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Coaguila-Llerena H, Raphael da Silva L, Faria G. Research methods assessing sodium hypochlorite cytotoxicity: A scoping review. Heliyon 2024; 10:e23060. [PMID: 38192787 PMCID: PMC10772573 DOI: 10.1016/j.heliyon.2023.e23060] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Revised: 10/26/2023] [Accepted: 11/24/2023] [Indexed: 01/10/2024] Open
Abstract
Sodium hypochlorite (NaOCl) cytotoxicity has been assessed using different methodologies, which has led to arbitrary interpretations. This scoping review aimed to discuss the different methodological protocols for assessing NaOCl cytotoxicity. A literature review performed in the PubMed and Embase databases up to July 2023 identified manuscripts reporting NaOCl cytotoxicity. The dataset identified 546 publications, further screened by 2 reviewers. Ninety studies were identified and mined methodologically to collect information on cell type, cytotoxicity assay, NaOCl dilution solutions, presence of fetal bovine serum (FBS), and NaOCl exposure time. The culture medium used in cytotoxicity assays contains buffering substances that neutralize the pH of NaOCl, thus reducing its cytotoxicity, an approach that may lead to bias when solutions with different pH are compared. For short exposure periods, as in simulations to evaluate the contact between irrigant and periapical tissue cells during chemo-mechanical preparation, NaOCl dilution should be performed with saline, which does not buffer the irrigant. For long exposure periods, as in simulations of irrigant extrusions, NaOCl should be diluted in the culture medium, to reproduce the expected buffering effect occurring in extrusions. The presence of FBS in culture medium can decrease NaOCl toxicity. There is no standardization of NaOCl cytotoxicity methodologies. This poses the risk of arriving at incorrect results and, therefore, pertinent tests must be refined.
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Affiliation(s)
- Hernán Coaguila-Llerena
- Department of Restorative Dentistry, Araraquara School of Dentistry, São Paulo State University -UNESP, Araraquara, São Paulo, Brazil
| | - Luana Raphael da Silva
- Department of Restorative Dentistry, Araraquara School of Dentistry, São Paulo State University -UNESP, Araraquara, São Paulo, Brazil
| | - Gisele Faria
- Department of Restorative Dentistry, Araraquara School of Dentistry, São Paulo State University -UNESP, Araraquara, São Paulo, Brazil
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Brochado Martins JF, Jautze A, Georgiou AC, Tulp BMT, Crielaard W, van der Waal SV. Well-being, postoperative pain and outcome after clinical application of a novel root canal irrigation fluid-RISA-in teeth with apical periodontitis: A first-in-human study. Int Endod J 2023; 56:1488-1498. [PMID: 37771316 DOI: 10.1111/iej.13977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 08/31/2023] [Indexed: 09/30/2023]
Abstract
AIM The aim of the study was to assess the tolerance to the new root canal irrigation fluid RISA after root canal treatment (RCT) by evaluating the subject's postoperative well-being, postoperative pain (PP) and treatment outcome. METHODOLOGY A single-arm prospective study with 16 subjects (17 teeth) diagnosed with asymptomatic apical periodontitis. Endodontic treatment in one session performed using RISA for root canal irrigation. Well-being was assessed on the same day and after 24 h by telephone. For pain intensity, a visual analogue scale was used at 0-5 days. Clinical and radiographic evaluations were performed at ≥12 months. Well-being, occurrence of PP and outcome were qualitatively reported. Friedman test for paired samples and Spearman correlation coefficient were used. Significance was set at p < .05. RESULTS At the same day and after 24 h, 14/16 subjects felt 'good'. 9/16 presented intra- or extra-oral swelling. The frequency of PP ≥36 (weak) was 82.4%. On the same day, 1 and 2 days postoperatively, there was more pain compared with preoperative pain p < .05. At Day 3, PP equalled preoperative pain (p > .05). 62.5% of subjects needed analgesics Day 0-2. The recall rate was 94.1%, and resolution of apical periodontitis was observed in 87.5%. CONCLUSIONS The well-being of subjects was good, and the overall PP intensity was low. However, postoperative intra- and extra-oral swelling occurred often. At the recall visit, the effectiveness of the RCT with RISA appeared high (87.5%). The encouraging outcome results plus the fact that RISA has a broader action range than NaOCl in vitro, justify further work on the RISA solution. To reduce postoperative swelling, it is advised to further investigate the optimal way of application of RISA in the laboratory before clinical application is recommended.
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Affiliation(s)
- João Filipe Brochado Martins
- Department of Endodontics, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands
| | - Anthony Jautze
- Department of Endodontics, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands
| | - Athina Christina Georgiou
- Department of Endodontics, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands
| | - Birgitte Maria Theresia Tulp
- Department of Endodontics, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands
| | - Wim Crielaard
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands
| | - Suzette Veronica van der Waal
- Department of Endodontics, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and VU University Amsterdam, Amsterdam, The Netherlands
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3
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Meire MA, van der Waal SV. A critical analysis of research methods and experimental models to study intracanal medicaments. Int Endod J 2022; 55 Suppl 2:330-345. [PMID: 35100452 DOI: 10.1111/iej.13694] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2021] [Accepted: 01/26/2022] [Indexed: 12/01/2022]
Abstract
In order to ensure predictable decontamination of the root canal system, chemo-mechanical preparation of the root canal space is sometimes supplemented with the use of intracanal medication. As microbial control of the root canal space is fundamental to the resolution of apical periodontitis, root canal disinfection strategies haven been researched intensively. The use of intracanal medication as a supplementary step to the chemo-mechanical preparation of the root canal space is one of them. Because of the costs and limitations of clinical research it is relevant and common practice to first evaluate alternative or new root canal disinfection modalities in laboratory studies. This involves the simulation of a root canal infection in a laboratory model, on which different disinfection strategies can be tested. When modelling the infected root canal, different levels of infection can be discriminated: suspended bacteria, microbial biofilms and infected dentine. This review describes the experimental models associated with these infection levels and critically appraises their value and methodological details. Suggestions for relevant research methods and experimental models are given, as well as some good practices for laboratory-based microbiological studies.
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Affiliation(s)
- M A Meire
- Department of Oral Health Sciences, Section of Endodontology, Ghent University, Ghent, Belgium
| | - S V van der Waal
- Department of Endodontology, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands
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4
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Pereira TC, Dijkstra RJB, Petridis X, Sharma PK, van de Meer WJ, van der Sluis LWM, de Andrade FB. Chemical and mechanical influence of root canal irrigation on biofilm removal from lateral morphological features of simulated root canals, dentine discs and dentinal tubules. Int Endod J 2020; 54:112-129. [PMID: 32880989 PMCID: PMC7839520 DOI: 10.1111/iej.13399] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 08/26/2020] [Indexed: 01/08/2023]
Abstract
Aim To investigate the anti‐biofilm efficacy of irrigation using a simulated root canal model, the chemical effect of irrigants against biofilms grown on dentine discs and their impact on biofilm viscoelasticity, the efficacy of the irrigants in decontaminating infected dentinal tubules and the capacity of bacteria to regrow. Methodology Biofilm removal, viscoelastic analysis of remaining biofilms and bacterial viability were evaluated using a simulated root canal model with lateral morphological features, dentine discs and a dentinal tubule model, respectively. Experiments were conducted using a two‐phase irrigation protocol. Phase 1: a modified salt solution (RISA) and sodium hypochlorite (NaOCl) were used at a low flow rate to evaluate the chemical action of the irrigants. Ultrasonic activation (US) of a chemically inert solution (buffer) was used to evaluate the mechanical efficacy of irrigation. Phase 2: a final irrigation with buffer at a high flow rate was performed for all groups. Optical coherence tomography (OCT), low load compression testing (LLCT) and confocal scanning laser microscopy analysis were used in the different models. One‐way analysis of variance (anova) was performed for the OCT and LLCT analysis, whilst Kruskal–Wallis and Wilcoxon ranked tests for the dentinal tubule model. Results US and high flow rate removed significantly more biofilm from the artificial lateral canal. For biofilm removal from the artificial isthmus, no significant differences were found between the groups. Within‐group analysis revealed significant differences between the steps of the experiment, with the exception of NaOCl. For the dentine discs, no significant differences regarding biofilm removal and viscoelasticity were detected. In the dentinal tubule model, NaOCl exhibited the greatest anti‐biofilm efficacy. Conclusions The mechanical effect of irrigation is important for biofilm removal. An extra high flow irrigation rate resulted in greater biofilm removal than US in the artificial isthmus. The mechanical effect of US seemed to be more effective when the surface contact biofilm–irrigant was small. After the irrigation procedures, the remaining biofilm could survive after a 5‐day period. RISA and NaOCl seemed to alter post‐treatment remaining biofilms.
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Affiliation(s)
- T C Pereira
- Department of Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Bauru, Brazil.,Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - R J B Dijkstra
- Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - X Petridis
- Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - P K Sharma
- Department of Biomedical Engineering, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - W J van de Meer
- Department of Orthodontics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - L W M van der Sluis
- Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - F B de Andrade
- Department of Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Bauru, Brazil
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Pereira TC, Dijkstra RJB, Petridis X, van der Meer WJ, Sharma PK, de Andrade FB, van der Sluis LWM. The influence of time and irrigant refreshment on biofilm removal from lateral morphological features of simulated root canals. Int Endod J 2020; 53:1705-1714. [PMID: 32502284 PMCID: PMC7754391 DOI: 10.1111/iej.13342] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 05/26/2020] [Accepted: 05/29/2020] [Indexed: 12/15/2022]
Abstract
Aim To evaluate the effect of irrigant refreshment and exposure time of a 2% sodium hypochlorite solution (NaOCl) on biofilm removal from simulated lateral root canal spaces using two different flow rates. Methodology A dual‐species biofilm was formed by a Constant Depth Film Fermenter (CDFF) for 96 h in plug inserts with anatomical features resembling an isthmus or lateral canal‐like structures. The inserts were placed in a root canal model facing the main canal. NaOCl 2% and demineralized water (control group) were used as irrigant solutions. Both substances were applied at a flow rate of 0.05 and 0.1 mL s−1. The samples were divided into three groups with zero, one or two refreshments in a total exposure time of 15 min. A three‐way analysis of variance (anova) was performed to investigate the interaction amongst the independent variables and the effect of consecutive irrigant refreshment on percentage of biofilm removal. A Tukey post hoc test was used to evaluate the effect of each independent variable on percentage biofilm removal in the absence of statistically significant interactions. Results For the lateral canal, NaOCl removed significantly more biofilm irrespective of the number of refreshments and exposure time (P = 0.005). There was no significant effect in biofilm removal between the consecutive irrigant refreshments measured in the same biofilm. For the isthmus, NaOCl removed significantly more biofilm irrespective of the number of refreshments and exposure time; both NaOCl and a high flow rate removed significantly more biofilm when the exposure time was analysed (P = 0.018 and P = 0.029, respectively). Evaluating the effect of consecutive irrigant refreshment on the same biofilm, 2% NaOCl, 0.1 mL s−1 flow rate and one or two refreshments removed significant more biofilm (P = 0.04, 0.034 and 0.003, <0.001, respectively). Conclusions In this model, refreshment did not improve biofilm removal from simulated lateral root canal spaces. NaOCl removed more biofilm from the lateral canal‐ and isthmus‐like structure. A higher flow rate removed significantly more biofilm from the isthmus‐like structure. There was always remaining biofilm left after the irrigation procedures.
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Affiliation(s)
- T C Pereira
- Department of Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Bauru, Brazil.,Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - R J B Dijkstra
- Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - X Petridis
- Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - W J van der Meer
- Department of Orthodontics, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - P K Sharma
- Department of Biomedical Engineering, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
| | - F B de Andrade
- Department of Dentistry, Endodontics and Dental Materials, Bauru School of Dentistry, University of São Paulo, Bauru, Brazil
| | - L W M van der Sluis
- Center for Dentistry and Oral Hygiene, University Medical Center Groningen, University of Groningen, Groningen, The Netherlands
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Coaguila-Llerena H, Rodrigues EM, Tanomaru-Filho M, Guerreiro-Tanomaru JM, Faria G. Effects of Calcium Hypochlorite and Octenidine Hydrochloride on L929 And Human Periodontal Ligament Cells. Braz Dent J 2019; 30:213-219. [DOI: 10.1590/0103-6440201902280] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2018] [Accepted: 12/05/2018] [Indexed: 02/05/2023] Open
Abstract
Abstract The aim of this study was to assess cytotoxicity and cell migration of calcium hypochlorite [Ca(OCl)2] and octenidine hydrochloride - OCT (Octenisept®, Schülke & Mayr, Norderstedt, Germany) in L929 and human periodontal ligament (hPDL) cells. The cells were exposed to different doses of different solutions: 2.5% and 5% Ca(OCl)2, 0.1% OCT, 2.5% NaOCl and 2% CHX for 10 min. Cell viability was assessed by methyl-thiazol-tetrazolium (MTT) and neutral red (NR) assays, and cell migration was determined by wound-healing assay. Statistical analysis was performed by two-way ANOVA and Bonferroni tests (α=0.05). The MTT and NR assays revealed that 0.1% OCT was less cytotoxic in hPDL cells (p<0.05), followed by 2% CHX and 2.5% Ca(OCl)2 (p<0.05). There was no significant difference between 2.5% NaOCl and 5% Ca(OCl)2 (p>0.05), but these solutions showed greater cytotoxicity than the others. The result was the same for L929 cells, except that there was no significant difference between 2% CHX and 2.5% Ca(OCl)2 (p>0.05). Wound-healing assay in L929 and hPDL cells showed that cell migration of 0.1% OCT, 2% CHX and 2.5% Ca(OCl)2 groups was higher than 5% Ca(OCl)2 and 2.5% NaOCl groups at 24 h (p<0.05). In conclusion, 0.1% OCT had lower cytotoxicity in tested cell lines than CHX, Ca(OCl)2 and NaOCl. Cell migration was higher for 0.1% OCT, 2% CHX and 2.5% Ca(OCl)2. Therefore, in terms of cytotoxicity, OCT and Ca(OCl)2 have the potential to be used as root canal irrigants.
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7
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de Almeida J, Pimenta AL, Pereira UA, Barbosa LCA, Hoogenkamp MA, van der Waal SV, Crielaard W, Felippe WT. Effects of three γ-alkylidene-γ-lactams on the formation of multispecies biofilms. Eur J Oral Sci 2018. [PMID: 29517121 DOI: 10.1111/eos.12411] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
This study evaluated the inhibitory effects of lactams on Streptococcus mutans, Enterococcus faecalis, and Candida glabrata multispecies biofilm formation. γ-Alkylidene-γ-lactams 1, 2, and 3 [solubilized in 3.5% dimethyl sulfoxide (DMSO)] were tested. Glass coverslips were conditioned with either the lactams or 3.5% DMSO (control) for 1 h, inoculated with microbial cultures, and incubated for 48 h. To assess the effect of the lactams on biofilm formation, the following parameters were determined: the biofilm biomass (by both crystal violet staining and protein determination); the amount of insoluble polysaccharides of the extracellular matrix; and the number of viable and total cells [by both colony-forming unit counting and quantitative real-time PCR (qPCR)]. Data were analysed using one-way anova and post-hoc Tukey tests. Lactams 1, 2, and 3 promoted a statistically significant reduction in the amount of biofilm biomass, but only lactam 3 resulted in a statistically significant reduction in the number of attached viable E. faecalis. Both total protein content and the amount of extracellular polysaccharides decreased significantly. The effects of γ-alkylidene-γ-lactams 1, 2, and 3 on the inhibition of multispecies biofilm formation were evident by their ability to reduce the amount of protein and extracellular polysaccharides.
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Affiliation(s)
- Josiane de Almeida
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, the Netherlands.,Department of Endodontics, Federal University of Santa Catarina (UFSC), Florianópolis, SC, Brazil.,Department of Endodontics, University of Southern Santa Catarina (UNISUL), Palhoça, SC, Brazil
| | - Andrea L Pimenta
- Department of Periodontics, Federal University of Santa Catarina (UFSC), Florianópolis, SC, Brazil.,Department of Biologie, Université de Cergy Pontoisé, Cergy Pontoise, France
| | - Ulisses A Pereira
- Department of Chemistry, Federal University of Viçosa (UFV), Viçosa, MG, Brazil
| | - Luiz C A Barbosa
- Department of Chemistry, Federal University of Viçosa (UFV), Viçosa, MG, Brazil.,Department of Chemistry, Federal University of Minas Gerais (UFMG), Belo Horizonte, MG, Brazil
| | - Michel A Hoogenkamp
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Suzette V van der Waal
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, the Netherlands.,Department of Endodontics, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Wim Crielaard
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), University of Amsterdam and Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Wilson T Felippe
- Department of Endodontics, Federal University of Santa Catarina (UFSC), Florianópolis, SC, Brazil
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Fernandez y Mostajo M, Exterkate RAM, Buijs MJ, Beertsen W, van der Weijden GA, Zaura E, Crielaard W. A reproducible microcosm biofilm model of subgingival microbial communities. J Periodontal Res 2017; 52:1021-1031. [DOI: 10.1111/jre.12473] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/29/2017] [Indexed: 12/19/2022]
Affiliation(s)
- M. Fernandez y Mostajo
- Department of Preventive Dentistry; Academic Centre for Dentistry Amsterdam (ACTA); Amsterdam the Netherlands
| | - R. A. M. Exterkate
- Department of Preventive Dentistry; Academic Centre for Dentistry Amsterdam (ACTA); Amsterdam the Netherlands
| | - M. J. Buijs
- Department of Preventive Dentistry; Academic Centre for Dentistry Amsterdam (ACTA); Amsterdam the Netherlands
| | - W. Beertsen
- Department of Periodontology; Academic Centre for Dentistry Amsterdam (ACTA); University of Amsterdam and VU University; Amsterdam the Netherlands
| | - G. A. van der Weijden
- Department of Periodontology; Academic Centre for Dentistry Amsterdam (ACTA); University of Amsterdam and VU University; Amsterdam the Netherlands
| | - E. Zaura
- Department of Preventive Dentistry; Academic Centre for Dentistry Amsterdam (ACTA); Amsterdam the Netherlands
| | - W. Crielaard
- Department of Preventive Dentistry; Academic Centre for Dentistry Amsterdam (ACTA); Amsterdam the Netherlands
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9
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van der Waal SV, de Almeida J, Krom BP, de Soet JJ, Crielaard W. Diffusion of antimicrobials in multispecies biofilms evaluated in a new biofilm model. Int Endod J 2016; 50:367-376. [PMID: 26993055 DOI: 10.1111/iej.12634] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 03/15/2016] [Indexed: 11/30/2022]
Abstract
AIM To describe the application of a newly-developed in vitro model in which the diffusion of antimicrobials in oral biofilms can be studied. METHODOLOGY In a flow chamber consisting of three parallel feeding channels connected with each other by eight perpendicular side channels, multispecies biofilms were grown from saliva of a single donor for 48 h. The dimensions of the side channels were 100 μm × 100 μm × 5130 μm (H × W × L). When one or more side channels were filled with biofilm, the biofilms were stained with fluorescent stains. Then, one side-channel biofilm was selected and treated with phosphate buffered saline, 2% sodium hypochlorite (NaOCl), 17% ethylenediaminetetra-acetic acid (EDTA) or modified salt solution (MSS). Diffusion of the irrigants was observed by acquiring fluorescence images at 10× objective every 15 s for 30 min. RESULTS It was possible to culture biofilms in the narrow (100 μm) channels. The biofilms varied in phenotype. In this model, no diffusion of NaOCl into the biofilms was seen after its application. Seventeen-percentage EDTA only diffused into the biofilm up to 200 μm in 30 min. MSS did diffuse in the biofilm over a distance of 450 μm within 2 min after a single application. CONCLUSIONS This new model enables the investigation of the diffusion of antimicrobials in biofilms. Other applications to improve our understanding of the characteristics of biofilms are now possible.
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Affiliation(s)
- S V van der Waal
- Department of Cariology, Endodontology, Pedodontology, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands.,Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands
| | - J de Almeida
- Department of Endodontics, School of Dentistry, Federal University of Santa Catarina, Florianópolis, SC, Brazil
| | - B P Krom
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands
| | - J J de Soet
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands
| | - W Crielaard
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands
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de Almeida J, Hoogenkamp M, Felippe WT, Crielaard W, van der Waal SV. Effectiveness of EDTA and Modified Salt Solution to Detach and Kill Cells from Enterococcus faecalis Biofilm. J Endod 2016; 42:320-3. [DOI: 10.1016/j.joen.2015.11.017] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 11/17/2015] [Accepted: 11/17/2015] [Indexed: 12/01/2022]
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11
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van der Waal SV, Connert T, Crielaard W, de Soet JJ. In mixed biofilms Enterococcus faecalis benefits from a calcium hydroxide challenge and culturing. Int Endod J 2015; 49:865-873. [PMID: 26333716 DOI: 10.1111/iej.12542] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2015] [Accepted: 08/29/2015] [Indexed: 11/28/2022]
Abstract
AIM To evaluate the fate of Enterococcus faecalis in dual-species and multispecies biofilms after treatment with calcium hydroxide (Ca(OH)2 ). METHODOLOGY Biofilms were cultured from laboratory strains of E. faecalis and Pseudomonas aeruginosa, or from microbiota retrieved from primary root canal infections. The biofilms were then treated with Ca(OH)2 . The proportion of E. faecalis and P. aeruginosa and their susceptibility to disinfection were evaluated in a viability assay. In the mixed-species assay, the presence and proportions of E. faecalis before and after Ca(OH)2 treatment were evaluated with a quantitative polymerase chain reaction assay. Groups were compared using Mann-Whitney U-test and Student's t-tests. An α <0.05 was considered statistically significant. RESULTS After Ca(OH)2 treatment in dual-species biofilms, the proportion of E. faecalis had increased (P < 0.001), whereas the total number of CFUs per biofilm was equal. Enterococcus faecalis was equally susceptible to disinfection by sodium hypochlorite (NaOCl) or by chlorhexidine. Pseudomonas aeruginosa had become more susceptible to NaOCl disinfection. The root canal isolates contained no detectable amounts of E. faecalis. After biofilm culturing or Ca(OH)2 treatment, it appeared that E. faecalis must have been present in 5 of 6 (83%) root canal samples. CONCLUSIONS Calcium hydroxide favours the population of E. faecalis in a dual-species biofilm. Culturing multispecies root canal isolates makes E. faecalis detectable. E. faecalis was often present in primary endodontic infections, albeit in low numbers.
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Affiliation(s)
- S V van der Waal
- Department of Cariology, Endodontology, Pedodontology, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands.,Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands
| | - T Connert
- Department of Periodontology, Endodontology and Cariology, University of Basel, Basel, Switzerland
| | - W Crielaard
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands
| | - J J de Soet
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands
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12
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van der Waal SV, Oonk CAM, Nieman SH, Wesselink PR, de Soet JJ, Crielaard W. Additional disinfection with a modified salt solution in a root canal model. J Dent 2015; 43:1280-4. [PMID: 26234625 DOI: 10.1016/j.jdent.2015.07.015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Revised: 07/22/2015] [Accepted: 07/28/2015] [Indexed: 11/28/2022] Open
Abstract
OBJECTIVES The aim of this study is to investigate the disinfecting properties of a modified salt solution (MSS) and calcium hydroxide (Ca(OH)2) in a non-direct-contact ex-vivo model. METHODS Seventy-four single-canal roots infected with Enterococcus faecalis were treated with 1% sodium hypochlorite (NaOCl) irrigation or with NaOCl irrigation with subsequent dressing with MSS or Ca(OH)2. After removal of the dressings, the roots were filled with bacterial growth medium and incubated for seven days to enable the surviving bacteria to repopulate the root canal lumen. Growth was determined by sampling the root canals with paper points before treatment (S1), after treatment (S2) and incubation after treatment (S3). The colony forming units were counted at S1 and S2. At S3, growth was determined as no/yes regrowth. The Kruskal-Wallis, McNemar and χ(2) test were used for statistical analyses. RESULTS At S2, in the NaOCl group, growth was found in 5 of 19 root canals. After the removal of MSS or Ca(OH)2 bacteria were retrieved from one root canal in both groups. At S3, repopulation of the root canals had occurred in 14 of 19 roots after sole NaOCl irrigation, 6 of 20 roots after MSS-dressing and in 14 of 20 roots after Ca(OH)2-dressing. MSS was more effective in preventing regrowth than Ca(OH)2 (P=0.009). CONCLUSIONS The modified salt solution prevented regrowth in roots which indicates that it can eliminate persistent bacteria. Dressing the root canals with Ca(OH)2 did not provide additional disinfection after NaOCl irrigation.
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Affiliation(s)
- Suzette V van der Waal
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), Gustav Mahlerlaan 3004, 1081 LA Amsterdam, The Netherlands; Department of Cariology, Endodontology and Pedodontology, Academic Centre for Dentistry Amsterdam (ACTA), Gustav Mahlerlaan 3004, 1081 LA Amsterdam, The Netherlands
| | - Charlotte A M Oonk
- Department of Cariology, Endodontology and Pedodontology, Academic Centre for Dentistry Amsterdam (ACTA), Gustav Mahlerlaan 3004, 1081 LA Amsterdam, The Netherlands
| | - Selma H Nieman
- Department of Cariology, Endodontology and Pedodontology, Academic Centre for Dentistry Amsterdam (ACTA), Gustav Mahlerlaan 3004, 1081 LA Amsterdam, The Netherlands
| | - Paul R Wesselink
- Department of Cariology, Endodontology and Pedodontology, Academic Centre for Dentistry Amsterdam (ACTA), Gustav Mahlerlaan 3004, 1081 LA Amsterdam, The Netherlands
| | - Johannes J de Soet
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), Gustav Mahlerlaan 3004, 1081 LA Amsterdam, The Netherlands
| | - Wim Crielaard
- Department of Preventive Dentistry, Academic Centre for Dentistry Amsterdam (ACTA), Gustav Mahlerlaan 3004, 1081 LA Amsterdam, The Netherlands
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