0; Conference name: European Conference on Biomedical Optics, ECBO 2007; Conference date: 17 June 2007 through 17 June 2007; Conference code: 104705},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
A photosensitizer formulation and strategy was developed based on the photophysical, photochemical and photobiological characteristics of methylene blue (MB) for the disinfection of root canal using light activated therapy. Disinfection of matured E. faecalis biofilms on root canal dentine was tried with the newly developed 'Advanced Non- Invasive Light Activated Disinfection' (ANILAD), conventional photodynamic therapy, and conventional root canal therapy alone or in combination with ANILAD. The results showed that, although complete disinfection of nonmatured biofilm is possible by ANILAD alone, a combination of conventional root canal treatment (RCT) with ANILAD could achieve significantly higher bacterial killing (6log10-7log10 bacterial reduction) compared to any other tested treatment in matured biofilm (p<0.001). © 2007 SPIE-OSA.
Kishen, A.; Vedantam, S.
Hydromechanics in dentine: Role of dentinal tubules and hydrostatic pressure on mechanical stress-strain distribution Journal Article
In: Dental Materials, vol. 23, no. 10, pp. 1296 – 1306, 2007, ISSN: 01095641, (Cited by: 39).
@article{Kishen20071296,
title = {Hydromechanics in dentine: Role of dentinal tubules and hydrostatic pressure on mechanical stress-strain distribution},
author = {A. Kishen and S. Vedantam},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-34547686127&doi=10.1016%2fj.dental.2006.11.018&partnerID=40&md5=e3908fe5aea5da54e49df62e5ec69e2f},
doi = {10.1016/j.dental.2006.11.018},
issn = {01095641},
year = {2007},
date = {2007-01-01},
journal = {Dental Materials},
volume = {23},
number = {10},
pages = {1296 – 1306},
abstract = {Objectives: This investigation is to understand the role of free water in the dentinal tubules on the mechanical integrity of bulk dentine. Methods: Three different experiments were conducted in this study. In experiment 1, three-dimensional models of dentine with gradient elastic modulus, homogenous elastic modulus, and with and without hydrostatic pressure were simulated using the finite element method. Static compressive loads of 15, 50 and 100 N were applied and the distribution of the principal stresses, von Mises stresses, and strains in loading direction were determined. In experiment 2, experimental compression testing of fully hydrated and partially dehydrated dentine (21 °C for 72 h) was conducted using a Universal testing machine. In experiment 3, Fourier transform infrared spectroscopic analysis of hydrated and partially dehydrated dentine was carried out. Results: The finite element analysis revealed that the dentine model with simulated hydrostatic pressure displayed residual tensile stresses and strains in the inner region adjacent to the root canal. When external compressive loads were applied to the model, the residual stresses and strains counteracted the applied loads. Similarly the hydrated specimens subjected to experimental compression loads showed greater toughness when compared to the partially dehydrated specimens. The stress at fracture was significantly higher in partially dehydrated specimens (p = 0.014), while the strain at fracture was significantly higher in hydrated dentine specimens (p = 0.037). Significance: These experiments highlighted the distinct role of free water in the dentinal tubules and hydrostatic pressure on the stress-strain distribution within the bulk dentine. © 2006 Academy of Dental Materials.},
note = {Cited by: 39},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Objectives: This investigation is to understand the role of free water in the dentinal tubules on the mechanical integrity of bulk dentine. Methods: Three different experiments were conducted in this study. In experiment 1, three-dimensional models of dentine with gradient elastic modulus, homogenous elastic modulus, and with and without hydrostatic pressure were simulated using the finite element method. Static compressive loads of 15, 50 and 100 N were applied and the distribution of the principal stresses, von Mises stresses, and strains in loading direction were determined. In experiment 2, experimental compression testing of fully hydrated and partially dehydrated dentine (21 °C for 72 h) was conducted using a Universal testing machine. In experiment 3, Fourier transform infrared spectroscopic analysis of hydrated and partially dehydrated dentine was carried out. Results: The finite element analysis revealed that the dentine model with simulated hydrostatic pressure displayed residual tensile stresses and strains in the inner region adjacent to the root canal. When external compressive loads were applied to the model, the residual stresses and strains counteracted the applied loads. Similarly the hydrated specimens subjected to experimental compression loads showed greater toughness when compared to the partially dehydrated specimens. The stress at fracture was significantly higher in partially dehydrated specimens (p = 0.014), while the strain at fracture was significantly higher in hydrated dentine specimens (p = 0.037). Significance: These experiments highlighted the distinct role of free water in the dentinal tubules and hydrostatic pressure on the stress-strain distribution within the bulk dentine. © 2006 Academy of Dental Materials.
Shrestha, A.; Tahir, R.; Kishen, A.
Optical sensor based system to monitor caries activity Conference
Optical Society of America (OSA), 2007, ISSN: 21622701, (Cited by: 0; Conference name: European Conference on Biomedical Optics, ECBO 2007; Conference date: 17 June 2007 through 17 June 2007; Conference code: 104705).
@conference{Shrestha2007b,
title = {Optical sensor based system to monitor caries activity},
author = {A. Shrestha and R. Tahir and A. Kishen},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85085401410&doi=10.1117%2f12.729438&partnerID=40&md5=ba52190ff3efc8f6ac878a2a1d4428eb},
doi = {10.1117/12.729438},
issn = {21622701},
year = {2007},
date = {2007-01-01},
journal = {Optics InfoBase Conference Papers},
publisher = {Optical Society of America (OSA)},
abstract = {The aim of the study is to evaluate the ability of a visible light based spectroscopic sensor system to monitor caries activity in saliva. In this study an optical sensor is utilized to monitor the bacterial-mediated acidogenic profile of stimulated saliva using a photosensitive pH indicator. Microbiological assessment of the saliva samples were carried out using the conventional culture methods. In addition, the shifts in the pH of saliva-sucrose samples were recorded using a pH meter. The absorption spectra obtained from the optical sensor showed peak maxima at 595nm, which decreased as a function of time. The microbiological assessment showed increase in the bacterial count as a function of time. A strong positive correlation was also observed between the rates of decrease in the absorption intensity measured using the optical sensor and the decrease in pH measured using the pH meter. This study highlights the potential advantages of using the optical sensor as a sensitive and rapid chairside system for monitoring caries activity by quantification of the acidogenic profile of saliva. © 2007 SPIE-OSA.},
note = {Cited by: 0; Conference name: European Conference on Biomedical Optics, ECBO 2007; Conference date: 17 June 2007 through 17 June 2007; Conference code: 104705},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
The aim of the study is to evaluate the ability of a visible light based spectroscopic sensor system to monitor caries activity in saliva. In this study an optical sensor is utilized to monitor the bacterial-mediated acidogenic profile of stimulated saliva using a photosensitive pH indicator. Microbiological assessment of the saliva samples were carried out using the conventional culture methods. In addition, the shifts in the pH of saliva-sucrose samples were recorded using a pH meter. The absorption spectra obtained from the optical sensor showed peak maxima at 595nm, which decreased as a function of time. The microbiological assessment showed increase in the bacterial count as a function of time. A strong positive correlation was also observed between the rates of decrease in the absorption intensity measured using the optical sensor and the decrease in pH measured using the pH meter. This study highlights the potential advantages of using the optical sensor as a sensitive and rapid chairside system for monitoring caries activity by quantification of the acidogenic profile of saliva. © 2007 SPIE-OSA.
George, S.; Kishen, A.
Optimization of an advanced non-invasive light activated disinfection strategy Conference
vol. 6633, SPIE, 2007, ISSN: 16057422, (Cited by: 5; Conference name: Biophotonics 2007: Optics in Life Science; Conference date: 18 June 2007 through 20 June 2007; Conference code: 70608).
@conference{George2007c,
title = {Optimization of an advanced non-invasive light activated disinfection strategy},
author = {S. George and A. Kishen},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-36249008063&doi=10.1364%2fecbo.2007.6633_43&partnerID=40&md5=a959e8d106a0ebd962cd93aba4d88dbd},
doi = {10.1364/ecbo.2007.6633_43},
issn = {16057422},
year = {2007},
date = {2007-01-01},
journal = {Progress in Biomedical Optics and Imaging - Proceedings of SPIE},
volume = {6633},
publisher = {SPIE},
abstract = {A photosensitizer formulation and strategy was developed based on the photophysical, photochemical and photobiological characteristics of methylene blue (MB) for the disinfection of root canal using light activated therapy. Disinfection of matured E. faecalis biofilms on root canal dentine was tried with the newly developed 'Advanced Non-Invasive Light Activated Disinfection' (ANILAD), conventional photodynamic therapy, and conventional root canal therapy alone or in combination with AÑILAD. The results showed that , although complete disinfection of non-matured biofilm is possible by ANILAD alone, a combination of conventional root canal treatment (RCT) with ANILAD could achieve significantly higher bacterial killing (6log10-7log10 bacterial reduction) compared to any other tested treatment in matured biofilm (p<0.001). © 2007 SPIE-OSA.},
note = {Cited by: 5; Conference name: Biophotonics 2007: Optics in Life Science; Conference date: 18 June 2007 through 20 June 2007; Conference code: 70608},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
A photosensitizer formulation and strategy was developed based on the photophysical, photochemical and photobiological characteristics of methylene blue (MB) for the disinfection of root canal using light activated therapy. Disinfection of matured E. faecalis biofilms on root canal dentine was tried with the newly developed 'Advanced Non-Invasive Light Activated Disinfection' (ANILAD), conventional photodynamic therapy, and conventional root canal therapy alone or in combination with AÑILAD. The results showed that , although complete disinfection of non-matured biofilm is possible by ANILAD alone, a combination of conventional root canal treatment (RCT) with ANILAD could achieve significantly higher bacterial killing (6log10-7log10 bacterial reduction) compared to any other tested treatment in matured biofilm (p<0.001). © 2007 SPIE-OSA.
Sokolova, Tatiana N.; Surmenko, Elena L.; Tuchin, Valery V.; Kishen, A.; Chebotarevsky, Yu. V.
Spectroscopic study of demineralization and restoration processes in dental enamel Conference
vol. 6628, SPIE, 2007, ISSN: 16057422, (Cited by: 0; Conference name: Diagnostic Optical Spectroscopy in Biomedicine IV; Conference date: 19 June 2007 through 21 June 2007; Conference code: 70603).
@conference{Sokolova2007,
title = {Spectroscopic study of demineralization and restoration processes in dental enamel},
author = {Tatiana N. Sokolova and Elena L. Surmenko and Valery V. Tuchin and A. Kishen and Yu. V. Chebotarevsky},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-36249020948&doi=10.1117%2f12.729408&partnerID=40&md5=4a4b678de3fc0922b67bb5fd9d6cf785},
doi = {10.1117/12.729408},
issn = {16057422},
year = {2007},
date = {2007-01-01},
journal = {Progress in Biomedical Optics and Imaging - Proceedings of SPIE},
volume = {6628},
publisher = {SPIE},
abstract = {Saratov State Technical University, ERL LTT, 77, Politechnicheskaya st., 410054, Saratov, Russia The spectroscopic study of dental enamel by LIBS (laser induced breakdown spectroscopy), FTIR (Fourier transform infrared) and XRD (X-ray diffraction) are represented. The changes of enamel structure and composition in process of natural (caries) and artificial demineralization and restoration were studied. In comparison of sound and carious enamel LIBS showed a decrease of the content of Ca, P and change of the content of some other macro-and trace elements (Mn, Na, Fe, Zn etc). The character of the elemental composition variation was stipulated by the concrete disease. Analysis of FTIR and XRD spectra of dental samples, subjected to artificial demineralization and restoration, showed that restoration action reveals slower, than demineralization. And in some cases the damage of crystals after restoration is more significant than after demineralization. © 2007 SPIE-OSA.},
note = {Cited by: 0; Conference name: Diagnostic Optical Spectroscopy in Biomedicine IV; Conference date: 19 June 2007 through 21 June 2007; Conference code: 70603},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Saratov State Technical University, ERL LTT, 77, Politechnicheskaya st., 410054, Saratov, Russia The spectroscopic study of dental enamel by LIBS (laser induced breakdown spectroscopy), FTIR (Fourier transform infrared) and XRD (X-ray diffraction) are represented. The changes of enamel structure and composition in process of natural (caries) and artificial demineralization and restoration were studied. In comparison of sound and carious enamel LIBS showed a decrease of the content of Ca, P and change of the content of some other macro-and trace elements (Mn, Na, Fe, Zn etc). The character of the elemental composition variation was stipulated by the concrete disease. Analysis of FTIR and XRD spectra of dental samples, subjected to artificial demineralization and restoration, showed that restoration action reveals slower, than demineralization. And in some cases the damage of crystals after restoration is more significant than after demineralization. © 2007 SPIE-OSA.
George, Saji; Kishen, Anil
Effect of Tissue Fluids on Hydrophobicity and Adherence of Enterococcus faecalis to Dentin Journal Article
In: Journal of Endodontics, vol. 33, no. 12, pp. 1421 – 1425, 2007, ISSN: 00992399, (Cited by: 29).
@article{George20071421,
title = {Effect of Tissue Fluids on Hydrophobicity and Adherence of Enterococcus faecalis to Dentin},
author = {Saji George and Anil Kishen},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-36248938654&doi=10.1016%2fj.joen.2007.07.035&partnerID=40&md5=83327fa783b5818c2ea5d0d80a088c0f},
doi = {10.1016/j.joen.2007.07.035},
issn = {00992399},
year = {2007},
date = {2007-01-01},
journal = {Journal of Endodontics},
volume = {33},
number = {12},
pages = {1421 – 1425},
abstract = {This in vitro study was carried out to determine (1) the hydrophobicity of selected oral bacteria, (2) the influence of growth media (saliva and serum) and mode of growth (planktonic or biofilm) on the hydrophobicity of Enterococcus faecalis, and (3) the influence of growth media and conditioning fluids on the adherence of E. faecalis to dentin. The ability to bind to a hydrocarbon phase (xylene) was used as an index of relative hydrophobicity of cells. Fluorescent microscopy-based technique was used to assay the bacterial adherence to dentin. Results showed that bacteria involved in the primary stage of oral biofilm formation such as Streptococcus mutans, Fusobacterium nucleatum, and Porphyromonas gingivalis are relatively more hydrophobic than E. faecalis. The hydrophobicity of E. faecalis was significantly increased during starvation and biofilm mode of growth (p < .05). The adherence of E. faecalis to dentin was appreciably increased after starvation and when dentin was conditioned with saliva. It was observed that surface conditioning of dentin with saliva and starvation can enhance the adherence of E. faecalis to dentin. The findings from this study indicated that the coronal leakage of saliva and the physiologic state of microbes might play an important role in the adherence and biofilm formation of bacteria to root canal dentin. © 2007 American Association of Endodontists.},
note = {Cited by: 29},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
This in vitro study was carried out to determine (1) the hydrophobicity of selected oral bacteria, (2) the influence of growth media (saliva and serum) and mode of growth (planktonic or biofilm) on the hydrophobicity of Enterococcus faecalis, and (3) the influence of growth media and conditioning fluids on the adherence of E. faecalis to dentin. The ability to bind to a hydrocarbon phase (xylene) was used as an index of relative hydrophobicity of cells. Fluorescent microscopy-based technique was used to assay the bacterial adherence to dentin. Results showed that bacteria involved in the primary stage of oral biofilm formation such as Streptococcus mutans, Fusobacterium nucleatum, and Porphyromonas gingivalis are relatively more hydrophobic than E. faecalis. The hydrophobicity of E. faecalis was significantly increased during starvation and biofilm mode of growth (p < .05). The adherence of E. faecalis to dentin was appreciably increased after starvation and when dentin was conditioned with saliva. It was observed that surface conditioning of dentin with saliva and starvation can enhance the adherence of E. faecalis to dentin. The findings from this study indicated that the coronal leakage of saliva and the physiologic state of microbes might play an important role in the adherence and biofilm formation of bacteria to root canal dentin. © 2007 American Association of Endodontists.
Sum, CheePeng; Mohanty, Samarendra; Gupta, P. K.; Kishen, Anil
vol. 6425, 2007, ISSN: 16057422, (Cited by: 0; Conference name: Lasers in Dentistry XIII; Conference date: 21 January 2007 through 22 January 2007; Conference code: 70150).
@conference{Sum2007,
title = {Laser scanning confocal microscopy and laser tweezers based experiments to understand dentine-bacteria interactions},
author = {CheePeng Sum and Samarendra Mohanty and P. K. Gupta and Anil Kishen},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-34548220077&doi=10.1117%2f12.701784&partnerID=40&md5=a513a0a33c5ad090077114acedf2a592},
doi = {10.1117/12.701784},
issn = {16057422},
year = {2007},
date = {2007-01-01},
journal = {Progress in Biomedical Optics and Imaging - Proceedings of SPIE},
volume = {6425},
abstract = {Failure of endodontic treatment is commonly due to Enterococcal infection. In this study influence of chemical treatments of type-I collagen membrane by chemical agents commonly used in endodontic treatment on Enterococcus faecalis cell adherence was evaluated. In order to determine the change in number of adhering bacteria after chemical treatment, confocal laser scanning microscopy was used. For this, overnight culture of E faecalis in All Culture broth was applied to chemically treated type-I collagen membrane. It was found that Ca(OH)2 treated groups had statistically significant (p value=0.05) increase in population of bacteria adherence. The change in adhesion force between bacteria and collagen was determined by using optical tweezers (1064 nm). For this experiment, Type-I collagen membrane was soaked for 5 mins in a media that contained 50% all culture media and 50% saturated Ca(OH)2. The membrane was spread on the coverslip, on which diluted bacterial suspension was added. The force of laser tweezers on the bacteria was estimated at different trap power levels using viscous drag method and trapping stiffness was calculated using Equipartition theorem method. Presence of Ca(OH)2 was found to increase the cell-substrate adherence force from 0.38pN to >2.1pN. Together, these experiments show that it was highly probable that the increase in adherence to collagen was due to a stronger adhesion in the presence of Ca (OH)2.},
note = {Cited by: 0; Conference name: Lasers in Dentistry XIII; Conference date: 21 January 2007 through 22 January 2007; Conference code: 70150},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
Failure of endodontic treatment is commonly due to Enterococcal infection. In this study influence of chemical treatments of type-I collagen membrane by chemical agents commonly used in endodontic treatment on Enterococcus faecalis cell adherence was evaluated. In order to determine the change in number of adhering bacteria after chemical treatment, confocal laser scanning microscopy was used. For this, overnight culture of E faecalis in All Culture broth was applied to chemically treated type-I collagen membrane. It was found that Ca(OH)2 treated groups had statistically significant (p value=0.05) increase in population of bacteria adherence. The change in adhesion force between bacteria and collagen was determined by using optical tweezers (1064 nm). For this experiment, Type-I collagen membrane was soaked for 5 mins in a media that contained 50% all culture media and 50% saturated Ca(OH)2. The membrane was spread on the coverslip, on which diluted bacterial suspension was added. The force of laser tweezers on the bacteria was estimated at different trap power levels using viscous drag method and trapping stiffness was calculated using Equipartition theorem method. Presence of Ca(OH)2 was found to increase the cell-substrate adherence force from 0.38pN to >2.1pN. Together, these experiments show that it was highly probable that the increase in adherence to collagen was due to a stronger adhesion in the presence of Ca (OH)2.
Sokolova, Tatiana N.; Surmenko, Elena L.; Tuchin, Valery V.; Kishen, A.; Chebotarevsky, Y. V.
Spectroscopic study of demineralization and restoration processes in dental enamel Conference
Optical Society of America (OSA), 2007, ISSN: 21622701, (Cited by: 0; Conference name: European Conference on Biomedical Optics, ECBO 2007; Conference date: 17 June 2007 through 17 June 2007; Conference code: 104705).
@conference{Sokolova2007b,
title = {Spectroscopic study of demineralization and restoration processes in dental enamel},
author = {Tatiana N. Sokolova and Elena L. Surmenko and Valery V. Tuchin and A. Kishen and Y. V. Chebotarevsky},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-84898790303&partnerID=40&md5=28a8734a2d21da24bce4d6849d03e9eb},
issn = {21622701},
year = {2007},
date = {2007-01-01},
journal = {Optics InfoBase Conference Papers},
publisher = {Optical Society of America (OSA)},
abstract = {The spectroscopic study of dental enamel by LIBS (laser induced breakdown spectroscopy), FTIR (Fourier transform infrared) and XRD (X-ray diffraction) are represented. The changes of enamel structure and composition in process of natural (caries) and artificial demineralization and restoration were studied. In comparison of sound and carious enamel LIBS showed a decrease of the content of Ca, P and change of the content of some other macro-and trace elements (Mn, Na, Fe, Zn etc). The character of the elemental composition variation was stipulated by the concrete disease. Analysis of FTIR and XRD spectra of dental samples, subjected to artificial demineralization and restoration, showed that restoration action reveals slower, than demineralization. And in some cases the damage of crystals after restoration is more significant than after demineralization. © 2007 SPIE-OSA.},
note = {Cited by: 0; Conference name: European Conference on Biomedical Optics, ECBO 2007; Conference date: 17 June 2007 through 17 June 2007; Conference code: 104705},
keywords = {},
pubstate = {published},
tppubtype = {conference}
}
The spectroscopic study of dental enamel by LIBS (laser induced breakdown spectroscopy), FTIR (Fourier transform infrared) and XRD (X-ray diffraction) are represented. The changes of enamel structure and composition in process of natural (caries) and artificial demineralization and restoration were studied. In comparison of sound and carious enamel LIBS showed a decrease of the content of Ca, P and change of the content of some other macro-and trace elements (Mn, Na, Fe, Zn etc). The character of the elemental composition variation was stipulated by the concrete disease. Analysis of FTIR and XRD spectra of dental samples, subjected to artificial demineralization and restoration, showed that restoration action reveals slower, than demineralization. And in some cases the damage of crystals after restoration is more significant than after demineralization. © 2007 SPIE-OSA.
Kishen, Anil; Asundi, Anand
Fundamentals and Applications of Biophotonics in Dentistry Book
World Scientific Publishing Co., 2006, ISBN: 978-186094883-1; 1860947042, (Cited by: 3).
@book{Kishen20061,
title = {Fundamentals and Applications of Biophotonics in Dentistry},
author = {Anil Kishen and Anand Asundi},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85136345107&doi=10.1142%2fp474&partnerID=40&md5=78d6ec98abb450b5ef9d6aaa40df8077},
doi = {10.1142/p474},
isbn = {978-186094883-1; 1860947042},
year = {2006},
date = {2006-01-01},
journal = {Fundamentals and Applications of Biophotonics in Dentistry},
pages = {1 – 328},
publisher = {World Scientific Publishing Co.},
abstract = {Biophotonics in dentistry is a rapidly growing area. Unlike other books, this invaluable compendium touches on the fundamental areas in biophotonics. Contributed by world-renowned authors, it provides a basic understanding on a range of topics for individuals of different backgrounds to acquire a minimum knowledge of research and development in biophotonics. The chapters are arranged in two major categories. The first describes the fundamental aspects of photonics, such as photomechanics, biomedical imaging, lasers and laser-tissue interaction, spectroscopy and photodynamic therapy. The second details the applications of biophotonics, with special relevance to dentistry, including dental photobiomechanics, Raman spectroscopy and dental tissue optics. © 2007 by Imperial College Press.},
note = {Cited by: 3},
keywords = {},
pubstate = {published},
tppubtype = {book}
}
Biophotonics in dentistry is a rapidly growing area. Unlike other books, this invaluable compendium touches on the fundamental areas in biophotonics. Contributed by world-renowned authors, it provides a basic understanding on a range of topics for individuals of different backgrounds to acquire a minimum knowledge of research and development in biophotonics. The chapters are arranged in two major categories. The first describes the fundamental aspects of photonics, such as photomechanics, biomedical imaging, lasers and laser-tissue interaction, spectroscopy and photodynamic therapy. The second details the applications of biophotonics, with special relevance to dentistry, including dental photobiomechanics, Raman spectroscopy and dental tissue optics. © 2007 by Imperial College Press.
Kishen, Anil; Asundi, Anand
PREFACE Book
World Scientific Publishing Co., 2006, ISBN: 978-186094883-1; 1860947042, (Cited by: 0).
@book{Kishen2006v,
title = {PREFACE},
author = {Anil Kishen and Anand Asundi},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-85136377116&partnerID=40&md5=a5218183c5b158aef13683ac98a8ce0c},
isbn = {978-186094883-1; 1860947042},
year = {2006},
date = {2006-01-01},
journal = {Fundamentals and Applications of Biophotonics in Dentistry},
pages = {v – vi},
publisher = {World Scientific Publishing Co.},
note = {Cited by: 0},
keywords = {},
pubstate = {published},
tppubtype = {book}
}
Kishen, A.; George, S.; Kumar, R.
Enterococcus faecalis-mediated biomineralized biofilm formation on root canal dentine in vitro Journal Article
In: Journal of Biomedical Materials Research - Part A, vol. 77, no. 2, pp. 406 – 415, 2006, ISSN: 15524965, (Cited by: 135).
@article{Kishen2006406,
title = {Enterococcus faecalis-mediated biomineralized biofilm formation on root canal dentine in vitro},
author = {A. Kishen and S. George and R. Kumar},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-33749065319&doi=10.1002%2fjbm.a.30622&partnerID=40&md5=4e54c7698df9ecc0c0789759d9683da8},
doi = {10.1002/jbm.a.30622},
issn = {15524965},
year = {2006},
date = {2006-01-01},
journal = {Journal of Biomedical Materials Research - Part A},
volume = {77},
number = {2},
pages = {406 – 415},
abstract = {Enterococcus faecalis is the most predominant bacteria in teeth with failed root canal therapy and is found to survive harsh conditions prevailing in the root canals of endodontically treated teeth. This study aims to investigate the interaction between E. faecalis and root canal dentine substrate. Towards this end, tooth specimens were prepared and divided into two groups. The tooth specimens in group 1 were incubated with E. faecalis for periods of 2-, 4-, and 6-week intervals and the chemical composition of the biofilm was determined using X-ray diffraction and Fourier transform infrared (FTIR) spectroscopy. The tooth specimens in group 2 were incubated with E. faecalis for a period of 6 weeks and the topography and ultrastructure of the biofilm were examined using scanning electron microscopy (SEM), light microscopy, and laser confocal scanning microscopy. The sediments formed from the bacterial interaction on the dentine (in group 1) were also examined by SEM and FTIR. These experiments highlighted different stages in the interaction of E. faecalis with root canal dentine. Further, a bacterial-induced apatite reprecipitation on mature biofilm was also observed. This ability of E. faecalis to form such calcified biofilm on root canal dentine may be a factor that contributes to their persistence after endodontic treatment. © 2006 Wiley Periodicals, Inc.},
note = {Cited by: 135},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Enterococcus faecalis is the most predominant bacteria in teeth with failed root canal therapy and is found to survive harsh conditions prevailing in the root canals of endodontically treated teeth. This study aims to investigate the interaction between E. faecalis and root canal dentine substrate. Towards this end, tooth specimens were prepared and divided into two groups. The tooth specimens in group 1 were incubated with E. faecalis for periods of 2-, 4-, and 6-week intervals and the chemical composition of the biofilm was determined using X-ray diffraction and Fourier transform infrared (FTIR) spectroscopy. The tooth specimens in group 2 were incubated with E. faecalis for a period of 6 weeks and the topography and ultrastructure of the biofilm were examined using scanning electron microscopy (SEM), light microscopy, and laser confocal scanning microscopy. The sediments formed from the bacterial interaction on the dentine (in group 1) were also examined by SEM and FTIR. These experiments highlighted different stages in the interaction of E. faecalis with root canal dentine. Further, a bacterial-induced apatite reprecipitation on mature biofilm was also observed. This ability of E. faecalis to form such calcified biofilm on root canal dentine may be a factor that contributes to their persistence after endodontic treatment. © 2006 Wiley Periodicals, Inc.
Kishen, Anil
FIBER OPTIC DIAGNOSTIC SENSORS Book
World Scientific Publishing Co., 2006, ISBN: 978-186094883-1; 1860947042, (Cited by: 1).
@book{Kishen2006301,
title = {FIBER OPTIC DIAGNOSTIC SENSORS},
author = {Anil Kishen},
url = {https://www.scopus.com/inward/record.uri?eid=2-s2.0-81855220409&doi=10.1142%2f9781860948831_0010&partnerID=40&md5=f57ecab2c39128f276c22b0c75c97b73},
doi = {10.1142/9781860948831_0010},
isbn = {978-186094883-1; 1860947042},
year = {2006},
date = {2006-01-01},
journal = {Fundamentals and Applications of Biophotonics in Dentistry},
pages = {301 – 327},
publisher = {World Scientific Publishing Co.},
abstract = {Fiber optic technology offers different advantages when applied for diagnosis in health care. This chapter provides an introduction to fiber optics and discusses different configurations and applications of fiber optic based, direct and indirect, diagnostic sensors. Relevant examples of fiber optic diagnostic sensors applied to dentistry are also presented. © 2007 by Imperial College Press.},
note = {Cited by: 1},
keywords = {},
pubstate = {published},
tppubtype = {book}
}
Fiber optic technology offers different advantages when applied for diagnosis in health care. This chapter provides an introduction to fiber optics and discusses different configurations and applications of fiber optic based, direct and indirect, diagnostic sensors. Relevant examples of fiber optic diagnostic sensors applied to dentistry are also presented. © 2007 by Imperial College Press.