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Chan AYY, Chang JWW, Cheung GSP, Neelakantan P, Zhang C, Lee AHC. Penetration of Calcium Silicate and Epoxy Resin Sealers Into the Lateral Canals. Int Dent J 2024:S0020-6539(24)00038-8. [PMID: 38350801 DOI: 10.1016/j.identj.2024.01.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 01/16/2024] [Accepted: 01/18/2024] [Indexed: 02/15/2024] Open
Abstract
OBJECTIVES The aim of this research was to compare the penetration ability of calcium silicate-based sealers (iRoot SP and TotalFill BC HiFlow) and an epoxy resin-based sealer (AH Plus) into the lateral canals using the single-cone (SC) or continuous wave compaction (CW) obturation techniques. METHODS Ninety single-rooted human teeth received canal instrumentation and diaphanisation before artificial lateral canals were created at 3 different root levels. The specimens were randomly allocated into 6 groups based on the combination of obturation technique and sealer used. Radiographic and photographic measurements evaluated the percentage of sealer penetration. Statistical analysis was performed to compare the penetration ability amongst different types of sealers, obturation methods, and root levels. RESULTS Although TotalFill BC HiFlow sealer combined with the CW technique demonstrated greater sealer penetration at the coronal level (P < .05), the overall penetration ability of iRoot SP, TotalFill BC HiFlow, and AH Plus was not significantly different. The deepest sealer penetration was observed at the apical root level. CONCLUSIONS All sealers showed similar penetration abilities into the lateral canals using the SC or CW techniques in vitro. Calcium silicate-based sealers have comparable penetration ability into lateral canals compared to epoxy resin-based sealers using SC or CW obturation techniques.
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Affiliation(s)
- Angel Yuk Yan Chan
- Restorative Dental Sciences, Endodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong, SAR, P. R. China
| | - Jeffrey Wen Wei Chang
- Restorative Dental Sciences, Endodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong, SAR, P. R. China
| | - Gary Shun Pan Cheung
- Restorative Dental Sciences, Endodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong, SAR, P. R. China
| | - Prasanna Neelakantan
- Department of Endodontics, Arthur A. Dugoni School of Dentistry, University of the Pacific, San Francisco, California, USA
| | - Chengfei Zhang
- Restorative Dental Sciences, Endodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong, SAR, P. R. China.
| | - Angeline Hui Cheng Lee
- Restorative Dental Sciences, Endodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong, SAR, P. R. China.
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Chan CY, Vishwanath V, Cheung HY, Cheng YTJ, Ki K, Airis Mok HM, Pudipeddi A, Lee AHC, Cheung GSP, Neelakantan P. Tissue Stabilization, Bacterial Adhesion, and Stem Cell Viability in Trans-cinnamaldehyde-conditioned Dentin. J Endod 2023; 49:1634-1640. [PMID: 37793567 DOI: 10.1016/j.joen.2023.09.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 09/11/2023] [Accepted: 09/26/2023] [Indexed: 10/06/2023]
Abstract
INTRODUCTION This laboratory study aimed to evaluate the effect of trans-cinnamaldehyde (TC) conditioning on dentin tissue stabilization, bacterial adhesion, and stem cell toxicity. METHODS Dentin beams (n = 204) from extracted human molars were demineralized in phosphoric acid and treated with TC (2.5, 5, and 7.5%), 50% ethanol-water mixture (vehicle control) or 2.5% glutaraldehyde (GA) (positive control) for 30 minutes. Demineralized but untreated specimens served as the negative control. After treatment, collagen crosslinking was characterized by measuring the elastic modulus (Er) and hardness (n = 5). Biodegradation resistance was examined by determining the loss of dry mass (n = 8), hydroxyproline release (n = 4) and scanning electron microscopy (n = 2), after exposure to bacterial collagenase. Inhibition of bacterial adhesion was investigated by colony counting assay (n = 12) and scanning electron microscopy (n = 2). Viability of stem cells of the apical papilla on TC-conditioned dentin was determined using the Cell Counting Kit-8 assay (n = 8). Data were statistically analyzed using one-way analysis of variance (ANOVA) test followed by Dunnett's multiple comparisons at a significance level of 5%. RESULTS TC-conditioned dentin showed a concentration-dependent increase in Er and hardness. The Er and hardness of 5% and 7.5% TC-conditioned dentin were significantly greater than that of the negative control and vehicle control groups (P < .05). There was no significant difference in the biodegradation resistance between GA and 5% TC-conditioned dentin (P > .05). TC-conditioned dentin showed a well-preserved collagen fibril network with clear cross-banding, comparable to GA-conditioned dentin. All concentrations of TC inhibited bacterial adhesion on dentin, significantly greater than the negative control (P < .05). There was no reduction in viability of stem cells of the apical papilla viability on TC-conditioned dentin compared to the negative control (P > .05). CONCLUSIONS TC conditioning stabilized the dentin and protected it from enzymatic degradation. TC prevented bacterial adhesion on the dentin but maintained stem cell viability.
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Affiliation(s)
- Chi Yan Chan
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR
| | | | - Hoi Yin Cheung
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR
| | | | - Kei Ki
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR
| | | | - Akhila Pudipeddi
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR
| | | | - Gary Shun Pan Cheung
- Department of Dental Surgery, University of Hong Kong-Shenzhen Hospital, Shenzhen, China.
| | - Prasanna Neelakantan
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR; Department of Endodontics, Arthur A. Dugoni School of Dentistry, University of the Pacific, San Francisco, California.
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Uçar AY, Kölüş T, Bozkurt DA, Neelakantan P, Ali IAA, Belli S. A laboratory investigation on the effect of biguanide- and pyridine-derived antiseptics on the adhesion of resin composites to dentin. AUST ENDOD J 2023; 49:599-605. [PMID: 37602727 DOI: 10.1111/aej.12791] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2023] [Revised: 08/06/2023] [Accepted: 08/13/2023] [Indexed: 08/22/2023]
Abstract
Optimal bonding of adhesive restorations to dentin is crucial to prevent microleakage and enhance the survival of root-filled teeth. The aim of this study was to investigate the effect of chlorhexidine (CHX), alexidine (ALX) and octenidine dihydrochloride (OCT) on the bond strength of resin composites to coronal dentin. Human coronal dentin specimens were treated with 2% CHX, 0.1% ALX, 0.1% OCT or saline then restored with traditional or bulk-fill resin composites. The adhesion strength between the resin and dentin was measured using the microtensile bond strength and failure mode was determined using a stereomicroscope. Treatment with ALX and OCT resulted in significantly greater μTBS compared with CHX and saline, irrespective of the resin composite used. Alexidine treatment predominantly resulted in mixed failure, while adhesive failures were frequently observed in CHX and saline-treated dentin. In conclusion, final irrigation with ALX or OCT improved the bonding of resin composites to dentin.
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Affiliation(s)
- Arzu Yağmur Uçar
- Department of Endodontics, Faculty of Dentistry, Selçuk University, Konya, Turkey
| | - Türkay Kölüş
- Department of Restorative Dentistry, Faculty of Dentistry, Karamanoğlu Mehmetbey University Ahmet Keleşoğlu, Karaman, Turkey
| | - D Alperen Bozkurt
- Department of Endodontics, Faculty of Dentistry, Necmettin Erbakan University, Konya, Turkey
| | - Prasanna Neelakantan
- Divison of Restorative Dental Sciences, Discipline of Endodontology, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, Hong Kong
| | - Islam A A Ali
- School of Dentistry, Oregon Health & Science University, Portland, Oregon, USA
| | - Sema Belli
- Department of Endodontics, Faculty of Dentistry, Selçuk University, Konya, Turkey
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Murbay S, Neelakantan P, Li KY, Pow EHN. Effect of magnifying loupes on tooth preparation of complete coverage crown: A quantitative assessment using a digital approach. Eur J Dent Educ 2023; 27:1053-1059. [PMID: 36715249 DOI: 10.1111/eje.12898] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Revised: 01/16/2023] [Accepted: 01/22/2023] [Indexed: 06/18/2023]
Abstract
OBJECTIVE The purpose of this study was to evaluate the use of magnifying loupes (×2.5) on the quality of tooth preparation for complete coverage crowns; performed by predoctoral students using an objective and quantitative digital method. MATERIALS AND METHODS Forty-two predoctoral students were randomly assigned into 2 groups to perform tooth preparation for a complete coverage crown on a mandibular first molar in a manikin, with and without the use of magnifying loupes. All preparations were digitally evaluated by PrepCheck 3.0 (Dentsply Sirona). Parameters including tooth reduction, total occlusal convergence (TOC), undercut, margin quality and surface quality were assessed. Continuous data were analysed using Paired t-tests or Wilcoxon Signed Ranks tests. Ordinal data were analysed by McNemer's tests. To further detect the majority pattern ( > 50%) in each group (with and without loupes), one-sample t-test or one-sample Wilcoxon Signed Rank test was performed. The level of significance was set at p = .001 after Bonferroni adjustments for multiple testing. RESULTS No significant differences in the measured outcomes were found between the groups with or without the use of magnifying loupes (p > .002). The majority (>50%) of both groups had no undercuts (99.3% and 99.4% both p < .001) and the preparation type was within tolerance (81.6% and 85.3%, both p < .001) with acceptable margin (86.4% and 86.3%, both p < .001) and acceptable surface quality (99.0% and 99.1%, both p < .001). However, the majority of both groups underprepared occlusally (96.0% and 95.4%, both p < .001) and axially (65.3% and 67%, both p < .001). Only 30.0%-42.1% of the participants achieved the TOC within 0-20°. CONCLUSIONS Within the limitations of this study, the use of magnification loupes does not appear to significantly improve the quality of tooth preparation for complete coverage crown. The TOC was also found to be overprepared and occlusally underprepared.
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Affiliation(s)
- Sukhdeep Murbay
- Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong, SAR, China
| | - Prasanna Neelakantan
- Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong, SAR, China
| | - Kar Yan Li
- Faculty of Dentistry, The University of Hong Kong, Hong Kong, SAR, China
| | - Edmond Ho Nang Pow
- Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong, SAR, China
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Ng WNI, Kalimuthu S, Law COK, Lee AHC, Lau TCK, Leung YY, Cheung GSP, Neelakantan P. Intracellular bacterial eradication using a novel peptide in vitro. Int Endod J 2023; 56:1360-1372. [PMID: 37615967 DOI: 10.1111/iej.13965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 08/09/2023] [Indexed: 08/25/2023]
Abstract
AIM To determine the effect of a novel antimicrobial peptide (AMP; OP145) and cell-penetrating peptide (Octa-arginine/R8) conjugate on the killing of intracellular Enterococcus faecalis, compared to OP145 and an antibiotic combination recommended for regenerative endodontic procedures. METHODOLOGY The biocompatible concentrations of OP145 and OP145-R8 were determined by assessing their cytotoxicity against human macrophages and red blood cells. Spatiotemporal internalization of the peptides into macrophages was investigated qualitatively and quantitatively by confocal laser scanning microscopy and flow cytometry respectively. Killing of extracellular and intracellular E. faecalis OG1RF by the peptides was determined by counting the colony-forming units (CFU). Intracellular antibacterial activity of the peptides was compared to a double antibiotic combination. Confocal microscopy was used to confirm the intracellular bacterial eradication. Significant differences between the different test groups were analysed using one-way analysis of variance. p < .05 was considered to be statistically significant. RESULTS Peptides at a concentration of 7.5 μmol/L were chosen for subsequent experiments based on the results of the alamarBlue™ cell viability assay and haemolytic assay. OP145-R8 selectively internalized into lysosomal compartments and the cytosol of macrophages. Conjugation with R8 improved the internalization of OP145 into macrophages in a temporal manner (70.53% at 1 h to 77.13% at 2 h), while no temporal increase was observed for OP145 alone (60.53% at 1 h with no increase at 2 h). OP145-R8 demonstrated significantly greater extracellular and intracellular antibacterial activity compared to OP145 at all investigated time-points and concentrations (p < .05). OP145-R8 at 7.5 μmol/L eradicated intracellular E. faecalis after 2 h (3.5 log reduction compared to the control; p < .05), while the antibiotics could not reduce more than 0.5 log CFU compared to the control (p > .05). Confocal microscopy showed complete absence of E. faecalis within the OP145-R8 treated macrophages. CONCLUSIONS The results of this study demonstrated that the conjugation of an AMP OP145 to a cell-penetrating peptide R8 eradicated extracellular and intracellular E. faecalis OG1RF without toxic effects on the host cells.
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Affiliation(s)
- Wing Nok Isaac Ng
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, Hong Kong
| | | | - Carmen Oi Kwan Law
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong SAR, Hong Kong
| | | | - Terrence Chi Kong Lau
- Department of Biomedical Sciences, City University of Hong Kong, Hong Kong SAR, Hong Kong
| | - Yiu Yan Leung
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, Hong Kong
| | - Gary Shun Pan Cheung
- Department of Dental Surgery, University of Hong Kong-Shenzhen Hospital, Shenzhen, China
| | - Prasanna Neelakantan
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, Hong Kong
- Department of Endodontics, Arthur A. Dugoni School of Dentistry, University of the Pacific, San Francisco, California, USA
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Kalimuthu S, Pudipeddi A, Braś G, Tanner JA, Rapala-Kozik M, Leung YY, Neelakantan P. A heptadeca amino acid peptide subunit of cathelicidin LL-37 has previously unreported antifungal activity. APMIS 2023; 131:584-600. [PMID: 37150907 DOI: 10.1111/apm.13322] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 04/11/2023] [Indexed: 05/09/2023]
Abstract
Yeasts such as Candida albicans, albeit being ubiquitous members of the skin, oral and vaginal microbiome, can cause superficial to life-threatening infections. Human cathelicidin LL-37-based peptides have antibacterial activity and yet, their antifungal activity remains to be thoroughly characterized. The aim of this study was to comprehensively investigate the activity of LL-37-based peptides against C. albicans. LL-37 and its derivatives were tested for their ability to kill C. albicans planktonic cells in the presence of various biological matrices (serum, plasma, saliva and urine), that have been reported to inactivate peptides. The antibiofilm activity, resistance development and biocompatibility were investigated for the lead peptide. GK-17, a 17 amino acid peptide, showed remarkable stability to fungal aspartyl proteases and rapidly killed planktonic C. albicans despite the presence of biological matrices. GK-17 also inhibited adhesion to biotic and abiotic substrates, inhibited biofilm formation and eradicated preformed biofilms in the presence of biological matrices. Compared to nystatin, GK-17 had a lower propensity to allow for resistance development by C. albicans. The peptide showed concentration-dependent biocompatibility to red blood cells, with only 30% hemolysis even at 4× the fungicidal concentration. Taken together, GK-17 is a novel antifungal peptide with promising effects against C. albicans.
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Affiliation(s)
- Shanthini Kalimuthu
- Faculty of Dentistry, The University of Hong Kong, Sai Ying Pun, Hong Kong SAR
| | - Akhila Pudipeddi
- Faculty of Dentistry, The University of Hong Kong, Sai Ying Pun, Hong Kong SAR
| | - Grażyna Braś
- Department of Comparative Biochemistry and Bioanalytics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Julian A Tanner
- School of Biomedical Sciences, The University of Hong Kong, Sai Ying Pun, Hong Kong SAR
| | - Maria Rapala-Kozik
- Department of Comparative Biochemistry and Bioanalytics, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Krakow, Poland
| | - Yiu Yan Leung
- Faculty of Dentistry, The University of Hong Kong, Sai Ying Pun, Hong Kong SAR
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Duane B, Yap T, Neelakantan P, Anthonappa R, Bescos R, McGrath C, McCullough M, Brookes Z. Mouthwashes: Alternatives and Future Directions. Int Dent J 2023; 73 Suppl 2:S89-S97. [PMID: 37867066 PMCID: PMC10690551 DOI: 10.1016/j.identj.2023.08.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Accepted: 08/21/2023] [Indexed: 10/24/2023] Open
Abstract
This narrative review summarises "alternative" or "natural" over-the-counter (OTC) mouthwashes not covered elsewhere in this supplement and newly emerging products, as potential mouthwashes of the future. The "natural" mouthwashes reviewed include saltwater, baking soda, coconut oil, charcoal, propolis, seaweeds, and probiotics. Other than essential oils, it is apparent that their clinical effectiveness is still under debate, but there is some evidence to suggest that propolis reduces plaque and gingivitis. This review also covers the host immune response, via novel anti-inmmunomodulant mouthwashes, such as erythropoietin to reduce inflammation with oral mucositis (OM) after radiotherapy. The emerging concept of nanoparticle-containing mouthwashes, such as iron oxide, is further discussed for OM, this agent having the potential for more targeted delivery of chemical antimicrobials. Unfortunately, there are impacts on the environment of widening mouthwash use with more new products, including increased use of packaging, antimicrobial resistance, and possible detrimental effects on marine life. Further, there are roadblocks, relating to regularly approvals and side effects, that still need to be overcome for any OTC deivered immunomodulant or nanoformulation mouthwashes. Despite these caveats, there are many new mouthwashes under development, which could help manage major oral diseases such as caries, gingivitis, and periodontal disease.
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Affiliation(s)
- Brett Duane
- Dublin Dental School and Hospital, Trinity College Dublin, Dublin, Ireland
| | - Tami Yap
- Faculty of Medicine, Dentistry & Health Sciences, Melbourne Dental School, University of Melbourne, Carlton, Australia
| | - Prasanna Neelakantan
- Department of Endodontics, University of the Pacific, Arthur A. Dugoni School of Dentistry, San Francisco, California, USA
| | | | - Raul Bescos
- School of Health Professions, Faculty of Health, University of Plymouth, Plymouth, UK
| | - Colman McGrath
- Applied Oral Sciences & Community Dental Care, Hong Kong
| | - Michael McCullough
- Faculty of Medicine, Dentistry & Health Sciences, Melbourne Dental School, University of Melbourne, Carlton, Australia
| | - Zoë Brookes
- Peninsula Dental School, Plymouth University, Plymouth, UK.
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Chan CW, Romeo VR, Lee A, Zhang C, Neelakantan P, Pedullà E. Accumulated Hard Tissue Debris and Root Canal Shaping Profiles Following Instrumentation with Gentlefile, One Curve, and Reciproc Blue. J Endod 2023; 49:1344-1351. [PMID: 37516238 DOI: 10.1016/j.joen.2023.07.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 07/19/2023] [Accepted: 07/20/2023] [Indexed: 07/31/2023]
Abstract
INTRODUCTION This laboratory study aimed to evaluate the accumulated hard tissue debris (AHTD) and shaping performance following root canal instrumentation with a novel stainless steel rotary system (Gentlefile; MedicNRG, Kibbutz Afikim, Israel) compared with two single-file nickel-titanium instruments of different kinematics through micro-computed tomography (micro-CT) analysis. METHODS Thirty isthmus-containing mesial roots of human mandibular molars with a curvature of 15°-35° were scanned with micro-CT at an isotropic resolution of 12 μm and randomly assigned to three groups (n = 10) according to the instruments used for canal preparation: Gentlefile (GF; #23/.04), One Curve (OC; #25/.06; Micro-Mega, Besancon, France), and Reciproc Blue R25 (RB; #25/.08; VDW, Munich, Germany). The AHTD, unprepared canal surface area, volume changes, surface area changes, and transportation were evaluated by comparing preoperative and postoperative micro-CT images. In addition, the time required for canal preparation was recorded. Data were statistically analyzed using the one-way analysis of variance (ANOVA) test or the Kruskal-Wallis test at a significance level of 5%. RESULTS No significant differences were observed in the percentage of AHTD or in the unprepared canal surface area between the three groups (P > .05). The RB group demonstrated a significantly greater percentage increase in volume and surface area than the GF group (P < .05). The GF and OC groups showed significantly less transportation at 3 mm from the apex than the RB group (P < .001). The OC group required significantly less time for instrumentation than the RB and GF groups (P < .05). CONCLUSIONS Instrumentation with GF (#23/.04), OC, and RB yielded similar levels of AHTD and unprepared surface area in isthmus-containing curved canals. GF achieved this with less dentin removal and apical transportation, at the expense of a longer preparation time.
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Affiliation(s)
- Chi Wai Chan
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | - Virginia Rosy Romeo
- Department of General Surgery and Medical-Surgical Specialties, University of Catania, Catania, Italy
| | - Angeline Lee
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | - Chengfei Zhang
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China.
| | - Prasanna Neelakantan
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China; Department of Endodontics, Arthur A. Dugoni School of Dentistry, University of the Pacific, San Francisco, CA.
| | - Eugenio Pedullà
- Department of General Surgery and Medical-Surgical Specialties, University of Catania, Catania, Italy
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Singh S, Kundra R, George SD, Hanosh S, Neelakantan P, Thomas MS. Effect of Dentine Conditioning with Silver Diamine Fluoride on Wettability of Root Canal Sealers. Chin J Dent Res 2023; 26:179-184. [PMID: 37732684 DOI: 10.3290/j.cjdr.b4330827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 09/22/2023]
Abstract
OBJECTIVE To test the null hypothesis that dentine treatment with silver diamine fluoride (SDF), a potent antimicrobial agent, following use of proteolytic and chelating agents does not influence the wettability of an epoxy resin (AH Plus, Dentsply Sirona, Charlotte, NC, USA) and a tricalcium silicate sealer (BioRoot RCS, Septodont, Saint-Maur-des-Fossés, France). METHODS Seventy-two intraradicular dentine specimens were divided into six groups based on the final irrigation solutions used: 2.5% sodium hypochlorite (NaOCl) and 17% ethylenediaminetetraacetic acid (EDTA) (NaOCl-EDTA) (group 1); NaOCl-EDTA-NaOCl (group 2); NaOCl-EDTA followed by 3.8% SDF, NaOCl-EDTA-SDF (group 3); NaOCl-EDTA-NaOCl-SDF (group 4); SDF (group 5) and saline (group 6). After irrigation, the specimens were divided into subgroups according to the sealer used, AH Plus or BioRoot RCS. Contact angles were measured using a contact angle analyser. The data were analysed using an independent t test, one-way analysis of variance (ANOVA) and Tamhane T2 post hoc test, with the level of significance set at P < 0.05. RESULTS In the epoxy resin sealer group, dentine surfaces treated with only SDF showed the lowest contact angle. This was significantly less than the groups in which NaOCl was used as the final irrigant (P < 0.05). In the tricalcium silicate-based sealer group, the groups treated with SDF showed significantly greater contact angles when compared to the control group (P < 0.05). CONCLUSION It was concluded that SDF conditioning of dentine favours the wettability of epoxy resin sealer but is detrimental to the wettability of tricalcium silicate sealer.
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Vera J, Castro-Nuñez MA, Troncoso-Cibrian MF, Carrillo-Varguez AG, Méndez Sánchez ER, Sarmiento V, Lanzagorta-Rebollo L, Neelakantan P, Romero M, Arias A. Effect of cryotherapy duration on experimentally induced connective tissue inflammation in vivo. Restor Dent Endod 2023; 48:e29. [PMID: 37675446 PMCID: PMC10477420 DOI: 10.5395/rde.2023.48.e29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2023] [Revised: 04/26/2023] [Accepted: 04/28/2023] [Indexed: 09/08/2023] Open
Abstract
Objectives This study tested the hypothesis that cryotherapy duration influences lipopolysaccharide (LPS)-induced inflammation in a rat model. Materials and Methods Six Wistar rats (Rattus norvegicus albinus) were used. Five sites were selected per animal and divided into 5 groups: a negative control group (NC), 2 positive control groups (PC1 and PC2), and 2 experimental groups (E1 and E2). Cryotherapy was applied for 1 minute (E1) or 5 minutes (E2). An acute inflammatory response was induced in the PC and E groups via subcutaneous administration of 0.5 mL/kg. In the PC2 group, a catheter was inserted without additional treatment. For the E1 and E2 groups, 2.5°C saline solution was administered through the implanted catheters for 1 and 5 minutes, respectively. The rats were sacrificed, and samples were obtained and processed for histological analysis, specifically examining the presence of polymorphonuclear neutrophils and hemorrhage. The χ2 test was used to compare the presence of acute inflammation across groups. Dependent variables were compared using the linear-by-linear association test. Results Inflammation and hemorrhage varied significantly among the groups (p = 0.001). A significantly higher degree of acute inflammation was detected (p = 0.0002) in the PC and E1 samples than in the E2 group, in which cryotherapy was administered for 5 minutes. The PC and E1 groups also exhibited significantly greater numbers of neutrophils (p = 0.007), which were essentially absent in both the NC and E2 groups. Conclusions Cryotherapy administration for 5 minutes reduced the acute inflammation associated with LPS and catheter implantation.
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Affiliation(s)
- Jorge Vera
- Department of Endodontics, University of Missouri, Kansas City, MO, USA
| | | | | | | | | | - Viviana Sarmiento
- Department of Endodontics, Autonomous University of Baja California (UABC), Tijuana, Mexico
| | | | - Prasanna Neelakantan
- Discipline of Endodontology, Division of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - Monica Romero
- Department of Endodontics, University of Missouri, Kansas City, MO, USA
| | - Ana Arias
- Faculty of Dentistry Complutense University of Madrid, Madrid, Spain
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Venkateswaran P, Vasudevan S, David H, Shaktivel A, Shanmugam K, Neelakantan P, Solomon AP. Revisiting ESKAPE Pathogens: virulence, resistance, and combating strategies focusing on quorum sensing. Front Cell Infect Microbiol 2023; 13:1159798. [PMID: 37457962 PMCID: PMC10339816 DOI: 10.3389/fcimb.2023.1159798] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Accepted: 06/08/2023] [Indexed: 07/18/2023] Open
Abstract
The human-bacterial association is long-known and well-established in terms of both augmentations of human health and attenuation. However, the growing incidents of nosocomial infections caused by the ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter sp.) call for a much deeper understanding of these organisms. Adopting a holistic approach that includes the science of infection and the recent advancements in preventing and treating infections is imperative in designing novel intervention strategies against ESKAPE pathogens. In this regard, this review captures the ingenious strategies commissioned by these master players, which are teamed up against the defenses of the human team, that are equally, if not more, versatile and potent through an analogy. We have taken a basketball match as our analogy, dividing the human and bacterial species into two teams playing with the ball of health. Through this analogy, we make the concept of infectious biology more accessible.
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Affiliation(s)
- Parvathy Venkateswaran
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Sahana Vasudevan
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Helma David
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Adityan Shaktivel
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Karthik Shanmugam
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Prasanna Neelakantan
- Division of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Adline Princy Solomon
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
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Shin JY, Kim MA, Kim HJ, Neelakantan P, Yu MK, Min KS. Evaluation of machine-assisted irrigation on removal of intracanal biofilm and extrusion of sodium hypochlorite using a three-dimensionally printed root canal model. J Oral Sci 2023:23-0025. [PMID: 37197929 DOI: 10.2334/josnusd.23-0025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
PURPOSE This study aimed to compare the biofilm removal and apical extrusion of sodium hypochlorite (NaOCl) following machine-assisted irrigation using a three-dimensionally (3D) printed dentin-insert model. METHODS Multispecies biofilms were formed in a 3D-printed curved root canal model with dentin insert. The model was then placed in a container that was filled with 0.2% agarose gel containing 0.1% m-Cresol purple. Root canals were irrigated with 1% NaOCl using syringe irrigation, sonically agitated (EndoActivator or EDDY) or ultrasonically activated (Endosonic Blue) irrigation. Samples were photographed and the color-changed area was measured. Biofilm removal was assessed using colony-forming unit counting, confocal laser scanning microscopic analysis and scanning electron microscopic observations. The data were analyzed using one-way ANOVA, followed by Tukey test (P < 0.05). RESULTS EDDY and Endosonic Blue demonstrated significantly greater reduction of biofilms compared to other groups. No significant differences were observed in the remaining biofilm volume in syringe irrigation and EndoActivator groups. Furthermore, EDDY and Endosonic Blue presented with numerous exposed dentinal tubules. EDDY showed significantly greater NaOCl extrusion compared to other groups. CONCLUSION Ultrasonic activation with a small-sized nickel-titanium file irrigation system may be beneficial in intracanal biofilm removal avoiding extrusion of NaOCl beyond the root apex.
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Affiliation(s)
- Ji-Yoon Shin
- Department of Conservative Dentistry, School of Dentistry, Jeonbuk National University
| | - Mi-Ah Kim
- Department of Conservative Dentistry, School of Dentistry, Jeonbuk National University
| | - Hee-Jin Kim
- Department of Dentistry, College of Medicine, Kosin University
| | - Prasanna Neelakantan
- Discipline of Endodontology, Department of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong
| | - Mi-Kyung Yu
- Department of Conservative Dentistry, School of Dentistry, Jeonbuk National University
- Research Institute of Clinical Medicine of Jeonbuk National University
- Biomedical Research Institute of Jeonbuk National University Hospital
| | - Kyung-San Min
- Department of Conservative Dentistry, School of Dentistry, Jeonbuk National University
- Research Institute of Clinical Medicine of Jeonbuk National University
- Biomedical Research Institute of Jeonbuk National University Hospital
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Zhang D, Zhang J, Kalimuthu S, Liu J, Song ZM, He BB, Cai P, Zhong Z, Feng C, Neelakantan P, Li YX. A systematically biosynthetic investigation of lactic acid bacteria reveals diverse antagonistic bacteriocins that potentially shape the human microbiome. Microbiome 2023; 11:91. [PMID: 37101246 PMCID: PMC10134562 DOI: 10.1186/s40168-023-01540-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2022] [Accepted: 03/31/2023] [Indexed: 05/12/2023]
Abstract
BACKGROUND Lactic acid bacteria (LAB) produce various bioactive secondary metabolites (SMs), which endow LAB with a protective role for the host. However, the biosynthetic potentials of LAB-derived SMs remain elusive, particularly in their diversity, abundance, and distribution in the human microbiome. Thus, it is still unknown to what extent LAB-derived SMs are involved in microbiome homeostasis. RESULTS Here, we systematically investigate the biosynthetic potential of LAB from 31,977 LAB genomes, identifying 130,051 secondary metabolite biosynthetic gene clusters (BGCs) of 2,849 gene cluster families (GCFs). Most of these GCFs are species-specific or even strain-specific and uncharacterized yet. Analyzing 748 human-associated metagenomes, we gain an insight into the profile of LAB BGCs, which are highly diverse and niche-specific in the human microbiome. We discover that most LAB BGCs may encode bacteriocins with pervasive antagonistic activities predicted by machine learning models, potentially playing protective roles in the human microbiome. Class II bacteriocins, one of the most abundant and diverse LAB SMs, are particularly enriched and predominant in the vaginal microbiome. We utilized metagenomic and metatranscriptomic analyses to guide our discovery of functional class II bacteriocins. Our findings suggest that these antibacterial bacteriocins have the potential to regulate microbial communities in the vagina, thereby contributing to the maintenance of microbiome homeostasis. CONCLUSIONS Our study systematically investigates LAB biosynthetic potential and their profiles in the human microbiome, linking them to the antagonistic contributions to microbiome homeostasis via omics analysis. These discoveries of the diverse and prevalent antagonistic SMs are expected to stimulate the mechanism study of LAB's protective roles for the microbiome and host, highlighting the potential of LAB and their bacteriocins as therapeutic alternatives. Video Abstract.
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Affiliation(s)
- Dengwei Zhang
- Department of Chemistry and The Swire Institute of Marine Science, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Jian Zhang
- Department of Chemistry and The Swire Institute of Marine Science, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Shanthini Kalimuthu
- Division of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - Jing Liu
- Department of Chemistry and The Swire Institute of Marine Science, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Zhi-Man Song
- Department of Chemistry and The Swire Institute of Marine Science, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Bei-Bei He
- Department of Chemistry and The Swire Institute of Marine Science, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Peiyan Cai
- Department of Chemistry and The Swire Institute of Marine Science, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Zheng Zhong
- Department of Chemistry and The Swire Institute of Marine Science, The University of Hong Kong, Pokfulam Road, Hong Kong, China
| | - Chenchen Feng
- Department of Urology, Huashan Hospital, Fudan University, Shanghai, 200040, China
| | - Prasanna Neelakantan
- Division of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - Yong-Xin Li
- Department of Chemistry and The Swire Institute of Marine Science, The University of Hong Kong, Pokfulam Road, Hong Kong, China.
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Gaeta C, Marruganti C, Ali IAA, Fabbro A, Pinzauti D, Santoro F, Neelakantan P, Pozzi G, Grandini S. The presence of Enterococcus faecalis in saliva as a risk factor for endodontic infection. Front Cell Infect Microbiol 2023; 13:1061645. [PMID: 37091670 PMCID: PMC10118032 DOI: 10.3389/fcimb.2023.1061645] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 03/02/2023] [Indexed: 04/09/2023] Open
Abstract
AimThe aim of the present study was to investigate and correlate the prevalence of Enterococcus faecalis in saliva and in root canals with different pulpal and periapical conditions.MethodologySixty-seven patients were divided into five groups based on pulpal and periapical tissue status: healthy vital teeth (HVT, n=7), healthy treated teeth without lesion (HTT, n=9), irreversible pulpitis (IP, n=13), necrosis (N, n=18), and post-treatment apical periodontitis (PTAP, n=20). Saliva, rubber dam, sterility control and pre-treatment root canal samples were collected and microbiologically processed by culture method. The phylogenetic relationship of E. faecalis isolates collected from root canals and saliva were investigated by whole genome sequencing. Fisher’s exact test was used to correlate the presence of E. faecalis in root canals or saliva with clinical and/or radiographic findings. Linear/logistic regression analyses were performed to establish the relationship between the presence of E. faecalis in root canals, saliva, and the status of periapical tissues.ResultsE. faecalis was found in 18 root canal and saliva samples. E. faecalis root canal isolates were recovered with the highest frequency from post-treatment apical periodontitis. The occurrence of E. faecalis in saliva was strongly associated with its detection in the root canals (P < 0.001). The pretreatment presence of E. faecalis in root canals was associated with significantly higher odds of having periapical lesions (OR=11.03; 95% CI, 1.27-95.70; p < 0.05). Saliva and root canal isolates from the same patient were highly correlated at the phylogenetic level (Jaccard index >0.95).ConclusionThis pilot study confirms the role of E. faecalis in developing peri-radicular lesions in secondary endodontic infections and suggests that saliva could be the main source of infection. Further studies are needed to investigate the exact origin of this bacteria and its true role in the pathogenesis of secondary/persistent endodontic infections.
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Affiliation(s)
- Carlo Gaeta
- Unit of Periodontology, Endodontic and Restorative Dentistry, Department of Medical Biotechnology, University of Siena, Siena, Italy
- *Correspondence: Carlo Gaeta,
| | - Crystal Marruganti
- Unit of Periodontology, Endodontic and Restorative Dentistry, Department of Medical Biotechnology, University of Siena, Siena, Italy
| | - Islam A. A. Ali
- Department of Endodontics, Faculty of Dentistry, Mansoura University, Mansoura, Egypt
| | - Andrea Fabbro
- Unit of Periodontology, Endodontic and Restorative Dentistry, Department of Medical Biotechnology, University of Siena, Siena, Italy
| | - David Pinzauti
- Unit of Periodontology, Endodontic and Restorative Dentistry, Department of Medical Biotechnology, University of Siena, Siena, Italy
| | - Francesco Santoro
- Unit of Periodontology, Endodontic and Restorative Dentistry, Department of Medical Biotechnology, University of Siena, Siena, Italy
| | - Prasanna Neelakantan
- Faculty of Dentistry, The University of Hong Kong, Sai Ying Pun, Hong Kong, Hong Kong SAR, China
| | - Gianni Pozzi
- Unit of Periodontology, Endodontic and Restorative Dentistry, Department of Medical Biotechnology, University of Siena, Siena, Italy
| | - Simone Grandini
- Unit of Periodontology, Endodontic and Restorative Dentistry, Department of Medical Biotechnology, University of Siena, Siena, Italy
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Brezhnev A, Tang FK, Kwan CS, Basabrain MS, Tsoi JKH, Matinlinna JP, Neelakantan P, Leung KCF. One-Pot Preparation of Cetylpyridinium Chloride-Containing Nanoparticles for Biofilm Eradication. ACS Appl Bio Mater 2023; 6:1221-1230. [PMID: 36862938 PMCID: PMC10031565 DOI: 10.1021/acsabm.2c01080] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
Quaternary ammonium compounds (QACs) have been widely used due to their excellent antimicrobial activity. However, using the technology where nanomaterials are employed as drug carriers to deliver QAC drugs has not been fully explored. In this study, mesoporous silica nanoparticles (MSNs) with short rod morphology were synthesized in a one-pot reaction using an antiseptic drug cetylpyridinium chloride (CPC). CPC-MSN were characterized via various methods and tested against three bacterial species (Streptococcus mutans, Actinomyces naeslundii, and Enterococcus faecalis), which are associated with oral infections, caries, and endodontic pathology. The nanoparticle delivery system used in this study prolonged the release of CPC. The manufactured CPC-MSN effectively killed the tested bacteria within the biofilm, and their size allowed them to penetrate into dentinal tubules. This CPC-MSN nanoparticle delivery system demonstrates potential for applications in dental materials.
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Affiliation(s)
- Alexander Brezhnev
- Restorative Dental Sciences, Discipline of Endodontology, Faculty of Dentistry, The University of Hong Kong, Hong Kong Island, Hong Kong SAR, P. R. China
| | - Fung-Kit Tang
- Department of Chemistry, State Key Laboratory of Environmental and Biological Analysis, Hong Kong Baptist University, Kowloon Tong, Kowloon, Hong Kong SAR, P. R. China
| | - Chak-Shing Kwan
- Department of Chemistry, State Key Laboratory of Environmental and Biological Analysis, Hong Kong Baptist University, Kowloon Tong, Kowloon, Hong Kong SAR, P. R. China
| | - Mohammed S Basabrain
- Restorative Dental Sciences, Discipline of Endodontology, Faculty of Dentistry, The University of Hong Kong, Hong Kong Island, Hong Kong SAR, P. R. China
| | - James Kit Hon Tsoi
- Applied Oral Sciences and Community Dental Care, Dental Materials Science, Faculty of Dentistry, The University of Hong Kong, Hong Kong Island, Hong Kong SAR, P. R. China
| | - Jukka P Matinlinna
- Applied Oral Sciences and Community Dental Care, Dental Materials Science, Faculty of Dentistry, The University of Hong Kong, Hong Kong Island, Hong Kong SAR, P. R. China
- Division of Dentistry, The University of Manchester, Manchester M13 9PL, U.K
| | - Prasanna Neelakantan
- Restorative Dental Sciences, Discipline of Endodontology, Faculty of Dentistry, The University of Hong Kong, Hong Kong Island, Hong Kong SAR, P. R. China
| | - Ken Cham-Fai Leung
- Department of Chemistry, State Key Laboratory of Environmental and Biological Analysis, Hong Kong Baptist University, Kowloon Tong, Kowloon, Hong Kong SAR, P. R. China
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16
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Ngai P, Lee AHC, Xu J, Chang JWW, Liu J, Hu M, Sun Z, Neelakantan P, Li X, Zhang C. Effects of L-Chg 10-Teixobactin on Viability, Proliferation, and Osteo/Odontogenic Differentiation of Stem Cells from Apical Papilla. J Endod 2023; 49:162-168. [PMID: 36592717 DOI: 10.1016/j.joen.2022.11.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 11/04/2022] [Accepted: 11/09/2022] [Indexed: 01/01/2023]
Abstract
INTRODUCTION Intracanal medicament is one of the essential steps for ensuring success in regenerative endodontic procedures. L-Chg10-teixobactin is a novel antimicrobial agent that exhibited potent antibacterial and antibiofilm effects against Enterococcusfaecalis at low concentrations compared with ampicillin. At the same time, its cytotoxicity on dental stem cells has not been studied. This study aimed to investigate the effects of L-Chg10-teixobactin on the viability, proliferation, migration, and osteo/odontogenic differentiation of stem cells from apical papilla (SCAPs). MATERIALS AND METHODS SCAPs isolated from immature human third molars were treated with various concentrations of L-Chg10-teixobactin, calcium hydroxide, and dimethyl sulfoxide. The viability and proliferation of SCAPs were assessed using the LIVE/DEAD Viability/Cytotoxicity Kit and Cell Counting Kit-8. A scratch wound healing test was used to evaluate the lateral migration capacity of SCAPs. Alkaline phosphatase (ALP) activity, calcium mineralization ability tests -ie, ALP staining and alizarin red S staining, and quantitative real-time polymerase chain reaction were performed to assess the osteo /odontogenic differentiation of SCAPs. RESULTS The tested concentrations of L-Chg10-teixobactin (0.01, 0.02, and 0.03 mg/mL), 1 mg/mL calcium hydroxide, and 0.03% dimethyl sulfoxide had no significant cytotoxic effect on SCAPs at any time point (P > .05). Besides, there were no significant differences between the control and experimental groups in SCAPs' viability, proliferation, and migration. L-Chg10-teixobactin upregulated the gene expression of osteo/odontogenic markers in SCAPs, while no significant difference was found in the ALP activity and alizarin red S staining. CONCLUSIONS L-Chg10-teixobactin demonstrated excellent biocompatibility on SCAPs at concentrations from 0.01 to 0.03 mg/mL and potentially enhance the osteo/odontogenic differentiation of SCAPs; suggesting its promising role as root canal medicament for regenerative endodontic procedures.
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Affiliation(s)
- Ping Ngai
- Restorative Dental Sciences, Endodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong, SAR, P. R. China
| | - Angeline Hui Cheng Lee
- Restorative Dental Sciences, Endodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong, SAR, P. R. China
| | - Jian Xu
- Department of Dentistry, Longgang ENT Hospital, Shenzhen Longgang Institute of Stomatology, Shenzhen, P. R. China
| | - Jeffrey Wen Wei Chang
- Restorative Dental Sciences, Endodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong, SAR, P. R. China
| | - Junqing Liu
- Restorative Dental Sciences, Endodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong, SAR, P. R. China
| | - Mingxin Hu
- Restorative Dental Sciences, Endodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong, SAR, P. R. China
| | - Zhenquan Sun
- Department of Chemistry, State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Hong Kong, SAR, P. R. China
| | - Prasanna Neelakantan
- Restorative Dental Sciences, Endodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong, SAR, P. R. China
| | - Xuechen Li
- Department of Chemistry, State Key Laboratory of Synthetic Chemistry, The University of Hong Kong, Hong Kong, SAR, P. R. China.
| | - Chengfei Zhang
- Restorative Dental Sciences, Endodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong, SAR, P. R. China.
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17
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Ghosh S, Qiao W, Yang Z, Orrego S, Neelakantan P. Engineering Dental Tissues Using Biomaterials with Piezoelectric Effect: Current Progress and Future Perspectives. J Funct Biomater 2022; 14:jfb14010008. [PMID: 36662055 PMCID: PMC9867283 DOI: 10.3390/jfb14010008] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 12/08/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
Dental caries and traumatic injuries to teeth may cause irreversible inflammation and eventual death of the dental pulp. Nevertheless, predictably, repair and regeneration of the dentin-pulp complex remain a formidable challenge. In recent years, smart multifunctional materials with antimicrobial, anti-inflammatory, and pro-regenerative properties have emerged as promising approaches to meet this critical clinical need. As a unique class of smart materials, piezoelectric materials have an unprecedented advantage over other stimuli-responsive materials due to their inherent capability to generate electric charges, which have been shown to facilitate both antimicrobial action and tissue regeneration. Nonetheless, studies on piezoelectric biomaterials in the repair and regeneration of the dentin-pulp complex remain limited. In this review, we summarize the biomedical applications of piezoelectric biomaterials in dental applications and elucidate the underlying molecular mechanisms contributing to the biological effect of piezoelectricity. Moreover, we highlight how this state-of-the-art can be further exploited in the future for dental tissue engineering.
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Affiliation(s)
- Sumanta Ghosh
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | - Wei Qiao
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | - Zhengbao Yang
- Department of Mechanical Engineering & Department of Materials Science and Engineering, City University of Hong Kong, Hong Kong, China
| | - Santiago Orrego
- Oral Health Sciences Department, Kornberg School of Dentistry, Temple University, Philadelphia, PA 19140, USA
- Bioengineering Department, College of Engineering, Temple University, Philadelphia, PA 19140, USA
| | - Prasanna Neelakantan
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
- Correspondence:
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18
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Hu M, Kalimuthu S, Zhang C, Ali IAA, Neelakantan P. Trans-cinnamaldehyde-Biosurfactant Complex as a Potent Agent against Enterococcus faecalis Biofilms. Pharmaceutics 2022; 14:2355. [PMID: 36365173 PMCID: PMC9692797 DOI: 10.3390/pharmaceutics14112355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2022] [Revised: 10/17/2022] [Accepted: 10/30/2022] [Indexed: 01/18/2024] Open
Abstract
Enterococcus faecalis is an opportunistic microbial pathogen frequently associated with diverse infections, including those of the skin and teeth, as well as those from surgical wounds. It forms robust biofilms that are highly tolerant to most antimicrobials and first-line antibiotics. Therefore, investigating alternative strategies to eradicate its biofilms is a critical need. We recently demonstrated that trans-cinnamaldehyde (TC) potently kills E. faecalis biofilm cells and prevents biofilm recovery, and yet, the extreme hydrophobicity of TC hampers clinical translation. Here, we report that a complex of TC with an FDA-approved biosurfactant (acidic sophorolipid/ASL) significantly reduces the bacterial viability and biomass of E. faecalis biofilms, compared to TC alone. A confocal laser-scanning microscopic analysis demonstrated that the TC-ASL treatment significantly decreased the biofilm thickness and volume. In conclusion, our study highlights the anti-biofilm potential of the newly developed TC-ASL.
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Affiliation(s)
- Mingxin Hu
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | | | - Chengfei Zhang
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | - Islam A. A. Ali
- Department of Endodontics, Faculty of Dentistry, Mansoura University, Mansoura 35516, Egypt
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Ali IAA, Cheung GS, Neelakantan P. Transition Metals and
Enterococcus faecalis
: Homeostasis, Virulence and Perspectives. Mol Oral Microbiol 2022; 37:276-291. [DOI: 10.1111/omi.12391] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 09/07/2022] [Indexed: 11/29/2022]
Affiliation(s)
- Islam A. A. Ali
- Department of Endodontics Faculty of Dentistry Mansoura University Mansoura Egypt
| | - Gary S.P. Cheung
- Discipline of Endodontology Division of Restorative Dental Sciences Faculty of Dentistry The University of Hong Kong Hong Kong SAR
| | - Prasanna Neelakantan
- Discipline of Endodontology Division of Restorative Dental Sciences Faculty of Dentistry The University of Hong Kong Hong Kong SAR
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20
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Pudipeddi A, Vasudevan S, Shanmugam K, Mohan S S, Vairaprakash P, Neelakantan P, Balraj AS, Solomon AP. Design, dynamic docking, synthesis, and in vitro validation of a novel DNA gyrase B inhibitor. J Biomol Struct Dyn 2022:1-14. [PMID: 35924774 DOI: 10.1080/07391102.2022.2107073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-intermediate-resistant Staphylococcus aureus (VRSA) are among the WHO's high priority pathogens. Among these two, MRSA is the most globally documented pathogen that necessitates the pressing demand for new classes of anti-MRSA drugs. Bacterial gyrase targeted therapeutics are unique strategies to overcome cross-resistance as they are present only in bacteria and absent in higher eukaryotes. The GyrB subunit is essential for the catalytic functions of the bacterial enzyme DNA Gyrase, thereby constituting a promising druggable target. The current study performed a structure-based virtual screening to designing GyrB target-specific candidate molecules. The de novo ligand design of novel hit molecules was performed using a rhodanine scaffold. Through a systematic in silico screening process, the hit molecules were screened for their synthetic accessibility, drug-likeness and pharmacokinetics properties in addition to its target specific interactions. Of the 374 hit molecules obtained through de novo ligand design, qsl-304 emerged as the most promising ligand. The molecular dynamic simulation studies confirmed the stable interaction between the key residues and qsl-304. qsl-304 was synthesized through a one-step chemical synthesis procedure, and the in vitro activity was proven, with an IC50 of 31.23 µg/mL against the novobiocin resistant clinical isolate, Staphylococcus aureus sa-P2003. Further studies on time-kill kinetics showed the bacteriostatic nature with the diminished recurrence of resistance. The on-target gyrB inhibition further proved the efficacy of qsl-304.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Akhila Pudipeddi
- Quorum Sensing Laboratory, Centre of Research in Infectious Diseases, School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India.,Faculty of Dentistry, The University of Hong Kong, Pok Fu Lam, Hong Kong
| | - Sahana Vasudevan
- Quorum Sensing Laboratory, Centre of Research in Infectious Diseases, School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Karthi Shanmugam
- Quorum Sensing Laboratory, Centre of Research in Infectious Diseases, School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India.,Department of Bioinformatics, School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Suma Mohan S
- Department of Bioinformatics, School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Pothiappan Vairaprakash
- Department of Chemistry, School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | | | - Alex Stanley Balraj
- Quorum Sensing Laboratory, Centre of Research in Infectious Diseases, School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India.,Department of Bioinformatics, School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Adline Princy Solomon
- Quorum Sensing Laboratory, Centre of Research in Infectious Diseases, School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
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Venkateswaran P, Lakshmanan PM, Muthukrishnan S, Bhagavathi H, Vasudevan S, Neelakantan P, Solomon AP. Hidden agenda of Enterococcus faecalis lifestyle transition: planktonic to sessile state. Future Microbiol 2022; 17:1051-1069. [PMID: 35899477 DOI: 10.2217/fmb-2021-0212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Enterococcus faecalis, a human gastrointestinal tract commensal, is known to cause nosocomial infections. Interestingly, the pathogen's host colonization and persistent infections are possibly linked to its lifestyle changes from planktonic to sessile state. Also, the multidrug resistance and survival fitness acquired in the sessile stage of E. faecalis has challenged treatment regimes. This situation exists because of the critical role played by several root genes and their molecular branches, which are part of quorum sensing, aggregation substance, surface adhesions, stress-related response and sex pheromones in the sessile state. It is therefore imperative to decode the hidden agenda of E. faecalis and understand the significant factors influencing biofilm formation. This would, in turn, augment the development of novel strategies to tackle E. faecalis infections.
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Affiliation(s)
- Parvathy Venkateswaran
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
| | - Priya M Lakshmanan
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
| | - Sudhiksha Muthukrishnan
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
| | - Hema Bhagavathi
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
| | - Sahana Vasudevan
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
| | | | - Adline P Solomon
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical & Biotechnology, SASTRA Deemed to be University, Thanjavur, 613401, India
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Jarkhi A, Lee AHC, Sun Z, Hu M, Neelakantan P, Li X, Zhang C. Antimicrobial Effects of L-Chg10-Teixobactin against Enterococcus faecalis In Vitro. Microorganisms 2022; 10:microorganisms10061099. [PMID: 35744616 PMCID: PMC9228388 DOI: 10.3390/microorganisms10061099] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2022] [Revised: 05/22/2022] [Accepted: 05/22/2022] [Indexed: 11/18/2022] Open
Abstract
Objective: Teixobactin and its analogues are a new class of antibiotics that have no detectable bacterial resistance. This study was designed to determine the antibacterial and antibiofilm activities of a novel teixobactin analogue, L-Chg10-teixobactin, against two strains of Enterococcus faecalis (E. faecalis). Materials and Methods: The efficacy of L-Chg10-teixobactin against two strains of E. faecalis (ATCC 29212 and 47077) was determined using Clinical and Laboratory Standards Institute methods. L-Chg10-teixobactin was prepared at a stock concentration of 1 mg/mL in 5% DMSO. The minimum inhibitory concentration (MIC) was calculated using a two-fold serial broth dilution method, utilizing a 96-well plate. The minimum bactericidal concentration (MBC) was determined by plating the bacteria onto agar to define the concentration that resulted in 99.9% of bacterial death. Ampicillin was used as the control. The effect of L-Chg10-teixobactin on the inhibition of ATCC 47077 strain biofilm formation was determined by measuring the minimum biofilm inhibitory concentration (MBIC) using the safranin assay, while the eradication of the preformed biofilm was determined by measuring the minimum biofilm eradication concentration (MBEC) using the XTT assay. For nonlinear data, the log dose–response curve was plotted to calculate the optimum concentration using Excel (version 16.51, Microsoft® excel. 2021, Microsoft Corporation, Reymond, WA, USA). The data are presented as mean ± standard deviation (SD). Results: The MIC and MBC values of L-Chg10-teixobactin against both strains of E. faecalis were 0.8 μg/mL. The MIC of ampicillin was 1.25 μg/mL for ATCC 29212 and ranged from 1.25 to 5 μg/mL for ATCC 47077. The MBC of ampicillin for ATCC 29212 and ATCC 47077 was 10 and 20 μg/mL, respectively. The MIC and MBC of ampicillin were much higher compared with those of L-Chg10-teixobactin. The MBEC80 of L-Chg10-teixobactin was 4.60 μg/mL for ATCC 47077, which was much lower than that of ampicillin (20 μg/mL). Conclusions:L-Chg10-teixobactin demonstrated potent antibacterial and antibiofilm effects against E. faecalis, suggesting its potential role an effective antibacterial and antibiofilm agent in endodontic treatment.
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Ali IAA, Neelakantan P. Antibiofilm activity of phytochemicals against Enterococcus faecalis: A literature review. Phytother Res 2022; 36:2824-2838. [PMID: 35522168 DOI: 10.1002/ptr.7488] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 02/17/2022] [Accepted: 04/19/2022] [Indexed: 12/11/2022]
Abstract
Enterococcus faecalis is a leading causative pathogen of recalcitrant infections affecting heart valves, urinary tract, surgical wounds and dental root canals. Its robust biofilm formation, production of virulence factors and antibiotic resistance contribute significantly to its pathogenicity in persistent infections. The decreased effectiveness of most of antibiotics in preventing and/or eradicating E. faecalis biofilms mandates the discovery of alternative novel antibiofilm agents. Phytochemicals are potential sources of antibiofilm agents due to their antivirulence activity, diversity of chemical structure and multiple mechanisms of action. In this review, we describe the phenotypic and genetic attributes that contribute to antimicrobial tolerance of E. faecalis biofilms. We illuminate the benefits of implementing the phytochemicals to tackle microbial pathogens. Finally, we report the antibiofilm activity of phytochemicals against E. faecalis, and explain their mechanisms of action. These compounds belong to different chemical classes such as terpenes, phenylpropenes, flavonoids, curcuminoids and alkaloids. They demonstrate the ability to inhibit the formation of and/or eradicate E. faecalis biofilms. However, the exact mechanisms of action of most of these compounds are not fully understood. Therefore, the future studies should elucidate the underlying mechanisms in detail.
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Affiliation(s)
- Islam A A Ali
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR
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24
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Neelakantan P, Vishwanath V, Taschieri S, Corbella S. Present status and future directions ‐ Minimally invasive root canal preparation and periradicular surgery. Int Endod J 2022; 55 Suppl 4:845-871. [DOI: 10.1111/iej.13750] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 04/06/2022] [Accepted: 04/11/2022] [Indexed: 11/30/2022]
Affiliation(s)
- P. Neelakantan
- Faculty of Dentistry The University of Hong Kong Hong Kong SAR
| | - V. Vishwanath
- Faculty of Dentistry The University of Hong Kong Hong Kong SAR
| | - S. Taschieri
- Department of Biomedical Surgical and Dental Sciences Università degli Studi di Milano Milan Italy
- IRCCS Istituto Ortopedico Galeazzi Milan Italy
- Department of Oral Surgery Institute of Dentistry I. M. Sechenov First Moscow State Medical University Moscow Russia
| | - S. Corbella
- Department of Biomedical Surgical and Dental Sciences Università degli Studi di Milano Milan Italy
- IRCCS Istituto Ortopedico Galeazzi Milan Italy
- Department of Oral Surgery Institute of Dentistry I. M. Sechenov First Moscow State Medical University Moscow Russia
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25
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Pedullà E, La Rosa GRM, Romano G, Leanza G, Rapisarda S, Isola G, Ferlito S, Neelakantan P, Generali L. Influence of kinematics and incidence angles on the cutting efficiency of two single-file nickel-titanium rotary instruments. AUST ENDOD J 2022; 48:58-64. [PMID: 34258843 PMCID: PMC9290840 DOI: 10.1111/aej.12543] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 06/15/2021] [Accepted: 06/26/2021] [Indexed: 02/05/2023]
Abstract
To compare the cutting efficiency of F6 Sky Taper (F6ST) and One Curve (OC) with different kinematics and cutting inclinations. Cutting efficiency of 80 new F6ST and OC was tested at 90° and 70° inclination in relation to the sample, in continuous rotation and reciprocation, against standardised gypsum samples for 120 seconds using a customised device. Data expressed as weight loss and length of the sample cut were analysed using two-way analysis of variance and Tukey t-test (P<.05). F6ST showed significantly higher cutting efficiency in reciprocation, while OC in continuous rotation. Regardless of inclination, F6ST showed statistically higher values than OC in reciprocation, while OC exhibited higher cutting ability in continuous rotation. The 70° inclination significantly improved the cutting efficiency of both files. Reciprocation improved the cutting efficiency of F6ST while continuous rotation enhanced cutting ability of OC. An inclined insertion improved the cutting ability, independently from the movement.
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Affiliation(s)
- Eugenio Pedullà
- Department of General Surgery and Medical ‐ Surgical SpecialtiesUniversity of CataniaCataniaItaly
| | - Giusy Rita Maria La Rosa
- Department of General Surgery and Medical ‐ Surgical SpecialtiesUniversity of CataniaCataniaItaly
| | - Giuseppe Romano
- Department of General Surgery and Medical ‐ Surgical SpecialtiesUniversity of CataniaCataniaItaly
| | - Giuseppe Leanza
- Department of General Surgery and Medical ‐ Surgical SpecialtiesUniversity of CataniaCataniaItaly
| | - Silvia Rapisarda
- Department of General Surgery and Medical ‐ Surgical SpecialtiesUniversity of CataniaCataniaItaly
| | - Gaetano Isola
- Department of General Surgery and Medical ‐ Surgical SpecialtiesUniversity of CataniaCataniaItaly
| | - Sebastiano Ferlito
- Department of General Surgery and Medical ‐ Surgical SpecialtiesUniversity of CataniaCataniaItaly
| | - Prasanna Neelakantan
- Discipline of EndodontologyFaculty of DentistryThe University of Hong KongThe Prince Philip Dental HospitalHong Kong SARChina
| | - Luigi Generali
- Endodontic SectionDepartment of Surgery, MedicineDentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO)School of DentistryUniversity of Modena and Reggio EmiliaModenaItaly
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26
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Kalimuthu S, Alshanta OA, Krishnamoorthy AL, Pudipeddi A, Solomon AP, McLean W, Leung YY, Ramage G, Neelakantan P. Small molecule based anti-virulence approaches against Candida albicans infections. Crit Rev Microbiol 2022; 48:743-769. [PMID: 35232325 DOI: 10.1080/1040841x.2021.2025337] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Fungi are considered "silent killers" due to the difficulty of, and delays in diagnosis of infections and lack of effective antifungals. This challenge is compounded by the fact that being eukaryotes, fungi share several similarities with human cellular targets, creating obstacles to drug discovery. Candida albicans, a ubiquitous microbe in the human body is well-known for its role as an opportunistic pathogen in immunosuppressed people. Significantly, C. albicans is resistant to all the three classes of antifungals that are currently clinically available. Over the past few years, a paradigm shift has been recommended in the management of C. albicans infections, wherein anti-virulence strategies are considered an alternative to the discovery of new antimycotics. Small molecules, with a molecular weight <900 Daltons, can easily permeate the cell membrane and modulate the signal transduction pathways to elicit desired virulence inhibitory actions against pathogens. This review dissects in-depth, the discoveries that have been made with small-molecule anti-virulence approaches to tackle C. albicans infections.
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Affiliation(s)
| | - Om Alkhir Alshanta
- Glasgow Endodontology Group, Glasgow Dental School, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences, Glasgow, UK
| | - Akshaya Lakshmi Krishnamoorthy
- Faculty of Dentistry, The University of Hong Kong, Hong Kong, China.,Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Akhila Pudipeddi
- Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - Adline Princy Solomon
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - William McLean
- Glasgow Endodontology Group, Glasgow Dental School, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences, Glasgow, UK
| | - Yiu Yan Leung
- Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - Gordon Ramage
- Glasgow Endodontology Group, Glasgow Dental School, School of Medicine, Dentistry and Nursing, College of Medical, Veterinary and Life Sciences, Glasgow, UK
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27
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Wong J, Manoil D, Näsman P, Belibasakis GN, Neelakantan P. Microbiological Aspects of Root Canal Infections and Disinfection Strategies: An Update Review on the Current Knowledge and Challenges. Front Oral Health 2022; 2:672887. [PMID: 35048015 PMCID: PMC8757850 DOI: 10.3389/froh.2021.672887] [Citation(s) in RCA: 51] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 05/17/2021] [Indexed: 02/06/2023] Open
Abstract
The oral cavity is the habitat of several hundreds of microbial taxa that have evolved to coexist in multispecies communities in this unique ecosystem. By contrast, the internal tissue of the tooth, i.e., the dental pulp, is a physiologically sterile connective tissue in which any microbial invasion is a pathological sign. It results in inflammation of the pulp tissue and eventually to pulp death and spread of inflammation/infection to the periradicular tissues. Over the past few decades, substantial emphasis has been placed on understanding the pathobiology of root canal infections, including the microbial composition, biofilm biology and host responses to infections. To develop clinically effective treatment regimens as well as preventive therapies, such extensive understanding is necessary. Rather surprisingly, despite the definitive realization that root canal infections are biofilm mediated, clinical strategies have been focused more on preparing canals to radiographically impeccable levels, while much is left desired on the debridement of these complex root canal systems. Hence, solely focusing on "canal shaping" largely misses the point of endodontic treatment as the current understanding of the microbial aetiopathogenesis of apical periodontitis calls for the emphasis to be placed on "canal cleaning" and chemo-mechanical disinfection. In this review, we dissect in great detail, the current knowledge on the root canal microbiome, both in terms of its composition and functional characteristics. We also describe the challenges in root canal disinfection and the novel strategies that attempt to address this challenge. Finally, we provide some critical pointers for areas of future research, which will serve as an important area for consideration in Frontiers in Oral Health.
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Affiliation(s)
- Jasmine Wong
- Discipline of Endodontology, Division of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
| | - Daniel Manoil
- Division of Oral Diseases, Department of Dental Medicine, Karolinska Institute, Huddinge, Sweden
| | - Peggy Näsman
- Division of Oral Diseases, Department of Dental Medicine, Karolinska Institute, Huddinge, Sweden
| | - Georgios N Belibasakis
- Division of Oral Diseases, Department of Dental Medicine, Karolinska Institute, Huddinge, Sweden
| | - Prasanna Neelakantan
- Discipline of Endodontology, Division of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China
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28
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Vasudevan S, Srinivasan P, Neelakantan P, Rayappan JBB, Solomon AP. Photoluminescence-Based Bioassay With Cysteamine-Capped TiO 2 Nanoparticles for the Selective Recognition of N-Acyl Homoserine Lactones. Front Bioeng Biotechnol 2021; 9:750933. [PMID: 34926417 PMCID: PMC8678280 DOI: 10.3389/fbioe.2021.750933] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Accepted: 11/08/2021] [Indexed: 11/13/2022] Open
Abstract
Currently available diagnostic procedures for infections are laborious and time-consuming, resulting in a substantial financial burden by increasing morbidity, increased costs of hospitalization, and mortality. Therefore, innovative approaches to design diagnostic biomarkers are imperative to assist in the rapid and sensitive diagnosis of microbial infections. Acyl homoserine lactones (AHLs) are ubiquitous bacterial signaling molecules that are found to be significantly upregulated in infected sites. In this pioneering work, we have developed a simple photoluminescence-based assay using cysteamine-capped titanium oxide (TiO2) nanoparticles for AHL detection. The PL intensity variation of the oxygen defect state of TiO2 was used for the biosensing measurements. The bioassays were validated using two well-studied AHL molecules (C4-HSL and 3-oxo-C12 HSL) of an important human pathogen, Pseudomonas aeruginosa. The developed system has a maximum relative response of 98%. Furthermore, the efficacy of the system in simulated host urine using an artificial urine medium showed a linear detection range of 10-160 nM. Also, we confirmed the relative response and specificity of the system in detecting AHLs produced by P. aeruginosa in a temporal manner.
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Affiliation(s)
- Sahana Vasudevan
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Parthasarathy Srinivasan
- Nanosensors Laboratory, School of Electrical & Electronics Engineering, Centre for Nanotechnology & Advanced Biomaterials (CeNTAB), SASTRA Deemed University, Thanjavur, India
- Department of Electronics and Communication Engineering, Amrita School of Engineering, AMRITA Vishwa Vidyapeetham Chennai Campus, Chennai, India
| | - Prasanna Neelakantan
- Faculty of Dentistry, The University of Hong Kong, Pokfulam, Hong KongSAR, China
| | - John Bosco Balaguru Rayappan
- Nanosensors Laboratory, School of Electrical & Electronics Engineering, Centre for Nanotechnology & Advanced Biomaterials (CeNTAB), SASTRA Deemed University, Thanjavur, India
| | - Adline Princy Solomon
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
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Ali IAA, Lévesque CM, Neelakantan P. Fsr quorum sensing system modulates the temporal development of Enterococcus faecalis biofilm matrix. Mol Oral Microbiol 2021; 37:22-30. [PMID: 34862746 DOI: 10.1111/omi.12357] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 11/13/2021] [Accepted: 11/30/2021] [Indexed: 11/27/2022]
Abstract
Quorum sensing (QS) is a cell-to-cell communication process that regulates major pathogenic attributes in bacteria including biofilm formation, secretion of virulence factors, and antimicrobial resistance. The two-component Fsr-QS system of the nosocomial pathogen Enterococcus faecalis controls the production of extracellular gelatinase that contributes to biofilm development by enhancing the release of nucleic acids into the biofilm matrix. However, the contribution of this system to the deposition of other biofilm matrix components such as polysaccharides and proteins remains unknown. Using wild type and mutant strains, we discovered that biofilm formation was attenuated by inactivation of the Fsr system or its downstream gelatinase production. Inactivation of the Fsr system caused a modest, yet significant reduction in biofilm metabolic activity without affecting cell counts. Inactivation of the QS-signal sensor FsrC and response regulator FsrA resulted in decreased extracellular polysaccharides and proteins in biofilms in a temporal manner. Irrespective of biofilm age, eDNA levels were reduced in the gelatinase mutant strain. Our results collectively suggest that the Fsr system contributes to the temporal deposition of polysaccharides and proteins into the extracellular polymeric matrix (EPS) of E. faecalis biofilm, without affecting bacterial viability. This understanding of the role of the Fsr-QS system in biofilm development may reveal a novel target to develop effective antibiofilm agents to tackle E. faecalis-mediated infections such as in dental root canals, heart valves, and surgical sites.
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Affiliation(s)
- Islam A A Ali
- Faculty of Dentistry, The University of Hong Kong, Sai Ying Pun, Hong Kong SAR, China
| | | | - Prasanna Neelakantan
- Faculty of Dentistry, The University of Hong Kong, Sai Ying Pun, Hong Kong SAR, China
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30
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Abiad RS, Neelakantan P, Buscema I, Ali IA, Conte G, LA Rosa GR, Generali L, Cicciù M, Pedullà E. A micro-computed tomographic analysis of obturation quality and retreatability of an epoxy resin-based sealer. Minerva Dent Oral Sci 2021; 71:131-138. [PMID: 34636216 DOI: 10.23736/s2724-6329.21.04588-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
BACKGROUND To evaluate the voids percentage and the retreatability by different supplementary irrigation techniques of a matched-taper single cone and epoxy resin-based sealer. METHODS A total of 72 single-rooted premolars were prepared and filled with gutta-percha and MM-Seal. The percentage of voids in the whole root canal and each anatomical part were evaluated by Micro-CT scans. After root filling removal, the teeth were randomly allocated (n=24) to group A, syringe irrigation; group B, Tornado Brush and group C, ultrasonically activated irrigation and rescanned to establish the volume of remnant root filling material. The data relative to voids and retreatment techniques were established by Kruskal-Wallis test. Differences in retreatment time were examined using one-way ANOVA and Tukey's test (P< .05). RESULTS No significant difference was found in the voids percentage between the different root-thirds and between the supplementary irrigation groups in the MM-Seal remnants for the whole root canal and each section. In all groups, the coronal region exhibited more remaining material than other sections. CONCLUSIONS MM-Seal showed low voids percentage and its removal was not significantly improved by supplementary irrigation techniques.
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Affiliation(s)
- Roula S Abiad
- Division of Endodontology, Faculty of Dentistry, Beirut Arab University, Beirut, Lebanon
| | - Prasanna Neelakantan
- Discipline of Endodontology, Faculty of Dentistry, The University of Hong Kong, Hong Kong
| | - Ivan Buscema
- Department of General Surgery and Medical-Surgical Specialties, University of Catania, Catania, Italy
| | - Islam A Ali
- Discipline of Endodontology, Faculty of Dentistry, The University of Hong Kong, Hong Kong
| | - Gianluca Conte
- Department of General Surgery and Medical-Surgical Specialties, University of Catania, Catania, Italy
| | - Giusy R LA Rosa
- Department of General Surgery and Medical-Surgical Specialties, University of Catania, Catania, Italy -
| | - Luigi Generali
- Endodontic Section, Department of Surgery, Medicine, Dentistry and Morphological Sciences with Transplant Surgery, Oncology and Regenerative Medicine Relevance (CHIMOMO), School of Dentistry, University of Modena and Reggio Emilia, Modena, Italy
| | - Marco Cicciù
- Department of Biomedical and Dental Sciences, Morphological and Functional Images, Azienda Ospedaliera Universitaria G. Martino, University of Messina, Messina, Italy
| | - Eugenio Pedullà
- Department of General Surgery and Medical-Surgical Specialties, University of Catania, Catania, Italy
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31
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Lee AHC, Neelakantan P, Dummer PMH, Zhang C. Cemental tear: Literature review, proposed classification and recommendations for treatment. Int Endod J 2021; 54:2044-2073. [PMID: 34403513 DOI: 10.1111/iej.13611] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 08/16/2021] [Indexed: 11/29/2022]
Abstract
Cemental tears are an important condition of relevance to Endodontics but are often overlooked. A cemental tear is the partial or complete detachment of the cementum from the cemento-dentinal junction or along the incremental line within the body of cementum. The limited attention received is most likely due to the limited awareness amongst dental professionals and challenges in accurately diagnosing them, resulting in misdiagnosis and erroneous treatment. The aim of this review is to describe the: (i) epidemiology and predisposing factors; (ii) clinical, radiographic and histological features and (iii) the clinical management and treatment outcomes of cemental tear. The review included 37 articles published in English that comprised eight observational studies and 29 case reports. The prevalence of cemental tears was reported to be lower than 2%; whilst the incidence remains unknown. Internal factors due to the inherent structural weakness of cementum and its interface with the dentine, and external factors that are associated with stress have been proposed as the two mechanisms responsible for the development and propagation of cemental tears. Predisposing factors that have been implicated were tooth type, gender, age, previous root canal treatment, history of dental trauma, occlusal trauma and excessive occlusal force; however, evidence is limited. Common clinical and radiographic manifestations of cemental tears resemble the presentations of primary endodontic diseases, primary periodontal diseases and combined endodontic-periodontal lesions. Clinical management tended to focus on complete removal of the torn fragments and periodontal treatment, often combined with regenerative treatment. In this article, a new classification for cemental tears is developed that consists of classes 0 to 6 and stages A, B, C and D based on the: (i) location and accessibility of the torn cemental fragment; (ii) the pattern and extension of the associated bony defect in relation to the root length and (iii) the number of root surface/s affected by the cemental tear/s and the associated bony defect. Recommendations for treatment strategies are also provided and linked to the classification to aid in streamlining the process of treatment decision making.
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Affiliation(s)
- Angeline H C Lee
- Division of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | - Prasanna Neelakantan
- Division of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | - Paul M H Dummer
- School of Dentistry, College of Biomedical and Life Sciences, Cardiff University, Cardiff, UK
| | - Chengfei Zhang
- Division of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
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Ng WNI, Marruganti C, Grandini S, Neelakantan P. Root canal debridement by negative pressure irrigation, ultrasonically activated irrigation and their combination. J Oral Sci 2021; 63:286-288. [PMID: 34108301 DOI: 10.2334/josnusd.21-0095] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
Abstract
Despite scientific evidence that root canal debridement is the cornerstone for successful treatment, the effectiveness of a combination of delivery and activation systems in cleaning root canals remains unknown. This study is the first to demonstrate the remaining pulp tissue in root canals after irrigation with various techniques such as positive pressure syringe-and-needle irrigation, ultrasonic activation, negative pressure irrigation and ultrasonic activation after negative pressure irrigation. The results showed that negative pressure irrigation alone and its combination with ultrasonic activation resulted in significantly superior effectiveness than positive pressure irrigation and ultrasonic activation alone in the apical-third of root canals.
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Affiliation(s)
- Wing Nok Isaac Ng
- Discipline of Endodontology, Division of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong
| | | | | | - Prasanna Neelakantan
- Discipline of Endodontology, Division of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong
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Choi MJ, Kim MA, Choi Y, Neelakantan P, Yu MK, Min KS. A novel three-dimensionally printed model to assess biofilm removal by ultrasonically activated irrigation. Int Endod J 2021; 54:1871-1877. [PMID: 34043827 DOI: 10.1111/iej.13579] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 05/19/2021] [Accepted: 05/24/2021] [Indexed: 02/05/2023]
Abstract
AIM To apply an innovative three-dimensionally printed tooth model to investigate the efficacy of three ultrasonically activated irrigation (UAI) systems in removing multispecies biofilms from dentine samples. METHODOLOGY Three-dimensionally printed teeth with a curved root canal were fabricated with a standardized slot in the apical third of the root to achieve precision fit of human root dentine specimens. Multispecies biofilms including Enterococcus faecalis, Streptococcus mitis and Campylobacter rectus were developed in the root canal for 21 days. The canals were allocated to be irrigated with 1% sodium hypochlorite (NaOCl) using a syringe and needle or ultrasonically activated NaOCl with a stainless-steel file (Irrisafe), a conventional nickel-titanium (Ni-Ti) file (CK) or a blue heat-treated Ni-Ti file (Endosonic Blue). Infected root canals irrigated with distilled water served as controls. Bacterial reduction was determined by colony-forming unit (CFU) counting (n = 20), whilst biofilms were analysed using confocal laser scanning microscopy (n = 7) and field emission scanning electron microscopy. For CFU counting, the independent two-sample t-test (Welch's t-test) was examined to compare overall bacterial reduction amongst groups. For CLSM analysis, the data were analysed using one-way analysis of variance (ANOVA), followed by the Scheffé post hoc test. The p-values <.05 were considered to indicate statistical significance. RESULTS All groups in which NaOCl was ultrasonically activated had significantly lower CFU values than the syringe-and-needle irrigation and control groups (p < .05). Ultrasonic activation with the stainless-steel file and blue heat-treated Ni-Ti file significantly reduced the biofilm volume compared with other groups (p < .05). Overall, UAI with the blue heat-treated file resulted in the highest antibacterial and biofilm removal efficacy. CONCLUSIONS UAI with different inserts had differential antibiofilm effects. The blue heat-treated Ni-Ti ultrasonic insert resulted in the greatest antibacterial and biofilm removal from dentine in this standardized root canal model.
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Affiliation(s)
- Min-Ji Choi
- Department of Conservative Dentistry, School of Dentistry, Jeonbuk National University, Jeonju, Korea
| | - Mi-Ah Kim
- Department of Conservative Dentistry, School of Dentistry, Jeonbuk National University, Jeonju, Korea
| | - Yoorina Choi
- Department of Conservative Dentistry, College of Dentistry, Wonkwang University, Iksan, Korea
| | - Prasanna Neelakantan
- Discipline of Endodontology, Department of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong, Hong Kong
| | - Mi-Kyung Yu
- Department of Conservative Dentistry, School of Dentistry, Jeonbuk National University, Jeonju, Korea.,Research Institute of Clinical Medicine of Jeonbuk National University, Jeonju, Korea.,Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Korea
| | - Kyung-San Min
- Department of Conservative Dentistry, School of Dentistry, Jeonbuk National University, Jeonju, Korea.,Research Institute of Clinical Medicine of Jeonbuk National University, Jeonju, Korea.,Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju, Korea
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Zhang T, Kalimuthu S, Rajasekar V, Xu F, Yiu YC, Hui TKC, Neelakantan P, Chu Z. Biofilm inhibition in oral pathogens by nanodiamonds. Biomater Sci 2021; 9:5127-5135. [PMID: 33997876 DOI: 10.1039/d1bm00608h] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Complex microbial communities, e.g., biofilms residing in our oral cavity, have recognized clinical significance, as they are typically the main cause for infections. Particularly, they show high resistance to conventional antibiotics, and alternatives including nanotechnology are being intensively explored nowadays to provide more efficient therapeutics. Diamond nanoparticles, namely, nanodiamonds (NDs) with many promising physico-chemical properties, have been demonstrated to work as an effective antibacterial agent against planktonic cells (free-floating state). However, little is known about the behaviors of NDs against biofilms (sessile state). In this study, we uncovered their role in inhibiting biofilm formation and their disrupting effect on preformed biofilms in several selected orally and systemically important organisms. The current findings will advance the mechanistic understanding of NDs on oral pathogens and might accelerate corresponding clinical translation.
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Affiliation(s)
- Tongtong Zhang
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong, China
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Spicciarelli V, Neelakantan P, Cantini E, Marzocco DA, Ounsi HF, Marruganti C, Grandini S. Immediate and Delayed Bond Strength of a Multimode Adhesive to Deep Coronal Dentin Following Different Root Canal Irrigation Regimens. J Adhes Dent 2021; 23:167-175. [PMID: 33825430 DOI: 10.3290/j.jad.b1079597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
PURPOSE To investigate the effects of root canal irrigants, dentin surface treatment, and timing of the restoration on the microtensile bond strength (μTBS) of a universal adhesive to deep coronal dentin. MATERIALS AND METHODS Ninety (90) intact molars were grouped according to the irrigation protocol: group 0 (saline, control group); group 1: 5.25% sodium hypochlorite (NaOCl), 17% ethylenediaminetetraacetic acid (EDTA) followed by 5.25% NaOCl; group 2: 18% etidronic acid (HEDP) + 5.25% NaOCl in a single mixture. Groups 1 and 2 were divided into 2 subgroups (n = = 10) according to the time of restoration: immediate (subgroup A) and after 7 days (subgroup B). Four other groups (n = 10) were created according to the dentin surface pretreatment and received an immediate restoration: group 3: 5.25% NaOCl - 17% EDTA and AH Plus Cleaner; group 4: 5.25% NaOCl - 17% EDTA and 100% ethanol; group 5: 5.25% NaOCl + 18% HEDP and AH Plus Cleaner; group 6: 5.25% NaOCl + 18% HEDP and 100% ethanol. μTBS testing was carried out for each subgroup and interfaces were analyzed through SEM. The μTBS was analyzed with Welch statistics and the post-hoc Games-Howell test for multiple comparisons (p < 0.05). RESULTS Statistically significant differences were observed between test groups and control groups (p < 0.001), except for group 3 (p = 0.349). No significant differences were recorded between groups 1A (27.5 ± 8.7 MPa), 2A (32.6 ± 14.5 MPa) and 3 (27.3 ± 14.3 MPa). Group 6 (48.6 ± 11.6 MPa) exhibited the highest μTBS among all tested groups. For groups 1 and 2, significantly higher values were recorded for subgroups 1B (39.3 ± 7.6 MPa) and 2B (43.8 ± 8.3 MPa) compared to subgroups 1A (27.5 ± 8.7 MPa) and 2A (32.6 ± 14.5 MPa). CONCLUSION When using NaOCl as root canal irrigant, it is advisable to delay the placement of a post-endodontic-treatment restoration.
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Elango AV, Vasudevan S, Shanmugam K, Solomon AP, Neelakantan P. Exploring the anti-caries properties of baicalin against Streptococcus mutans: an in vitro study. Biofouling 2021; 37:267-275. [PMID: 33719751 DOI: 10.1080/08927014.2021.1897789] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
Plant-derived molecules are excellent alternatives to antibiotics as anti-infective agents owing to their minimal cytotoxicity. Herein, the anti-infective property of the hydroxyflavone baicalin, was investigated against biofilms of the key dental caries pathogen Streptococcus mutans. Baicalin inhibited sucrose-dependent biofilm formation at a concentration of 500 µg ml-1 without affecting bacterial growth. It significantly inhibited acid production for an extended period of 8 h. Microscopic analysis revealed a 6-fold reduction in the number of adhered cells with baicalin treatment. Transcriptomic analysis of the mid-log phase and biofilm cells showed marked downregulation of the virulence genes required for biofilm formation and acid production. This study sheds significant new light on the potential for baicalin to be developed into an anti-caries agent.
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Affiliation(s)
- Arval Viji Elango
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Sahana Vasudevan
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Karthi Shanmugam
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Adline Princy Solomon
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - Prasanna Neelakantan
- Division of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong, SAR
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Vijayakumar A, Sarveswari HB, Vasudevan S, Shanmugam K, Solomon AP, Neelakantan P. Baicalein Inhibits Streptococcus mutans Biofilms and Dental Caries-Related Virulence Phenotypes. Antibiotics (Basel) 2021; 10:215. [PMID: 33670013 PMCID: PMC7926557 DOI: 10.3390/antibiotics10020215] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/19/2021] [Accepted: 02/19/2021] [Indexed: 12/15/2022] Open
Abstract
Dental caries, the most common oral disease, is a major public healthcare burden and affects more than three billion people worldwide. The contemporary understanding of the need for a healthy microbiome and the emergence of antimicrobial resistance has resulted in an urgent need to identify compounds that curb the virulence of pathobionts without microbial killing. Through this study, we have demonstrated for the first time that 5,6,7-trihydroxyflavone (Baicalein) significantly downregulates crucial caries-related virulence phenotypes in Streptococcus mutans. Baicalein significantly inhibited biofilm formation by Streptococcus mutans UA159 (MBIC50 = 200 μM), without significant growth inhibition. Notably, these concentrations of baicalein did not affect the commensal S. gordonii. Strikingly, baicalein significantly reduced cell surface hydrophobicity, autoaggregation and acid production by S. mutans. Mechanistic studies (qRT-PCR) showed downregulation of various genes regulating biofilm formation, surface attachment, quorum sensing, acid production and competence. Finally, we demonstrate the potential translational value of baicalein by reporting synergistic interaction with fluoride against S. mutans biofilms.
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Affiliation(s)
- Aparna Vijayakumar
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur 613401, India; (A.V.); (H.B.S.); (S.V.); (K.S.)
| | - Hema Bhagavathi Sarveswari
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur 613401, India; (A.V.); (H.B.S.); (S.V.); (K.S.)
| | - Sahana Vasudevan
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur 613401, India; (A.V.); (H.B.S.); (S.V.); (K.S.)
| | - Karthi Shanmugam
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur 613401, India; (A.V.); (H.B.S.); (S.V.); (K.S.)
| | - Adline Princy Solomon
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur 613401, India; (A.V.); (H.B.S.); (S.V.); (K.S.)
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Rajasekar V, Darne P, Prabhune A, Kao RYT, Solomon AP, Ramage G, Samaranayake L, Neelakantan P. A curcumin-sophorolipid nanocomplex inhibits Candida albicans filamentation and biofilm development. Colloids Surf B Biointerfaces 2021; 200:111617. [PMID: 33592455 DOI: 10.1016/j.colsurfb.2021.111617] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2020] [Revised: 01/29/2021] [Accepted: 02/03/2021] [Indexed: 12/20/2022]
Abstract
Candida albicans is an opportunistic fungal pathogen that is highly resistant to contemporary antifungals, due to their biofilm lifestyle. The ability of C. albicans to invade human tissues is due to its filamentation. Therefore, inhibition of biofilms and filamentation of the yeast are high value targets to develop the next-generation antifungals. Curcumin (CU) is a natural polyphenol with excellent pharmacological attributes, but limitations such as poor solubility, acid, and enzyme tolerance have impeded its practical utility. Sophorolipids (SL) are biologically-derived surfactants that serve as efficient carriers of hydrophobic molecules such as curcumin into biofilms. Here, we synthesised a curcumin-sophorolipid nanocomplex (CUSL), and comprehensively evaluated its effects on C. albicans biofilms and filamentation. Our results demonstrated that sub-inhibitory concentration of CUSL (9.37 μg/mL) significantly inhibited fungal adhesion to substrates, and subsequent biofilm development, maturation, and filamentation. This effect was associated with significant downregulation of a select group of biofilm, adhesins, and hyphal regulatory genes. In conclusion, the curcumin-sophorolipid nanocomplex is a potent inhibitor of the two major virulence attributes of C. albicans, biofilm formation and filamentation, thus highlighting its promise as a putative anti-fungal agent with biofilm penetrative potential.
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Affiliation(s)
- Vidhyashree Rajasekar
- Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region; Quorum Sensing Laboratory, Centre of Research in Infectious Diseases, School of Chemical and Biotechnology, SASTRA Deemed to Be University, Thanjavur, India
| | - Priti Darne
- Green Pyramid Biotech Private Limited, Pune, India
| | | | - Richard Y T Kao
- Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Adline Princy Solomon
- Quorum Sensing Laboratory, Centre of Research in Infectious Diseases, School of Chemical and Biotechnology, SASTRA Deemed to Be University, Thanjavur, India
| | - Gordon Ramage
- Oral Sciences Research Group, Glasgow Dental School, School of Medicine, Dentistry & Nursing, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, Scotland, United Kingdom
| | - Lakshman Samaranayake
- Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Prasanna Neelakantan
- Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region.
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Affiliation(s)
- Mirza Muhammad Faran Ashraf Baig
- Biomedical Engineering and Biofunctional Materials Theme, Restorative Dental Sciences, Faculty of Dentistry The University of Hong Kong Hong Kong SAR China
| | - Ting Zou
- Biomedical Engineering and Biofunctional Materials Theme, Restorative Dental Sciences, Faculty of Dentistry The University of Hong Kong Hong Kong SAR China
| | - Prasanna Neelakantan
- Biomedical Engineering and Biofunctional Materials Theme, Restorative Dental Sciences, Faculty of Dentistry The University of Hong Kong Hong Kong SAR China
| | - Chengfei Zhang
- Biomedical Engineering and Biofunctional Materials Theme, Restorative Dental Sciences, Faculty of Dentistry The University of Hong Kong Hong Kong SAR China
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Krishnamoorthy AL, Lemus AA, Solomon AP, Valm AM, Neelakantan P. Interactions between Candida albicans and Enterococcus faecalis in an Organotypic Oral Epithelial Model. Microorganisms 2020; 8:E1771. [PMID: 33187237 PMCID: PMC7696566 DOI: 10.3390/microorganisms8111771] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 11/06/2020] [Accepted: 11/10/2020] [Indexed: 12/23/2022] Open
Abstract
Candida albicans as an opportunistic pathogen exploits the host immune system and causes a variety of life-threatening infections. The polymorphic nature of this fungus gives it tremendous advantage to breach mucosal barriers and cause oral and disseminated infections. Similar to C. albicans, Enterococcus faecalis is a major opportunistic pathogen, which is of critical concern in immunocompromised patients. There is increasing evidence that E. faecalis co-exists with C. albicans in the human body in disease samples. While the interactive profiles between these two organisms have been studied on abiotic substrates and mouse models, studies on their interactions on human oral mucosal surfaces are non-existent. Here, for the first time, we comprehensively characterized the interactive profiles between laboratory and clinical isolates of C. albicans (SC5314 and BF1) and E. faecalis (OG1RF and P52S) on an organotypic oral mucosal model. Our results demonstrated that the dual species biofilms resulted in profound surface erosion and significantly increased microbial invasion into mucosal compartments, compared to either species alone. Notably, several genes of C. albicans involved in tissue adhesion, hyphal formation, fungal invasion, and biofilm formation were significantly upregulated in the presence of E. faecalis. By contrast, E. faecalis genes involved in quorum sensing, biofilm formation, virulence, and mammalian cell invasion were downregulated. This study highlights the synergistic cross-kingdom interactions between E. faecalis and C. albicans in mucosal tissue invasion.
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Affiliation(s)
- Akshaya Lakshmi Krishnamoorthy
- Faculty of Dentistry, The University of Hong Kong, Pok Fu Lam, Hong Kong;
- Quorum Sensing Laboratory, Center of Research in Infectious Diseases, School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur 613401, India;
| | - Alex A. Lemus
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA; (A.A.L.); (A.M.V.)
| | - Adline Princy Solomon
- Quorum Sensing Laboratory, Center of Research in Infectious Diseases, School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur 613401, India;
| | - Alex M. Valm
- Department of Biological Sciences, University at Albany, State University of New York, Albany, NY 12222, USA; (A.A.L.); (A.M.V.)
- The RNA Institute, University at Albany, State University of New York, Albany, NY 12222, USA
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Rath PP, Yiu CKY, Matinlinna JP, Kishen A, Neelakantan P. The effects of sequential and continuous chelation on dentin. Dent Mater 2020; 36:1655-1665. [PMID: 33162115 DOI: 10.1016/j.dental.2020.10.010] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 06/26/2020] [Accepted: 10/14/2020] [Indexed: 11/30/2022]
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.
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Affiliation(s)
- Priti P Rath
- Discipline of Endodontology, Department of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Cynthia K Y Yiu
- Discipline of Pediatric Dentistry, Department of Pediatric Dentistry and Orthodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Jukka P Matinlinna
- Dental Materials Science, Department of Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region
| | - Anil Kishen
- Faculty of Dentistry, The University of Toronto, Dentistry; Mount Sinai Hospital, Toronto, ON, Canada
| | - Prasanna Neelakantan
- Discipline of Endodontology, Department of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong Special Administrative Region.
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Abdalla MM, Ali IA, Khan K, Mattheos N, Murbay S, Matinlinna JP, Neelakantan P. The Influence of Surface Roughening and Polishing on Microbial Biofilm Development on Different Ceramic Materials. J Prosthodont 2020; 30:447-453. [DOI: 10.1111/jopr.13260] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/10/2020] [Indexed: 01/08/2023] Open
Affiliation(s)
- Mohamed Mahmoud Abdalla
- Faculty of Dentistry The University of Hong Kong Hong Kong SAR
- Dental Biomaterials Department, Faculty of Dental Medicine Al‐Azhar University Cairo Egypt
| | - Islam A.A. Ali
- Faculty of Dentistry The University of Hong Kong Hong Kong SAR
| | - Khadija Khan
- Faculty of Dentistry The University of Hong Kong Hong Kong SAR
| | - Nikos Mattheos
- Department of Dental Medicine Karolinska Institutet Stockholm Sweden
- Chulalongkorn University Thailand
| | - Sukhdeep Murbay
- Faculty of Dentistry The University of Hong Kong Hong Kong SAR
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Shetty H, Shetty S, Kakade A, Mali S, Shetty A, Neelakantan P. Three-dimensional qualitative and quantitative analyses of the effect of periradicular lesions on the outcome of regenerative endodontic procedures: A prospective clinical study. Clin Oral Investig 2020; 25:691-700. [PMID: 32954475 DOI: 10.1007/s00784-020-03583-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 09/11/2020] [Indexed: 02/07/2023]
Abstract
OBJECTIVES Qualitative and quantitative evaluation of the outcomes of regenerative endodontic procedure (REP) on human immature necrotic teeth with apical periodontitis using cone-beam computed tomography (CBCT) MATERIALS AND METHODS: Immature permanent teeth (n = 50) with necrotic pulp and periradicular pathosis were treated with a cell-homing concept-based REP. Following the procedure, a limited field-of-view CBCT scan was obtained. At each recall session (6, 12, 18 months), clinical tests were performed, and a digital periapical radiograph was taken. When significant radiographic changes were evident in the follow-up, a final CBCT scan was taken for qualitative and quantitative assessment. These initial and follow-up CBCT scans were assessed for quantification of changes in root length, pulp space diameter and periradicular lesion size. The data were statistically analysed using t test, one-way ANOVA, post hoc test and paired t test (P = 0.05). RESULTS Of the teeth, 94.6% were clinically successful based on the lack or regression of signs and symptoms after 48 months follow-up. REP resulted in a statistically significant increase in root length, decrease in pulp space diameter and periradicular radiolucency (P < 0.05). CBCT images illustrated various patterns of root maturation including an increased thickening of the canal walls and continued root maturation (37.1%), continued root development with the apical foramen remaining open (57.1%), severe calcification (obliteration) of the canal space (2.9%) and hard tissue barrier formation in the canal space between the coronal plug and the root apex (2.9%). CONCLUSION This study highlighted that the expected outcome of radiographic root development was less predictable when immature permanent teeth with periradicular pathosis were treated with REP. CLINICAL RELEVANCE The size and extent (expansion/destruction of the cortical plate) of periradicular lesions and abscesses influence the outcome of REP. These factors must be taken into consideration during treatment planning.
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Affiliation(s)
- Heeresh Shetty
- Department of Conservative Dentistry and Endodontics, Nair Hospital Dental College, Mumbai, India
- Department of Conservative Dentistry and Endodontics, A.B. Shetty Memorial Institute of Dental Sciences, Mangalore, India
| | - Shishir Shetty
- Department of Conservative Dentistry and Endodontics, A.B. Shetty Memorial Institute of Dental Sciences, Mangalore, India
| | - Adesh Kakade
- Department of Pediatric Dentistry, Nair Hospital Dental College, Mumbai, India
| | - Sayali Mali
- Department of Pediatric Dentistry, Nair Hospital Dental College, Mumbai, India
| | - Aditya Shetty
- Department of Conservative Dentistry and Endodontics, A.B. Shetty Memorial Institute of Dental Sciences, Mangalore, India
| | - Prasanna Neelakantan
- Discipline of Endodontology, Division of Restorative Dental Sciences, Faculty of Demtistry, The University of Hong Kong, 34, Hospital Road, Sai Ying Pun, Hong Kong SAR.
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Ali IAA, Cheung BPK, Matinlinna J, Lévesque CM, Neelakantan P. Trans-cinnamaldehyde potently kills Enterococcus faecalis biofilm cells and prevents biofilm recovery. Microb Pathog 2020; 149:104482. [PMID: 32920147 DOI: 10.1016/j.micpath.2020.104482] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 09/03/2020] [Accepted: 09/03/2020] [Indexed: 10/23/2022]
Abstract
Enterococcus faecalis is a biofilm-forming, nosocomial pathogen that is frequently isolated from failed root canal treatments. Contemporary root canal disinfectants are ineffective in eliminating these biofilms and preventing reinfection. As a result, there is a pressing need to identify novel and safe antibiofilm molecules. The effect of short-term (5 and 15 min) and long-term (24 h) treatments of trans-cinnamaldehyde (TC) on the viability of E. faecalis biofilms was compared with currently used root canal disinfectants. Treatment for 15 min with TC reduced biofilm metabolic activity as effective as 1% sodium hypochlorite and 2% chlorhexidine. Treatment with TC for 24 h was significantly more effective than 2% chlorhexidine in reducing the viable cell counts of biofilms. This serendipitous effect of TC was sustained for 10 days under growth-favoring conditions. For the first time, our study highlights the strong antibacterial activity of TC against E. faecalis biofilms, and notably, its ability to prevent biofilm recovery after treatment.
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Affiliation(s)
- Islam A A Ali
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | - Becky P K Cheung
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | - JukkaP Matinlinna
- Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
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Rath PP, Yiu CKY, Matinlinna JP, Kishen A, Neelakantan P. The effect of root canal irrigants on dentin: a focused review. Restor Dent Endod 2020; 45:e39. [PMID: 32839720 PMCID: PMC7431934 DOI: 10.5395/rde.2020.45.e39] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 06/03/2020] [Accepted: 06/09/2020] [Indexed: 11/15/2022] Open
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.
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Affiliation(s)
- Priti Pragati Rath
- Discipline of Endodontology, Division of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR
| | - Cynthia Kar Yung Yiu
- Discipline of Pediatric Dentistry, Division of Pediatric Dentistry and Orthodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR
| | - Jukka Pekka Matinlinna
- Dental Materials Science, Division of Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR
| | - Anil Kishen
- Faculty of Dentistry, The University of Toronto, Toronto, ON, Canada.,Dentistry, Mount Sinai Hospital, Toronto, ON, Canada
| | - Prasanna Neelakantan
- Discipline of Endodontology, Division of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR
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Yeung AWK, Harper B, Zhang C, Neelakantan P, Bornstein MM. Do different cone beam computed tomography exposure protocols influence subjective image quality prior to and after root canal treatment? Clin Oral Investig 2020; 25:2119-2127. [PMID: 32840680 PMCID: PMC7966640 DOI: 10.1007/s00784-020-03524-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 08/11/2020] [Indexed: 12/13/2022]
Abstract
Objectives The current study aimed to evaluate different CBCT exposure protocols and influencing factors affecting the subjective image quality of scans taken for endodontic indications. Materials and methods Twelve extracted teeth, comprising of two sets of maxillary molars, premolars, canines and incisors, mandibular premolars, and molars, were endodontically treated, and either received a fiber or metal post. The teeth were scanned by CBCT imaging before and after root canal treatment, and after post insertion. Each scan was performed thrice, using an ultra low dose (ULD), standard (SM), and high-resolution mode (HR), respectively. Twelve observers—4 endodontists, 4 periodontists, and 4 radiologists—assessed the subjective image quality using visual analogue scales (VAS). Potential influencing factors were evaluated including acquisition mode, observer specialty, stage of treatment, type of post, and type of tooth, using one-way ANOVA and T test. Results Teeth scanned with the ULD had the highest average VAS score (72.5), followed by HR (70.2), and SM (69.0) for values pooled from all teeth and observers. CBCT acquisition mode was not a significant influencing factor on the VAS scores. Observer specialty, stage of treatment, type of post, and type of tooth were significant influencing factors. Conclusions Based on the present in vitro data, a low-dose CBCT mode seems not to negatively affect the perception of image quality. Clinical relevance The findings from this in vitro study demonstrate that a low-dose CBCT mode might have potential for diagnostics prior to or following endodontic treatment.
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Affiliation(s)
- Andy Wai Kan Yeung
- Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | - Basak Harper
- Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | - Chengfei Zhang
- Endodontology, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | - Prasanna Neelakantan
- Endodontology, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China
| | - Michael M Bornstein
- Oral and Maxillofacial Radiology, Applied Oral Sciences and Community Dental Care, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, China.
- Department of Oral Health & Medicine, University Center for Dental Medicine Basel UZB, University of Basel, Basel, Switzerland.
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Ramaraj S, Kim MA, Rosa V, Neelakantan P, Shon WJ, Min KS. Combined Effect of Melittin and DNase on Enterococcus faecalis Biofilms and Its Susceptibility to Sodium Hypochlorite. Materials (Basel) 2020; 13:ma13173740. [PMID: 32847080 PMCID: PMC7503955 DOI: 10.3390/ma13173740] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 08/20/2020] [Accepted: 08/21/2020] [Indexed: 12/11/2022]
Abstract
Biofilm communities are tolerant to antimicrobials and difficult to eradicate. This study aimed to investigate the effect of melittin, an antimicrobial peptide, either alone or in combination with deoxyribonuclease (DNase), an inhibitor of extracellular deoxyribonucleic acid (eDNA), against Enterococcus faecalis (E. faecalis) biofilms, and biofilm susceptibility to sodium hypochlorite (NaOCl). Biofilms of E. faecalis were developed in root canals of bovine teeth. The biofilms were treated with distilled water (control), melittin, DNase, or DNase+melittin. The antibiofilm effects of the treatments were analyzed using colony forming unit (CFU) assay, crystal violet staining, confocal laser scanning microscopy (CLSM), and field emission scanning electron microscope (FE-SEM). The susceptibility of DNase+melittin-treated biofilms to NaOCl (0%, 2.5% and 5%) was investigated by the CFU assay. The data were statistically analyzed using one-way analysis of variance, followed by Tukey's test. A p-value of <0.05 was considered significant. Specimens treated with DNase+melittin showed a more significant decrease in the CFUs, eDNA level, and biofilm formation rate than those treated only with melittin or DNase (p < 0.05). CLSM analysis showed DNase+melittin treatment significantly reduced the volume of biofilms and extracellular polymeric substance compared to either treatment alone (p < 0.05). FE-SEM images showed a high degree of biofilm disruption in specimens that received DNase+melittin. 2.5% NaOCl in specimens pretreated with DNase+melittin showed higher antibacterial activity than those treated only with 5% NaOCl (p < 0.05). This study highlighted that DNase improved the antibiofilm effects of melittin. Moreover, DNase+melittin treatment increased the susceptibility of biofilms to NaOCl. Thus, the complex could be a clinical strategy for safer use of NaOCl by reducing the concentration.
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Affiliation(s)
- Sujitha Ramaraj
- Department of Conservative Dentistry, School of Dentistry and Institute of Oral Bioscience, Jeonbuk National University, Jeonju 54896, Korea; (S.R.); (M.-A.K.)
| | - Mi-Ah Kim
- Department of Conservative Dentistry, School of Dentistry and Institute of Oral Bioscience, Jeonbuk National University, Jeonju 54896, Korea; (S.R.); (M.-A.K.)
| | - Vinicius Rosa
- Discipline of Oral Sciences, Faculty of Dentistry, National University of Singapore, Singapore 119085, Singapore;
| | - Prasanna Neelakantan
- Discipline of Endodontology, Department of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China;
| | - Won-Jun Shon
- Department of Conservative Dentistry, School of Dentistry, Seoul National University, Seoul 03080, Korea
- Correspondence: (W.-J.S.); (K.-S.M.); Tel.: +82-63-270-4982 (K.-S.M.); Fax: +82-63-250-2129 (K.-S.M.)
| | - Kyung-San Min
- Department of Conservative Dentistry, School of Dentistry and Institute of Oral Bioscience, Jeonbuk National University, Jeonju 54896, Korea; (S.R.); (M.-A.K.)
- Research Institute of Clinical Medicine of Jeonbuk National University, Jeonju 54907, Korea
- Biomedical Research Institute of Jeonbuk National University Hospital, Jeonju 54907, Korea
- Correspondence: (W.-J.S.); (K.-S.M.); Tel.: +82-63-270-4982 (K.-S.M.); Fax: +82-63-250-2129 (K.-S.M.)
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Kalimuthu S, Cheung BP, Yau JY, Shanmugam K, Solomon AP, Neelakantan P. A Novel Small Molecule, 1,3-di-m-tolyl-urea, Inhibits and Disrupts Multispecies Oral Biofilms. Microorganisms 2020; 8:E1261. [PMID: 32825310 PMCID: PMC7570320 DOI: 10.3390/microorganisms8091261] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 08/18/2020] [Accepted: 08/19/2020] [Indexed: 12/18/2022] Open
Abstract
An imbalance of homeostasis between the microbial communities and the host system leads to dysbiosis in oral micro flora. DMTU (1,3-di-m-tolyl-urea) is a biocompatible compound that was shown to inhibit Streptococcus mutans biofilm by inhibiting its communication system (quorum sensing). Here, we hypothesized that DMTU is able to inhibit multispecies biofilms. We developed a multispecies oral biofilm model, comprising an early colonizer Streptococcus gordonii, a bridge colonizer Fusobacterium nucleatum, and late colonizers Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. We performed comprehensive investigations to demonstrate the effect of DMTU on planktonic cells and biofilms. Our findings showed that DMTU inhibits and disrupts multispecies biofilms without bactericidal effects. Mechanistic studies revealed a significant down regulation of biofilm and virulence-related genes in P. gingivalis. Taken together, our study highlights the potential of DMTU to inhibit polymicrobial biofilm communities and their virulence.
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Affiliation(s)
- Shanthini Kalimuthu
- Faculty of Dentistry, The University of Hong Kong, Pok Fu Lam, Hong Kong; (S.K.); (B.P.K.C.); (J.Y.Y.Y.)
- Quorum Sensing Laboratory, Center of Research in Infectious Diseases, School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur 613401, India;
| | - Becky P.K. Cheung
- Faculty of Dentistry, The University of Hong Kong, Pok Fu Lam, Hong Kong; (S.K.); (B.P.K.C.); (J.Y.Y.Y.)
| | - Joyce Y.Y. Yau
- Faculty of Dentistry, The University of Hong Kong, Pok Fu Lam, Hong Kong; (S.K.); (B.P.K.C.); (J.Y.Y.Y.)
| | - Karthi Shanmugam
- Quorum Sensing Laboratory, Center of Research in Infectious Diseases, School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur 613401, India;
| | - Adline Princy Solomon
- Quorum Sensing Laboratory, Center of Research in Infectious Diseases, School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur 613401, India;
| | - Prasanna Neelakantan
- Faculty of Dentistry, The University of Hong Kong, Pok Fu Lam, Hong Kong; (S.K.); (B.P.K.C.); (J.Y.Y.Y.)
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Balasubramanian AR, Vasudevan S, Shanmugam K, Lévesque CM, Solomon AP, Neelakantan P. Combinatorial effects of trans-cinnamaldehyde with fluoride and chlorhexidine on Streptococcus mutans. J Appl Microbiol 2020; 130:382-393. [PMID: 32707601 DOI: 10.1111/jam.14794] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 07/06/2020] [Accepted: 07/18/2020] [Indexed: 01/03/2023]
Abstract
AIMS The aim of this study was to investigate the effects of trans-cinnamaldehyde (TC) and its synergistic activity with chlorhexidine (CHX) and fluoride against Streptococcus mutans. METHODS AND RESULTS Streptococcus mutans UA159 was treated with TC alone and in combination with CHX or sodium fluoride. The synergy profile was analysed using the Zero Interaction Potency model. TC showed strong synergism (synergy score of 21·697) with CHX, but additive effect (synergy score of 5·298) with fluoride. TC and the combinations were tested for acid production (glycolytic pH drop) and biofilm formation by S. mutans, and nitric oxide production in macrophages. TC significantly inhibited sucrose-dependent biofilm formation and acid production by S. mutans. Mechanistic studies were carried out by qRT-PCR-based transcriptomic studies which showed that TC acts by impairing genes related to metabolism, quorum sensing, bacteriocin expression, stress tolerance and biofilm formation. CONCLUSIONS trans-Cinnamaldehyde potentiates CHX and sodium fluoride in inhibiting S. mutans biofilms and virulence through multiple mechanisms. This study sheds significant new light on the potential to develop TC as an anti-caries treatment. SIGNIFICANCE AND IMPACT OF THE STUDY Oral diseases were classified as a 'silent epidemic' in the US Surgeon General's Report on Oral Health. Two decades later, >4 billion people are still affected worldwide by caries, having significant effects on the quality of life. There is an urgent need to develop novel compounds and strategies to combat dental caries. Here, we prove that TC downregulates multiple pathways and potentiates the CHX and fluoride to prevent S. mutans biofilms and virulence. This study sheds significant new light on the potential to develop TC in combination with CHX or fluoride as novel treatments to arrest dental caries.
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Affiliation(s)
- A R Balasubramanian
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - S Vasudevan
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - K Shanmugam
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - C M Lévesque
- Faculty of Dentistry, University of Toronto, Toronto, ON, Canada
| | - A P Solomon
- Quorum Sensing Laboratory, Centre for Research in Infectious Diseases (CRID), School of Chemical and Biotechnology, SASTRA Deemed to be University, Thanjavur, India
| | - P Neelakantan
- Faculty of Dentistry, The University of Hong Kong, Hong Kong, Hong Kong SAR
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Ozlek E, Neelakantan P, Khan K, Cheung GSP, Rossi-Fedele G. Debris extrusion during root canal preparation with nickel-titanium instruments using liquid and gel formulations of sodium hypochlorite in vitro. AUST ENDOD J 2020; 47:130-136. [PMID: 32748569 DOI: 10.1111/aej.12424] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 07/07/2020] [Accepted: 07/08/2020] [Indexed: 11/30/2022]
Abstract
This study compared the amount of apically extruded debris during root canal preparation with three single-file systems using liquid and gel-based formulations of sodium hypochlorite (NaOCl) or distilled water. Seventy-two single-canalled roots were divided into three groups: HyFlex EDM (Coltene-Whaledent); Reciproc Blue (VDW); and F-One Blue (Shanghai Fanta) and then divided into three subgroups: NaOCl liquid (Imicrly), NaOCl gel (Cerkamed Medical) and distilled water. The amount of extruded debris was calculated by determining the dry weight of the debris collected. Data were analysed using Kruskal-Wallis test with Bonferroni correction. Debris extrusion occurred in all subgroups. Both the instrument and the irrigant had an impact. The F-One Blue tended to extrude the least debris, though no significant difference was observed in the pairwise comparisons between instruments. NaOCl liquid resulted in significantly more extruded debris than NaOCl gel or distilled water. The results lead us to conclude that the NaOCl gel reduced debris extrusion compared to NaOCl liquid.
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Affiliation(s)
- Esin Ozlek
- Department of Endodontics, Faculty of Dentistry, The University of Van Yuzuncu Yil, Van, Turkey
| | - Prasanna Neelakantan
- Discipline of Endodontology, Division of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, Hong Kong
| | - Khadija Khan
- Discipline of Endodontology, Division of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, Hong Kong
| | - Gary S P Cheung
- Discipline of Endodontology, Division of Restorative Dental Sciences, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR, Hong Kong
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