@article{Li2020,

title = {Microtissue Engineering Root Dentin with Photodynamically Cross-linked Nanoparticles Improves Fatigue Resistance of Endodontically Treated Teeth},

author = {Fang-Chi Li and Eric Nicholson and Chandra Veer Singh and Anil Kishen},

doi = {10.1016/j.joen.2020.01.021},

issn = {1878-3554},

year  = {2020},

date = {2020-01-01},

journal = {Journal of Endodontics},

volume = {46},

issue = {5},

pages = {668-674},

abstract = {INTRODUCTION: Microtissue engineering root canal dentin with biopolymeric nanoparticles has the potential to improve mechanical properties of iatrogenically compromised root dentin. This study aims to characterize the surface mechanical property, bulk biomechanical response, and fatigue resistance of microtissue-engineered root dentin using photodynamically (photodynamic-activated [PDA]) cross-linked chitosan nanoparticles (CSnps). METHODS: Experiments were conducted in 3 parts: part 1, root canal dentin sections were subjected to nanoindentations before/after treatment with CSnps and chemically (1-ethyl-3-[3-dimethylaminopropyl]carbodiimide [EDC] cross-linked CSnps) and photodynamically cross-linked CSnps to determine the properties of treated surfaces (n = 84 points/group); part 2, root canal dentin specimens treated with PDA cross-linked CSnps were subjected to strain analysis using customized moir\'{e} interferometry (n = 5/group); and part 3, root canal dentin specimens treated with EDC cross-linked CSnps, PDA cross-linked CSnps, and instrumented controls were tested using an accelerated fatigue loading protocol to evaluate the sustained loads and cycles at failure (n = 15/group). Data were analyzed using the paired sample t test, trend analysis, and Kaplan-Meier with log-rank tests at a significance of .05 in each experiment. 

RESULTS: Root dentin microtissue engineered with PDA cross-linked CSnps showed a 16.8% increase in elastic modulus and a conspicuous decrease in strain distribution in cervical root dentin (P .01). There was a significant reduction in the tensile strain formed at the apical region of the instrumented root dentin after treatment (P .05). Survival analysis showed a statistically significant difference (P .05) among evaluated conditions in fatigue resistance (ie, PDA cross-linked CSnps EDC cross-linked CSnps control). 

CONCLUSIONS: This study highlighted the potential of root canal dentin microtissue engineering with PDA cross-linked CSnps to diminish radicular strain distribution and improve resistance to fatigue loads in endodontically treated teeth.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Hussein2020,

title = {Antibiofilm and Immune Response of Engineered Bioactive Nanoparticles for Endodontic Disinfection},

author = {Hebatullah Hussein and Anil Kishen},

doi = {10.3390/jcm9030730},

issn = {2077-0383},

year  = {2020},

date = {2020-01-01},

journal = {Journal of Clinical Medicine},

volume = {9},

issue = {3},

pages = {E730},

abstract = {The biological aim of root canal treatment is to facilitate periapical tissue healing following endodontic therapy. This study aimed to develop an organotypic infected root canal model to understand the interaction of bacterial biofilm with macrophages and study the therapeutic effect of engineered bioactive chitosan nanoparticles (CSnp) on macrophages. Ex-vivo experiments were conducted in two phases; Phase-1: Enterococcus faecalis biofilms (two and six weeks old) developed in organotypic root canal model were used to characterize residual biofilm after conventional chemical treatment alone and combined with CSnp utilizing Confocal Laser Scanning Microscopy, Scanning Electron Microscopy and colony-forming units from pulverized dentin. Phase-2: The interaction of post-treatment biofilm and RAW macrophages was evaluated regarding pro/anti-inflammatory markers, cell viability and spreading at 24, 48 and 72 h. Compared to conventionally disinfected six-week-old biofilm, CSnp resulted in less viable bacteria (p 0.01). Scanning electron micrographs demonstrated disruption of the biofilm. CSnp exhibited less residual bacterial load in pulverized dentin (p 0.001). Macrophage interaction with CSnp-treated biofilm reduced proinflammatory markers (nitric oxide, TNF-α, IL-1β, and IL-6), increased anti-inflammatory marker (TGF-β1) and enhanced cell survival and spreading over time (p 0.01 at 72 h). Engineered chitosan nanoparticles concurrently inactivated biofilm and altered the inflammatory response of macrophages that would promote healing.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Azarpazhooh2020d,

title = {Insights into the April 2020 Issue of the Journal of Endodontics},

author = {Amir Azarpazhooh and Anibal R Diogenes and Ashraf F Fouad and Gerald N Glickman and Mo K Kang and Anil Kishen and Linda Levin and Robert S Roda and Christine M Sedgley and Franklin R Tay and Kenneth M Hargreaves},

doi = {10.1016/j.joen.2020.02.008},

issn = {1878-3554},

year  = {2020},

date = {2020-01-01},

journal = {Journal of Endodontics},

volume = {46},

issue = {4},

pages = {453-454},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Azarpazhooh2020e,

title = {Insights into the May 2020 Issue of the Journal of Endodontics},

author = {Amir Azarpazhooh and Anibal R Diogenes and Ashraf F Fouad and Gerald N Glickman and Anil Kishen and Linda Levin and Robert S Roda and Christine M Sedgley and Franklin R Tay and Kenneth M Hargreaves},

doi = {10.1016/j.joen.2020.03.023},

issn = {1878-3554},

year  = {2020},

date = {2020-01-01},

journal = {Journal of Endodontics},

volume = {46},

issue = {5},

pages = {561-562},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Ionescu2020,

title = {Electrokinetic transport and distribution of antibacterial nanoparticles for endodontic disinfection},

author = {A Ionescu and D Harris and P R Selvaganapathy and A Kishen},

doi = {10.1111/iej.13321},

issn = {1365-2591},

year  = {2020},

date = {2020-01-01},

journal = {International Endodontic Journal},

volume = {53},

issue = {8},

pages = {1120-1130},

abstract = {AIM: To assess a novel, noninvasive intervention capable of mobilizing charged antibacterial nanoparticles to the apical portions of the root canal system, utilizing the principles of electrokinetics. 

METHODS: Experiments were conducted in three stages. Stage-1: A computer model was generated to predict and visualize the electric field and current density distribution generated by the proposed intervention. Stage-2: Transport of chitosan nanoparticles (CSnp) was evaluated qualitatively using a transparent microfluidic model with fluorescent-labelled CSnp. Stage-3: An ex vivo model was utilized to study the antimicrobial efficacy of the proposed treatment against 3-week-old monospecies E. faecalis biofilms. Scanning electron microscopy (SEM) was also utilized in this stage to confirm the deposition of CSnp. 

RESULTS: The results of the computer simulations predicted an electric field and current density that reach their maxima at the apical constriction of the root canal. Correspondingly, the microfluidic experiments demonstrated rapid, controlled CSnp transport throughout the simulated root canal anatomy with subsequent distribution and deposition in the apical constriction as well as periapical regions. Infected root canals when subjected to the novel treatment method resulted in a mean bacterial reduction of 2.1 log CFU. SEM analysis revealed electrophoretic deposition of chitosan nanoparticles onto the root canal dentine walls in the apical region. 

CONCLUSION: The findings from this study demonstrate that the combination of cationic antibacterial nanoparticles with a low-intensity electric field results in particle transportation (electrophoresis) and deposition within the root canal. This results in a synergistic antibiofilm efficacy and has the potential to enhance root canal disinfection.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Xiong2020,

title = {Effect of Crosslinked Chitosan Nanoparticles on the Bonding Quality of Fiber Posts in Root Canals},

author = {Jie Xiong and Lipei Shen and Qingsong Jiang and Anil Kishen},

doi = {10.3290/j.jad.a44555},

issn = {1757-9988},

year  = {2020},

date = {2020-01-01},

journal = {The Journal of Adhesive Dentistry},

volume = {22},

issue = {3},

pages = {321-330},

abstract = {PURPOSE: To investigate the effects of root-canal dentin pretreatment with the crosslinker EDC combined with chitosan nanoparticles (Csnp) on the bonding quality of fiber posts in root canals in terms of bond strength, nanoleakage, quantification of collagen degradation, and degree of conversion (DC) of adhesive. 

MATERIALS AND METHODS: Forty-eight single-rooted teeth were prepared endodontically and etched using UNI-ETCH (Bisco) as per the adhesive procedure for fiber posts. They were randomly divided into three groups before adhesive (All-Bond 3) application, according to different pretreatments: a. immersed in 2.5% glutaraldehyde for 24 h; b. treated with Csnp solution under ultrasonic agitation for 60 s and immersed in EDC crosslinker for 24 h; c. without treatment (control). Bond strength, nanoleakage, DC within the interface, and collagen fiber degradation were evaluated. RESULTS: The pretreatments had a significant influence on the bonding stability of fiber posts in root canals, but not on the degree of conversion (p = 0.552). Enzymatic degradation significantly influenced bond strength for all groups (p = 0.001), with the greatest effect found in group c. The amount of amino acids released from the adhesive interface differed significantly between groups after hydrolysis and enzymatic degradation (p = 0.000); group c released the highest amount of amino acids. 

CONCLUSIONS: Csnp binding to dentin in combination with EDC reduced degradation of dentinal collagen and improved the stability of the adhesive interface without jeopardizing adhesive polymerization.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Azarpazhooh2020f,

title = {Insights into the June 2020 Issue of the JOE},

author = {Amir Azarpazhooh and Anibal R Diogenes and Ashraf F Fouad and Gerald N Glickman and Anil Kishen and Linda Levin and Robert S Roda and Christine M Sedgley and Franklin R Tay and Kenneth M Hargreaves},

doi = {10.1016/j.joen.2020.04.009},

issn = {1878-3554},

year  = {2020},

date = {2020-01-01},

journal = {Journal of Endodontics},

volume = {46},

issue = {6},

pages = {705-706},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Kishen2020,

title = {Bioactive molecule carrier systems in endodontics},

author = {Anil Kishen and Hebatullah Hussein},

doi = {10.1080/17425247.2020.1777981},

issn = {1744-7593},

year  = {2020},

date = {2020-01-01},

journal = {Expert Opinion on Drug Delivery},

volume = {17},

issue = {8},

pages = {1093-1112},

abstract = {INTRODUCTION: Bioactive molecule carrier systems (BACS) are biomaterial-based substrates that facilitate the delivery of active signaling molecules for different biologically based therapeutic applications, which include regenerative endodontic procedures. Tissue regeneration or organized repair in regenerative endodontic procedures is governed by the dynamic orchestration of interactions between stem/progenitor cells, bioactive molecules, and extracellular matrix. BACS aid in mimicking some of the complex physiological processes, overcoming some of the challenges faced in the clinical translation of regenerative endodontic procedures. 

AREAS COVERED: This narrative review addresses the role of BACS in stem/progenitor cell proliferation, migration, and differentiation with the application for dentin-pulp tissue engineering both in vitro and in vivo. BACS shield the bioactivity of the immobilized molecules against environmental factors, while its design allows the pre-programmed release of bioactive molecules in a spatial and temporal-controlled manner. The polymeric and non-polymeric materials used to synthesize micro and nanoscale-based BACS are reviewed. 

EXPERT OPINION: Comprehensive characterization of well-designed and customized BACS is necessary to be able to deliver multiple bioactive molecules in spatiotemporally controlled manner and to address the release kinetics required for potential in vivo application. This warrants further laboratory-based experiments and rigorous clinical investigations to enable their clinical translation for regenerative endodontic procedures.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Bafail2020,

title = {Effect of protease inhibitor specificity on dentin matrix properties},

author = {Arwa Bafail and Marcela Rocha Carrilho and Anil Kishen and Anuradha Prakki},

doi = {10.1016/j.jmbbm.2020.103861},

issn = {1878-0180},

year  = {2020},

date = {2020-01-01},

journal = {Journal of the Mechanical Behavior of Biomedical Materials},

volume = {109},

pages = {103861},

abstract = {OBJECTIVE: To evaluate protease activity of dentin matrices subjected to treatment with non-specific (chlorhexidine - CHX), cysteine cathepsin specific (E-64), and cysteine cathepsin-K (CT-K) specific (Odanacatib - ODN) inhibitors. METHODS: Pulverized dentin powder obtained from human dentin disks (0.5 mm thickness) completely demineralized with 10% H3PO4 were challenged in 1 mL lactic acid (LA) (0.1M, pH 5.5) or stored in deionized water for 30 min. Aliquots of dentin powder were then immersed in 1 mL of CHX (2%), E-64 (10 μM and 20 μM) or Odanacatib (0.2 nM and 1 μM) for 30min. Degradation of dentin collagen was determined by telopeptide assays measuring the sub-product release of C-terminal cross-linked telopeptides (ICTP) and C-terminal peptide (CTX) in incubation media, which correlates with matrix metalloproteinases (MMP) and CT-K activities respectively (n = 3). The ICTP and CTX data were normalized to concentration of total protein (ICTPtp and CTXtp) in the media, measured by bicinchoninic acid assay. Dentin matrix properties were also measured by gravimetric change (n = 8) and ultimate tensile strength (UTS) (n = 10). Data were analyzed by one-way ANOVA followed by Tukey's post-hoc test and independent t-test (α = 5%). 

RESULTS: Telopeptide assays showed significantly lower CTXtp values after treatment with E-64 and Odanacatib. E-64 and Odanacatib at all tested concentrations significantly reduced the release of ICTPtp. Gravimetric analysis showed no significant difference between the tested inhibitors and control except for CHX after lactic acid challenge. UTS results showed significantly higher values for E-64 (20 μM) and Odanacatib (0.2 nM and 1 μM) groups in deionized water. 

SIGNIFICANCE: Dentin therapies targeting enzymes such as CT-K by specific inhibitors may provide superior pharmacokinetics and optimum efficacy due to precise protein binding, consequently limiting collagen degradation directly or indirectly by enzyme related pathways.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{nokey,

title = {Middle Mesial Canal Preparation Enhances the Risk of Fracture in Mesial Root of Mandibular Molars},

author = {Ali Kele\c{s} and Cang\"{u}l Keskin and Emrah Karata\c{s}lıo\u{g}lu and Anil Kishen and Marco Aur\'{e}lio Versiani},

doi = {10.1016/j.joen.2020.05.019},

issn = {1878-3554},

year  = {2020},

date = {2020-01-01},

journal = {Journal of Endodontics},

volume = {46},

issue = {9},

pages = {1323-1329},

abstract = {INTRODUCTION: The aim of this investigation was to evaluate the effect of the presence and preparation of middle mesial (MM) canals on the fracture resistance of the mesial root of mandibular molars. METHODS: Forty intact mesial roots of mandibular first molars having 2 (n = 20) or 3 (n = 20) independent canals from the furcation level for up to at least 5 mm apically were selected based on preoperative micro-computed tomographic scanning. The selected roots were then distributed into 2 experimental (n = 10) and 2 control groups (n = 10) according to the root length, canal configuration (2 or 3 independent canals), and root thickness at the furcation level. In the experimental groups 1 (2 independent canals) and 3 (3 independent canals), root canals were enlarged up to the ProTaper Next X3 rotary instrument (Dentsply Sirona, Ballaigues, Switzerland), whereas in groups 2 (2 independent canals) and 4 (3 independent canals) root canals were not prepared. The specimens were embedded in acrylic resin after their surfaces were coated with a thin layer of silicone and subjected to a fracture strength using a universal testing machine. The types of fracture extension and course were recorded and statistically compared with the chi-square test, whereas fracture strength was analyzed using 1-way analysis of variance and post hoc Tukey tests (α = 5%). 

RESULTS: No statistical difference in fracture strength was observed between nonprepared roots with 2 (group 2, 696.1 ± 186.3 N) or 3 (group 4, 558.4 ± 154.6 N) independent canals (P .05), whereas the lowest values were obtained in the prepared roots with an MM canal (groups 3, 377.1 ± 77.2 N) (P .05). The mean fracture strength observed in the prepared roots with 2 canals (group 1, 528.4 ± 134.3 N) showed no statistically significant difference compared with nonprepared roots with 3 canals (group 4, 558.4 ± 154.6 N) (P .05). The chi-square test revealed no significant differences in fracture extent, types, and courses among groups (P .05). Fracture extensions in all groups were mostly central and buccal-central types, whereas the highest frequency of fracture course was the curved and zigzag types. 

CONCLUSIONS: The fracture resistance of the mesial roots of the mandibular molars decreased after the preparation of mesial canals with large-tapered instruments. Preparation of the MM canal further diminished the fracture resistance of the mesial roots. The resultant fracture displayed a distinct pattern in the buccolingual plane.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Azarpazhooh2020g,

title = {Insights into the July 2020 Issue of the Journal of Endodontics},

author = {Amir Azarpazhooh and Anibal R Diogenes and Ashraf F Fouad and Gerald N Glickman and Anil Kishen and Linda Levin and Robert S Roda and Christine M Sedgley and Franklin R Tay and Kenneth M Hargreaves},

doi = {10.1016/j.joen.2020.05.017},

issn = {1878-3554},

year  = {2020},

date = {2020-01-01},

journal = {Journal of Endodontics},

volume = {46},

issue = {7},

pages = {907-908},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Azarpazhooh2020h,

title = {Insights into the August 2020 Issue of the JOE},

author = {Amir Azarpazhooh and Anibal R Diogenes and Ashraf F Fouad and Gerald N Glickman and Anil Kishen and Linda Levin and Robert S Roda and Christine M Sedgley and Franklin R Tay and Kenneth M Hargreaves},

doi = {10.1016/j.joen.2020.06.042},

issn = {1878-3554},

year  = {2020},

date = {2020-01-01},

journal = {Journal of Endodontics},

volume = {46},

issue = {8},

pages = {1015-1016},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Ramachandran2020,

title = {In Vivo Strain Alterations in Mandibular Molars after Root Canal Treatment Procedures},

author = {Prameet Ramachandran and Angambakkam Rajasekaran PradeepKumar and Periasamy Ravishankar and Anil Kishen},

doi = {10.1016/j.joen.2020.07.021},

issn = {1878-3554},

year  = {2020},

date = {2020-01-01},

journal = {Journal of Endodontics},

volume = {46},

issue = {12},

pages = {1849-1855},

abstract = {INTRODUCTION: The aim of this investigation was to determine the coronal strain variations in mandibular molars under an in vivo bite load after root canal treatment procedures. 

METHODS: The coronal strain in carious mandibular first molars with symptomatic irreversible pulpitis (experimental group) was compared with that of intact contralateral teeth (control group) in patients 20-40 years old. Experiments were conducted in 2 stages. In stage 1, the maximum bite force on the first molar region was determined on the experimental and control teeth using a customized load cell. In stage 2, strain gauges were bonded to the buccal aspect of teeth, and the strain was recorded after the application of a bite load on the intact (control) teeth; and the experimental teeth before and after endodontic access cavity preparation, cleaning/shaping procedures, root filling, and composite core restoration. RESULTS: The mean maximum bite force on the experimental teeth (91 ± 48 N) and the contralateral control teeth (91 ± 49 N) was not significantly different (P = .989). The preoperative strain (microstrain) in the experimental teeth was significantly higher (125 ± 36},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Rath2020,

title = {The effect of root canal irrigants on dentin: a focused review},

author = {Priti Pragati Rath and Cynthia Kar Yung Yiu and Jukka Pekka Matinlinna and Anil Kishen and Prasanna Neelakantan},

doi = {10.5395/rde.2020.45.e39},

issn = {2234-7658},

year  = {2020},

date = {2020-01-01},

journal = {Restorative Dentistry \& Endodontics},

volume = {45},

issue = {3},

pages = {e39},

abstract = {Despite the vast literature on the effects of root canal irrigants on the dentin characteristics, the precise effects of clinically relevant irrigation sequences remain unclear. In this review, we systematically dissect the role of different sequential irrigation approaches that are used in clinical endodontics. Using a systematic search strategy, we attempt to answer the question: 'Which irrigating sequence has the most deleterious effects on dentin structure and properties?' The effect of irrigants on the dentin composition and mechanical properties have been reviewed. A wide variety of concentrations, duration and techniques have been employed to characterize the effects of chemicals on dentin properties, thus making it impossible to draw guidelines or recommendations of irrigant sequences to be followed clinically. It was apparent that all the studied irrigation sequences potentially result in some deleterious effects on dentin such as decrease in the flexural strength, microhardness, modulus of elasticity and inorganic content and organic-inorganic ratio of the dentin. However, the literature still lacks comprehensive investigations to compare the deleterious effect of different irrigation sequences, using a wide variety of qualitative and quantitative methods. Such investigations are essential to make clinical recommendations and strategize efforts to minimize chemically-induced damage to dentin characteristics.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Azarpazhooh2020i,

title = {Insights into the September 2020 Issue of the Journal of Endodontics},

author = {Amir Azarpazhooh and Anibal R Diogenes and Ashraf F Fouad and Gerald N Glickman and Anil Kishen and Linda Levin and Robert S Roda and Christine M Sedgley and Franklin R Tay and Kenneth M Hargreaves},

doi = {10.1016/j.joen.2020.07.027},

issn = {1878-3554},

year  = {2020},

date = {2020-01-01},

journal = {Journal of Endodontics},

volume = {46},

issue = {9},

pages = {1165-1166},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Azarpazhooh2020j,

title = {Insights into the October 2020 Issue of the JOE},

author = {Amir Azarpazhooh and Anibal R Diogenes and Ashraf F Fouad and Gerald N Glickman and Anil Kishen and Linda Levin and Robert S Roda and Christine M Sedgley and Franklin R Tay and Kenneth M Hargreaves},

doi = {10.1016/j.joen.2020.08.019},

issn = {1878-3554},

year  = {2020},

date = {2020-01-01},

journal = {Journal of Endodontics},

volume = {46},

issue = {10},

pages = {1369-1370},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Azarpazhooh2020k,

title = {Insights into the November 2020 issue of the JOE},

author = {Amir Azarpazhooh and Anibal R Diogenes and Ashraf F Fouad and Gerald N Glickman and Anil Kishen and Linda Levin and Robert S Roda and Christine M Sedgley and Franklin R Tay and Kenneth M Hargreaves},

doi = {10.1016/j.joen.2020.10.001},

issn = {1878-3554},

year  = {2020},

date = {2020-01-01},

journal = {Journal of Endodontics},

volume = {46},

issue = {11},

pages = {1537-1538},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Rath2020b,

title = {The effects of sequential and continuous chelation on dentin},

author = {Priti P Rath and Cynthia K Y Yiu and Jukka P Matinlinna and Anil Kishen and Prasanna Neelakantan},

doi = {10.1016/j.dental.2020.10.010},

issn = {1879-0097},

year  = {2020},

date = {2020-01-01},

journal = {Dental Materials: Official Publication of the Academy of Dental Materials},

volume = {36},

issue = {12},

pages = {1655-1665},

abstract = {OBJECTIVE: Proteolytic and demineralizing agents have a profound influence on the dentin ultrastructure, which plays a key role in the mechanical integrity of the tooth and integrity of dentin-biomaterial interfaces. In-depth characterization of dentin treated with a novel root canal irrigation protocol comprising sodium hypochlorite (NaOCl) and etidronate (HEDP) is lacking. This study comprehensively characterized and compared the effects of the continuous chelation (NaOCl/HEDP) and sequential chelation (NaOCl/EDTA) protocols on dentin. METHODS: Dentin blocks, dentin powder and root canals of mandibular premolars were distributed into Group 1, Saline (control); Group 2, NaOCl/EDTA; and Group 3, NaOCl/HEDP. Ultrastructural characteristics of the treated dentin were investigated using electron microscopy and light microscopy, while the surface roughness was analyzed using atomic force microscopy. Chemical compositional changes were characterized using Fourier transform infrared spectroscopy (FTIR) and energy-dispersive-X-ray spectroscopy (EDS), while collagen degradation was determined using ninhydrin assay. Data were statistically analyzed using multiple-factor one-way ANOVA and Tukey HSD tests (P = 0.05). 

RESULTS: NaOCl/HEDP resulted in partially degraded, yet mineralized collagen fibers, with minimal alteration to the subsurface matrix. Conversely, NaOCl/EDTA dissolved the hydroxyapaptite encapsulation, exposing collagen fibre bundles. There was no significant difference in the surface roughness between the two protocols (P 0.05). NaOCl/HEDP resulted in homogenous distribution of organic and inorganic components on the treated surface. 

SIGNIFICANCE: This study highlighted that continuous chelation (NaOCl/HEDP) resulted in a frail surface collagen layer while sequential chelation (NaOCl/EDTA) exposed bare collagen fibres. These surface and sub-surface effects potentially contribute to structural failures of dentin and/or dentin-biomaterial interfacial failures.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Azarpazhooh2020l,

title = {Insights into the December 2020 Issue of the JOE},

author = {Amir Azarpazhooh and Anibal R Diogenes and Ashraf F Fouad and Gerald N Glickman and Anil Kishen and Linda Levin and Robert S Roda and Christine M Sedgley and Franklin R Tay and Kenneth M Hargreaves},

doi = {10.1016/j.joen.2020.10.021},

issn = {1878-3554},

year  = {2020},

date = {2020-01-01},

journal = {Journal of Endodontics},

volume = {46},

issue = {12},

pages = {1809-1810},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Ramirez2019,

title = {Inflammatory potential of monospecies biofilm matrix components},

author = {T Ramirez and A Shrestha and A Kishen},

doi = {10.1111/iej.13093},

issn = {1365-2591},

year  = {2019},

date = {2019-01-01},

journal = {International Endodontic Journal},

volume = {52},

issue = {7},

pages = {1020-1027},

abstract = {AIM: To assess the inflammatory potential of biofilm matrix constituents of Enterococcus faecalis and Pseudomonas aeruginosa monospecies biofilms on macrophages. 

METHODOLOGY: In vitro biofilms of E. faecalis and P. aeruginosa were grown (7 days) in aerobic and anaerobic conditions. The biofilm matrix components: exopolysaccharides (EPS) and extracellular DNA (eDNA) were extracted and quantified. The inflammatory potential of EPS and eDNA was assessed on macrophage cell lines (RAW 267.4) using nitric oxide (NO), and enzyme-linked immunosorbent assay for tumour necrosis factor (TNF-α) and interleukin-6 (IL-6) expressions. LPS from P. aeruginosa and planktonic bacteria were positive controls. One-way analysis of variance and the Tukey post hoc test were used for statistical analysis. 

RESULTS: Extracted EPS from both biofilm strains was associated with higher levels than eDNA in both growth conditions (P 0.05). The biofilm components had less inflammatory potential compared to planktonic bacteria and LPS. EPS produced higher levels of inflammatory response compared to eDNA for both strains (P 0.05). IL-6 and TNF-α, and NO expression showed no difference for E. faecalis EPS (P ≥ 0.05). In contrast, P. aeruginosa EPS and eDNA had significant levels of IL-6 compared to TNF-α and NO (P 0.05). 

CONCLUSIONS: Monospecies biofilm matrix EPS and eDNA from the bacterial strains tested had the ability to induce a low-grade inflammatory response when compared to planktonic bacteria and LPS. This study highlights the potential of biofilm matrix/components, devoid of bacteria to induce low-grade chronic inflammation.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}