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Andreadis D, Angelopoulos I, Aggelidou E, Gousopoulou E, Volk J, Poulopoulos A, Kritis A, Geurtsen W, Bakopoulou A. Minor salivary gland stem cells: a comparative study of the biological properties under clinical-grade culture conditions. Cell Tissue Res 2023; 393:321-342. [PMID: 37249709 PMCID: PMC10406694 DOI: 10.1007/s00441-023-03789-z] [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: 04/27/2022] [Accepted: 05/12/2023] [Indexed: 05/31/2023]
Abstract
Development of clinical-grade, cell preparations is central to cGMP (good manufacturing practice compliant) conditions. This study aimed to investigate the potential of two serum/xeno-free, cGMP (StemPro, StemMacs) culture media to maintain "stemness" of human minor salivary gland stem cell (mSG-SC) cultures compared to a complete culture medium (CCM). Overall, StemMacs resulted in higher proliferation rates after p.6 compared to the conventional serum-based medium, while StemPro showed substantial delays in cell proliferation after p.9. The mSG-SCs cultures exhibited two distinct cell populations at early passages a mesenchymal subpopulation and an epithelial-like subpopulation. Expression of several markers (CD146, STRO-1, SSEA-4, CD105, CD106, CD34, K 7/8, K14, K18) variably decreased with prolonged passaging (all three media). The percentage of SA-β-gal positive cells was initially higher for StemMacs compared to StemPro/CCM and increased with prolonged passaging in all cases. The telomere fragment length decreased with prolonged passaging in all three media but more pronouncedly for the CCM. Expansion under serum-free conditions caused pronounced upregulation of ALP and BMP-2, with parallel complete elimination of the baseline expressions of LPL (all three media) and ACAN (serum-free media), therefore, showing a preferential shift of the mSG-SCs towards osteogenic phenotypes. Finally, several markers (Nanog, SOX-2, PDX-1, OTX2, GSC, HCG) decreased with prolonged culture, indicating successive loss of "stemness". Based on the findings, it seems that StemPro preserve stemness of the mSG-SCs after prolonged culture. Nevertheless, there is still a vacant role for the ideal development of clinical-grade culture conditions.
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Affiliation(s)
- Dimitrios Andreadis
- Department of Oral Medicine/Pathology, School of Dentistry, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece.
| | - Ioannis Angelopoulos
- Department of Prosthodontics, Tissue Engineering Core Unit, School of Dentistry, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Elena Aggelidou
- Department of Physiology and Pharmacology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
- cGMP Regenerative Medicine Facility, Department of Physiology and Pharmacology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Evangelia Gousopoulou
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School (MHH), Hannover, Germany
| | - Joachim Volk
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School (MHH), Hannover, Germany
| | - Athanasios Poulopoulos
- Department of Oral Medicine/Pathology, School of Dentistry, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Aristeidis Kritis
- Department of Physiology and Pharmacology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
- cGMP Regenerative Medicine Facility, Department of Physiology and Pharmacology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Werner Geurtsen
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School (MHH), Hannover, Germany
| | - Athina Bakopoulou
- Department of Prosthodontics, Tissue Engineering Core Unit, School of Dentistry, Faculty of Health Sciences, Aristotle University of Thessaloniki, Thessaloniki, Greece
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Gousopoulou E, Bakopoulou A, Apatzidou DA, Leyhausen G, Volk J, Staufenbiel I, Geurtsen W, Adam K. Evaluation of stemness properties of cells derived from granulation tissue of peri-implantitis lesions. Clin Exp Dent Res 2021; 7:739-753. [PMID: 33605088 PMCID: PMC8543464 DOI: 10.1002/cre2.406] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/31/2020] [Accepted: 01/29/2021] [Indexed: 12/12/2022] Open
Abstract
Objectives Peri‐implantitis (PI) is an inflammatory disease associated with peri‐implant bone loss and impaired healing potential. There is limited evidence about the presence of mesenchymal stromal cells (MSCs) and their regenerative properties within the granulation tissue (GT) of infrabony peri‐implantitis defects. The aim of the present study was to characterize the cells derived from the GT of infrabony PI lesions (peri‐implantitis derived mesenchymal stromal cells—PIMSCs). Material and Methods PIMSC cultures were established from GT harvested from PI lesions with a pocket probing depth ≥6 mm, bleeding on probing/suppuration, and radiographic evidence of an infrabony component from four systemically healthy individuals. Cultures were analyzed for embryonic (SSEA4, NANOG, SOX2, OCT4A), mesenchymal (CD90, CD73, CD105, CD146, STRO1) and hematopoietic (CD34, CD45) stem cell markers using flow cytometry. PIMSC cultures were induced for neurogenic, angiogenic and osteogenic differentiation by respective media. Cultures were analyzed for morphological changes and mineralization potential (Alizarin Red S method). Gene expression of neurogenic (NEFL, NCAM1, TUBB3, ENO2), angiogenic (VEGFR1, VEGFR2, PECAM1) and osteogenic (ALPL, BGLAP, BMP2, RUNX2) markers was determined by quantitative RT‐PCR. Results PIMSC cultures demonstrated high expression of embryonic and mesenchymal stem cell markers with inter‐individual variability. After exposure to neurogenic, angiogenic and osteogenic conditions, PIMSCs showed pronounced tri‐lineage differentiation potential, as evidenced by their morphology and expression of respective markers. High mineralization potential was observed. Conclusions This study provides evidence that MSC‐like populations reside within the GT of PI lesions and exhibit a multilineage differentiation potential. Further studies are needed to specify the biological role of these cells in the healing processes of inflamed PI tissues and to provide indications for their potential use in regenerative therapies.
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Affiliation(s)
- Evangelia Gousopoulou
- Department of Preventive Dentistry, Periodontology & Implant Biology, School of Dentistry, Faculty of Health Sciences, Aristotle University of Thessaloniki (AUTh), Thessaloniki, Greece.,Department of Conservative Dentistry, Periodontology & Preventive Dentistry, School of Dentistry, Hannover Medical School (MHH), Hannover, Germany
| | - Athina Bakopoulou
- Department of Conservative Dentistry, Periodontology & Preventive Dentistry, School of Dentistry, Hannover Medical School (MHH), Hannover, Germany.,Department of Prosthodontics, School of Dentistry, Faculty of Health Sciences, Aristotle University of Thessaloniki (AUTh), Thessaloniki, Greece
| | - Danae Anastasia Apatzidou
- Department of Preventive Dentistry, Periodontology & Implant Biology, School of Dentistry, Faculty of Health Sciences, Aristotle University of Thessaloniki (AUTh), Thessaloniki, Greece
| | - Gabriele Leyhausen
- Department of Conservative Dentistry, Periodontology & Preventive Dentistry, School of Dentistry, Hannover Medical School (MHH), Hannover, Germany
| | - Joachim Volk
- Department of Conservative Dentistry, Periodontology & Preventive Dentistry, School of Dentistry, Hannover Medical School (MHH), Hannover, Germany
| | - Ingmar Staufenbiel
- Department of Conservative Dentistry, Periodontology & Preventive Dentistry, School of Dentistry, Hannover Medical School (MHH), Hannover, Germany
| | - Werner Geurtsen
- Department of Conservative Dentistry, Periodontology & Preventive Dentistry, School of Dentistry, Hannover Medical School (MHH), Hannover, Germany
| | - Knut Adam
- Department of Conservative Dentistry, Periodontology & Preventive Dentistry, School of Dentistry, Hannover Medical School (MHH), Hannover, Germany
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Jochums A, Volk J, Perduns R, Plum M, Schertl P, Bakopoulou A, Geurtsen W. Influence of 2-hydroxyethyl methacrylate (HEMA) exposure on angiogenic differentiation of dental pulp stem cells (DPSCs). Dent Mater 2021; 37:534-546. [PMID: 33579530 DOI: 10.1016/j.dental.2020.12.008] [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] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 11/13/2020] [Accepted: 12/30/2020] [Indexed: 12/11/2022]
Abstract
OBJECTIVE The angiogenic differentiation of dental pulp stem cells (DPSCs) is important for tissue homeostasis and wound healing. In this study the influence of 2-hydroxyethyl methacrylate (HEMA) on angiogenic differentiation was investigated. METHODS To evaluate HEMA effects on angiogenic differentiation, DPSCs were cultivated in angiogenic differentiation medium (ADM) in the presence or absence of non-toxic HEMA concentrations (0.1 mM and 0.5 mM). Subsequently, angiogenic differentiation was analyzed on the molecular level by qRT-PCR and protein profiler analyzes of angiogenic markers and flow cytometry of PECAM1. The influence of HEMA on angiogenic phenotypes was analyzed by cell migration and sprouting assays. RESULTS Treatment with 0.5 mM HEMA during differentiation can lead to a slight reduction of angiogenic markers on mRNA level. HEMA also seems to slightly reduce the quantity of angiogenic cytokines (not significant). However, these HEMA concentrations have no detectable influence on cell migration, the abundance of PECAM1 and the formation of capillaries. Higher concentrations caused primary cytotoxic effects in angiogenic differentiation experiments conducted for longer periods than 72 h. SIGNIFICANCE Non-cytotoxic HEMA concentrations seem to have a minor impact on the expression of angiogenic markers, essentially on the mRNA level, without affecting the angiogenic differentiation process itself on a detectable level.
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Affiliation(s)
- André Jochums
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, D-30625 Hannover, Germany.
| | - Joachim Volk
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, D-30625 Hannover, Germany.
| | - Renke Perduns
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, D-30625 Hannover, Germany.
| | - Melanie Plum
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, D-30625 Hannover, Germany.
| | - Peter Schertl
- Department of Cell Biology and Biophysics, Leibniz University Hannover, D-30419 Hannover, Germany
| | - Athina Bakopoulou
- Department of Prosthodontics, School of Dentistry, Faculty of Health Sciences, Aristotle University of Thessaloniki (A.U.Th), Greece.
| | - Werner Geurtsen
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, D-30625 Hannover, Germany.
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Adam K, Staufenbiel I, Geurtsen W, Günay H. Root coverage using a connective tissue graft with epithelial striation in combination with enamel matrix derivatives - a long-term retrospective clinical interventional study. BMC Oral Health 2019; 19:148. [PMID: 31307447 PMCID: PMC6631897 DOI: 10.1186/s12903-019-0849-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [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: 07/06/2018] [Accepted: 07/04/2019] [Indexed: 11/10/2022] Open
Abstract
Background The application of a connective tissue graft with epithelial striation (CTG-ES) has been shown to improve the outcome of root coverage (RC) using the coronally advanced flap (CAF) and adjunctive administration of enamel matrix derivatives (EMD). Aim of the present study was to evaluate the long-term (mean: 16.19 ± 1.80 years, range: 13 to 18 years) stability of this treatment method with special focus on the location of the gingival margin and the width of keratinized tissue (WKT). Methods 16 patients (10 female, 6 male, aged 35.36 ± 14.70 years at surgery) with 25 Miller class I or II gingival recession (GR) defects were treated using the CAF combined with the CTG-ES and EMD. The clinical measurements recorded at baseline (t0), 6 months (t1), and 13 to 18 years (t2) after surgery included recession depth (RED), probing pocket depth (PPD), clinical attachment level (CAL), and WKT. In addition, the number of sites with complete RC (CRC) and the mean RC (MRC) were documented at t1 and t2. The statistical analysis was performed using a linear mixed model. Results The RED (t0: 4.52 ± 1.56 mm; t1: 0.36 ± 0.76 mm; t2: 0.30 ± 0.60 mm) and CAL (t0: 6.16 ± 1.62 mm; t1: 1.86 ± 0.87 mm; t2: 1.54 ± 0.92 mm) were significantly reduced at t1 and t2 compared to t0 (p < 0.001). The PPD was significantly reduced at t2 compared to t0 (p = 0.016). The WKT (t0: 1.18 ± 1.28 mm; t1: 3.26 ± 0.98 mm; t2: 4.26 ± 1.83 mm) significantly increased from t0 to t1, from t0 to t2 (p < 0.001) and from t1 to t2 (p = 0.007). A CRC was recorded at 19 sites (76.0%) at t1 and t2. The MRC was 93.6 ± 12.8% at t1 and 93.3 ± 13.3% at t2. Conclusions The use of the CAF combined with CTG-ES and EMD leads to stable long-term outcomes on teeth with Miller Class I or II GR defects. The CTG-ES represents a hybrid graft with increased position stability and advantageous properties for the healing process. We assume that the ES is responsible for the increase of the WKT.
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Affiliation(s)
- Knut Adam
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
| | - Ingmar Staufenbiel
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | - Werner Geurtsen
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
| | - Hüsamettin Günay
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, Carl-Neuberg-Str. 1, 30625, Hannover, Germany
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Perduns R, Volk J, Plum M, Gutzki F, Kaever V, Geurtsen W. Effects of HEMA on Nrf2-related gene expression using a newly developed 3D co-culture model of the oral mucosa. Dent Mater 2019; 35:1214-1226. [PMID: 31146961 DOI: 10.1016/j.dental.2019.05.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [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: 02/15/2019] [Revised: 04/26/2019] [Accepted: 05/07/2019] [Indexed: 01/09/2023]
Abstract
OBJECTIVE 2-Hydroxyethyl methacrylate (HEMA) is a component of many resin-modified materials and elutes from dental restorations into the oral cavity. Objective of our investigation was to determine the impact of HEMA on oral keratinocytes (OKF6/TERT2) and gingival fibroblasts (HGFs) in a newly established 3D co-culture model (3D-CCM) and to analyze the permeability of OKF6/TERT2 cells for HEMA. METHODS Well-characterized 3D-CCMs, consisting of confluent OKF6/TERT2 cells on cell culture inserts above HGF-containing collagen gels, were treated supra-epithelial with HEMA. Mass spectrometry was used to measure the supra- and sub-epithelial distribution of HEMA after 24 h. The impact of HEMA on nuclear factor erythroid 2-related factor 2 (Nrf2) target genes was measured by qRT-PCR and western blot analysis. RESULTS Mass spectrometry showed that HEMA was evenly distributed above and below the keratinocyte layer after 24 h. Analyzed target genes of Nrf2 were induced in both cell types on the mRNA-level but less pronounced in HGFs. On the protein-level, both cell types showed similar effects: At 5 mM HEMA, heme oxygenase-1 was induced 5.1-fold in OKF6/TERT2 cells and 4.1-fold in HGFs. NAD(P)H quinone dehydrogenase-1 was approximately induced 1.85-fold in both cell types. SIGNIFICANCE Our 3D-CCM is suitable to analyze the biocompatibility of dental materials due to an improved simulation of the oral mucosa compared to monolayer cultures. Our results indicate that HEMA is able to penetrate a dense layer of keratinocytes and to activate the cellular oxidative defense response. This may be due to the activation of the Nrf2-pathway in both cell types.
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Affiliation(s)
- Renke Perduns
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, D-30625 Hannover, Germany.
| | - Joachim Volk
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, D-30625 Hannover, Germany.
| | - Melanie Plum
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, D-30625 Hannover, Germany.
| | - Frank Gutzki
- Research Core Unit Metabolomics, Hannover Medical School, D-30625 Hannover, Germany.
| | - Volkhard Kaever
- Research Core Unit Metabolomics, Hannover Medical School, D-30625 Hannover, Germany.
| | - Werner Geurtsen
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, D-30625 Hannover, Germany.
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Perduns R, Volk J, Schertl P, Leyhausen G, Geurtsen W. HEMA modulates the transcription of genes related to oxidative defense, inflammatory response and organization of the ECM in human oral cells. Dent Mater 2019; 35:501-510. [DOI: 10.1016/j.dental.2019.01.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2018] [Revised: 10/19/2018] [Accepted: 01/11/2019] [Indexed: 12/21/2022]
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Schertl P, Volk J, Perduns R, Adam K, Leyhausen G, Bakopoulou A, Geurtsen W. Impaired angiogenic differentiation of dental pulp stem cells during exposure to the resinous monomer triethylene glycol dimethacrylate. Dent Mater 2018; 35:144-155. [PMID: 30502225 DOI: 10.1016/j.dental.2018.11.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Revised: 11/06/2018] [Accepted: 11/07/2018] [Indexed: 01/08/2023]
Abstract
OBJECTIVE Dental pulp stem cells (DPSCs) can differentiate into tissue specific lineages to support dental pulp regeneration after injuries. Triethylene glycol dimethacrylate (TEGDMA) is a widely used co-monomer in restorative dentistry with adverse effects on cellular metabolism. Aim of this study was to analyze the impact of TEGDMA on the angiogenic differentiation potential of DPSCs. METHODS DPSCs were characterized by flow cytometry. Short-term (max. 72h) cytotoxicity of TEGDMA was assessed by MTT assay. To evaluate TEGDMA effects on angiogenic differentiation, DPSCs were cultivated in angiogenic differentiation medium (ADM) in the presence or absence of short-term non-toxic TEGDMA concentrations (0.1mM and 0.25mM). Subsequently, angiogenic differentiation was analyzed by qRT-PCR analysis of mRNA markers and in vitro spheroid sprouting assays. RESULTS DPSCs treated with 0.25mM TEGDMA revealed downregulation of angiogenesis-related marker genes PECAM1 (max. 3.8-fold), VEGF-A (max. 2.4-fold) and FLT1 (max. 2.9-fold) compared to respective untreated control. In addition, a reduction of the sprouting potential of DPSCs cultured in the presence of 0.25mM TEGDMA was detectable. Larger spheroidal structures were detectable in the untreated control in comparison to cells treated with 0.25mM TEGDMA. In contrast, TEGDMA at 0.1mM was not affecting angiogenic potential in the investigated time period (up to 28 days). SIGNIFICANCE The results of the present study show that TEGDMA concentration dependently impair the angiogenic differentiation potential of DPSCs and may affect wound healing and the formation of granulation tissue.
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Affiliation(s)
- Peter Schertl
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, D-30625 Hannover, Germany.
| | - Joachim Volk
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, D-30625 Hannover, Germany.
| | - Renke Perduns
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, D-30625 Hannover, Germany.
| | - Knut Adam
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, D-30625 Hannover, Germany.
| | - Gabriele Leyhausen
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, D-30625 Hannover, Germany.
| | - Athina Bakopoulou
- Department of Fixed Prosthesis and Implant Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki (A.U.TH.), Thessaloniki, Greece.
| | - Werner Geurtsen
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, D-30625 Hannover, Germany.
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Volk J, Ziemann C, Leyhausen G, Geurtsen W. Genotoxic and mutagenic potential of camphorquinone in L5178/TK +/- mouse lymphoma cells. Dent Mater 2018; 34:519-530. [PMID: 29373133 DOI: 10.1016/j.dental.2017.12.013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [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: 09/01/2017] [Revised: 12/12/2017] [Accepted: 12/21/2017] [Indexed: 12/17/2022]
Abstract
OBJECTIVES Camphorquinone (CQ) is the most important photoinitiator used in dental composite resins. Sparse data indicate a mutagenic potential of CQ. Therefore, it was aim of this study to evaluate the cytotoxicity, genotoxicity, and mutagenicity of CQ in L5178Y TK+/- mouse lymphoma cells. METHODS L5178Y/TK+/- cells were exposed to different concentrations of non-irradiated CQ (0.25-2.5mM). Cytotoxicity was evaluated by propidium iodide assay, determination of suspension growth rate, relative total growth and the mitotic index. Intracellular levels of reactive oxygen/nitrogen species (ROS/RNS) were quantified by 2',7'-dichlorofluoresceine diacetate (DCFH-DA). Early induction of DNA strand breaks and oxidative DNA base lesions was assessed using the 8-hydroxyguanine DNA-glycosylase 1 (hOGG1)-modified alkaline comet assay, whereas mutagenicity of CQ was determined in the mouse lymphoma TK assay (MLA), according to OECD Guideline No. 490. RESULTS CQ (0.5-2.5mM) induced concentration- and time-dependent inhibition of cell growth associated with increased ROS/RNS production, amounting to 2342%±1108% of controls after 90min at 2.5mM. Additionally, CQ concentration-dependently caused direct DNA-damage, i.e. formation of DNA strand breaks and 8-hydroxy-2'-deoxyguanosine. Whereas the MLA indicated lack of mutagenicity of CQ after a 4h of treatment, CQ concentration-dependently increased total mutant frequency (MF) after 24h (about 2-fold at 2.5mM). But, based on the global evaluation factor concept, increase in MF did not reach biologically relevance. SIGNIFICANCE CQ induced concentration-dependent, cytotoxic and genotoxic effects in L5178Y/TK+/- cells, most likely due to oxidative stress, but without mediating obvious biological relevant mutagenicity.
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Affiliation(s)
- J Volk
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, 30625 Hannover, Germany.
| | - C Ziemann
- Fraunhofer Institute for Toxicology and Experimental Medicine ITEM, 30625 Hannover, Germany
| | - G Leyhausen
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, 30625 Hannover, Germany
| | - W Geurtsen
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, 30625 Hannover, Germany
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Bakopoulou A, Apatzidou D, Aggelidou E, Gousopoulou E, Leyhausen G, Volk J, Kritis A, Koidis P, Geurtsen W. Isolation and prolonged expansion of oral mesenchymal stem cells under clinical-grade, GMP-compliant conditions differentially affects "stemness" properties. Stem Cell Res Ther 2017; 8:247. [PMID: 29096714 PMCID: PMC5667471 DOI: 10.1186/s13287-017-0705-0] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [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: 08/03/2017] [Revised: 10/17/2017] [Accepted: 10/19/2017] [Indexed: 02/08/2023] Open
Abstract
Background Development of clinical-grade cell preparations is central to meeting the regulatory requirements for cellular therapies under good manufacturing practice-compliant (cGMP) conditions. Since addition of animal serum in culture media may compromise safe and efficient expansion of mesenchymal stem cells (MSCs) for clinical use, this study aimed to investigate the potential of two serum/xeno-free, cGMP culture systems to maintain long-term “stemness” of oral MSCs (dental pulp stem cells (DPSCs) and alveolar bone marrow MSCs (aBMMSCs)), compared to conventional serum-based expansion. Methods DPSC and aBMMSC cultures (n = 6/cell type) were established from pulp and alveolar osseous biopsies respectively. Three culture systems were used: StemPro_MSC/SFM_XenoFree (Life Technologies); StemMacs_MSC/XF (Miltenyi Biotek); and α-MEM (Life Technologies) with 15% fetal bovine serum. Growth (population doublings (PDs)), immunophenotypic (flow cytometric analysis of MSC markers) and senescence (β-galactosidase (SA-β-gal) activity; telomere length) characteristics were determined during prolonged expansion. Gene expression patterns of osteogenic (ALP, BMP-2), adipogenic (LPL, PPAR-γ) and chondrogenic (ACAN, SOX-9) markers and maintenance of multilineage differentiation potential were determined by real-time PCR. Results Similar isolation efficiency and stable growth dynamics up to passage 10 were observed for DPSCs under all expansion conditions. aBMMSCs showed lower cumulative PDs compared to DPSCs, and when StemMacs was used substantial delays in cell proliferation were noted after passages 6–7. Serum/xeno-free expansion produced cultures with homogeneous spindle-shaped phenotypes, while serum-based expansion preserved differential heterogeneous characteristics of each MSC population. Prolonged expansion of both MSC types but in particular the serum/xeno-free-expanded aBMMSCs was associated with downregulation of CD146, CD105, Stro-1, SSEA-1 and SSEA-4, but not CD90, CD73 and CD49f, in parallel with an increase of SA-gal-positive cells, cell size and granularity and a decrease in telomere length. Expansion under both serum-free systems resulted in “osteogenic pre-disposition”, evidenced by upregulation of osteogenic markers and elimination of chondrogenic and adipogenic markers, while serum-based expansion produced only minor changes. DPSCs retained a diminishing (CCM, StemPro) or increasing (StemMacs) mineralization potential with passaging, while aBMMSCs lost this potential after passages 6–7 under all expansion conditions. Conclusions These findings indicate there is still a vacant role for development of qualified protocols for clinical-grade expansion of oral MSCs; a key milestone achievement for translation of research from the bench to clinics. Electronic supplementary material The online version of this article (doi:10.1186/s13287-017-0705-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Athina Bakopoulou
- Department of Prosthodontics, School of Dentistry, Faculty of Health Sciences, Aristotle University of Thessaloniki (A.U.Th), GR-54124, Thessaloniki, Greece. .,cGMP Regenerative Medicine Facility, Department of Physiology and Pharmacology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki (A.U.Th), Thessaloniki, Greece. .,Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School (MHH), Hannover, Germany.
| | - Danae Apatzidou
- Department of Preventive Dentistry, Periodontology and Implant Biology, School of Dentistry, Faculty of Health Sciences, Aristotle University of Thessaloniki (A.U.Th), Thessaloniki, Greece
| | - Eleni Aggelidou
- Department of Physiology and Pharmacology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki (A.U.Th), Thessaloniki, Greece.,cGMP Regenerative Medicine Facility, Department of Physiology and Pharmacology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki (A.U.Th), Thessaloniki, Greece
| | - Evangelia Gousopoulou
- Department of Preventive Dentistry, Periodontology and Implant Biology, School of Dentistry, Faculty of Health Sciences, Aristotle University of Thessaloniki (A.U.Th), Thessaloniki, Greece.,Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School (MHH), Hannover, Germany
| | - Gabriele Leyhausen
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School (MHH), Hannover, Germany
| | - Joachim Volk
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School (MHH), Hannover, Germany
| | - Aristeidis Kritis
- Department of Physiology and Pharmacology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki (A.U.Th), Thessaloniki, Greece.,cGMP Regenerative Medicine Facility, Department of Physiology and Pharmacology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki (A.U.Th), Thessaloniki, Greece
| | - Petros Koidis
- Department of Prosthodontics, School of Dentistry, Faculty of Health Sciences, Aristotle University of Thessaloniki (A.U.Th), GR-54124, Thessaloniki, Greece
| | - Werner Geurtsen
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School (MHH), Hannover, Germany
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10
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Abstract
Previous in vivo studies have revealed that resins may generate a persistent inflammation of oral tissues and cell death as well. Apoptosis is an important regulated process that results in rapid cell death. This study tested the hypothesis that the comonomer triethyleneglycol-dimethacrylate (TEGDMA) causes apoptosis. The effects of TEGDMA on proliferation and apoptosis in primary oral fibroblasts were analyzed by light microscopy and flow cytometry (FACS; Annexin V-assay). TEGDMA at 5 and 7.5 mM inhibited proliferation after 24 hrs. No increased frequency of apoptosis or necrosis was observed with 1 mM or 2.5 mM TEGDMA after 24 hrs. Apoptosis and Annexin V-positive cells were observed with 5 mM and 7.5 mM TEGDMA by light microscopy after 24 hrs. A dramatic increase in apoptotic cells was detected by FACS after 24 hrs with 7.5 mM TEGDMA. Thus, TEGDMA was cytotoxic and “apoptotic” in a dose- and time-dependent manner.
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Affiliation(s)
- V Janke
- Department of Conservative Dentistry & Periodontology, Medical University Hannover, Germany
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11
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Müller WE, Neufurth M, Tolba E, Wang S, Geurtsen W, Feng Q, Schröder HC, Wang X. A biomimetic approach to ameliorate dental hypersensitivity by amorphous polyphosphate microparticles. Dent Mater 2016; 32:775-83. [DOI: 10.1016/j.dental.2016.03.027] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 02/10/2016] [Accepted: 03/22/2016] [Indexed: 12/30/2022]
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12
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Jacker-Guhr S, Ibarra G, Oppermann LS, Lührs AK, Rahman A, Geurtsen W. Evaluation of microleakage in class V composite restorations using dye penetration and micro-CT. Clin Oral Investig 2015; 20:1709-18. [DOI: 10.1007/s00784-015-1676-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 11/19/2015] [Indexed: 10/22/2022]
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13
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Bakopoulou A, Kritis A, Andreadis D, Papachristou E, Leyhausen G, Koidis P, Geurtsen W, Tsiftsoglou A. Angiogenic Potential and Secretome of Human Apical Papilla Mesenchymal Stem Cells in Various Stress Microenvironments. Stem Cells Dev 2015. [PMID: 26203919 DOI: 10.1089/scd.2015.0197] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Stem cells from the apical papilla (SCAP) of human adult teeth are considered an accessible source of cells with angiogenic properties. The aims of this study were to investigate the endothelial transdifferentiation of SCAP, the secretion of pro- and antiangiogenic factors from SCAP, and the paracrine effects of SCAP when exposed to environmental stress to stimulate tissue damage. SCAP were exposed to serum deprivation (SD), glucose deprivation (GD), and oxygen deprivation/hypoxia (OD) conditions, individually or in combination. Endothelial transdifferentiation was evaluated by in vitro capillary-like formation assays, real-time polymerase chain reaction, western blot, and flow cytometric analyses of angiogenesis-related markers; secretome by antibody arrays and enzyme-linked immunosorbent assays (ELISA); and paracrine impact on human umbilical vein endothelial cells (HUVECs) by in vitro transwell migration and capillary-like formation assays. The short-term exposure of SCAP to glucose/oxygen deprivation (GOD) in the presence, but mainly in deprivation, of serum (SGOD) elicited a proangiogenesis effect indicated by expression of angiogenesis-related genes involved in vascular endothelial growth factor (VEGF)/VEGFR and angiopoietins/Tie pathways. This effect was unachievable under SD in normoxia, suggesting that the critical microenvironmental condition inducing rapid endothelial shift of SCAP is the combination of SGOD. Interestingly, SCAP showed high adaptability to these adverse conditions, retaining cell viability and acquiring a capillary-forming phenotype. SCAP secreted higher numbers and amounts of pro- (angiogenin, IGFBP-3, VEGF) and lower amounts of antiangiogenic factors (serpin-E1, TIMP-1, TSP-1) under SGOD compared with SOD or SD alone. Finally, secretome obtained under SGOD was most effective in inducing migration and capillary-like formation by HUVECs. These data provide new evidence on the microenvironmental factors favoring endothelial transdifferentiation of SCAP, uncovering the molecular mechanisms regulating their fate. They also validate the angiogenic properties of their secretome giving insights into preconditioning strategies enhancing their therapeutic potential.
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Affiliation(s)
- Athina Bakopoulou
- 1 Department of Fixed Prosthesis and Implant Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki (A.U.TH.) , Thessaloniki, Greece .,2 Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School (MHH) , Hannover, Germany
| | - Aristeidis Kritis
- 3 Department of Physiology and Pharmacology, School of Medicine, Aristotle University of Thessaloniki (A.U.TH.) , Thessaloniki, Greece
| | - Dimitrios Andreadis
- 4 Department of Oral Medicine and Pathology, School of Dentistry, Aristotle University of Thessaloniki (A.U.TH.) , Thessaloniki, Greece
| | - Eleni Papachristou
- 1 Department of Fixed Prosthesis and Implant Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki (A.U.TH.) , Thessaloniki, Greece
| | - Gabriele Leyhausen
- 2 Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School (MHH) , Hannover, Germany
| | - Petros Koidis
- 1 Department of Fixed Prosthesis and Implant Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki (A.U.TH.) , Thessaloniki, Greece
| | - Werner Geurtsen
- 2 Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School (MHH) , Hannover, Germany
| | - Asterios Tsiftsoglou
- 5 Laboratory of Pharmacology, School of Pharmaceutical Sciences, Aristotle University of Thessaloniki (A.U.TH.) , Thessaloniki, Greece
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Wessels M, Rimkus J, Leyhausen G, Volk J, Geurtsen W. Genotoxic effects of camphorquinone and DMT on human oral and intestinal cells. Dent Mater 2015; 31:1159-68. [PMID: 26187530 DOI: 10.1016/j.dental.2015.06.007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [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: 12/29/2014] [Accepted: 06/08/2015] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Released components of oral biomaterials can leach into the oral cavity and may subsequently reach the gastrointestinal tract. Camphorquinone (CQ) is the most common used photoinitiator in resinous restorative materials and is often combined with the co-initiator N,N-dimethyl-p-toluidine (DMT). It has been shown that CQ exerts cytotoxic effects, at least partially due to the generation of reactive oxygen species (ROS). Objective of this study was to examine the cytotoxic and genotoxic potential of CQ in human oral keratinocytes (OKF6/TERT2) and immortalized epithelial colorectal adenocarcinoma cells (Caco-2). Furthermore, the effects of visible-light irradiation and the co-initiator DMT were investigated as well as the generation of ROS, the potential protective effect of glutathione (GSH) and a recovery period of CQ-treated Caco-2 cells. METHODS The alkaline comet assay was used to determine DNA damage. Additionally, an enzyme modified comet assay was applied, which detects 7,8-dihydro-8-oxoguanine (8-oxoguanine), a reliable marker for oxidative stress. RESULTS Our data revealed that high concentrations of CQ induced DNA lesions in OKF6/TERT2 cells. This DNA damage is at least partly caused by the generation of 8-oxoguanine. In addition, CQ and DMT increased ROS formation and induced DNA damage in Caco-2 cells. CQ-treatment resulted in generation of 8-oxoguanine. The antioxidant GSH efficiently prevented CQ-associated DNA damage. Furthermore, a recovery following CQ-treatment significantly reduced DNA damage. SIGNIFICANCE We conclude that CQ-induced DNA damage is caused by oxidative stress in oral and intestinal cells. These lesions can be prevented and possibly repaired by GSH-treatment and recovery of cells after the photoinitiator is removed from cultures.
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Affiliation(s)
- Miriam Wessels
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
| | - Julia Rimkus
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Gabriele Leyhausen
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Joachim Volk
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
| | - Werner Geurtsen
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany
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15
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Rothmund L, Shehata M, Van Landuyt KL, Schweikl H, Carell T, Geurtsen W, Hellwig E, Hickel R, Reichl FX, Högg C. Release and protein binding of components from resin based composites in native saliva and other extraction media. Dent Mater 2015; 31:496-504. [DOI: 10.1016/j.dental.2015.01.016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 01/24/2015] [Accepted: 01/28/2015] [Indexed: 01/06/2023]
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16
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Bakopoulou A, Leyhausen G, Volk J, Papachristou E, Koidis P, Geurtsen W. Wnt/β-catenin signaling regulates Dental Pulp Stem Cells' responses to pulp injury by resinous monomers. Dent Mater 2015; 31:542-55. [PMID: 25735758 DOI: 10.1016/j.dental.2015.02.004] [Citation(s) in RCA: 27] [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: 10/19/2014] [Revised: 02/03/2015] [Accepted: 02/09/2015] [Indexed: 01/11/2023]
Abstract
OBJECTIVES Aim of this study was to investigate whether Dental Pulp Stem Cells-DPSCs responses to pulp injury caused by resinous monomers is be mediated through activation of Wnt/β-catenin signaling. METHODS DPSCs cultures were established from third molars of healthy donors and characterized for stem cell markers with flow cytometry. Cells were exposed to TEGDMA (T: 0.5-2mM) with or without presence of the Wnt-1 ligand (W:25-100ng/ml) or the GSK3β inhibitor Lithium (L:1-10mM), used both as activators of Wnt/β-catenin signaling. Cell viability was evaluated by MTT assay, cell cycle profiles by flow cytometry and expression of key molecules of Wnt/β-catenin signaling by Real-time PCR and Western Blot. RESULTS DPSC exposure to TEGDMA caused a concentration-dependent cytotoxicity, accompanied by G1 arrest at lower and G2/M arrest at higher concentrations or after prolonged exposure. Lithium caused a dual effect, by stimulating/inhibiting cell proliferation at lower/higher concentrations respectively and causing a G2/M arrest in a concentration-dependent manner. Wnt signaling could be activated in DPSCs after Lithium or Wnt-1 treatment, as shown by accumulation of β-catenin, its translocation into the nucleus and enhanced expression of key pathway players, like LEF1 and Cyclin D1. Importantly, exposure to TEGDMA caused a more pronounced activation of the pathway, whereas cumulative effects were observed after T/L or T/W co-treatment, indicating a very strong activation of Wnt signaling after treatment of already "activated" (by Lithium or Wnt-1) cells with TEGDMA. SIGNIFICANCE These findings highlight the important role of Wnt canonical signaling in pulp repair responses to common injuries.
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Affiliation(s)
- Athina Bakopoulou
- Department of Fixed Prosthesis & Implant Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki GR-54124, Greece; Department of Conservative Dentistry, Periodontology & Preventive Dentistry, School of Dentistry, Hannover Medical School, Hannover D-30625, Germany
| | - Gabriele Leyhausen
- Department of Conservative Dentistry, Periodontology & Preventive Dentistry, School of Dentistry, Hannover Medical School, Hannover D-30625, Germany
| | - Joachim Volk
- Department of Conservative Dentistry, Periodontology & Preventive Dentistry, School of Dentistry, Hannover Medical School, Hannover D-30625, Germany
| | - Eleni Papachristou
- Department of Fixed Prosthesis & Implant Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki GR-54124, Greece
| | - Petros Koidis
- Department of Fixed Prosthesis & Implant Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki GR-54124, Greece
| | - Werner Geurtsen
- Department of Conservative Dentistry, Periodontology & Preventive Dentistry, School of Dentistry, Hannover Medical School, Hannover D-30625, Germany.
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Martins CA, Leyhausen G, Volk J, Geurtsen W. Effects of alendronate on osteoclast formation and activity in vitro. J Endod 2014; 41:45-9. [PMID: 25442070 DOI: 10.1016/j.joen.2014.07.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [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: 02/11/2014] [Revised: 05/13/2014] [Accepted: 07/07/2014] [Indexed: 11/17/2022]
Abstract
INTRODUCTION Root resorption is a common complication after replantation following traumatic dental avulsion. Endodontic therapy combined with local and intracanal medications aims to avoid osteoclastic activity. In such cases, the application of alendronate (ALN), a bisphosphonate widely used for the treatment of bone disorders, could be of clinical relevance. This study evaluated alendronate biocompatibility on periodontal ligament cells as well as its effects on an in vitro osteoclastogenesis model. METHODS Alendronate cytotoxicity (10(-3) to 10(-9) mol/L) in human periodontal ligament fibroblasts, human osteogenic sarcoma cells, and murine osteoclastic precursors (RAW 264.7) was analyzed using cell number determination, cell viability, and proliferation assays. ALN (10(-6) to 10(-12) mol/L) effects on RANKL-induced osteoclastogenesis of RAW cells were assessed by tartrate-resistant acid phosphatase (TRAP) staining and activity and real-time polymerase chain reaction. RESULTS ALN at higher concentrations was cytotoxic for all cell types, inhibiting significantly the proliferation of human osteogenic sarcoma cells and human periodontal ligament fibroblasts (≥10(-5) mol/L). TRAP activity and expression of the osteoclast markers TRAP and cathepsin K by RAW-derived osteoclasts decreased significantly with ALN at low concentrations, reaching the maximum effect at 10(-10) mol/L. CONCLUSIONS We showed that ALN at very low concentrations is an effective inhibitor of RANKL-generated osteoclasts, without causing cytotoxic effects on their precursors or periapical cells. ALN at such concentrations might be useful to prevent replacement resorption in avulsed teeth.
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Affiliation(s)
- Caroline A Martins
- Department of Conservative/Preventive Dentistry and Periodontology, Hannover Medical School, Hannover, Germany
| | - Gabriele Leyhausen
- Department of Conservative/Preventive Dentistry and Periodontology, Hannover Medical School, Hannover, Germany
| | - Joachim Volk
- Department of Conservative/Preventive Dentistry and Periodontology, Hannover Medical School, Hannover, Germany
| | - Werner Geurtsen
- Department of Conservative/Preventive Dentistry and Periodontology, Hannover Medical School, Hannover, Germany.
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18
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Lührs AK, De Munck J, Geurtsen W, Van Meerbeek B. Composite cements benefit from light-curing. Dent Mater 2014; 30:292-301. [DOI: 10.1016/j.dental.2013.11.012] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Revised: 11/25/2013] [Accepted: 11/28/2013] [Indexed: 11/25/2022]
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Lührs AK, Pongprueksa P, De Munck J, Geurtsen W, Van Meerbeek B. Curing mode affects bond strength of adhesively luted composite CAD/CAM restorations to dentin. Dent Mater 2014; 30:281-91. [DOI: 10.1016/j.dental.2013.11.016] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2013] [Revised: 11/25/2013] [Accepted: 11/28/2013] [Indexed: 11/28/2022]
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Volk J, Leyhausen G, Wessels M, Geurtsen W. Reduced glutathione prevents camphorquinone-induced apoptosis in human oral keratinocytes. Dent Mater 2014; 30:215-26. [DOI: 10.1016/j.dental.2013.11.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 08/22/2013] [Accepted: 11/20/2013] [Indexed: 12/13/2022]
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21
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Staufenbiel I, Hauschild C, Kahl-Nieke B, Vahle-Hinz E, von Kodolitsch Y, Berner M, Bauss O, Geurtsen W, Rahman A. Periodontal conditions in patients with Marfan syndrome - a multicenter case control study. BMC Oral Health 2013; 13:59. [PMID: 24165013 PMCID: PMC3816571 DOI: 10.1186/1472-6831-13-59] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [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: 08/28/2013] [Accepted: 10/22/2013] [Indexed: 11/10/2022] Open
Abstract
Background Marfan syndrome (MFS) is a disorder of the connective tissues. Alterations of the elastic fibers may manifest in different tissues especially in the skeletal, cardiovascular and ocular system. Oral manifestations like orthodontic or skeletal anomalies and fragility of the temporomandibular joint have been well described by various authors. However, no data are available regarding a possible periodontal involvement of MFS. Hence, the aim of the present study was to investigate for the first time if MFS may increase the susceptibility to periodontitis. Methods A comprehensive periodontal examination including documentation of probing pocket depth, gingival recession, clinical attachment level, and bleeding on probing was conducted in all patients. In addition, dental conditions were assessed by determining the Index for Decayed, Missing and Filled Teeth (DMFT) and a self-administered questionnaire was filled out by patients. For statistical analysis, the unpaired t-Test was applied (level of significance: p < 0.05). Both groups were matched concerning well known periodontal risk factors like age, gender and smoking habits. Results 82 participants, 51 patients with MFS (30 female and 21 male, mean age: 40.20 ± 15.35 years) and 31 sound controls (17 female and 14 male, mean age: 40.29 ± 13.94 years), were examined. All assessed periodontal and dental parameters were not significantly different between groups. Conclusions Based on our data, patients with MFS did not reveal a higher prevalence of periodontitis compared to the control group. However, Marfan patients showed a tendency to more inflammation signs, which can be explained by the crowded teeth. Therefore, a regular professional cleaning of the teeth is recommendable (i.e., 6 months intervals) in order to reduce the bacterial biofilm in the oral cavity and thus resulting in a decreased risk of systemic diseases, specifically endocarditis.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Alexander Rahman
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, Carl-Neuberg-Strasse 1, 30625, Hannover, Germany.
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22
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Shehata M, Durner J, Eldenez A, Van Landuyt K, Styllou P, Rothmund L, Hickel R, Scherthan H, Geurtsen W, Kaina B, Carell T, Reichl FX. Cytotoxicity and induction of DNA double-strand breaks by components leached from dental composites in primary human gingival fibroblasts. Dent Mater 2013; 29:971-9. [DOI: 10.1016/j.dental.2013.07.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2012] [Revised: 03/05/2013] [Accepted: 07/03/2013] [Indexed: 01/22/2023]
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23
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Müller WE, Schröder HC, Schlossmacher U, Neufurth M, Geurtsen W, Korzhev M, Wang X. The enzyme carbonic anhydrase as an integral component of biogenic Ca-carbonate formation in sponge spicules. FEBS Open Bio 2013; 3:357-62. [PMID: 24251096 PMCID: PMC3821024 DOI: 10.1016/j.fob.2013.08.004] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [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: 07/06/2013] [Revised: 08/07/2013] [Accepted: 08/08/2013] [Indexed: 11/30/2022] Open
Abstract
The inorganic scaffold of the spicules, the skeletal elements of the calcareous sponges, is formed of calcium carbonate (CaCO3). The growth of the approximately 300-μm large spicules, such as those of the calcareous sponge Sycon raphanus used in the present study, is a rapid process with a rate of about 65 μm/h. The formation of CaCO3 is predominantly carried out by the enzyme carbonic anhydrase (CA). The enzyme from the sponge S. raphanus was isolated and prepared by recombination. The CA-driven deposition of CaCO3 crystallites is dependent on temperature (optimal at 52 °C), the pH value of the reaction assay (7.5/8.0), and the substrate concentration (CO2 and Ca(2+)). During the initial phase of crystallite formation, ≈40 μm large round-shaped deposits are formed that remodel to larger prisms. These crystal-like prisms associate to each other and form either rope-/bundle-like aggregates or arrange perfectly with their smaller planes along opposing surfaces of the sponge spicule rays. The CA-dependent CaCO3 deposition can be inhibited by the CA-specific inhibitor acetazolamide. The Michaelis-Menten constant for the CA-driven mineralization has been determined to be around 8 mM with respect to CaCO3. The deposits formed have a Martens hardness of ≈5 GPa. The data presented here highlights for the first time that calcite deposition in the sponge system is decisively controlled enzymatically. This data will contribute to the development of new strategies applicable for the fabrication of novel biomaterials.
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Affiliation(s)
- Werner E.G. Müller
- ERC Advanced Investigator Grant Research Group at Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, Mainz D-55128, Germany
| | - Heinz C. Schröder
- ERC Advanced Investigator Grant Research Group at Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, Mainz D-55128, Germany
| | - Ute Schlossmacher
- ERC Advanced Investigator Grant Research Group at Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, Mainz D-55128, Germany
| | - Meik Neufurth
- ERC Advanced Investigator Grant Research Group at Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, Mainz D-55128, Germany
| | - Werner Geurtsen
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, Carl-Neuberg-Strasse 1, Hannover 30625, Germany
| | - Michael Korzhev
- ERC Advanced Investigator Grant Research Group at Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, Mainz D-55128, Germany
| | - Xiaohong Wang
- ERC Advanced Investigator Grant Research Group at Institute for Physiological Chemistry, University Medical Center of the Johannes Gutenberg University Mainz, Duesbergweg 6, Mainz D-55128, Germany
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Meyer K, Khorshidi-Böhm M, Geurtsen W, Günay H. An early oral health care program starting during pregnancy—a long-term study—phase V. Clin Oral Investig 2013; 18:863-72. [DOI: 10.1007/s00784-013-1059-3] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2013] [Accepted: 07/16/2013] [Indexed: 11/27/2022]
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25
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Bakopoulou A, Leyhausen G, Volk J, Koidis P, Geurtsen W. Comparative characterization of STRO-1(neg)/CD146(pos) and STRO-1(pos)/CD146(pos) apical papilla stem cells enriched with flow cytometry. Arch Oral Biol 2013; 58:1556-68. [PMID: 23871383 DOI: 10.1016/j.archoralbio.2013.06.018] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2013] [Revised: 05/18/2013] [Accepted: 06/19/2013] [Indexed: 01/09/2023]
Abstract
OBJECTIVE Stem Cells residing in the Apical Papilla (SCAP) of human permanent teeth represent a promising cell source for dental tissue regeneration. Therefore, the functional and molecular properties of specific subpopulations existing within heterogeneous cultures should be further investigated to give insight whether their selection could be beneficial for targeted therapeutic applications. DESIGN In this study we extensively characterized SCAP cultures established from 10 healthy subjects, as well as their STRO-1(pos/)CD146(pos) and STRO-1(neg/)CD146(pos) subpopulations isolated with fluorescence-activated cell sorting. SCAP were analyzed for embryonic (Nanog, Oct3/4, SSEA-3, TRA-1-60), mesenchymal (STRO-1, CD146/MUC18, CD105/endoglin, CD24, CD90/Thy-1, CD81-TAPA, CD34, CD49f/a6-integrin), neural (CD271/NGFR, nestin) and hematopoietic (CD117/c-kit, CD45) stem cell (SC) markers using flow cytometry. Multipotentiality was evaluated with culture specific staining (Alizarin-Red-S, Oil- Red-O) and RT-PCR analysis for osteo/odontogenic (DSPP, BSP, ALP, osteocalcin, osteonectin, BMP-2, Runx2), adipogenic (lipoprotein-lipase-LPL) and neurogenic (Neurofilament/NFL-L, nestin, β-tubulin-III, NCAM) markers. RESULTS Our results showed that the STRO-1(pos)/CD146(pos) subpopulation demonstrated higher CFU efficiency and much higher expression of several embryonic and mesenchymal SC markers compared to the non-sorted SCAP. They also showed enhanced odontogenic differentiation potential, as evidenced by higher mineralization capacity and expression of osteo/odontogenic markers. By contrast, absence of STRO-1 in the STRO-1(neg)/CD146(pos) subpopulation yielded the opposite results and was associated with significant downgrading of the above-mentioned properties. CONCLUSIONS These results suggest that STRO-1(pos)/CD146(pos) SCAP cells represent a very promising adult MSCs source with enhanced multipotent SC properties that could be easily isolated with simple flow cytometric methods to be used for tissue engineering applications.
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Affiliation(s)
- A Bakopoulou
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School (MHH), Germany
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Staufenbiel I, Weinspach K, Förster G, Geurtsen W, Günay H. Periodontal conditions in vegetarians: a clinical study. Eur J Clin Nutr 2013; 67:836-40. [DOI: 10.1038/ejcn.2013.101] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2013] [Revised: 04/19/2013] [Accepted: 04/23/2013] [Indexed: 11/09/2022]
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Lührs AK, De Munck J, Geurtsen W, Van Meerbeek B. Does inhibition of proteolytic activity improve adhesive luting? Eur J Oral Sci 2013; 121:121-31. [PMID: 23489902 DOI: 10.1111/eos.12018] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/01/2012] [Indexed: 11/30/2022]
Abstract
Endogenous enzymes may be involved in the biodegradation of adhesive restoration-tooth interfaces. Inhibitors of matrix metalloproteinases (MMPs) have been suggested to retard the bond-degradation process. Limited data are available on whether composite cements may also benefit from MMP inhibitors. Therefore, the aim of this study was to determine the effect of two MMP inhibitors--chlorhexidine digluconate (CHX) and galardin--on the microtensile bond strength (μTBS) of two self-adhesive composite cements to dentin. Ceramic specimens were cemented to bur-cut dentin surfaces using the self-adhesive composite cements RelyX Unicem 2 (3M ESPE) or Clearfil SA (Kuraray), or the etch-and-rinse composite cement Nexus 3 (Kerr) that served as the control. The surfaces were left untreated or were pretreated with MMP inhibitors (2% CHX or 0.2 mM galardin). The μTBS was determined 'immediately' and upon ageing (water storage for 6 months). Statistical analysis revealed a significant effect of the factors 'composite cement' and 'storage', as well as all interactions, but no effect of the MMP inhibitors. After 6 months of ageing, the μTBS decreased for all cements, except for the multistep etch-and-rinse luting composite when it was applied without MMP inhibitors. The MMP inhibitors could not prevent the decrease in μTBS upon ageing and therefore do not improve the luting durability of the composite cements tested.
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Affiliation(s)
- Anne-Katrin Lührs
- KU Leuven-BIOMAT, Department of Oral Health Sciences, KU Leuven (University of Leuven), & Dentistry, University Hospitals Leuven, Leuven, Belgium.
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Martins CA, Leyhausen G, Geurtsen W, Volk J. Intracellular glutathione: A main factor in TEGDMA-induced cytotoxicity? Dent Mater 2012; 28:442-8. [DOI: 10.1016/j.dental.2011.11.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Revised: 11/28/2011] [Accepted: 11/28/2011] [Indexed: 01/11/2023]
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Bakopoulou A, Leyhausen G, Volk J, Koidis P, Geurtsen W. Effects of resinous monomers on the odontogenic differentiation and mineralization potential of highly proliferative and clonogenic cultured apical papilla stem cells. Dent Mater 2012; 28:327-39. [DOI: 10.1016/j.dental.2012.01.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2011] [Revised: 12/01/2011] [Accepted: 01/04/2012] [Indexed: 01/09/2023]
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Fricke U, Geurtsen W, Staufenbiel I, Rahman A. Periodontal status of HIV-infected patients undergoing antiretroviral therapy compared to HIV-therapy naive patients: a case control study. Eur J Med Res 2012; 17:2. [PMID: 22472296 PMCID: PMC3337541 DOI: 10.1186/2047-783x-17-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [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: 06/23/2011] [Accepted: 01/30/2012] [Indexed: 11/27/2022] Open
Abstract
Background Although severe oral opportunistic infections decreased with the implementation of highly active antiretroviral therapy, periodontitis is still a commonly described problem in patients infected with human immunodeficiency virus (HIV). The objective of the present investigation was to determine possible differences in periodontal parameters between antiretroviral treated and untreated patients. Methods The study population comprised 80 patients infected with HIV divided into two groups. The first group was receiving antiretroviral therapy while the second group was therapy naive. The following parameters were examined: probing pocket depth, gingival recession, clinical attachment level, papilla bleeding score, periodontal screening index and the index for decayed, missed and filled teeth. A questionnaire concerning oral hygiene, dental care and smoking habits was filled out by the patients. Results There were no significant differences regarding the periodontal parameters between the groups except in the clinical marker for inflammation, the papilla bleeding score, which was twice as high (P < 0.0001) in the antiretroviral untreated group (0.58 ± 0.40 versus 1.02 ± 0.59). The participants of this investigation generally showed a prevalence of periodontitis comparable to that in healthy subjects. The results of the questionnaire were comparable between the two groups. Conclusion There is no indication for advanced periodontal damage in HIV-infected versus non-infected patients in comparable age groups. Due to their immunodeficiency, HIV-infected patients should be monitored closely to prevent irreversible periodontal damage. Periodontal monitoring and early therapy is recommended independent of an indication for highly active antiretroviral therapy.
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Affiliation(s)
- Ulrich Fricke
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, Carl-Neuberg-Strasse 1, Hannover 30625, Germany
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Volk J, Leyhausen G, Geurtsen W. Glutathione level and genotoxicity in human oral keratinocytes exposed to TEGDMA. J Biomed Mater Res B Appl Biomater 2011; 100:391-9. [PMID: 22121138 DOI: 10.1002/jbm.b.31960] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [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: 04/11/2011] [Revised: 07/25/2011] [Accepted: 08/14/2011] [Indexed: 11/11/2022]
Abstract
Triethylene-glycol dimethacrylate (TEGDMA) is an important matrix comonomer used in many resin-modified dental materials. As the monomer-polymer conversion of these biomaterials is up to 80% at best, TEGDMA may leach into the oral cavity and the pulp in millimolar concentrations. Objective of this study was to evaluate whether TEGDMA is genotoxic in immortalized human oral keratinocytes (OKF6/TERT2), for example, due to formation of oxidative DNA-lesions. OKF6-TERT2 cells were exposed to TEGDMA at concentrations ranging from 0.5 mM to 5.0 mM. Cell viability was analyzed by the fluorescent probe propidium iodide (PI), intracellular levels of reactive oxygen species (ROS) were measured by 2',7'-dichlorofluorescein diacetate, whereas glutathione concentrations (GSH) were read using monobromobimane. Genotoxicity was determined quantitatively by the alkaline comet assay. To explore the presence of oxidized bases that could be produced by oxidative events during short-term treatment with TEGDMA, the 8-hydroxyguanine DNA-glycosylase 1 (hOGG1)-modified comet assay was used. TEGDMA induced an early and rapid GSH-depletion in a concentration-dependent manner (p < 0.05). A total of 5 mM TEGDMA reduced GSH to 57.8% ± 8.6% of control values already after 30 min. There was no significant reduction in cell viability during 6 h of incubation, and only moderate ROS-formation was detected after 4 h of treatment with TEGDMA. But after 24 h, TEGDMA-concentrations of ≥2.5 mM induced a significant reduction of total cell numbers and cells' viability. Furthermore, TEGDMA caused a concentration-dependent DNA damage in OKF6/TERT2 cultures, which was not associated with a detectable formation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in the cellular genome. In conclusion, our results show that TEGDMA influences the intracellular redox metabolism and may exhibit pronounced cyto- and genotoxic effects in human immortalized oral keratinocytes. However, it may be concluded that oxidative stress is not causative for TEGDMA-dependent genotoxicity in these cells.
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Affiliation(s)
- Joachim Volk
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, 30625 Hannover, Germany
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Weinspach K, Demling A, Günay H, Geurtsen W, Schwestka-Polly R, Staufenbiel I. Short-term periodontal and microbiological changes following orthognathic surgery. J Craniomaxillofac Surg 2011; 40:467-72. [PMID: 21880501 DOI: 10.1016/j.jcms.2011.08.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Revised: 08/01/2011] [Accepted: 08/03/2011] [Indexed: 11/30/2022] Open
Abstract
OBJECTIVE Aim of the present study was to evaluate the influence of orthognathic surgery on the development of periodontal and microbiological changes. MATERIALS AND METHODS Fifteen consecutively treated patients with a mean age of 24.9±7.7 years receiving orthognathic surgery were included in the present study. Plaque index (PI) and concentrations of 11 periodonto-pathogenic bacteria were recorded one day prior to surgery (t(0)) and one week (t(1)) and six weeks (t(2)) post-surgery. In addition, a complete periodontal examination including pocket probing depth (PPD), gingival recession (GR), clinical attachment level (CAL), bleeding on probing (BOP) and width of keratinized gingiva (WKG) was conducted at t(0) and t(2). For statistical analysis, general linear model and paired t-test were applied. RESULTS A significant increase of PI (t(0)-t(1), p=0.037) was followed by a significant decrease (t(1)-t(2), p=0.017). Apart from Eikenella corrodens (p=0.036), no significant microbiological changes were recorded. PPD significantly increased on oral sites (p=0.045) and GR especially on buccal sites (p=0.001). In the incision area the development of GR was significantly higher on the test (buccal) than on the control sites (oral). Both gingival biotypes were affected by GR. CONCLUSIONS Orthognathic surgery causes statistically significant changes of periodontal parameters, but these changes do not necessarily impair the aesthetic appearance of the gingival margin.
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Affiliation(s)
- Knut Weinspach
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry (Head: Prof. Dr. Werner Geurtsen), Hannover Medical School, Carl-Neuberg-Str. 1, 30625 Hannover, Germany.
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Dimitrouli M, Geurtsen W, Lührs AK. Comparison of the push-out strength of two fiber post systems dependent on different types of resin cements. Clin Oral Investig 2011; 16:899-908. [DOI: 10.1007/s00784-011-0571-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2010] [Accepted: 05/18/2011] [Indexed: 10/18/2022]
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Günay H, Geurtsen W, Lührs AK. Conservative treatment of periodontal recessions with class V-defects using gingiva-shaded composite--A systematic treatment concept. ACTA ACUST UNITED AC 2011; 38:124-6, 128-30, 132. [PMID: 21500623 DOI: 10.12968/denu.2011.38.2.124] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
UNLABELLED Periodontal recessions can cause aesthetic and functional problems, especially in the anterior region or when combined with exposed crown margins. A combination of periodontal disease, recession with exposed root surface, hard-tissue defects and age emphasizes the need for treating these defects. If crown margins are exposed and surgical treatment is not possible, aesthetics and function can only be improved by replacement of the restoration. The restorative treatment option with a gingiva-shaded composite is especially valuable for dental fear patients or older patients with general or local risk factors, surgical contra-indications or Class III and IV recessions with questionable prognosis of surgery. The step-by-step-approach described in this article is an alternative, minimal-invasive treatment concept for cervical lesions in combination with all kinds of periodontal recessions, that is especially suitable for wedge-shaped defects next to exposed crown margins. CLINICAL RELEVANCE With this treatment concept, the reader should be able to use gingiva-shaded composite for different indications, such as exposed root surfaces or crown margins in combination with recessions.
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Affiliation(s)
- Hüsamettin Günay
- Department of Conservative Dentistry, Periodontology and Preventive Dentistry, Hannover Medical School, Carl-Neuberg-Strale 1, D-30625 Hannover, Germany
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Lührs AK, Görmann B, Jacker-Guhr S, Geurtsen W. Repairability of dental siloranes in vitro. Dent Mater 2011; 27:144-9. [DOI: 10.1016/j.dental.2010.09.009] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2009] [Revised: 09/20/2010] [Accepted: 09/20/2010] [Indexed: 10/18/2022]
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Bakopoulou A, Leyhausen G, Volk J, Tsiftsoglou A, Garefis P, Koidis P, Geurtsen W. Assessment of the impact of two different isolation methods on the osteo/odontogenic differentiation potential of human dental stem cells derived from deciduous teeth. Calcif Tissue Int 2011; 88:130-41. [PMID: 21153807 DOI: 10.1007/s00223-010-9438-0] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Accepted: 10/31/2010] [Indexed: 12/13/2022]
Abstract
Human deciduous teeth have been proposed as a promising source of mesenchymal stem cells for application in bone and dental tissue engineering. We established cultures of mesenchymal stem cells from the pulp of human deciduous teeth (deciduous teeth stem cells, DTSCs) and analyzed their morphologic, growth, immunophenotypic, and osteo/odontogenic differentiation characteristics using different isolation methods and culturing environments. We compared the biologic behavior of DTSCs isolated either by enzymatic dissociation (DTSCs-ED) or by direct outgrowth from pulp tissue explants (DTSCs-OG). We found that different isolation methods give rise to different populations/lineages of cells with respect to their phenotypic and differentiation characteristics. DTSCs-ED cultures comprised heterogeneous cell populations, whereas DTSCs-OG comprised more homogenous spindle-shaped cells. We have characterized DTSCs as STRO-1(+)/CD146(+)/CD34(+)/CD45(-) cells. However, the percentage of STRO-1(+) and CD34(+) cells was higher in DTSCs-ED (STRO-1, 17.01 ± 5.04%; CD34, 19.79 ± 4.66%) compared to DTSCs-OG cultures (STRO-1, 5.18 ± 2.39%; CD34, 9.94 ± 3.41%), probably as a result of a higher release of stem/progenitor cells from the perivascular niche during enzymatic dissociation. DTSCs isolated using either method displayed an active potential for cellular migration and biomineralization, giving rise to 3D mineralized structures when challenged with dexamethasone, monopotassium phosphate, and β-glycerophosphate. These cellular aggregates progressively expressed differentiation markers of functional odontoblasts, including dentin sialophosphoprotein, bone sialoprotein, osteocalcin, and alkaline phosphatase, having the characteristics of osteodentin. However, in DTSCs-ED, the mineralization rate and the amount of mineralized matrix produced was higher compared to DTSCs-OG cultures. Therefore, DTSCs-ED cells display enhanced biomineralization potential, which might be of advantage for application in clinical therapy.
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Affiliation(s)
- Athina Bakopoulou
- Department of Fixed Prosthesis and Implant Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki, Greece
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Bakopoulou A, Leyhausen G, Volk J, Tsiftsoglou A, Garefis P, Koidis P, Geurtsen W. Comparative analysis of in vitro osteo/odontogenic differentiation potential of human dental pulp stem cells (DPSCs) and stem cells from the apical papilla (SCAP). Arch Oral Biol 2011; 56:709-21. [PMID: 21227403 DOI: 10.1016/j.archoralbio.2010.12.008] [Citation(s) in RCA: 211] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2010] [Revised: 12/07/2010] [Accepted: 12/14/2010] [Indexed: 12/11/2022]
Abstract
OBJECTIVE The aim of this study was to compare the in vitro osteo/odontogenic differentiation potential of mesenchymal stem cells (MSCs) derived from the dental pulp (dental pulp stem cells - DPSCs) or the apical papilla (stem cells from the apical papilla - SCAP) of permanent developing teeth. DESIGN DPSCs and SCAP cultures were established from impacted third molars of young healthy donors at the stage of root development. Cultures were analysed for stem cell markers, including STRO-1, CD146, CD34 and CD45 using flow cytometry. Cells were then induced for osteo/odontogenic differentiation by media containing dexamethasone, KH(2)PO(4) and β-glycerophosphate. Cultures were analysed for morphology, growth characteristics, mineralization potential (Alizarin Red method) and differentiation markers (dentine sialophosphoprotein-DSPP, bone sialoprotein-BSP, osteocalcin-OCN, alkaline phosphatase-ALP), using immunocytochemistry and reverse transcriptase-polymerase chain reaction. RESULTS All DPSCs and SCAP cultures were positive for STRO-1, CD146 and CD34, in percentages varying according to cell type and donor, but negative for CD45. Both types of MSCs displayed an active potential for cellular migration, organization and mineralization, producing 3D mineralized structures. These structures progressively expressed differentiation markers, including DSPP, BSP, OCN, ALP, having the characteristics of osteodentin. SCAP, however, showed a significantly higher proliferation rate and mineralization potential, which might be of significance for their use in bone/dental tissue engineering. CONCLUSIONS This study provides evidence that different types of dental MSCs can be used in tissue engineering/regeneration protocols as an approachable stem cell source for osteo/odontogenic differentiation and biomineralization that could be further applied for stem cell-based clinical therapies.
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Affiliation(s)
- A Bakopoulou
- Department of Fixed Prosthesis & Implant Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki, Greece
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Meyer K, Geurtsen W, Günay H. An early oral health care program starting during pregnancy: results of a prospective clinical long-term study. Clin Oral Investig 2009; 14:257-64. [PMID: 19543927 DOI: 10.1007/s00784-009-0297-x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2008] [Accepted: 05/26/2009] [Indexed: 10/20/2022]
Abstract
This study covers phase IV of a prospective clinical long-term study. Objective of this clinical investigation was to analyze the effects of a long-term prevention program on dental and oral health of teenagers at the age of 13 to 14 years. The entire study was subdivided into four phases. Phase I comprised an individual preventive care during pregnancy ("primary-primary prevention"); phase II assessed mothers and their young children until the age of 3 years ("primary prevention"); and in phase III, mothers and children at the age of 6 years were investigated. In phase IV of the study, the oral health of 13- to 14-year-old teenagers was examined (13.4 +/- 0.5 years; n = 29). All phases consisted of an examination, education about oral health care, and treatment based on the concept of an early oral health care promotion. The control group consisted of randomly selected adolescents at the same age (n = 30). The following clinical parameters were assessed: decayed/missing/filled teeth (DMF-T)/decayed, missing, and filled surface teeth index, hygiene index, papilla bleeding index, Periodontal Screening Index, and Streptococcus mutans/Lactobacillus concentration in saliva. The teenagers of the "prevention" group of phase IV of our prospective study revealed a share of 89.7% caries-free dentitions (65.5% sound; 24.2% caries-free with fillings). Mean DMF-T was 0.55 +/- 1.0. The control group showed a significantly higher mean DMF-T of 1.5 +/- 1.5 (p < 0.05) and revealed 56.7% of caries-free dentitions (30% sound, 26.7% caries-free with restorations). Our data clearly document that an early oral health care promotion starting during pregnancy may cause a sustained and long-term improvement of the oral health of children.
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Affiliation(s)
- Karen Meyer
- Department of Conservative Dentistry, Hannover Medical School, Carl-Neuberg-Str 1, 30625 Hannover, Germany
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Lührs AK, Guhr S, Günay H, Geurtsen W. Shear bond strength of self-adhesive resins compared to resin cements with etch and rinse adhesives to enamel and dentin in vitro. Clin Oral Investig 2009; 14:193-9. [DOI: 10.1007/s00784-009-0279-z] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2008] [Accepted: 04/08/2009] [Indexed: 10/20/2022]
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Gunay H, Dogan S, Geurtsen W. Harvesting technique using a mucotome and modified surgical procedure for root coverage with enamel matrix derivatives with and without a connective tissue graft. INT J PERIODONT REST 2008; 28:497-507. [PMID: 18991001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The aim of this clinical study was to evaluate the coverage of gingival recession defects with enamel matrix derivatives (EMD) with or without a connective tissue graft (CTG). Twenty-five patients (16 female, 9 male) from 16 to 58 years of age (mean: 32.2; SD: 11.2) with 92 gingival recessions (Miller Class I and II) and with at least 4.0 mm of clinical attachment loss were treated with a modified surgical technique for root coverage by CTG with EMD (45 recession defects) or EMD only (47 recession defects). Vertical recession depth, probing depth, clinical attachment level, dehiscence depth, width of keratinized gingiva (vertical), and recession coverage were recorded before surgery (baseline) and at 12 and 24 months. The average presurgical recession depth was 4.4 mm (SD: 1.3) with EMD and CTG versus 3.2 mm (SD: 1.1) with EMD only. Both treatment modalities led to a significant decrease in recession and a gain in attachment. Mean root coverage 12 months postoperatively was 92.7% (SD: 13.5) (EMD and CTG) versus 96.3% (SD: 11.5) (EMD only). Compared to the mean root coverage of recession after 24 months, the change was not significant. The results confirmed that the applied modified surgical techniques are safe and predictable, with better clinical outcomes at the donor and recipient sites.
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Affiliation(s)
- Husamettin Gunay
- Department for Conservative Dentistry, Periodontology, and Preventative Dentistry, Hannover Medical School, Hannover, Germany.
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Lührs AK, Guhr S, Schilke R, Borchers L, Geurtsen W, Günay H. Shear Bond Strength of Self-etch Adhesives to Enamel with Additional Phosphoric Acid Etching. Oper Dent 2008; 33:155-62. [DOI: 10.2341/07-63] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Clinical Relevance
When using self-etch adhesives to bond composite materials to enamel, there is concern about the ability to achieve bond strengths comparable to approved etch-and-rinse systems. An additional phosphoric acid etching can improve the shear bond strength of self-etch adhesives to enamel.
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Müller WEG, Boreiko A, Wang X, Krasko A, Geurtsen W, Custódio MR, Winkler T, Lukić-Bilela L, Link T, Schröder HC. Morphogenetic activity of silica and bio-silica on the expression of genes controlling biomineralization using SaOS-2 cells. Calcif Tissue Int 2007; 81:382-93. [PMID: 17957327 DOI: 10.1007/s00223-007-9075-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2007] [Accepted: 09/07/2007] [Indexed: 11/29/2022]
Abstract
In a previous study (Schröder et al., J Biomed Mater Res B Appl Biomater 75:387-392, 2005) we demonstrated that human SaOS-2 cells, when cultivated on bio-silica matrices, respond with an increased hydroxyapatite deposition. In the present contribution we investigate if silica-based components (Na-silicate, tetraethyl orthosilicate [TEOS], silica-nanoparticles) (1) change the extent of biomineralization in vitro (SaOS-2 cells) and (2) cause an alteration of the expression of the genes amelogenin, ameloblastin, and enamelin, which are characteristic for an early stage of osteogenesis. We demonstrate that the viability of SaOS-2 cells was not affected by the silica-based components. If Na-silicate or TEOS was added together with ss-glycerophosphate, an organic phosphate donor, a significant increase in biomineralization was measured. Finally, expression levels of the amelogenin, ameloblastin, and enamelin genes were determined in SaOS-2 cells during exposure to the silica-based components. After exposure for 2 days, expression levels of amelogenin and enamelin strongly increased in response to the silica-based components, while no significant change was seen for ameloblastin. In contrast, exposure of SaOS-2 cells to ss-glycerophosphate resulted in increased expression of all three genes. We conclude that the levels of the structural molecules of the enamel matrix, amelogenin and enamelin, increase in the presence of silica-based components and substantially contribute to the extent of hydroxyapatite crystallite formation. These results demonstrate that silica-based components augment hydroxyapatite deposition in vitro and suggest that enzymatically synthesized bio-silica (via silicatein) might be a promising route for tooth reconstruction in vivo.
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Affiliation(s)
- Werner E G Müller
- Institut für Physiologische Chemie, Abteilung Angewandte Molekularbiologie, Universität, Duesbergweg 6, D-55099 Mainz, Germany.
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Müller WEG, Wang X, Kropf K, Ushijima H, Geurtsen W, Eckert C, Tahir MN, Tremel W, Boreiko A, Schlossmacher U, Li J, Schröder HC. Bioorganic/inorganic hybrid composition of sponge spicules: matrix of the giant spicules and of the comitalia of the deep sea hexactinellid Monorhaphis. J Struct Biol 2007; 161:188-203. [PMID: 18054502 DOI: 10.1016/j.jsb.2007.10.009] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2007] [Revised: 10/16/2007] [Accepted: 10/17/2007] [Indexed: 10/22/2022]
Abstract
The giant basal spicules of the siliceous sponges Monorhaphis chuni and Monorhaphis intermedia (Hexactinellida) represent the largest biosilica structures on earth (up to 3m long). Here we describe the construction (lamellar organization) of these spicules and of the comitalia and highlight their organic matrix in order to understand their mechanical properties. The spicules display three distinct regions built of biosilica: (i) the outer lamellar zone (radius: >300 microm), (ii) the bulky axial cylinder (radius: <75 microm), and (iii) the central axial canal (diameter: <2 microm) with its organic axial filament. The spicules are loosely covered with a collagen net which is regularly perforated by 7-10 microm large holes; the net can be silicified. The silica layers forming the lamellar zone are approximately 5 microm thick; the central axial cylinder appears to be composed of almost solid silica which becomes porous after etching with hydrofluoric acid (HF). Dissolution of a complete spicule discloses its complex structure with distinct lamellae in the outer zone (lamellar coating) and a more resistant central part (axial barrel). Rapidly after the release of the organic coating from the lamellar zone the protein layers disintegrate to form irregular clumps/aggregates. In contrast, the proteinaceous axial barrel, hidden in the siliceous axial cylinder, is set up by rope-like filaments. Biochemical analysis revealed that the (dominant) molecule of the lamellar coating is a 27-kDa protein which displays catalytic, proteolytic activity. High resolution electron microscopic analysis showed that this protein is arranged within the lamellae and stabilizes these surfaces by palisade-like pillars. The mechanical behavior of the spicules was analyzed by a 3-point bending assay, coupled with scanning electron microscopy. The load-extension curve of the spicule shows a biphasic breakage/cracking pattern. The outer lamellar zone cracks in several distinct steps showing high resistance in concert with comparably low elasticity, while the axial cylinder breaks with high elasticity and lower stiffness. The complex bioorganic/inorganic hybrid composition and structure of the Monorhaphis spicules might provide the blueprint for the synthesis of bio-inspired material, with unusual mechanical properties (strength, stiffness) without losing the exceptional properties of optical transmission.
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Affiliation(s)
- Werner E G Müller
- Institut für Physiologische Chemie, Abteilung Angewandte Molekularbiologie, Universität, Duesbergweg 6, D-55099 Mainz, Germany.
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Abstract
Most cast dental restorations are made from alloys or commercially pure titanium (cpTi). Many orthodontic appliances are also fabricated from metallic materials. It has been documented in vitro and in vivo that metallic dental devices release metal ions, mainly due to corrosion. Those metallic components may be locally and systemically distributed and could play a role in the etiology of oral and systemic pathological conditions. The quality and quantity of the released cations depend upon the type of alloy and various corrosion parameters. No general correlation has been observed between alloy nobility and corrosion. However, it has been documented that some Ni-based alloys, such as beryllium-containing Ni alloys, exhibit increased corrosion, specifically at low pH. Further, microparticles are abraded from metallic restorations due to wear. In sufficient quantities, released metal ions-particularly Cu, Ni, Be, and abraded microparticles-can also induce inflammation of the adjacent periodontal tissues and the oral mucosa. While there is also some in vitro evidence that the immune response can be altered by various metal ions, the role of these ions in oral inflammatory diseases such as gingivitis and periodontitis is unknown. Allergic reactions due to metallic dental restorations have been documented. Ni has especially been identified as being highly allergenic. Interestingly, from 34% to 65.5% of the patients who are allergic to Ni are also allergic to Pd. Further, Pd allergy always occurrs with Ni sensitivity. In contrast, no study has been published which supports the hypothesis that dental metallic materials are mutagenic/genotoxic or might be a carcinogenic hazard to man. Taken together, very contradictory data have been documented regarding the local and systemic effects of dental casting alloys and metallic ions released from them. Therefore, it is of critical importance to elucidate the release of cations from metallic dental restorations in the oral environment and to determine the biological interactions of released metal components with oral and systemic tissues.
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Affiliation(s)
- Werner Geurtsen
- Department of Conservative Dentistry and Periodontology, Medical University Hannover, Hannover, Germany.
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Ibarra G, Johnson GH, Geurtsen W, Vargas MA. Microleakage of porcelain veneer restorations bonded to enamel and dentin with a new self-adhesive resin-based dental cement. Dent Mater 2007; 23:218-25. [PMID: 16499961 DOI: 10.1016/j.dental.2006.01.013] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [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: 09/29/2005] [Revised: 12/19/2005] [Accepted: 01/10/2006] [Indexed: 10/25/2022]
Abstract
UNLABELLED Cementation technique of bonded ceramic restorations is a time-consuming and technique-sensitive procedure critical to long-term success. OBJECTIVE Evaluate the performance of a self-adhesive, modified-resin dental cement (Rely-X UniCem, 3M-ESPE) for the cementation of ceramic veneer restorations without previous conditioning of the tooth surface, and in combination with a one-bottle adhesive and a self-etching adhesive. METHODS Thirty-six premolars received a veneer preparation that extended into dentin. Leucite-reinforced pressed glass ceramic (Empress 1) veneers were cemented following manufacturers' instructions, according to the following treatment groups (n=9): (1) Variolink-Excite Ivoclar-Vivadent (V+E control), (2) Unicem+Single Bond 3M-ESPE (U+SB), (3) Unicem+Adper Prompt L-Pop 3M-ESPE (U+AP), (4) Unicem 3M-ESPE (U). After 24h storage at 37 degrees C, teeth were thermocycled (2000 cycles) at 5 and 55 degrees C, immersed in ammoniacal silver nitrate for 24h, placed in a developer solution overnight and sectioned using a slow-speed saw. Three 1mm longitudinal sections were obtained from each tooth and evaluated for leakage with a microscope (1x to 4x). Imaging software was used to measure stain penetration along the dentin and enamel surfaces. RESULTS ANOVA with SNK (alpha=0.05) revealed that on dentin, U had significantly less leakage than U+SB and U+AP, but no different than V+E; on enamel U had leakage values that were significantly greater than the groups with adhesives. SIGNIFICANCE The self-adhesive cement U gave low leakage on dentin that was comparable to the cement that employed an adhesive for sealing dentin, whereas this cement benefits from use of an adhesive when cementing to enamel.
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Affiliation(s)
- Gabriela Ibarra
- School of Dentistry, Department of Restorative Dentistry, University of Washington, Seattle, WA 98195-7456, USA.
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Lee S, Pagoria D, Raigrodski A, Geurtsen W. Effects of combinations of ROS scavengers on oxidative DNA damage caused by visible-light-activated camphorquinone/N,N-dimethyl-p-toluidine. J Biomed Mater Res B Appl Biomater 2007; 83:391-9. [PMID: 17443666 DOI: 10.1002/jbm.b.30808] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
The objective of this investigation was to analyze whether various combinations of the ROS scavengers glutathione (GSH), N-acetyl-cysteine (NAC), and vitamins C and E decrease DNA damage due to visible-light-irradiated (VL-irradiated) camphorquinone/N,N-dimethyl-p-toluidine (CQ/DMT) compared with individual vitamin C or E. PhiX-174 RF plasmid DNA was used to determine single and double strand breaks as parameters of DNA damage. Individual ROS scavengers and combinations of the antioxidants were added to plasmid DNA treated with VL-irradiated CQ/DMT/Cu (II). After incubation, DNA was loaded into a 1% agarose gel. Following electrophoresis, gels stained with 0.5 microg/mL ethidium bromide were photographed under ultraviolet illumination and analyzed with NIH ImageJ software. Results were evaluated between groups for statistical significance using Student's paired t-test (p < 0.05). Glutathione significantly reduced oxidative DNA damage at all test concentrations when combined with vitamin C or vitamin E. The concentration of damaged DNA observed in the presence of combinations of GSH with vitamin C or vitamin E was significantly lower compared with all other combinations of antioxidants investigated in our study (p < 0.05). In contrast to GSH, NAC was not able to compensate the pro-oxidative effects of vitamin C and vitamin E. Only at a concentration of 2 mM, NAC combined with vitamin C efficiently prevented CQ/DMT/Cu (II)-associated DNA damage. Our data indicate that solely the combinations of GSH with vitamin C or vitamin E significantly reduce the severity of oxidative DNA damage caused by CQ/DMT, whereas NAC may even increase the pro-oxidant activity of vitamin C and vitamin E.
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Affiliation(s)
- Seungbum Lee
- Department of Restorative Dentistry, School of Dentistry, University of Washington, Box 357456, Seattle, Washington 98195-7456, USA
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Ibarra G, Vargas MA, Geurtsen W. Interfacial and surface characterization of two self-etching adhesive systems and a total-etch adhesive after bonding to ground and unground bovine enamel—a qualitative study. Clin Oral Investig 2006; 10:331-41. [PMID: 17120077 DOI: 10.1007/s00784-006-0081-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [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: 06/20/2006] [Accepted: 09/21/2006] [Indexed: 11/28/2022]
Abstract
The purpose of the study was to evaluate the enamel surface and interface morphology of two self-etching adhesive systems (SAS) vs a total-etch control, after bonding to ground and unground enamel using field emission scanning electron microscopy (FESEM). Thirty bovine incisors were used in this study. The buccal enamel surface of 15 teeth was ground flat to resemble freshly cut enamel. The rest of the teeth were left intact. Two SAS, Clearfil SE Bond (CSE, Kuraray) and Prompt L-Pop (3M-ESPE), and a conventional adhesive system, Scotchbond Multipurpose (3M-ESPE, control), were used to condition the surface of unground and ground enamel on 12 teeth. A composite button was bonded to the remaining 18 teeth; a cross-section (1 mm thick) was obtained from each and the bonded interface was polished. All specimens were dehydrated in ascending grades of ethanol, gold-sputter-coated, and observed under FESEM (Hitachi S-4000) to evaluate the ultrastructural morphology of the enamel surface and the enamel-dentin interface. The etching patterns and adhesive penetration varied according to the aggressiveness of the SAS, with CSE being the mildest and H3PO4 being the most aggressive. There were no significant differences on the ultrastructural morphology of the enamel surface between unground and ground specimens. It appears that microporosities within enamel prisms provide sufficient enamel-resin hybridization in unground enamel. The enamel dissolution pattern and depth of infiltration depend on the type of SAS used, with no significant differences in unground and ground enamel.
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Affiliation(s)
- Gabriela Ibarra
- Department of Restorative Dentistry, University of Washington, D-770 Health Sciences Building, P.O. Box 367456, Seattle, WA 98195-7456, USA.
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Volk J, Leyhausen G, Dogan S, Geurtsen W. Additive effects of TEGDMA and hydrogenperoxide on the cellular glutathione content of human gingival fibroblasts. Dent Mater 2006; 23:921-6. [PMID: 17049977 DOI: 10.1016/j.dental.2006.08.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [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: 03/31/2006] [Revised: 08/09/2006] [Accepted: 08/10/2006] [Indexed: 11/19/2022]
Abstract
OBJECTIVES Only few data are available about cytotoxic effects of leachable dental resin compounds in combination with hydrogen peroxide (H(2)O(2)) segregated from dental bleaching agents. Therefore, the purpose of this study was to evaluate the effects of various concentrations of triethylene-glycol dimethacrylate (TEGDMA) and H(2)O(2) on intracellular glutathione levels (GSH) and viability of human gingival fibroblasts (HGF) that are primary target cells of cytotoxic actions of these substances. METHODS HGF were grown in 96-well plates for 24h, treated with various concentrations of TEGDMA (0.5-5.0mM) for 24h and subsequently for 90min with 0.2mM H(2)O(2) or culture medium (control). The relative intracellular GSH concentration was determined using a fluorescence assay with monobromobimane. Readings were normalized to cell numbers, which were determined by a propidium iodide assay. Data were statistically analyzed by t-test and ANOVA with Tukey's post test. A significance level of p<0.05 was used. RESULTS Exposure to TEGDMA reduced the viability of HGF at concentrations > or =1.0mM. TEGDMA induced a decrease of the GSH pool in a concentration-dependent manner (p<0.05). The depletion of GSH was correlated with a reduction of viability (p<0.05) and the total cell number. Furthermore, a significant decrease of the intracellular GSH content was found when cells were exposed to TEGDMA in combination with H(2)O(2), compared to experiments without H(2)O(2). SIGNIFICANCE We conclude from our findings that TEGDMA and H(2)O(2) have additive adverse effects on GSH metabolism and cell viability.
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Affiliation(s)
- Joachim Volk
- Department of Conservative Dentistry and Periodontology, Medical University Hannover, Hannover, Germany
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Volk J, Engelmann J, Leyhausen G, Geurtsen W. Effects of three resin monomers on the cellular glutathione concentration of cultured human gingival fibroblasts. Dent Mater 2006; 22:499-505. [PMID: 16198408 DOI: 10.1016/j.dental.2005.06.002] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.3] [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: 03/21/2005] [Revised: 06/09/2005] [Accepted: 06/16/2005] [Indexed: 11/22/2022]
Abstract
OBJECTIVES Oral and systemic cells are permanently exposed to various types of xenobiotics, such as dental restorative materials, which may subsequently cause adverse effects. Objective of the present investigation was to analyze the effects of three important resin monomers on the glutathione metabolism of human gingival fibroblasts after an incubation period of 4h. METHODS Cells were exposed to various concentrations of 2-hydroxyethyl methacrylate (HEMA; 0.1-10 mM), triethylene-glycol dimethacrylate (TEGDMA; 0.05-2.5 mM), and urethane dimethacrylate (UDMA; 0.005-0.25 mM). Subsequently, cellular glutathione (GSH) concentrations were determined after a treatment period of 4h using the monobromobimane assay. Data were statistically evaluated using Tukey ANOVA with p<0.05. RESULTS GSH depletion was dependent on the type of the resin monomer: UDMA>TEGDMA>HEMA. The concentrations for a 50%-reduction of cellular GSH varied between 0.1 mM (0.05 mM) (UDMA), 0.33 mM (0.09 mM) (TEGDMA), and 1.6 mM (0.8 mM) (HEMA). Simultaneously, no decrease of cell numbers was found at any tested concentration. SIGNIFICANCE These data indicate that the investigated resins may cause cell damage due to depletion of intracellular GSH level even at low concentrations within a short period of time. The decrease of GSH is an early reaction, which is triggered prior to other cytotoxic alterations.
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Affiliation(s)
- J Volk
- Department of Conservative Dentistry and Periodontology, Medical University Hannover, D-30625 Hannover, Germany
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