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De Nys S, Turkalj M, Duca RC, Covaci A, Elskens M, Godderis L, Vanoirbeek J, Van Meerbeek B, Van Landuyt KL. Level of BPA contamination in resin composites determines BPA release. Dent Mater 2024; 40:1025-1030. [PMID: 38755042 DOI: 10.1016/j.dental.2024.05.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 04/29/2024] [Accepted: 05/03/2024] [Indexed: 05/18/2024]
Abstract
OBJECTIVES Resin composites may release bisphenol A (BPA) due to impurities present in the monomers. However, there is a lack of knowledge regarding the leaching characteristics of BPA from resin composites. Therefore, experimental resin composites were prepared with known amounts of BPA. The objective of this study was (1) to determine which amount of BPA initially present in the material leaches out in the short term and, (2) how this release is influenced by the resin composition. METHODS BPA (0, 0.001, 0.01, or 0.1 wt%) was added to experimental resin composites containing 60 mol% BisGMA, BisEMA(3), or UDMA, respectively, as base monomer and 40 mol% TEGDMA as diluent monomer. Polymerized samples (n = 5) were immersed at 37 °C for 7 days in 1 mL of water, which was collected and refreshed daily. BPA release was quantified with UPLC-MS/MS after derivatization with pyridine-3-sulfonyl chloride. RESULTS Between 0.47 to 0.67 mol% of the originally added BPA eluted from the resin composites after 7 days. Similar elution trends were observed irrespective of the base monomer. Two-way ANOVA showed a significant effect of the base monomer on BPA release, but the differences were small and not consistent. SIGNIFICANCE The released amount of BPA was directly proportional to the quantity of BPA present in the resin composite as an impurity. BPA release was mainly diffusion-based, while polymer composition seemed to play a minor role. Our results underscore the importance for manufacturers only to use monomers of the highest purity in dental resin composites to avoid unnecessary BPA exposure in patients.
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Affiliation(s)
- Siemon De Nys
- KU Leuven, Department of Oral Health Sciences, BIOMAT & University Hospitals Leuven (UZ Leuven), Dentistry, Leuven, Belgium
| | - Marko Turkalj
- KU Leuven, Department of Oral Health Sciences, BIOMAT & University Hospitals Leuven (UZ Leuven), Dentistry, Leuven, Belgium
| | - Radu Corneliu Duca
- Environment and Health, Department of Public Health and Primary Care, KU Leuven, Kapucijnenvoer 35, 3000 Leuven, Belgium; Unit Environmental Hygiene and Human Biological Monitoring, Department of Health Protection, National Health Laboratory (LNS), 3555 Dudelange, Luxembourg
| | - Adrian Covaci
- Toxicological Centre, University of Antwerp, Universiteitsplein 1, D.S.551, 2610 Wilrijk, Belgium
| | - Marc Elskens
- Laboratory of Analytical, Environmental and Geo-Chemistry, Vrije Universiteit Brussel, Pleinlaan 2, 1050 Ixelles, Belgium
| | - Lode Godderis
- Environment and Health, Department of Public Health and Primary Care, KU Leuven, Kapucijnenvoer 35, 3000 Leuven, Belgium; IDEWE, External service for prevention and protection at work, Heverlee, Belgium
| | - Jeroen Vanoirbeek
- Environment and Health, Department of Public Health and Primary Care, KU Leuven, Kapucijnenvoer 35, 3000 Leuven, Belgium
| | - Bart Van Meerbeek
- KU Leuven, Department of Oral Health Sciences, BIOMAT & University Hospitals Leuven (UZ Leuven), Dentistry, Leuven, Belgium
| | - Kirsten L Van Landuyt
- KU Leuven, Department of Oral Health Sciences, BIOMAT & University Hospitals Leuven (UZ Leuven), Dentistry, Leuven, Belgium.
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Lau XE, Liu X, Chua H, Wang WJ, Dias M, Choi JJE. Heat generated during dental treatments affecting intrapulpal temperature: a review. Clin Oral Investig 2023; 27:2277-2297. [PMID: 37022531 PMCID: PMC10159962 DOI: 10.1007/s00784-023-04951-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 03/14/2023] [Indexed: 04/07/2023]
Abstract
INTRODUCTION Heat is generated and transferred to the dentine-pulp complex during various dental procedures, such as from friction during cavity preparations, exothermic reactions during the polymerisation of restorative materials and when polishing restorations. For in vitro studies, detrimental effects are possible when intra-pulpal temperature increases by more than 5.5°C (that is, the intra-pulpal temperature exceeds 42.4°C). This excessive heat transfer results in inflammation and necrosis of the pulp. Despite numerous studies stating the importance of heat transfer and control during dental procedures, there are limited studies that have quantified the significance. Past studies incorporated an experimental setup where a thermocouple is placed inside the pulp of an extracted human tooth and connected to an electronic digital thermometer. METHODS This review identified the opportunity for future research and develop both the understanding of various influencing factors on heat generation and the different sensor systems to measure the intrapulpal temperature. CONCLUSION Various steps of dental restorative procedures have the potential to generate considerable amounts of heat which can permanently damage the pulp, leading to pulp necrosis, discoloration of the tooth and eventually tooth loss. Thus, measures should be undertaken to limit pulp irritation and injury during procedures. This review highlighted the gap for future research and a need for an experimental setup which can simulate pulp blood flow, temperature, intraoral temperature and intraoral humidity to accurately simulate the intraoral conditions and record temperature changes during various dental procedures.
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Affiliation(s)
- Xin Er Lau
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, 310 Great King Street, Dunedin, 9016, New Zealand
| | - Xiaoyun Liu
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, 310 Great King Street, Dunedin, 9016, New Zealand
| | - Helene Chua
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, 310 Great King Street, Dunedin, 9016, New Zealand
| | - Wendy Jingwen Wang
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, 310 Great King Street, Dunedin, 9016, New Zealand
| | - Maykon Dias
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, 310 Great King Street, Dunedin, 9016, New Zealand
| | - Joanne Jung Eun Choi
- Sir John Walsh Research Institute, Faculty of Dentistry, University of Otago, 310 Great King Street, Dunedin, 9016, New Zealand.
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Melatonin Mitigates iNOS-Related Effects of HEMA and Camphorquinone in Human Dental Pulp Cells: Relevance for Postoperative Sensitivity Mechanism in Type 2 Diabetes. Int J Mol Sci 2023; 24:ijms24032562. [PMID: 36768884 PMCID: PMC9916734 DOI: 10.3390/ijms24032562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Revised: 01/09/2023] [Accepted: 01/23/2023] [Indexed: 01/31/2023] Open
Abstract
High elution and diffusion of 2-hydroxylethyl methacrylate (HEMA) and camphorquinone (CQ) through dentinal tubules may induce pulp injury and postoperative sensitivity. We aimed to investigate the melatonin protective effect in HEMA- and CQ-treated human dental pulp cells (hDPCs) as well as its relevance in a mechanism for postoperative sensitivity in diabetic patients. hDPCs were exposed to HEMA (5 mM) and/or CQ (1 mM) in the absence and presence of melatonin (MEL) (0.1 mM and 1 mM). Heme oxygenase-1 (HMOX1), NADPH oxidase-4 (NOX4), BCL-2-associated X-protein (BAX), B-cell lymphoma-2 (BCL-2) and caspase-3 (CASP3) gene expression levels, and superoxide dismutase (SOD) activity were measured in hDPCs while inducible nitric oxide synthase (iNOS) and melatonin protein expression were measured in human dental pulp as well, by RT-PCR, by ELISA, and spectrophotometrically. Bioinformatic analyses were performed by using the ShinyGO (v.0.75) application. Type 2 diabetic patients showed a higher incidence of postoperative sensitivity and lower melatonin and higher iNOS content in dental pulp tissue compared with non-diabetic patients. Melatonin, when co-added in hDPC culture, reverses HEMA and CQ cytotoxic effects via anti-apoptotic and anti-inflammatory/antioxidant iNOS-related effects. Enrichment analyses showed that genes/proteins, altered by HEMA and CQ and normalized by melatonin, are the most prominently overrepresented in type 2 diabetes mellitus pathways and that they share subcellular localization in different oligomeric protein complexes consisting of anti- and pro-apoptotic regulators. This is the first evidence of the ability of melatonin to counteract iNOS-mediated inflammatory and stress effects in HEMA- and CQ-treated hDPCs, which could be of significance for the modulation of presently observed immediate postoperative sensitivity after composite restoration in type 2 diabetic patients.
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Yılmaz MN, Gul P. Monomer release from dental restorative materials containing dimethacrylate resin after bleaching. Clin Oral Investig 2022; 26:4647-4662. [PMID: 35301596 DOI: 10.1007/s00784-022-04446-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2021] [Accepted: 03/08/2022] [Indexed: 01/17/2023]
Abstract
OBJECTIVE The aim of this study is to determine the type and amount of monomer released over time after bleaching was applied to dental restorative materials containing dimethacrylate resin. MATERIALS AND METHODS Thirteen different restorative materials containing dimethacrylate resin were used in this study. Twenty samples were prepared from each material and the samples were randomly divided into 4 subgroups, namely, office bleaching, home bleaching, and separate control group for each of the bleaching methods. After bleaching, the samples were stored in 75% ethanol solution for 1, 14, and 28 days. Analysis of the samples collected to determine the type and amount of residual monomer released from the materials was performed using a liquid chromatography-tandem mass/mass spectrometer (LC-MS/MS). Data were analyzed using Friedman and Kruskal-Wallis tests. Statistical significance level was taken as p < 0.05. RESULTS In terms of bleaching groups, mostly no significant difference was found between the groups in each time period in restorative materials (p > 0.05). In terms of time periods, it was determined that the amount of release of all monomers was decreased over time. In terms of restorative materials, the highest monomer release was detected in composite resin groups and the least monomer release was detected in CAD/CAM blocks. CONCLUSION Although monomers were released from all materials, bleaching did not affect the amount of released monomer. Amounts of released monomers were generally below toxic limits. CLINICAL RELEVANCE Within the limits of this study, bleaching does not significantly affect monomer release in restorative materials containing dimethacrylate resin.
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Affiliation(s)
- Merve Nur Yılmaz
- Department of Restorative Dentistry, Faculty of Dentistry, Bolu Abant Izzet Baysal University, Bolu, Turkey
| | - Pinar Gul
- Department of Restorative Dentistry, Faculty of Dentistry, Atatürk University, TR-25240, Erzurum, Turkey.
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Alkattan R, Banerji S, Deb S. A multi-functional dentine bonding system combining a phosphate monomer with eugenyl methacrylate. Dent Mater 2022; 38:1030-1043. [PMID: 35473789 DOI: 10.1016/j.dental.2022.04.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 03/28/2022] [Accepted: 04/01/2022] [Indexed: 11/18/2022]
Abstract
OBJECTIVE The tooth-resin composite interface is frequently associated with failure because of microbial contamination, hydrolytic and collagenolytic degradation. Thus, designing a dentine bonding system (DBS) with an intrinsically antimicrobial polymerisable monomer is of significance especially if it can be used with self-etching primers enabling resistance to degradation of the interface. METHODS Experimental adhesives were developed incorporating eugenyl methacrylate (EgMA) at concentrations of 0,10 or 20 wt%, designated as EgMA0, EgMA10 and EgMA20, respectively, for use as a two-step self-etch DBS with the functional monomer bis[2-(methacryloyloxy) ethyl] phosphate (BMEP) in the primer. The curing, thermal and wettability properties of the adhesives were determined, and hybrid layer formation was characterised by confocal laser scanning microscopy, microtensile bond strengths (µTBS) and nanoleakage by back-scattered SEM. In situ zymography was used to assess MMP inhibitory activity of the BMEP-EgMA DBS. RESULTS EgMA in the adhesives lowered the polymerisation exotherm and resulted in higher Tg, without negatively affecting degree of conversion. Water sorption and solubility were significantly lower with higher concentrations of EgMA in the adhesive. The formation of a distinct hybrid layer was evident from confocal images with the different adhesives, whilst EgMA20 yielded the highest µTBS post water storage challenges and lowest nanoleakage after 6 months. The experimental DBS exhibited minimal to no MMP activity at 3 months. SIGNIFICANCE The hydrophobic nature of EgMA and high cross-link density exerts considerable benefits in lowering water uptake and polymerisation exotherm. The application of EgMA, adhesives in conjunction with BMEP in a multi-functional self-etching DBS can resist MMP activity, hence, enhance longevity of the dentine-resin composite interface.
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Affiliation(s)
- Rana Alkattan
- Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, UK; Department of Restorative Dental Science, King Saud bin Abdulaziz University for Health Sciences, Riyadh, Saudi Arabia
| | - Subir Banerji
- Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, UK; Department of Prosthodontics, University of Melbourne, Melbourne, Australia
| | - Sanjukta Deb
- Faculty of Dentistry, Oral and Craniofacial Sciences, King's College London, London, UK.
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Sayed ME, Dewan H, Kharaf R, Athlawi M, Alfaifi M, Mugri MH, Bosly RAA, Fageehi NY, Hadi M, Zurbtan BJ, Shaabi FI, Alsurayyie FH, Bukhary DM, Alshali RZ, Chohan H. Efficacy of Three Commercially Available Desensitizers in Reducing Post-Operative Sensitivity Following Composite Restorations: A Randomized Controlled Clinical Trial. Polymers (Basel) 2022; 14:polym14071417. [PMID: 35406289 PMCID: PMC9003402 DOI: 10.3390/polym14071417] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 03/26/2022] [Accepted: 03/28/2022] [Indexed: 02/04/2023] Open
Abstract
One of the most widely used esthetic restorations in dentistry is composite. The widespread application of composites can be related to advancements in biomaterials. However, due to various factors, composites are commonly associated with dental sensitivity. Hence, the present study evaluates and compares the effectiveness of three desensitizing agents in reducing post-treatment sensitivity for Class I composite restoration. Eighty subjects with Class I cavities were selected according to the inclusion criteria, and a randomized, double-blind, controlled clinical trial was carried out. Twenty patients were randomly assigned to four groups: Group C (Control group), Group GL (Gluma group), Group SF (Shield Force Plus group), and Group TC (Telio CS group). The desensitizers were applied after Class 1 cavity preparation and acid etching in all the groups, except the Control group, and thereafter, composite restoration was completed in a conventional manner. Questionnaires were provided to all the participants to record the post-operative pain/sensitivity level according to the visual analogue scale (VAS) on intake of cold drinks, intake of hot drinks, and intake of sugar for different periods of time. Significant variation was observed between the three desensitizers for all three stimuli. However, no significant variations were seen with the various age groups and between the maxillary and the mandibular teeth at the different time periods. Group GL performed better than Group SF and Group TC. It can be proposed that the application of the desensitizers reduced the post-restorative sensitivity in the composite restorations and improved acceptance.
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Affiliation(s)
- Mohammed E. Sayed
- Department of Prosthetic Dental Sciences, College of Dentistry, Jazan University, Jazan 45142, Saudi Arabia; (F.I.S.); (F.H.A.)
- Correspondence: (M.E.S.); (H.D.)
| | - Harisha Dewan
- Department of Prosthetic Dental Sciences, College of Dentistry, Jazan University, Jazan 45142, Saudi Arabia; (F.I.S.); (F.H.A.)
- Correspondence: (M.E.S.); (H.D.)
| | - Rawabi Kharaf
- College of Dentistry, Jazan University, Jazan 45142, Saudi Arabia; (R.K.); (M.A.); (M.A.)
| | - Maram Athlawi
- College of Dentistry, Jazan University, Jazan 45142, Saudi Arabia; (R.K.); (M.A.); (M.A.)
| | - Munira Alfaifi
- College of Dentistry, Jazan University, Jazan 45142, Saudi Arabia; (R.K.); (M.A.); (M.A.)
| | - Maryam Hassan Mugri
- Department of Maxillofacial Surgery and Diagnostic Sciences, College of Dentistry, Jazan University, Jazan 45142, Saudi Arabia;
| | - Razan Abu-Alqasem Bosly
- Jazan Specialty Dental Center, Ministry of Health, Jazan 45142, Saudi Arabia; (R.A.-A.B.); (N.Y.F.)
| | - Nada Yousef Fageehi
- Jazan Specialty Dental Center, Ministry of Health, Jazan 45142, Saudi Arabia; (R.A.-A.B.); (N.Y.F.)
| | - Maryam Hadi
- Primary Care Administration, Ministry of Health, Jazan 45142, Saudi Arabia;
| | | | - Fawzia Ibraheem Shaabi
- Department of Prosthetic Dental Sciences, College of Dentistry, Jazan University, Jazan 45142, Saudi Arabia; (F.I.S.); (F.H.A.)
| | - Fatimah H. Alsurayyie
- Department of Prosthetic Dental Sciences, College of Dentistry, Jazan University, Jazan 45142, Saudi Arabia; (F.I.S.); (F.H.A.)
| | - Dalea Mohammed Bukhary
- Department of Oral and Maxillofacial Prosthodontics, Faculty of Dentistry, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (D.M.B.); (R.Z.A.)
| | - Ruwaida Zaki Alshali
- Department of Oral and Maxillofacial Prosthodontics, Faculty of Dentistry, King Abdulaziz University, Jeddah 21589, Saudi Arabia; (D.M.B.); (R.Z.A.)
| | - Hitesh Chohan
- Department of Restorative Dental Sciences, College of Dentistry, Jazan University, Jazan 45142, Saudi Arabia;
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Salar Amoli M, EzEldeen M, Jacobs R, Bloemen V. Materials for Dentoalveolar Bioprinting: Current State of the Art. Biomedicines 2021; 10:biomedicines10010071. [PMID: 35052751 PMCID: PMC8773444 DOI: 10.3390/biomedicines10010071] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 12/25/2021] [Accepted: 12/27/2021] [Indexed: 12/19/2022] Open
Abstract
Although current treatments can successfully address a wide range of complications in the dentoalveolar region, they often still suffer from drawbacks and limitations, resulting in sub-optimal treatments for specific problems. In recent decades, significant progress has been made in the field of tissue engineering, aiming at restoring damaged tissues via a regenerative approach. Yet, the translation into a clinical product is still challenging. Novel technologies such as bioprinting have been developed to solve some of the shortcomings faced in traditional tissue engineering approaches. Using automated bioprinting techniques allows for precise placement of cells and biological molecules and for geometrical patient-specific design of produced biological scaffolds. Recently, bioprinting has also been introduced into the field of dentoalveolar tissue engineering. However, the choice of a suitable material to encapsulate cells in the development of so-called bioinks for bioprinting dentoalveolar tissues is still a challenge, considering the heterogeneity of these tissues and the range of properties they possess. This review, therefore, aims to provide an overview of the current state of the art by discussing the progress of the research on materials used for dentoalveolar bioprinting, highlighting the advantages and shortcomings of current approaches and considering opportunities for further research.
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Affiliation(s)
- Mehdi Salar Amoli
- Surface and Interface Engineered Materials (SIEM), Campus Group T, KU Leuven, Andreas Vesaliusstraat 13, 3000 Leuven, Belgium;
- OMFS IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven and Oral and Maxillofacial Surgery, University Hospitals Leuven, Kapucijnenvoer 33, 3000 Leuven, Belgium; (M.E.); (R.J.)
| | - Mostafa EzEldeen
- OMFS IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven and Oral and Maxillofacial Surgery, University Hospitals Leuven, Kapucijnenvoer 33, 3000 Leuven, Belgium; (M.E.); (R.J.)
- Department of Oral Health Sciences, KU Leuven and Paediatric Dentistry and Special Dental Care, University Hospitals Leuven, Kapucijnenvoer 33, 3000 Leuven, Belgium
| | - Reinhilde Jacobs
- OMFS IMPATH Research Group, Department of Imaging and Pathology, Faculty of Medicine, KU Leuven and Oral and Maxillofacial Surgery, University Hospitals Leuven, Kapucijnenvoer 33, 3000 Leuven, Belgium; (M.E.); (R.J.)
- Department of Dental Medicine, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Veerle Bloemen
- Surface and Interface Engineered Materials (SIEM), Campus Group T, KU Leuven, Andreas Vesaliusstraat 13, 3000 Leuven, Belgium;
- Prometheus, Division of Skeletal Tissue Engineering, KU Leuven, Herestraat 49, 3000 Leuven, Belgium
- Correspondence: ; Tel.: +32-16-30-10-95
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Gornig DC, Maletz R, Ottl P, Warkentin M. Influence of artificial aging: mechanical and physicochemical properties of dental composites under static and dynamic compression. Clin Oral Investig 2021; 26:1491-1504. [PMID: 34453210 PMCID: PMC8817055 DOI: 10.1007/s00784-021-04122-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Accepted: 08/01/2021] [Indexed: 11/25/2022]
Abstract
OBJECTIVE The aim of the study was to evaluate the influence of filler content, degradation media and time on the mechanical properties of different dental composites after in vitro aging. MATERIALS AND METHODS Specimens (1 mm3) of three commercially available composites (GrandioSO®, Arabesk Top®, Arabesk Flow®) with respect to their filler content were stored in artificial aging media: artificial saliva, ethanol (60%), lactic acid (pH 5) and citric acid (pH 5). Parameters (Vickers microhardness, compressive strength, elastic modulus, water sorption and solubility) were determined in their initial state (control group, n = 3 for microhardness, n = 5 for the other parameters) and after 14, 30, 90 and 180 days (n = 3 for microhardness, n = 5 for the other parameters for each composite group, time point and media). Specimens were also characterized with dynamic-mechanical-thermal analysis (compression tests, F = ± 7 N; f = 0.5 Hz, 1 Hz and 3.3 Hz; t = 0-170 °C). RESULTS Incorporation of fillers with more than 80 w% leads to significantly better mechanical properties under static and dynamic compression tests and a better water sorption behavior, even after chemical degradation. The influence of degradation media and time is of subordinate importance for chemical degradation. CONCLUSION Although the investigated composites have a similar matrix, they showed different degradation behavior. Since dentine and enamel occur only in small layer thickness, a test specimen geometry with very small dimensions is recommended for direct comparison. Moreover, the use of compression tests to determine the mechanical parameters for the development of structure-compatible and functionally adapted composites makes sense as an additional standard. Clinical relevance Preferential use of highly filled composites for occlusal fillings is recommended.
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Affiliation(s)
- D. C. Gornig
- Dres. Irina & Thorsten Brandt, Orthodontic Practice, Wiesbaden, Germany
| | - R. Maletz
- Department of Material Science and Medical Engineering, Faculty of Mechanical Engineering and Marine Technology, University of Rostock, Rostock, Germany
| | - P. Ottl
- Department of Prosthodontics and Material Science, Faculty of Medicine, University of Rostock, Rostock, Germany
| | - M. Warkentin
- Department of Material Science and Medical Engineering, Faculty of Mechanical Engineering and Marine Technology, University of Rostock, Rostock, Germany
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Pomès B, Behin P, Jordan L, Legoff S, Stoclet G, Richaud E, Nguyen JF. Influence of polymerization pressure and post-cure treatment on conversion degree and viscoelastic properties of polymer infiltrated ceramic network. J Mech Behav Biomed Mater 2020; 115:104286. [PMID: 33383378 DOI: 10.1016/j.jmbbm.2020.104286] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/11/2020] [Accepted: 12/13/2020] [Indexed: 12/14/2022]
Abstract
This study aimed at determining an optimum polymerization pressure for Polymer Infiltrated Ceramic Network (PICN) blocks by characterizing the conversion degree (DC) and the viscoelastic properties of experimental PICN blocks polymerized at 90 °C under various high pressures followed or not by post-cure treatment (PC). Near infrared analysis and dynamic mechanical analysis were used to characterize DC and viscoelastic properties of sixteen PICN: one control (thermo-cured) and fifteen experimental groups (one thermo-cured followed by PC and fourteen high pressure polymerized PICN, in the range of 50-350 MPa without and with PC). Conversion degree of high pressure polymerized PICN blocks without post curing displays an optimum between 100 and 150 MPa resulting in an improved E' and Tg. Post curing induces a higher DC with a controversial effect on thermomechanical properties. The results suggested that 100-150 MPa without PC is an optimum polymerization parameter, resulting in PICN blocks with significantly better DC, Tg, E'.
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Affiliation(s)
- Benjamin Pomès
- UFR d'Odontologie Université de Paris, F-75006, Paris, France; Arts et Métiers ParisTech, Laboratoire de Procédés et Ingénierie en Mécanique et Matériaux (PIMM), CNRS, CNAM, UMR, 8006, F-75013, Paris, France
| | | | - Laurence Jordan
- UFR d'Odontologie Université de Paris, F-75006, Paris, France; PSL Research University, Chimie ParisTech -CNRS, Institut de Recherche de Chimie Paris, F-75005, Paris, France
| | - Stéphane Legoff
- Unité de Recherches Biomatériaux Innovants et Interfaces (URB2I-EA4462), Faculté de Chirurgie Dentaire, Université de Paris, Paris, France
| | - Gregory Stoclet
- Université de Lille, CNRS, INRA, ENSCL, UMR 8207 - UMET - Unité Matériaux et Transformations, F-59000, Lille, France
| | - Emmanuel Richaud
- Arts et Métiers ParisTech, Laboratoire de Procédés et Ingénierie en Mécanique et Matériaux (PIMM), CNRS, CNAM, UMR, 8006, F-75013, Paris, France
| | - Jean-François Nguyen
- UFR d'Odontologie Université de Paris, F-75006, Paris, France; PSL Research University, Chimie ParisTech -CNRS, Institut de Recherche de Chimie Paris, F-75005, Paris, France.
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Kaufman G, Skrtic D. N-Acetyl Cysteine Modulates the Inflammatory and Oxidative Stress Responses of Rescued Growth-Arrested Dental Pulp Microtissues Exposed to TEGDMA in ECM. Int J Mol Sci 2020; 21:ijms21197318. [PMID: 33023018 PMCID: PMC7582816 DOI: 10.3390/ijms21197318] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 09/30/2020] [Accepted: 10/01/2020] [Indexed: 12/13/2022] Open
Abstract
Dental pulp is exposed to resin monomers leaching from capping materials. Toxic doses of the monomer, triethyleneglycol dimethacrylate (TEGDMA), impact cell growth, enhance inflammatory and oxidative stress responses, and lead to tissue necrosis. A therapeutic agent is required to rescue growth-arrested tissues by continuing their development and modulating the exacerbated responses. The functionality of N-Acetyl Cysteine (NAC) as a treatment was assessed by employing a 3D dental pulp microtissue platform. Immortalized and primary microtissues developed and matured in the extracellular matrix (ECM). TEGDMA was introduced at various concentrations. NAC was administered simultaneously with TEGDMA, before or after monomer addition during the development and after the maturation stages of the microtissue. Spatial growth was validated by confocal microscopy and image processing. Levels of inflammatory (COX2, NLRP3, IL-8) and oxidative stress (GSH, Nrf2) markers were quantified by immunoassays. NAC treatments, in parallel with TEGDMA challenge or post-challenge, resumed the growth of the underdeveloped microtissues and protected mature microtissues from deterioration. Growth recovery correlated with the alleviation of both responses by decreasing significantly the intracellular and extracellular levels of the markers. Our 3D/ECM-based dental pulp platform is an efficient tool for drug rescue screening. NAC supports compromised microtissues development, and immunomodulates and maintains the oxidative balance.
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Jeannin C, Gritsch K, Liodénot JJ, Grosgogeat B. MARIO: the first chewing bench used for ageing and analysis the released compounds of dental materials. Comput Methods Biomech Biomed Engin 2019. [DOI: 10.1080/10255842.2020.1713480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Affiliation(s)
- C. Jeannin
- SCTD des Hospices Civils de Lyon, Université Claude Bernard Lyon 1, Villeurbanne, France
- Laboratoire des Multimatériaux et Interfaces, UMR CNRS 5615, UCBL1
| | - K. Gritsch
- SCTD des Hospices Civils de Lyon, Université Claude Bernard Lyon 1, Villeurbanne, France
- Laboratoire des Multimatériaux et Interfaces, UMR CNRS 5615, UCBL1
| | | | - B. Grosgogeat
- SCTD des Hospices Civils de Lyon, Université Claude Bernard Lyon 1, Villeurbanne, France
- Laboratoire des Multimatériaux et Interfaces, UMR CNRS 5615, UCBL1
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Stewart CA, Finer Y. Biostable, antidegradative and antimicrobial restorative systems based on host-biomaterials and microbial interactions. Dent Mater 2018; 35:36-52. [PMID: 30301624 DOI: 10.1016/j.dental.2018.09.013] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2018] [Revised: 09/23/2018] [Accepted: 09/23/2018] [Indexed: 10/28/2022]
Abstract
OBJECTIVES Despite decades of development and their status as the restorative material of choice for dentists, resin composite restoratives and adhesives exhibit a number of shortcomings that limit their long-term survival in the oral cavity. Herein we review past and current work to understand these challenges and approaches to improve dental materials and extend restoration service life. METHODS Peer-reviewed work from a number of researchers as well as our own are summarized and analyzed. We also include yet-unpublished work of our own. Challenges to dental materials, methods to assess new materials, and recent material improvements and research directions are presented. RESULTS Mechanical stress, host- and bacterial-biodegradation, and secondary caries formation all contribute to restoration failure. In particular, several host- and bacterial-derived enzymes degrade the resin and collagen components of the hybrid layer, expanding the marginal gap and increasing access to bacteria and saliva. Furthermore, the virulence of cariogenic bacteria is up-regulated by resin biodegradation by-products, creating a positive feedback loop that increases biodegradation. These factors work synergistically to degrade the restoration margin, leading to secondary caries and restoration failure. Significant progress has been made to produce hydrolytically stable resins to resist biodegradation, as well as antimicrobial materials to reduce bacterial load around the restoration. Ideally, these two approaches should be combined in a holistic approach to restoration preservation. SIGNIFICANCE The oral cavity is a complex environment that poses an array of challenges to long-term material success; materials testing conditions should be comprehensive and closely mimic pathogenic oral conditions.
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Affiliation(s)
- Cameron A Stewart
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada
| | - Yoav Finer
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, Ontario, Canada; Faculty of Dentistry, University of Toronto, Toronto, Ontario, Canada.
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Tigani EK, Skrtic D, Valerio MS, Kaufman G. Assessing the effect of triethyleneglycol dimethacrylate on tissue repair in 3D organotypic cultures. J Appl Toxicol 2018; 39:247-259. [PMID: 30229966 DOI: 10.1002/jat.3714] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 07/14/2018] [Accepted: 07/19/2018] [Indexed: 12/17/2022]
Abstract
Leachables from dental restoratives induce toxicity in gingival and pulp tissues and affect tissue regeneration/healing. Appropriate testing of these materials requires a platform that mimics the in vivo environment and allows the architectural self-assembly of cells into tissue constructs. In this study, we employ a new 3D model to assess the impact of triethyleneglycol dimethacrylate (TEGDMA) on early organization and advanced recruitment/accumulation of immortalized mouse gingival fibroblasts (GFs) and dental papilla mesenchymal cells (DPMCs) in extracellular matrix. We hypothesize that TEGDMA (1) interferes with the developmental architecture of GFs and DPMCs, and (2) inhibits the deposition of mineral. To test these hypotheses, GFs and DPMCs were incubated with the soluble TEGDMA at concentrations (0-2.5) mmol/L. Diameter and thickness of the constructs were determined by microscopic analysis. Cell differentiation was assessed by immunocytochemistry and the secreted mineral detected by alizarin-red staining. TEGDMA interfered with the development of GFs and/or DPMCs microtissues in a dose-dependent manner by inhibiting growth of inter-spherical cell layers and decreasing spheroid size (four to six times). At low/moderate TEGDMA levels, GFs organoids retained their structures while reducing thickness up to 21%. In contrast, at low TEGDMA doses, architecture of DPMC organoids was altered and thickness decreased almost twofold. Overall, developmental ability of TEGDMA-exposed GFs and DPMCs depended on TEGDMA level. GFs constructs were more resistant to structural modifications. The employed 3D platform was proven as an efficient tool for quantifying the effects of leachables on tissue repair capacities of gingiva and dental pulp.
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Affiliation(s)
- Elise K Tigani
- Volpe Research Center, American Dental Association Foundation, Gaithersburg, MD, 20899, USA
| | - Drago Skrtic
- Volpe Research Center, American Dental Association Foundation, Gaithersburg, MD, 20899, USA
| | - Michael S Valerio
- Volpe Research Center, American Dental Association Foundation, Gaithersburg, MD, 20899, USA
| | - Gili Kaufman
- Volpe Research Center, American Dental Association Foundation, Gaithersburg, MD, 20899, USA
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Influence of Dental Restorations on Oxidative Stress in Gingival Crevicular Fluid. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:1823189. [PMID: 30140362 PMCID: PMC6081590 DOI: 10.1155/2018/1823189] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Accepted: 03/25/2018] [Indexed: 12/14/2022]
Abstract
Biocompatibility of dental materials (DM) can be evaluated by gingival crevicular fluid (GCF) oxidative stress (OS) status. The goal of the study was to ascertain influence of dental caries degree, teeth position, and type and amount of applied DM on GCF OS profile. For this purpose, we tested six DMs that were sealed in one session: amalgam (Amg), composites: Tetric EvoCeram and Beautifil (BF), phosphate cement-zinc phosphate and polycarboxylate cements-zinc polycarboxylate cements, and glass ionomer cement (GIC). The study included 88 dental outpatients. Follow-up was scheduled at 7th and 30th day. Oxidative stress parameters (malondialdehyde (MDA) and glutathione (GSH) levels and total superoxide dismutase (tSOD) activity) were measured before (0th day) and after the treatment (7th and 30th day) in GCF. Control teeth were mirror-positioned healthy teeth. The DM accomplished the following effects (listed in descending order): increase of GSH in GCF was realized by ZPoC > BF > GIC > Amg; tSOD activity increase by ZPoC > BF > Amg; and MDA decrease by ZPoC > ZPhC > Amg > TEC. Dental caries provokes insignificant rise of OS in GCF. ZPoC and ZPhC showed the highest antioxidant effect, contrary to GIC. Restorations with antioxidant properties may reduce gum diseases initiated by caries lesion, what is of great clinical relevance in dentistry.
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In-vitro transdentinal diffusion of monomers from adhesives. J Dent 2018; 75:91-97. [PMID: 29864446 DOI: 10.1016/j.jdent.2018.05.023] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 05/29/2018] [Accepted: 05/31/2018] [Indexed: 01/09/2023] Open
Abstract
OBJECTIVES Biocompatibility of adhesives is important since adhesives may be applied on dentin near the pulp. Accurate knowledge of the quantity of monomers reaching the pulp is important to determine potential side effects. The aim of this study was to assess the transdentinal diffusion of residual monomers from dental adhesive systems using an in-vitro pulp chamber model. METHODS Dentin disks with a thickness of 300 μm were produced from human third molars. These disks were fixed between two open glass tubes, representing an in-vitro pulp chamber. The etch-and-rinse adhesive OptiBond FL and the self-etch adhesive Clearfil SE Bond were applied to the dentin side of the disks, while on in the pulpal side, the glass tube was filled with 600 μl water. The transdentinal diffusion of different monomers was quantified using ultra-performance liquid chromatography-tandem mass spectrometry. RESULTS The monomers HEMA, CQ, BisGMA, GPDM, 10-MDP and UDMA eluted from the dental materials and were able to diffuse through the dentin disks to a certain extent. Compounds with a lower molecular weight (uncured group: HEMA 7850 nmol and CQ 78.2 nmol) were more likely to elute and diffuse compared to monomers with a higher molecular weight (uncured group: BisGMA 0.42 nmol). When the adhesives were left uncured, diffusion was up to 10 times higher compared to the cured conditions. CONCLUSIONS This in-vitro research resulted in the quantification of various monomers able to diffuse through dentin and therefore contributes to a more detailed understanding about the potential exposure of the dental pulp to monomers from dental adhesives. CLINICAL SIGNIFICANCE Biocompatibility of adhesives is important since adhesives may be applied on dentin near the pulp, where tubular density and diameter are greatest.
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Kamonwanon P, Hirose N, Yamaguchi S, Sasaki JI, Kitagawa H, Kitagawa R, Thaweboon S, Srikhirin T, Imazato S. SiO 2-nanocomposite film coating of CAD/CAM composite resin blocks improves surface hardness and reduces susceptibility to bacterial adhesion. Dent Mater J 2016; 36:88-94. [PMID: 27928105 DOI: 10.4012/dmj.2016-135] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Composite resin blocks for computer-aided design/computer-aided manufacturing (CAD/CAM) applications have recently become available. However, CAD/CAM composite resins have lower wear resistance and accumulate more plaque than CAD/CAM ceramic materials. We assessed the effects of SiO2-nanocomposite film coating of four types of CAD/CAM composite resin blocks: Cerasmart, Katana Avencia block, Lava Ultimate, and Block HC on surface hardness and bacterial attachment. All composite blocks with coating demonstrated significantly greater Vickers hardness, reduced surface roughness, and greater hydrophobicity than those without coating. Adhesion of Streptococcus mutans to the coated specimens was significantly less than those for the uncoated specimens. These reduced levels of bacterial adherence on the coated surface were still evident after treatment with saliva. Surface modification by SiO2-nanocomposite film coating has potential to improve wear resistance and susceptibility to plaque accumulation of CAD/CAM composite resin restorations.
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Chen S, Mestres G, Lan W, Xia W, Engqvist H. Cytotoxicity of modified glass ionomer cement on odontoblast cells. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2016; 27:116. [PMID: 27221819 DOI: 10.1007/s10856-016-5729-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 05/14/2016] [Indexed: 06/05/2023]
Abstract
Recently a modified glass ionomer cement (GIC) with enhanced bioactivity due to the incorporation of wollastonite or mineral trioxide aggregate (MTA) has been reported. The aim of this study was to evaluate the cytotoxic effect of the modified GIC on odontoblast-like cells. The cytotoxicity of a conventional GIC, wollastonite modified GIC (W-mGIC), MTA modified GIC (M-mGIC) and MTA cement has been evaluated using cement extracts, a culture media modified by the cement. Ion concentration and pH of each material in the culture media were measured and correlated to the results of the cytotoxicity study. Among the four groups, conventional GIC showed the most cytotoxicity effect, followed by W-mGIC and M-mGIC. MTA showed the least toxic effect. GIC showed the lowest pH (6.36) while MTA showed the highest (8.62). In terms of ion concentration, MTA showed the largest Ca(2+) concentration (467.3 mg/L) while GIC showed the highest concentration of Si(4+) (19.9 mg/L), Al(3+) (7.2 mg/L) and Sr(2+) (100.3 mg/L). Concentration of F(-) was under the detection limit (0.02 mg/L) for all samples. However the concentrations of these ions are considered too low to be toxic. Our study showed that the cytotoxicity of conventional GIC can be moderated by incorporating calcium silicate based ceramics. The modified GIC might be promising as novel dental restorative cements.
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Affiliation(s)
- Song Chen
- Ångström Laboratory, Department of Engineering Science, Applied Materials Science, Uppsala University, Box 534, 75121, Uppsala, Sweden
| | - Gemma Mestres
- Ångström Laboratory, Department of Engineering Science, Applied Materials Science, Uppsala University, Box 534, 75121, Uppsala, Sweden
| | - Weihua Lan
- Ångström Laboratory, Department of Engineering Science, Applied Materials Science, Uppsala University, Box 534, 75121, Uppsala, Sweden
| | - Wei Xia
- Ångström Laboratory, Department of Engineering Science, Applied Materials Science, Uppsala University, Box 534, 75121, Uppsala, Sweden.
| | - Håkan Engqvist
- Ångström Laboratory, Department of Engineering Science, Applied Materials Science, Uppsala University, Box 534, 75121, Uppsala, Sweden
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Gul P, Senol O, Yaman ME, Kadıoglu Y. Quantification and identification of components released from dental composites using different chromatographic techniques. J LIQ CHROMATOGR R T 2016. [DOI: 10.1080/10826076.2016.1185730] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Affiliation(s)
- Pinar Gul
- Department of Restorative Dentistry, School of Dentistry, Atatürk University, Erzurum, Turkey
| | - Onur Senol
- Department of Analytical Chemistry, School of Pharmacy, Atatürk University, Erzurum, Turkey
| | - Mehmet Emrah Yaman
- Department of Analytical Chemistry, School of Pharmacy, Atatürk University, Erzurum, Turkey
| | - Yücel Kadıoglu
- Department of Analytical Chemistry, School of Pharmacy, Atatürk University, Erzurum, Turkey
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Effects of High-Temperature-Pressure Polymerized Resin-Infiltrated Ceramic Networks on Oral Stem Cells. PLoS One 2016; 11:e0155450. [PMID: 27196425 PMCID: PMC4873200 DOI: 10.1371/journal.pone.0155450] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Accepted: 04/28/2016] [Indexed: 12/28/2022] Open
Abstract
OBJECTIVES The development of CAD-CAM techniques called for new materials suited to this technique and offering a safe and sustainable clinical implementation. The infiltration of resin in a ceramic network under high pressure and high temperature defines a new class of hybrid materials, namely polymer infiltrated ceramics network (PICN), for this purpose which requires to be evaluated biologically. We used oral stem cells (gingival and pulpal) as an in vitro experimental model. METHODS Four biomaterials were grinded, immersed in a culture medium and deposed on stem cells from dental pulp (DPSC) and gingiva (GSC): Enamic (VITA®), Experimental Hybrid Material (EHM), EHM with initiator (EHMi) and polymerized Z100™ composite material (3M®). After 7 days of incubation; viability, apoptosis, proliferation, cytoskeleton, inflammatory response and morphology were evaluated in vitro. RESULTS Proliferation was insignificantly delayed by all the tested materials. Significant cytotoxicity was observed in presence of resin based composites (MTT assay), however no detectable apoptosis and some dead cells were detected like in PICN materials. Cell morphology, major cytoskeleton and extracellular matrix components were not altered. An intimate contact appeared between the materials and cells. CLINICAL SIGNIFICANCE The three new tested biomaterials did not exhibit adverse effects on oral stem cells in our experimental conditions and may be an interesting alternative to ceramics or composite based CAD-CAM blocks.
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Hedayat A, Nagy N, Packota G, Monteith J, Allen D, Wysokinski T, Zhu N. Synchrotron-radiation-based X-ray micro-computed tomography reveals dental bur debris under dental composite restorations. JOURNAL OF SYNCHROTRON RADIATION 2016; 23:777-782. [PMID: 27140158 DOI: 10.1107/s1600577516002198] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 02/04/2016] [Indexed: 06/05/2023]
Abstract
Dental burs are used extensively in dentistry to mechanically prepare tooth structures for restorations (fillings), yet little has been reported on the bur debris left behind in the teeth, and whether it poses potential health risks to patients. Here it is aimed to image dental bur debris under dental fillings, and allude to the potential health hazards that can be caused by this debris when left in direct contact with the biological surroundings, specifically when the debris is made of a non-biocompatible material. Non-destructive micro-computed tomography using the BioMedical Imaging & Therapy facility 05ID-2 beamline at the Canadian Light Source was pursued at 50 keV and at a pixel size of 4 µm to image dental bur fragments under a composite resin dental filling. The bur's cutting edges that produced the fragment were also chemically analyzed. The technique revealed dental bur fragments of different sizes in different locations on the floor of the prepared surface of the teeth and under the filling, which places them in direct contact with the dentinal tubules and the dentinal fluid circulating within them. Dispersive X-ray spectroscopy elemental analysis of the dental bur edges revealed that the fragments are made of tungsten carbide-cobalt, which is bio-incompatible.
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Affiliation(s)
- Assem Hedayat
- College of Dentistry, University of Saskatchewan, 123-105 Wiggins Road, Saskatoon, Saskatchewan, Canada S7N 5E4
| | - Nicole Nagy
- Department of Mechanical and Mechatronics Engineering, University of Waterloo, Ontario, Canada
| | - Garnet Packota
- College of Dentistry, University of Saskatchewan, 123-105 Wiggins Road, Saskatoon, Saskatchewan, Canada S7N 5E4
| | - Judy Monteith
- College of Dentistry, University of Saskatchewan, 123-105 Wiggins Road, Saskatoon, Saskatchewan, Canada S7N 5E4
| | - Darcy Allen
- College of Dentistry, University of Saskatchewan, 123-105 Wiggins Road, Saskatoon, Saskatchewan, Canada S7N 5E4
| | | | - Ning Zhu
- Canadian Light Source, Saskatoon, Saskatchewan, Canada
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Lee Y, An SY, Park YJ, Yu FH, Park JC, Seo DG. Cytotoxic effects of one-step self-etching adhesives on an odontoblast cell line. SCANNING 2016; 38:36-42. [PMID: 26186405 DOI: 10.1002/sca.21236] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 06/09/2015] [Accepted: 06/11/2015] [Indexed: 06/04/2023]
Abstract
The aim of this study was to evaluate the cytotoxic effects of one-step self-etching adhesives. Cells from an immortalized mouse odontoblast cell line (MDPC-23) were cultured with six different dental adhesive systems (diluted to concentrations of 0.5% for 4 h): Adper Easy Bond (EB), Xeno V (XV), iBond (IB), AdheSE One (AO), Clearfil SE primer (CS), and Adper Single Bond 2 (SB). MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and flow cytometric apoptosis assays were used to evaluate cell viability and the rate of apoptosis. The odontoblasts were also examined under a scanning electron microscope. While all of the cultures with adhesives showed reduced viability, the viabilities in the IB and SB groups were not significantly different from the control group. Although increased apoptosis rates were observed in all of the cultures with adhesives, the rate in the SB group was not significantly different from the rate in the control. The control group showed the lowest apoptosis rate followed by the SB, AO, IB, EB, XV, and CS groups. When examined under a scanning electron microscope, control odontoblasts and the SB group exhibited relatively large cytoplasmic extensions. In contrast, in the EB and CS groups, fewer fibroblasts remained adhered to the plate surface. Cytoplasmic membrane shrinkage and cell-free areas with residual membrane fragments from dead cells were observed. In conclusion, all cultures with one-step self-etching adhesives showed increased apoptotic activity. SB, an etch-and-rinse adhesive, was comparable to the control group, and CS and EB showed the lowest odontoblast viabilities according to the MTT assay.
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Affiliation(s)
- Yoon Lee
- Department of Conservative Dentistry, Wonju Severance Christian Hospital, Wonju College of Medicine, Yonsei University, Wonju, Republic of Korea
| | - So-Youn An
- Department of Pediatric Dentistry, College of Dentistry, Wonkwang University, Iksan, Republic of Korea
| | - Yoon-Jung Park
- Department of Nutritional Science and Food Management, Ewha Womans University, Seoul, Republic of Korea
| | - Frank H Yu
- Program in Neurobiology, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Joo-Cheol Park
- Department of Oral Histology-Developmental Biology, School of Dentistry, Seoul National University, Seoul, Republic of Korea
| | - Deog-Gyu Seo
- Department of Conservative Dentistry and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Republic of Korea
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Ginzkey C, Zinnitsch S, Steussloff G, Koehler C, Hackenberg S, Hagen R, Kleinsasser NH, Froelich K. Assessment of HEMA and TEGDMA induced DNA damage by multiple genotoxicological endpoints in human lymphocytes. Dent Mater 2015; 31:865-76. [DOI: 10.1016/j.dental.2015.04.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 02/13/2015] [Accepted: 04/17/2015] [Indexed: 10/23/2022]
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Ge X, Ye Q, Song L, Laurence JS, Spencer P. Synthesis and evaluation of a novel co-initiator for dentin adhesives: polymerization kinetics and leachables study. JOM (WARRENDALE, PA. : 1989) 2015; 67:796-803. [PMID: 26052187 PMCID: PMC4452206 DOI: 10.1007/s11837-015-1335-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A new tertiary amine co-initiator (TUMA) containing three methacrylate-urethane groups was synthesized for application in dentin adhesives. The photopolymerization kinetics and leaching of unreacted components from methacrylate-based dental polymers formulated with this new co-initiator were determined. The newly synthesize co-initiator showed good chemical stability and decreased amine release from the initiator system. This study provides important information for the future development of biocompatible dentin adhesives/composites.
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Affiliation(s)
- Xueping Ge
- Bioengineering Research Center, School of Engineering, University of Kansas, Lawrence, KS, USA
| | - Qiang Ye
- Bioengineering Research Center, School of Engineering, University of Kansas, Lawrence, KS, USA
| | - Linyong Song
- Bioengineering Research Center, School of Engineering, University of Kansas, Lawrence, KS, USA
| | - Jennifer S. Laurence
- Department of Pharmaceutical Chemistry, University of Kansas, 2095 Constant Ave, Lawrence, KS 66047-3729, USA
| | - Paulette Spencer
- Bioengineering Research Center, School of Engineering, University of Kansas, Lawrence, KS, USA
- Department of Mechanical Engineering, University of Kansas, Lawrence, KS, USA
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Huang GTJ, Garcia-Godoy F. Missing Concepts in De Novo Pulp Regeneration. J Dent Res 2014; 93:717-24. [PMID: 24879576 DOI: 10.1177/0022034514537829] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2014] [Accepted: 05/08/2014] [Indexed: 12/13/2022] Open
Abstract
Regenerative endodontics has gained much attention in the past decade because it offers an alternative approach in treating endodontically involved teeth. Instead of filling the canal space with artificial materials, it attempts to fill the canal with vital tissues. The objective of regeneration is to regain the tissue and restore its function to the original state. In terms of pulp regeneration, a clinical protocol that intends to reestablish pulp/dentin tissues in the canal space has been developed--termed revitalization or revascularization. Histologic studies from animal and human teeth receiving revitalization have shown that pulp regeneration is difficult to achieve. In tissue engineering, there are 2 approaches to regeneration tissues: cell based and cell free. The former involves transplanting exogenous cells into the host, and the latter does not. Revitalization belongs to the latter approach. A number of crucial concepts have not been well discussed, noted, or understood in the field of regenerative endodontics in terms of pulp/dentin regeneration: (1) critical size defect of dentin and pulp, (2) cell lineage commitment to odontoblasts, (3) regeneration vs. repair, and (4) hurdles of cell-based pulp regeneration for clinical applications. This review article elaborates on these missing concepts and analyzes them at their cellular and molecular levels, which will in part explain why the non-cell-based revitalization procedure is difficult to establish pulp/dentin regeneration. Although the cell-based approach has been proven to regenerate pulp/dentin, such an approach will face barriers--with the key hurdle being the shortage of the current good manufacturing practice facilities, discussed herein.
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Affiliation(s)
- G T-J Huang
- Department of Bioscience Research, University of Tennessee Health Science Center, College of Dentistry, Memphis, TN 38163
| | - F Garcia-Godoy
- Department of Bioscience Research, University of Tennessee Health Science Center, College of Dentistry, Memphis, TN 38163
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Tadin A, Marovic D, Galic N, Kovacic I, Zeljezic D. Composite-induced toxicity in human gingival and pulp fibroblast cells. Acta Odontol Scand 2014; 72:304-11. [PMID: 23964631 DOI: 10.3109/00016357.2013.824607] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
OBJECTIVE The most important requirement for a material to be used in medical applications is its biocompatibility. Dental composite materials come into direct contact with oral tissues, especially gingival and pulpal cells. This study was performed to evaluate possible DNA damage in cells of human origin exposed to dental composites in vitro using a cytogenetic assay. MATERIALS AND METHODS Two composite resins (Vertise Flow, Kalore) were tested on human gingival and pulp fibroblasts using the acridine orange/ethidium bromide viability staining and alkaline comet assay. Cultures were treated with polymerized composites in two different concentrations (20 mg/ml, 40 mg/ml) for 14 days. Chi-square and Kruskall-Wallis non-parametric test were used for the statistical analysis (p < 0.05). RESULTS Significant cytotoxicity was observed for 40 mg/ml of Vertise Flow in both cultures, while Kalore (40 mg/ml) showed cytotoxic effect only on human pulp fibroblasts. A significant level of DNA damage was detected for both materials and concentrations, in both cell cultures. CONCLUSION If the two cell cultures are compared, the pulp cells were more sensitive to the cyto/genotoxic effects of dental composites. Based on the results, one can conclude that the use of tested materials may cause cellular damage in gingival and pulp fibroblasts in vitro.
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Affiliation(s)
- Antonija Tadin
- Department of Endodontics and Restorative Dental Medicine, Study of Dental Medicine, School of Medicine, University of Split , Split , Croatia
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The Effect of UDMA/TEGDMA Mixtures and Bioglass Incorporation on the Mechanical and Physical Properties of Resin and Resin-Based Composite Materials. ACTA ACUST UNITED AC 2014. [DOI: 10.1155/2014/646143] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Incorporating Bioglass into dental composites may improve biocompatibility and aid tooth and bone tissue remineralisation. This study aimed to determine the impact of Bioglass and silica filler on the mechanical and physical properties of cured photopolymers. Hardness (Vickers microhardness test), flexural strength (FS), and flexural modulus (FM) (three-point bend test) of resins containing various urethane dimethacrylate (UDMA)/triethylene glycol dimethacrylate (TEGDMA) and bisphenol A-glycidyl methacrylate (bisGMA)/TEGDMA concentrations (20–80 mass%) were tested. Degree of conversion (DC), FS, and FM of resin composites containing nonsilanised irregular 45S5-Bioglass (50 μm; 5–40 mass%) and/or silanised silicate glass filler particulates (0.7 μm; 30–70 mass%) were tested. Data was analysed using one-way ANOVA. UDMA/TEGDMA resins exhibited increased hardness and FM compared with bisGMA/TEGDMA resins. Addition of Bioglass particles to 60/40 wt% UDMA/TEGDMA or bisGMA/TEGDMA resins may enable the development of new materials that exhibit higher or at least equivalent values of DC, FS, and FM compared with conventional resin composites.
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28
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Cho SG, Lee JW, Heo JS, Kim SY. Gene Expression Change in Human Dental Pulp Cells Exposed to a Low-Level Toxic Concentration of Triethylene Glycol Dimethacrylate: An RNA-seq Analysis. Basic Clin Pharmacol Toxicol 2014; 115:282-90. [DOI: 10.1111/bcpt.12197] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Accepted: 01/02/2014] [Indexed: 12/17/2022]
Affiliation(s)
- Sung-Geun Cho
- Department of Conservative Dentistry; School of Dentistry; Kyung Hee University; Seoul Korea
| | - Jin-Woo Lee
- Department of Conservative Dentistry; School of Dentistry; Kyung Hee University; Seoul Korea
| | - Jung Sun Heo
- Department of Maxillofacial Biomedical Engineering; School of Dentistry; Kyung Hee University; Seoul Korea
| | - Sun-Young Kim
- Department of Conservative Dentistry; School of Dentistry; Kyung Hee University; Seoul Korea
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29
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Chang HH, Chang MC, Wang HH, Huang GF, Lee YL, Wang YL, Chan CP, Yeung SY, Tseng SK, Jeng JH. Urethane dimethacrylate induces cytotoxicity and regulates cyclooxygenase-2, hemeoxygenase and carboxylesterase expression in human dental pulp cells. Acta Biomater 2014; 10:722-31. [PMID: 24140606 DOI: 10.1016/j.actbio.2013.10.006] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2013] [Revised: 09/28/2013] [Accepted: 10/10/2013] [Indexed: 02/06/2023]
Abstract
The toxic effect of urethane dimethacrylate (UDMA), a major dental resin monomer, on human dental pulp is not fully clear. In this study, we investigated the influence of UDMA on the cytotoxicity, cell cycle distribution, apoptosis and related gene expression of dental pulp cells. The role of reactive oxygen species, hemeoxygenase-1 (HO-1) and carboxylesterase (CES) in UDMA cytotoxicity, was evaluated. UDMA induced morphological changes of pulp cells and decreased cell viability by 29-49% at concentrations of 0.1-0.35 mM. UDMA induced G0/G1, G2/M cell cycle arrest and apoptosis. The expression of cdc2, cyclinB1 and cdc25C was inhibited by UDMA. Moreover, UDMA stimulated COX-2, HO-1 and CES2 mRNA expression of pulp cells. The cytotoxicity of UDMA was attenuated by N-acetyl-l-cysteine, catalase and esterase, but was enhanced by Zn-protoporphyrin (HO-1 inhibitor), BNPP (CES inhibitor) and loperamide (CES2 inhibitor). Exposure of UDMA may potentially induce the inflammation and toxicity of dental pulp. These findings are important for understanding the clinical response of human pulp to resin monomers after operative restoration and pulp capping, and also provide clues for improvement of dental materials.
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Affiliation(s)
- Hsiao-Hua Chang
- Laboratory of Pharmacology, Toxicology & Pulp Biology, Department of Dentistry and School of Dentistry, National Taiwan University Hospital and National Taiwan University Medical College, Taipei, Taiwan, ROC
| | - Mei-Chi Chang
- Biomedical Science Team, Chang Gung University of Science and Technology, Taoyuan, Taiwan, ROC.
| | - Hsin-Hui Wang
- Laboratory of Pharmacology, Toxicology & Pulp Biology, Department of Dentistry and School of Dentistry, National Taiwan University Hospital and National Taiwan University Medical College, Taipei, Taiwan, ROC
| | - Guay-Fen Huang
- Laboratory of Pharmacology, Toxicology & Pulp Biology, Department of Dentistry and School of Dentistry, National Taiwan University Hospital and National Taiwan University Medical College, Taipei, Taiwan, ROC
| | - Yuan-Ling Lee
- Laboratory of Pharmacology, Toxicology & Pulp Biology, Department of Dentistry and School of Dentistry, National Taiwan University Hospital and National Taiwan University Medical College, Taipei, Taiwan, ROC
| | - Yin-Lin Wang
- Laboratory of Pharmacology, Toxicology & Pulp Biology, Department of Dentistry and School of Dentistry, National Taiwan University Hospital and National Taiwan University Medical College, Taipei, Taiwan, ROC
| | - Chiu-Po Chan
- Department of Dentistry, Chang Gung Memorial Hospital, Taipei, Taiwan, ROC
| | - Sin-Yuet Yeung
- Biomedical Science Team, Chang Gung University of Science and Technology, Taoyuan, Taiwan, ROC
| | - Shuei-Kuen Tseng
- Laboratory of Pharmacology, Toxicology & Pulp Biology, Department of Dentistry and School of Dentistry, National Taiwan University Hospital and National Taiwan University Medical College, Taipei, Taiwan, ROC
| | - Jiiang-Huei Jeng
- Laboratory of Pharmacology, Toxicology & Pulp Biology, Department of Dentistry and School of Dentistry, National Taiwan University Hospital and National Taiwan University Medical College, Taipei, Taiwan, ROC.
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30
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Moilanen LH, Dahms JK, Hoberman AM. Reproductive toxicity evaluation of the dental resin monomer bisphenol a glycidyl methacrylate (CAS 1565-94-2) in mice. Int J Toxicol 2013; 32:415-25. [PMID: 24231940 DOI: 10.1177/1091581813511995] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The reproductive toxicity potential of the dental resin monomer bisphenol A glycidyl methacrylate (BisGMA; CASRN 1565-94-2) was investigated in male and female Crl: CD1(ICR) mice, 4 dosage groups, and 25 mice/sex/group. Formulations of BisGMA (0, 0.008, 0.08, or 0.8 mg/kg/d) in 0.8% ethanol in deionized water were intubated once daily beginning 28 days before cohabitation and continuing through mating (males) or through gestation day 17. The following parameters were evaluated: viability, clinical signs, body weights, estrous cyclicity, necropsy observations, organ weights, sperm concentration/motility/morphology, cesarean sectioning and litter observations, and histopathological evaluation of select tissues. No deaths or clinical signs related to BisGMA occurred. No significant changes in male and female body weights and body weight gains were recorded at any of the administered dosages of BisGMA. All mating and fertility parameters, and all litter and fetal data, were considered to be unaffected by dosages of BisGMA as high as 0.8 mg/kg/d. Gross or histopathologic tissue changes attributable to the test article were not observed. Reproductive and developmental no observed effect levels (NOAELs) for BisGMA were 0.8 mg/kg/d, the highest dose tested. Comparison of this NOAEL value to published probabilistic estimates of human BisGMA exposure from dental products suggests a margin of safety of at least 280- to nearly 2000-fold. Under the conditions of this study, BisGMA is not a reproductive toxicant.
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Affiliation(s)
- Lori H Moilanen
- 3M Company, Medical Department, 3M Center Bldg 220-6E-03, St Paul, MN 55144, USA.
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31
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Karaarslan ES, Altintas S, Bulbul M, Cebe MA, Usumez A. High performance liquid chromatography analysis of monomers from one composite resin cured with different polymerisation methods. ACTA ACUST UNITED AC 2013. [DOI: 10.1179/143307511x12998222918912] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Affiliation(s)
- E S Karaarslan
- Department of Operative DentistryFaculty of Dentistry, Gaziantep University, Gaziantep, Turkey
| | - S Altintas
- Department of ProsthodonticsFaculty of Dentistry, Karadeniz Technical University, Trabzon, Turkey
| | - M Bulbul
- Department of ProsthodonticsFaculty of Dentistry, Gaziantep University, Gaziantep, Turkey
| | - M A Cebe
- Department of Operative DentistryFaculty of Dentistry, Gaziantep University, Gaziantep, Turkey
| | - A Usumez
- Department of ProsthodonticsFaculty of Dentistry, Gaziantep University, Gaziantep, Turkey
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32
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Ruiz-de-Castañeda E, Gatón-Hernández P, Rodriguez EG, Silva RAB, Nelson-Filho P, Silva LAB. Pulpal and Periapical Response After Restoration of Deep Cavities in Dogs' Teeth With Filtek Silorane and Filtek Supreme XT Systems. Oper Dent 2013; 38:73-81. [DOI: 10.2341/11-341-l] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
SUMMARY
Objective:
This study evaluated, histopathologically, the pulpal and periapical response to a silorane-based resin (Filtek Silorane) and a methacrylate-based nanoparticle resin (Filtek Supreme XT) in deep cavities in dogs, having zinc oxide and eugenol-based cement (ZOE) as a control.
Methods:
The tooth/bone blocks were collected after 10 and 90 days and processed for microscopic analysis of the dentin, pulp, and periapical tissues using a score system. Data were analyzed statistically by Kruskal-Wallis and Dunn post-test (α=0.05).
Results:
At 10 days, the pulp, connective tissue, and periodontal ligament showed normal characteristics. No resorption areas were observed. Both resins caused significantly less (p<0.05) periapical and pulpal inflammatory response than ZOE. At 90 days, for all materials, the connective pulp tissue was healthy and dense, with a normal blood vessel system. The apical and periapical region had normal structure and thickness.
Conclusions:
The use of the Filtek Silorane and the Filtek Supreme XT resins caused no adverse pulpal and periapical reactions after restoration of deep dentin cavities in vivo.
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Affiliation(s)
- E Ruiz-de-Castañeda
- Esther Ruiz-de-Castañeda, MS, Catalan Society of Dentistry and Stomatology, Academy of Medical Sciences and Health of Catalonia and Balears, Barcelona, Spain
| | - P Gatón-Hernández
- Patricia Gatón-Hernández, PhD, School of Dentistry, University of Barcelona, Barcelona, Spain
| | - EG Rodriguez
- Encarnación G. Rodriguez, PhD, School of Dentistry, University of Granada, Granada, Spain
| | - RAB Silva
- Raquel A.B. Silva, PhD, School of Dentistry of Ribeirão Preto, University of São Paulo, Department of Pediatric Clinic, Preventive and Community Dentistry, Ribeirão Preto, SP, Brazil
| | - P Nelson-Filho
- Paulo Nelson-Filho, PhD, School of Dentistry of Ribeirão Preto, University of São Paulo, Department of Pediatric Clinic, Preventive and Community Dentistry, Ribeirão Preto, SP, Brazil
| | - LAB Silva
- Raquel A.B. Silva, PhD, School of Dentistry of Ribeirão Preto, University of São Paulo, Department of Pediatric Clinic, Preventive and Community Dentistry, Ribeirão Preto, SP, Brazil
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Effect of thermal aging on the tensile bond strength at reduced areas of seven current adhesives. Odontology 2012; 101:177-85. [PMID: 22790477 DOI: 10.1007/s10266-012-0073-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2011] [Accepted: 05/19/2012] [Indexed: 10/28/2022]
Abstract
The purpose of this study was to determine the micro-tensile bond strength (MTBS) to dentin of seven adhesive systems (total and self-etch adhesives) after 24 h and 5,000 thermocycles. Dentin surfaces of human third molars were exposed and bonded with two total-etch adhesives (Adper Scotchbond 1 XT and XP Bond), two two-step self-etch adhesives (Adper Scotchbond SE and Filtek Silorane Adhesive System) and three one-step self-etch adhesives (G-Bond, Xeno V and Bond Force). All adhesive systems were applied following manufacturers' instructions. Composite buildups were constructed and the bonded teeth were then stored in water (24 h, 37 °C) or thermocycled (5,000 cycles) before being sectioned and submitted to MTBS test. Two-way ANOVA and subsequent comparison tests were applied at α = 0.05. Characteristic de-bonded specimens were analyzed using scanning electron microscopy (SEM). After 24 h water storage, MTBS values were highest with XP Bond, Adper Scotchbond 1 XT, Filtek Silorane Adhesive System and Adper Scotchbond SE and lowest with the one-step self-etch adhesives Bond Force, Xeno V and G-Bond. After thermocycling, MTBS values were highest with XP Bond, followed by Filtek Silorane Adhesive System, Adper Scotchbond SE and Adper Scotchbond 1 XT and lowest with the one-step self-etch adhesives Bond Force, Xeno V and G-Bond. Thermal aging induced a significant decrease in MTBS values with all adhesives tested. The resistance of resin-dentin bonds to thermal-aging degradation was material dependent. One-step self-etch adhesives obtained the lowest MTBS results after both aging treatments, and their adhesive capacity was significantly reduced after thermocycling.
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34
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Costa CADS, Ribeiro APD, Giro EMA, Randall RC, Hebling J. Pulp response after application of two resin modified glass ionomer cements (RMGICs) in deep cavities of prepared human teeth. Dent Mater 2011; 27:e158-70. [DOI: 10.1016/j.dental.2011.04.002] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Revised: 11/23/2010] [Accepted: 04/04/2011] [Indexed: 11/17/2022]
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35
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Porto IC, Oliveira DC, Raele RA, Ribas KH, Montes MA, De Castro CM. Cytotoxicity of current adhesive systems: In vitro testing on cell cultures of primary murine macrophages. Dent Mater 2011; 27:221-8. [DOI: 10.1016/j.dental.2010.10.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2009] [Revised: 03/22/2010] [Accepted: 10/14/2010] [Indexed: 12/25/2022]
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Drozdz K, Wysokinski D, Krupa R, Wozniak K. Bisphenol A-glycidyl methacrylate induces a broad spectrum of DNA damage in human lymphocytes. Arch Toxicol 2010; 85:1453-61. [PMID: 20878393 PMCID: PMC3204149 DOI: 10.1007/s00204-010-0593-x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Accepted: 09/09/2010] [Indexed: 11/27/2022]
Abstract
Bisphenol A-glycidyl methacrylate (BisGMA) is monomer of dental filling composites, which can be released from these materials and cause adverse biologic effects in human cells. In the present work, we investigated genotoxic effect of BisGMA on human lymphocytes and human acute lymphoblastic leukemia cell line (CCRF-CEM) cells. Our results indicate that BisGMA is genotoxic for human lymphocytes. The compound induced DNA damage evaluated by the alkaline, neutral, and pH 12.1 version of the comet assay. This damage included oxidative modifications of the DNA bases, as checked by DNA repair enzymes EndoIII and Fpg, alkali-labile sites and DNA double-strand breaks. BisGMA induced DNA-strand breaks in the isolated plasmid. Lymphocytes incubated with BisGMA at 1 mM were able to remove about 50% of DNA damage during 120-min repair incubation. The monomer at 1 mM evoked a delay of the cell cycle in the S phase in CCRF-CEM cells. The experiment with spin trap—DMPO demonstrated that BisGMA induced reactive oxygen species, which were able to damage DNA. BisGMA is able to induce a broad spectrum of DNA damage including severe DNA double-strand breaks, which can be responsible for a delay of the cell cycle in the S phase.
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Affiliation(s)
- Kinga Drozdz
- Department of Molecular Genetics, University of Lodz, Lodz, Poland
| | | | - Renata Krupa
- Laboratory of DNA Repair, Department of Molecular Genetics, University of Lodz, Lodz, Poland
| | - Katarzyna Wozniak
- Laboratory of DNA Repair, Department of Molecular Genetics, University of Lodz, Lodz, Poland
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Kermanshahi S, Santerre JP, Cvitkovitch DG, Finer Y. Biodegradation of resin-dentin interfaces increases bacterial microleakage. J Dent Res 2010; 89:996-1001. [PMID: 20505047 DOI: 10.1177/0022034510372885] [Citation(s) in RCA: 109] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Bis-GMA-containing resin composites and adhesives undergo biodegradation by human-saliva-derived esterases, yielding Bis-hydroxy-propoxy-phenyl-propane (Bis-HPPP). The hypothesis of this study is that the exposure of dental restorations to saliva-like esterase activities accelerates marginal bacterial microleakage. Resin composites (Scotchbond, Z250, 3M) bonded to human dentin were incubated in either buffer or dual-esterase media (pseudocholinesterase/cholesterol-esterase; PCE+CE), with activity levels simulating those of human saliva, for up to 90 days. Incubation solutions were analyzed for Bis-HPPP by high-performance liquid chromatography. Post-incubation, specimens were suspended in a chemostat-based biofilm fermentor cultivating Streptococcus mutans NG8, a primary species associated with dental caries, for 7 days. Bacterial microleakage was assessed by confocal laser scanning microscopy. Bis-HPPP production and depth and spatial volume of bacterial cell penetration within the interface increased with incubation time and were higher for 30- and 90-day PCE+CE vs. buffer-incubated groups, suggesting that biodegradation can contribute to the formation of recurrent decay.
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Affiliation(s)
- S Kermanshahi
- Biomaterials Discipline, Dental Research Institute, Faculty of Dentistry, University of Toronto, 124 Edward Street, Toronto, ON, Canada M5G 1G6
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38
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Caviedes-Bucheli J, Correa-Ortiz JA, Ballestero AC, Jimenez M, Munoz A, Rivero C, Lombana N, Munoz HR. The effect of dentine-bonding agents on substance P release in human dental pulp. Int Endod J 2010; 43:95-101. [PMID: 20078697 DOI: 10.1111/j.1365-2591.2009.01646.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIM To quantify the effect of dentine-bonding agents on Substance P (SP) release in healthy human dental pulp tissue. METHODOLOGY Forty pulp samples were obtained from healthy pre-molars where extraction was indicated for orthodontic reasons. In thirty of these pre-molars, a standardized Class V cavity preparation was performed, and teeth were divided equally into three groups: (i) Unetched-cavity control group: Class V cavities only; (ii) Experimental Group I: 'One-step' self-etch bonding agent was placed in the cavity; and (iii) Experimental Group II: 'Two-step' total-etch bonding agent was placed in the cavity. The remaining ten healthy pre-molars where extracted without treatment and served as an intact-teeth control group. SP was measured by radioimmunoassay. RESULTS Greater SP release was found in the 'one-step' bonding agent group, followed by the 'two-step' bonding agent group and the unetched-cavity control group. The lower SP values were for the intact-teeth control group. anova showed statistically significant differences between groups (P = 0.0001). Tukey HSD post hoc tests showed statistically significant differences in SP release between the intact-teeth control group and the three other groups (P < 0.01) and between the unetched-cavity control group and the 'one-step' bonding agent group (P < 0.05). No significant difference was found between the 'two-step' bonding agent and the unetched-cavity control group. CONCLUSION Dentine-bonding agents placed over Class V cavity preparations increased SP release. One-step dentine-bonding agents increased SP release most.
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Affiliation(s)
- J Caviedes-Bucheli
- Endodontic Department, School of Dentistry, Pontificia Universidad Javeriana, Bogota, Colombia.
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Bakopoulou A, Papadopoulos T, Garefis P. Molecular toxicology of substances released from resin-based dental restorative materials. Int J Mol Sci 2009; 10:3861-3899. [PMID: 19865523 PMCID: PMC2769064 DOI: 10.3390/ijms10093861] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2009] [Revised: 08/24/2009] [Accepted: 09/02/2009] [Indexed: 01/22/2023] Open
Abstract
Resin-based dental restorative materials are extensively used today in dentistry. However, significant concerns still remain regarding their biocompatibility. For this reason, significant scientific effort has been focused on the determination of the molecular toxicology of substances released by these biomaterials, using several tools for risk assessment, including exposure assessment, hazard identification and dose-response analysis. These studies have shown that substances released by these materials can cause significant cytotoxic and genotoxic effects, leading to irreversible disturbance of basic cellular functions. The aim of this article is to review current knowledge related to dental composites' molecular toxicology and to give implications for possible improvements concerning their biocompatibility.
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Affiliation(s)
- Athina Bakopoulou
- Department of Fixed & Implant Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki 541 24, Greece; E-Mails: (B.A.); (G.P.)
| | - Triantafillos Papadopoulos
- Department of Biomaterials, School of Dentistry, National and Kapodistrian University of Athens, Athens, 115 27, Greece
| | - Pavlos Garefis
- Department of Fixed & Implant Prosthodontics, School of Dentistry, Aristotle University of Thessaloniki, Thessaloniki 541 24, Greece; E-Mails: (B.A.); (G.P.)
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40
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Reactions of connective tissue to self-etching/priming dentin bonding systems: oxidative stress, tumor necrosis factor α expression, and tissue reactions. J Dent Sci 2009. [DOI: 10.1016/s1991-7902(09)60019-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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41
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Tabatabaee MH, Mahdavi H, Zandi S, Kharrazi MJ. HPLC analysis of eluted monomers from two composite resins cured with LED and halogen curing lights. J Biomed Mater Res B Appl Biomater 2009; 88:191-6. [PMID: 18618467 DOI: 10.1002/jbm.b.31167] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
This study investigated the leaching of monomers (Bis-GMA and TEGDMA) from nano-hybrid (Filtek Supreme) and flowable (Filtek Flow) dental composite resins cured with LED or conventional halogen curing lights, and immersed in saliva or water for 24 h. Nine disc specimens were made for each experimental group. After the polymerization process, the specimens were immersed in either water or saliva and incubated at 37 degrees C for 24 h. Eluted Bis-GMA and TEGDMA monomers were detected using high performance liquid chromatography (HPLC). The data were analyzed using three-way ANOVA (p = 0.05) and the independent samples t test. TEGDMA (53.15-1 microg/L) was leached from the resins at a higher level than Bis-GMA (28-0.5 microg/L) (p < 0.01), regardless of the affecting factors: composite type, solvent (media) and type of curing light. In general, Filtek Flow resin released more TEGDMA than Filtek Supreme (p < 0.05), but the Supreme resin released more Bis-GMA than TEGDMA (p < 0.05). Halogen light induced greater monomer elution than LED light immersion in water. Saliva released more TEGDMA than water (p < 0.05). We conclude that (1) total leached TEGDMA was higher than total Bis-GMA, (2) saliva and halogen light (lower intensity than LED) leached more monomers from the resins, and (3) the flowable composite resin leached more TEGDMA than the nano-hybrid.
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Affiliation(s)
- Masumeh Hasani Tabatabaee
- Department of Restorative Dentistry, Faculty of Dentistry, Tehran University of Medical Sciences and Dental Research Center, Tehran, Iran.
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42
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Poplawski T, Pawlowska E, Wisniewska-Jarosinska M, Ksiazek D, Wozniak K, Szczepanska J, Blasiak J. Cytotoxicity and genotoxicity of glycidyl methacrylate. Chem Biol Interact 2009; 180:69-78. [PMID: 19428346 DOI: 10.1016/j.cbi.2009.02.001] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2008] [Revised: 02/02/2009] [Accepted: 02/04/2009] [Indexed: 12/11/2022]
Abstract
Methacrylates are used in the polymer form as composite restorative materials in dentistry. However, the polymers can release monomers and co-monomers into the oral cavity and pulp, from where they can migrate into the bloodstream reaching virtually all organs. The local concentration of the released monomers can be in the millimolar range, high enough to induce adverse biological effects. Genotoxicity of methacrylate monomers is of a special significance due to potential serious phenotypic consequences, including cancer, and long latency period. In the present work, we investigated cytotoxicity and genotoxicity of glycidyl methacrylate (GMA) in the human peripheral blood lymphocytes and the CCR-CM human cancer cells. GMA at concentrations up to 5mM evoked a concentration-dependent decrease in the viability of the lymphocytes up to about 80%, as assessed by flow cytometry. This agent did not induce strand breaks in the isolated plasmid DNA, but evoked concentration-dependent DNA damage in the human lymphocytes evaluated by the alkaline and neutral comet assay. This damage included oxidative modifications to the DNA bases, as checked by DNA repair enzymes Endo III and Fpg as well as single and double DNA strand breaks. The lymphocytes exposed to GMA at 2.5 microM were able to remove about 90% of damage to their DNA in 120 min. The ability of GMA to induce DNA double-strand breaks was confirmed by pulsed field gel electrophoresis. The drug evoked apoptosis and induced an increase in the G2/M cell population, accompanied by a decrease in the S cell population and an increase in G0/G1 cell population. Due to broad spectrum of GMA genotoxicity, including DNA double-strand breaks, and a potential long-lasting exposure to this compound, its use should be accompanied by precautions, reducing the chance of its release into blood stream and the possibility to induce adverse biological effects.
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Affiliation(s)
- Tomasz Poplawski
- Department of Molecular Genetics, University of Lodz, Lodz, Poland
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Khalichi P, Singh J, Cvitkovitch DG, Santerre JP. The influence of triethylene glycol derived from dental composite resins on the regulation of Streptococcus mutans gene expression. Biomaterials 2009; 30:452-9. [DOI: 10.1016/j.biomaterials.2008.09.053] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2008] [Accepted: 09/28/2008] [Indexed: 10/21/2022]
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Schmidlin PR, Huber T, Göhring TN, Attin T, Bindl A. Effects of Total and Selective Bonding on Marginal Adaptation and Microleakage of Class I Resin Composite Restorations In Vitro. Oper Dent 2008; 33:629-35. [DOI: 10.2341/07-158] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Clinical Relevance
Within the limitations of the current study, the use of glass ionomer liners improves the margin quality of Class I resin composite restorations and reduces leakage.
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Cem Güngör H, Uysal S, Altay N. A retrospective evaluation of crown-fractured permanent teeth treated in a pediatric dentistry clinic. Dent Traumatol 2007; 23:211-7. [PMID: 17635353 DOI: 10.1111/j.1600-9657.2005.00446.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A retrospective study was carried out on the dental trauma records of 93 patients (55 boys, 38 girls) with 129 crown-fractured teeth. The patients' average age was 9.57 years (SD 1.57), ranging between 7 and 15 years. Uncomplicated crown facture (comprising enamel-dentin) was the most observed type of injury (n = 107, 83%). Only 15 patients (16.13%) sought treatment in less than 24 h following the injury. Of 41 injured teeth (31.79%) the apices were open at the time of presentation at the clinic. The initial treatment of these injured teeth were interim restoration with acid-etch and composite (69%), Cvek amputation (2.33%), fragment reattachment (1.55%), apexification (APX, 10.07%), and root-canal treatment (RCT, 17.05%). Out of 94 teeth, which were diagnosed as vital on admittance, 23 (24.46%) later developed pulp necrosis and required APX or RCT depending on their apical status. In 66 teeth (51.16%) definitive treatment was provided with only esthetic restoration (ER), while in 15.50% and 26.68% of injured teeth ER was carried out following APX and RCT, and RCT, respectively. Definitive treatment was provided in 3-6 months for 29.45% of the injured teeth, while 27.13% and 20.16% of teeth received definitive treatment within 1-3 months and 6 months to 1 year, respectively. Type of crown-fracture, elapsed time following injury, and vitality of the tooth on admittance and pulp necrosis observed were significantly related to the total time spent for definitive treatment (P < 0.05).
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Affiliation(s)
- Hamdi Cem Güngör
- Department of Pedodontics, Faculty of Dentistry, Hacettepe University, Ankara, Turkey.
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DAHL JONE, ØRSTAVIK DAG. Responses of the pulp-dentin organ to dental restorative biomaterials. ACTA ACUST UNITED AC 2007. [DOI: 10.1111/j.1601-1546.2010.00250.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Brackett MG, Bouillaguet S, Lockwood PE, Rotenberg S, Lewis JB, Messer RLW, Wataha JC. In vitro cytotoxicity of dental composites based on new and traditional polymerization chemistries. J Biomed Mater Res B Appl Biomater 2007; 81:397-402. [PMID: 17022055 DOI: 10.1002/jbm.b.30676] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
UNLABELLED The biological response to dental restorative polymer composites is mediated by the release of unpolymerized residual monomers. Several new composite formulations claim to reduce unpolymerized residual mass. The current study assessed the cytotoxic responses to several of these new formations and compared them with more traditional formulations. Our hypothesis predicted that if these new polymerization chemistries reduce unpolymerized residual mass, the cytotoxicity of these materials also should be reduced relative to traditional formulations. METHODS Materials (HerculiteXRV, Premise, Filtek Supreme, CeramxDuo, Hermes, and Quixfil) were tested in vitro in direct contact with Balb mouse fibroblasts, initially, then after aging in artificial saliva for 0, 1, 3, 5, or 8 weeks. The toxicity was determined by using the MTT assay to the estimate SDH activity. Knoop hardness of the materials also was measured at 0 and 8 weeks to determine whether surface breakdown of the materials in artificial saliva contributed to cytotoxic responses. RESULTS Materials with traditional methacrylate chemistries (Herculite, Premise, Filtek Supreme) were severely (>50%) cytotoxic throughout the 8-week interval, but materials with newer chemistries or filling strategies (Hermes, CeramXDuo, and Quixfil) improved over time of aging in artificial saliva. Hermes showed the least cytotoxicity at 8 weeks, and was statistically equivalent to Teflon negative controls. Hardness of the materials was unaffected by exposure to artificial saliva. CONCLUSIONS Newer polymerization and filling strategies for dental composites show promise for reducing the release of unpolymerized components and cytotoxicity.
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Affiliation(s)
- M Goël Brackett
- School of Dentistry, Medical College of Georgia, Augusta, Georgia 30912-1100, USA
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Ratih DN, Palamara JEA, Messer HH. Dentinal fluid flow and cuspal displacement in response to resin composite restorative procedures. Dent Mater 2007; 23:1405-11. [PMID: 17296218 DOI: 10.1016/j.dental.2006.11.029] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2005] [Revised: 07/12/2006] [Accepted: 11/16/2006] [Indexed: 10/23/2022]
Abstract
OBJECTIVES The aim of this study was to correlate the rate and magnitude of dentinal fluid flow (DFF) with cuspal displacement in response to resin composite restorative procedures. METHODS Ten extracted human maxillary premolar teeth with an extensive MOD cavity preparation were connected to an automated fluid flow measurement apparatus (Flodec), and a direct current differencial transformer (DCDT) was attached to each cusp. The rate, magnitude and direction of DFF and cuspal displacement were recorded simultaneously in response to each stage of resin composite restorative procedures. RESULTS Cuspal displacement and DFF in outward and inward directions accompanied each stage of the procedures. Drying produced rapid cuspal contraction. Bonding caused slight cuspal expansion, whereas light curing of resin induced gradual but extensive cuspal contraction, which persisted following light curing. During baseline outward DFF was low and increased slightly during etching. In contrast, substantial outward DFF occurred during drying. Light curing of the bonding agent and the resin composite produced inward DFF. Following light curing, an outward DFF began and continued for at least 15 min. SIGNIFICANCE The large, rapid fluid movement and cuspal displacement during restoration, and the prolonged outward fluid flow post-curing have implications for post-operative sensitivity. While mechanical stresses within dentin associated with cuspal displacement appear capable of inducing DFF, the net fluid movement is the result of complex interactions either directly or indirectly of several stimuli (thermal, evaporation, osmotic, and possibly mechanical).
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Affiliation(s)
- Diatri N Ratih
- Department of Restorative Dentistry, School of Dental Science, The University of Melbourne, 720 Swanston Street, Melbourne, Victoria 3010, Australia
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Noda M, Wataha JC, Kachi H, Lewis JB, Messer RL, Sano H. Radicals produced by blue-light–resin interactions alter the redox status of THP1 human monocytes. J Biomed Mater Res A 2007; 83:123-9. [PMID: 17385233 DOI: 10.1002/jbm.a.31222] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Resin composites are widely used in dentistry, and are polymerized in situ using a blue-light activated, free-radical polymerization mechanism. Blue light (400-500nm) is used to activate camphoroquinone (CQ), which decomposes to form free radicals that are stabilized by dimethyl-p-toludine (DMPT). CQ and DMPT are applied near tooth pulpal tissues and are irradiated during restorative procedures, suggesting that pulpal cells are exposed to free radicals. Because glutathione is a major component of the cellular redox management system, we tested the hypothesis that blue light irradiation would shift cellular glutathione redox balance of cells exposed to CQ and DMPT. We also measured NFkappaB activation, a redox-sensitive transcription factor that regulates inflammatory responses and glutathione synthetic enzyme levels. THP1 human monocytes were exposed to sublethal levels of CQ (0.4 mM) or DMPT (1.0 mM), with or without blue light exposure (25 J/cm(2)) from a quartz-tungsten-halogen source. The ratio of reduced to oxidized glutathione was measured using as assay based on 5,5'-dithio-bis(2-nitrobenszoic acid). NFkappaB transactivation was measured by transfection of an NFkappaB-containing plasmid linked to a luciferase reporter. Our results showed that blue light, CQ, or DMPT alone had no significant effect on cellular glutathione redox balance, but that the combination of these agents induced a marked oxidative bias, and reduced total glutathione levels up to 50%. On the other hand, light, CQ, and DMPT alone or in combination suppressed NFkappaB transactivation by >70%. Our results suggest that CQ and DMPT pose risks to pulpal tissues with or without blue light irradiation, and that multiple, interacting mechanisms shape the response to these agents.
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Affiliation(s)
- M Noda
- Center for Dental Clinics, Hokkaido University Hospital, Hokkaido University, Sapporo, Japan.
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Abstract
Monomers are released from dental resin materials, and thus cause adverse biological effects in mammalian cells. Cytotoxicity and genotoxicity of some of these methacrylates have been identified in a vast number of investigations during the last decade. It has been well-established that the co-monomer triethylene glycol dimethacrylate (TEGDMA) causes gene mutations in vitro. The formation of micronuclei is indicative of chromosomal damage and the induction of DNA strand breaks detected with monomers like TEGDMA and 2-hydroxyethyl methacrylate (HEMA). As a consequence of DNA damage, the mammalian cell cycle was delayed in both G1 and G2/M phases, depending on the concentrations of the monomers. Yet, the mechanisms underlying the genetic and cellular toxicology of resin monomers have remained obscure until recently. New findings indicate that increased oxidative stress results in an impairment of the cellular pro- and anti-oxidant redox balance caused by monomers. It has been demonstrated that monomers reduced the levels of the natural radical scavenger glutathione (GSH), which protects cell structures from damage caused by reactive oxygen species (ROS). Depletion of the intracellular GSH pool may then significantly contribute to cytotoxicity, because a related increase in ROS levels can activate pathways leading to apoptosis. Complementary, cytotoxic, and genotoxic effects of TEGDMA and HEMA are inhibited in the presence of ROS scavengers like N-acetylcysteine (NAC), ascorbate, and Trolox (vitamin E). Elevated intracellular levels of ROS can also activate a complex network of redox-responsive macromolecules, including redox-sensitive transcription factors like nuclear factor kappaB (NF-kappaB). It has been shown that NF-kappaB is activated probably to counteract HEMA-induced apoptosis. The induction of apoptosis by TEGDMA in human pulp cells has been associated with an inhibition of the phosphatidylinositol 3-kinase (PI3-K) cell-survival signaling pathway. Although the details of the mechanisms leading to cell death, genotoxicity, and cell-cycle delay are not completely understood, resin monomers may be able to alter the functions of the cells of the oral cavity. Pathways regulating cellular homeostasis, dentinogenesis, or tissue repair may be modified by monomers at concentrations well below those which cause acute cytotoxicity.
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Affiliation(s)
- H Schweikl
- Department of Operative Dentistry and Periodontology, University of Regensburg, D-93042 Regensburg, Germany.
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