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Świderska, Jolanta, Zbigniew Czech i Agnieszka Kowalczyk. "Polymerization shrinkage by investigation of uv curable dental restorative composites containing multifunctional methacrylates". Polish Journal of Chemical Technology 15, nr 2 (1.07.2013): 81–85. http://dx.doi.org/10.2478/pjct-2013-0027.
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Typical commercial restorative dental compositions in the form of medical resins contain in-organic fillers, multifunctional methacrylates and photoinitiators. The currently used resins for direct composite restoratives have been mainly based on acrylic chemistry to this day. The main problem with the application and radiation curing process is the shrinkage of photoreactive dental materials during and after UV curing. Shrinkage of restorative radiation curable dental composites is a phenomenon of polymerization shrinkage, typical behavior of multifunctional methacrylates during the polymerization process. The important factors in curing of dental composites are: the kind and concentration of the used methacrylate, its functionality, double bond concentration, the kind and concentration of the added photoinitiator and UV dose emitted by the UV-lamp. They are investigated multifunctional 1,3-butanediol dimethacrylate (1,3-BDDMA), diethylene glycol dimethacrylate (DEGDMA), triethylene glycol dimethacrylate (TEGDMA), trimethylolpropane trimethacrylate (TMPTMA), 2,2-bis-[4-(2-hydroxy-3-methacryxloyloxypropyl) phenyl]propane (Bis-GMA), ethoxylated Bis-GMA (EBPDMA) and dodecandiol dimethacrylate (DDDMA). Reduction of polymerization shrinkage of restorative dental compositions is at the moment a major problem of dental technology. This problem can be solved through an application of photoreactive non-tacky multifunctional methacrylates in the investigated dental adhesive fillings.
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Bonta, Dan Florin, Sergiu Alexandru Tofan, Liana Todor, Mariana Miron, Cristina Ioana Talpos, Raluca Mioara Cosroaba, florin Borcan i Ramona Amina Popovici. "In vitro Study on Mechanical Properties of Polyacid-modified Composite Resins (Compomers)". Materiale Plastice 59, nr 1 (5.04.2022): 90–98. http://dx.doi.org/10.37358/mp.22.1.5562.
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At the beginning of the 90 s on the market of dental restoration materials appeared compomers, polyacid modified composite resins (PMC). The term compomer suggests a combination of glass-ionomer and composite technology. This has led to confusion about how it relates to dental structures. The properties and adhesion of compomers to dental structures suggest a closer connection with composites than with glass ionomers. They do not have direct chemical adhesion to any tooth structure it adheres similar to the composites through a separate binding agent. However, their proximity to composites does not make them substitutes of composites. Compomers are a versatile class of dental restorative biomaterials, whose clinical benefits are particularly useful in pediatric dentistry.
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Alreshaid, L., W. El-Badrawy, HP Lawrence, MJ Santos i A. Prakki. "Composite versus Amalgam Restorations Placed in Canadian Dental Schools". Operative Dentistry 46, nr 6 (1.11.2021): 621–30. http://dx.doi.org/10.2341/20-212-c.
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SUMMARY Objectives To investigate the latest teaching policies of posterior composite placement versus amalgam and to determine the actual numbers of posterior composites versus amalgam restorations placed in Canadian dental schools, over the years from 2008 to 2018. Methods Emails were sent to Chairs/Heads of Restorative Departments and Clinic Directors of all 10 Canadian dental schools to collect data in the forms of: 1) Questionnaire on current teaching policies of posterior composite and amalgam restorations; 2) data entry form to collect the actual numbers of posterior composite and amalgam restorations placed in their clinics. Results For the teaching questionnaire, the response rate was 90% (n=9). Seven (78%) of the responding schools reported that they assign 25%–50% of their preclinical restorative teaching time towards posterior composite placement. While, three (33%) of the responding schools allocated 50%–75% of their restorative teaching towards amalgam placement. Data entry response rate was 80% (n=8). Amalgam material was dominant in the restoration distribution from 2008 to 2012. While from 2013 to 2018, resin composite material was dominant in all eight responding schools. Linear regression analysis revealed a significant increasing trend in placing posterior composites in all the responding schools over time (p<0.05). Conclusions Data analysis revealed a clear trend towards an increase of posterior composite restoration placement and a decrease in the number of amalgam restorations placed. However, the teaching time assigned for posterior composite is not aligned with quantity placed. Review and adjustment of time allocated for teaching and training of each material are recommended.
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Cheng, Jingru, Yuyi Deng, Yujin Tan, Jiawei Li, Yongsheng Fei, Congcong Wang, Jingjing Zhang, Chenxi Niu, Qian Fu i Lingbin Lu. "Preparation of Silica Aerogel/Resin Composites and Their Application in Dental Restorative Materials". Molecules 27, nr 14 (9.07.2022): 4414. http://dx.doi.org/10.3390/molecules27144414.
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As the most advanced aerogel material, silica aerogel has had transformative industrial impacts. However, the use of silica aerogel is currently limited to the field of thermal insulation materials, so it is urgent to expand its application into other fields. In this work, silica aerogel/resin composites were successfully prepared by combining silica aerogel with a resin matrix for dental restoration. The applications of this material in the field of dental restoration, as well as its performance, are discussed in depth. It was demonstrated that, when the ratio of the resin matrix Bis-GMA to TEGDMA was 1:1, and the content of silica aerogel with 50 μm particle size was 12.5%, the composite achieved excellent mechanical properties. The flexural strength of the silica aerogel/resin composite reached 62.9546 MPa, which was more than five times that of the pure resin. Due to the presence of the silica aerogel, the composite also demonstrated outstanding antibacterial capabilities, meeting the demand for antimicrobial properties in dental materials. This work successfully investigated the prospect of using commercially available silica aerogels in dental restorative materials; we provide an easy method for using silica aerogels as dental restorative materials, as well as a reference for their application in the field of biomedical materials.
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Huyang, George, i Jirun Sun. "Clinically Applicable Self-Healing Dental Resin Composites". MRS Advances 1, nr 8 (2016): 547–52. http://dx.doi.org/10.1557/adv.2016.86.
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ABSTRACTSelf-healing is one of the most desired material properties. Herein, we present the design and development of a new self-healing dental composite (SHDC) that can heal micro-cracks autonomously. The SHDC has two functional components in addition to contemporary dental composites: healing powder (HP) and healing liquid (HL) encapsulated in silica microcapsules. The autonomous healing is triggered by micro-cracks which fracture microcapsules in their propagation path and release the HL. As a consequence, the released HL dissolves and reacts with the HP, and then fill the micro-cracks with a cement-like new material. This 3-step crack-release-heal process prevents micro-cracks from causing restoration failure, thus improving the service life of dental restorative material. The mechanical performance of the SHDC prepared were evaluated in terms of elastic modulus and fracture toughness, which were in the upper level compared to commercial dental restorative materials, and the self-healing capability was confirmed through fracture toughness recovery test. In addition, the SHDCs were made with clinically-tested, biocompatible materials, which makes them readily applicable as medical devices.
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Malara, P., i W. Świderski. "Contemporary aesthetic restorative dental composite materials". Journal of Achievements in Materials and Manufacturing Engineering 78, nr 1 (1.08.2016): 32–40. http://dx.doi.org/10.5604/01.3001.0010.1493.
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Purpose: This is a review paper that gives an insight into the most popular group ofaesthetic dental materials - dental composite materials. This article describes the historicalbackground, the main features of this group of materials, the cathegorization of the materialsin relation to clinical applications and the polymerization proces.Design/methodology/approach: This review is based on the contemporary scientificliterature most relevant to the topic. The literature search has been made in Elsevier -Science Direct.Findings: Light-curing dental composites exhibit some resemblance to the constructionof the hard tissues of the tooth. They also consist of two basic components. These are:an organic matrix and an inorganic filler. The third component, which is regularly added, isso-called binding agent. According to the composition of the materials they make a goodchoice for aesthetic restoration in natural dentition.Practical implications: In the clinical observations there are many complications resultingfrom inadequate polymerization of composite materials. This may be the result of poorquality of curing lights of a very low intensity, too long distance between the tip of the lampand the surface of the material or improper exposure timeOriginality/value: Dental composite materials are the only group of dental materialsin which these features are combined together, ensuring naturally looking final effect ofthe restoration. Easy handling of the dental composite materials together with effectivepolymerization process with portable light units make these materials a good choice forclinical use.
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Seifan, Mostafa, Zahra Sarabadani i Aydin Berenjian. "Development of an Innovative Urease-Aided Self-Healing Dental Composite". Catalysts 10, nr 1 (7.01.2020): 84. http://dx.doi.org/10.3390/catal10010084.
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Dental restorative materials suffer from major drawbacks, namely fracture and shrinkage, which result in failure and require restoration and replacement. There are different methods to address these issues, such as increasing the filler load or changing the resin matrix of the composite. In the present work, we introduce a new viable process to heal the generated cracks with the aid of urease enzyme. In this system, urease breaks down the salivary urea which later binds with calcium to form calcium carbonate (CaCO3). The formation of insoluble CaCO3 fills any resultant fracture or shrinkage from the dental composure hardening step. The healing process and the formation of CaCO3 within dental composites were successfully confirmed by optical microscope, scanning electron microscopy (SEM), and energy-dispersive X-ray (EDS) methods. This research demonstrates a new protocol to increase the service life of dental restoration composites in the near future.
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Nicholson, John W. "Fluoride-Releasing Dental Restorative Materials: An Update". Balkan Journal of Dental Medicine 18, nr 2 (1.07.2014): 60–69. http://dx.doi.org/10.1515/bjdm-2015-0010.
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SUMMARYThe fluoride ion has a well-established beneficial role in dentistry in protecting the teeth from assault by caries. It is known to contribute to the dynamic mineralisation process of the natural tooth mineral, and also to become incorporated with the mineral phase, forming a thin layer of fluorapatite. This is more resistant to acid attack than the native hydroxyapatite, hence protects the tooth against further decay. Other recently discovered aspects of the role and uptake of fluoride will also be discussed.One of the widely used dental restoratives, the glass-ionomer dental cement, is able to release fluoride in a sustained manner that may continue for many years, and this is seen as clinically beneficial. The closely related resin-modified glass-ionomer cement, and also the polyacid-modified composite resin (“compomer”) are able to do the same. There are also fluoride-containing conventional composite resins able to release fluoride.These various materials are reviewed and the way in which they release fluoride are described, as well as the effectiveness of the release at the levels involved. Studies of effectiveness of fluoride release from these various classes of material are reviewed, and shown to suggest that release from conventional and resin-modified glass-ionomers is more beneficial than from composite resins. This is attributed to 2 causes: firstly, that it is not possible to replace the lost fluoride in composites, unlike glass-ionomers, and secondly because the other ions released from glass-ionomers (calcium, phosphate) are able to contribute to local remineralisation of the tooth. The absence of these other ions in fluoridated composites means that remineralisation is able to occur to a lesser extent, if at all.
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Basudan, Thuraya, Aymen Neyaz, Norah Alnasser, Afaf Alabdali, Walaa Alqahtan, Ghadah Asiri, Latifah Alshammari i in. "Improvement of Quality of Life through Nanoparticles in Restorative Dentistry". Journal of Healthcare Sciences 02, nr 12 (2022): 560–67. http://dx.doi.org/10.52533/johs.2022.21209.
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Dental methods aimed at dental rehabilitation, regional anesthesia, orthodontic realigning, permanent hypersensitivity treatment, covalent bonding diamondized enamel, dental health preservation using mechanical dentifrobots, and the formation of artificial bone and teeth are among the possible uses of nanotools in dentistry. The evaluation and treatment of problems affecting the teeth and their surrounding tissues are the focus of restorative dentistry. For the restoration of tooth function and the repair and replacement of damaged tooth structures as well as better aesthetics, advanced procedures are required. In the past few years, resin-based dental restorative materials have made significant progress. Dental composite resin's mechanical performance, minimal polymerization contraction, strong wear resistance, and surface hardness can all be considerably improved by adding nanoparticles to the matrix. To date, nanocomposites for the repair of tooth structure have made one of the most significant contributions to restorative and cosmetic dentistry. Nanocomposites' characteristics aid in minimizing polymerization loss. Their microhardness is higher than that of already employed posterior resin-based composites, and the improved polishability properties in turn result in a smoother surface with better shade qualities. Nanocomposites have a number of benefits, including reduced weight, excellent thermal and electrical properties, antimicrobial activity, and the ability to remineralize dental defects. The other nanotools used in restorative dentistry are nanoadhesives, nanoionomers and nanoendodontic sealants. Nanoadhesives protect against failure of a restoration from bacterial invasion occurs due to spaces between restorative material and preparation margins. Nanoionomers chemically adhere to the surface of the tooth and offer advantages of enhanced bond strength, chemical stability, and insoluble nature. Nano endodontic sealers have the advantage of sealing better than conventional sealers and employing nanoparticles effectively acts as an antibacterial agent. Due to its potential uses and advantages, there is a growing demand for and interest in nano-based dental materials.
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Dhar, V., KL Hsu, JA Coll, E. Ginsberg, BM Ball, S. Chhibber, M. Johnson, M. Kim, N. Modaresi i N. Tinanoff. "Evidence-based Update of Pediatric Dental Restorative Procedures: Dental Materials". Journal of Clinical Pediatric Dentistry 39, nr 4 (1.06.2015): 303–10. http://dx.doi.org/10.17796/1053-4628-39.4.303.
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Background: The science of dental materials and restorative care in children and adolescent is constantly evolving, and the ongoing search for ideal restorative materials has led to plethora of research. Aim: To provide an evidence base to assist dental practitioners choose appropriate restorative care for children and adolescents. Study design: This evidence-based review appraises this literature, primarily between the years 1995–2013, for efficacy of dental amalgam, composites, glass ionomer cements, compomers, preformed metal crowns and anterior esthetic restorations. The assessment of evidence for each dental material was based on a strong evidence, evidence in favor, expert opinion, and evidence against by consensus of the authors. Results: There is varying level of evidence for the use of restorative materials like amalgam, composites, glass ionomers, resin-modified glass-ionomers, compomers, stainless steel crowns and anterior crowns for both primary and permanent teeth. Conclusions: A substantial amount data is available on restorative materials used in pediatric dentistry; however, there exists substantial evidence from systematic reviews and randomized clinical trials and clinicians need to examine and understand the available literature evidence carefully to aid them in clinical decision making.
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Hu¨bsch, P. F., i J. Middleton. "Asymptotic Analysis of the Stress Field in Adhering Dental Restorations". Journal of Biomechanical Engineering 122, nr 4 (28.02.2000): 408–15. http://dx.doi.org/10.1115/1.1286564.
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Polymer-based composites are widely used in restorative dentistry as alternatives to metals and ceramics to fill cavities in teeth. They adhere to the walls of the cavity in the tooth, thus forming a composite body consisting of dentine, enamel, and composite resin. Geometric discontinuities along the interfaces between these materials can induce singularities in the stress field, which in turn lead to premature failure of the restoration. In the present investigation, a complex stress function technique is employed to derive the order of the stress singularity. It is shown that the order of the singularity depends on both the material properties of the restorative material and the local geometry of the cavity. It is also shown that the singularity in the stress field can be avoided through careful design of the cavity shape. The results presented correlate well with experimental results reported in the literature. [S0148-0731(00)01504-1]
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Zhao, Donglei, John Botsis i James L. Drummond. "Fracture studies of selected dental restorative composites". Dental Materials 13, nr 3 (maj 1997): 198–207. http://dx.doi.org/10.1016/s0109-5641(97)80027-9.
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AGHAZADEH MOHANDESI, Jamshid, Mohammad Ali RAFIEE, Vahid BARZEGARAN i Farhad SHAFIEI. "Compressive Fatigue Behavior of Dental Restorative Composites". Dental Materials Journal 26, nr 6 (2007): 827–37. http://dx.doi.org/10.4012/dmj.26.827.
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Balhaddad, Abdulrahman A., Isadora M. Garcia, Lamia Mokeem, Rashed Alsahafi, Fabrício Mezzomo Collares i Mary Anne Sampaio de Melo. "Metal Oxide Nanoparticles and Nanotubes: Ultrasmall Nanostructures to Engineer Antibacterial and Improved Dental Adhesives and Composites". Bioengineering 8, nr 10 (19.10.2021): 146. http://dx.doi.org/10.3390/bioengineering8100146.
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Advances in nanotechnology have unlocked exclusive and relevant capabilities that are being applied to develop new dental restorative materials. Metal oxide nanoparticles and nanotubes perform functions relevant to a range of dental purposes beyond the traditional role of filler reinforcement—they can release ions from their inorganic compounds damaging oral pathogens, deliver calcium phosphate compounds, provide contrast during imaging, protect dental tissues during a bacterial acid attack, and improve the mineral content of the bonding interface. These capabilities make metal oxide nanoparticles and nanotubes useful for dental adhesives and composites, as these materials are the most used restorative materials in daily dental practice for tooth restorations. Secondary caries and material fractures have been recognized as the most common routes for the failure of composite restorations and bonding interface in the clinical setting. This review covers the significant capabilities of metal oxide nanoparticles and nanotubes incorporated into dental adhesives and composites, focusing on the novel benefits of antibacterial properties and how they relate to their translational applications in restorative dentistry. We pay close attention to how the development of contemporary antibacterial dental materials requires extensive interdisciplinary collaboration to accomplish particular and complex biological tasks to tackle secondary caries. We complement our discussion of dental adhesives and composites containing metal oxide nanoparticles and nanotubes with considerations needed for clinical application. We anticipate that readers will gain a complete picture of the expansive possibilities of using metal oxide nanoparticles and nanotubes to develop new dental materials and inspire further interdisciplinary development in this area.
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Kukhta, V. S., i О. S. Kyrmanov. "THE EVALUATION OF CURRENT RESEARCH ON THE STRENGTH OF DENTAL RESTORATIVE COMPOSITE MATERIALS". Ukrainian Dental Almanac, nr 2 (27.06.2022): 5–9. http://dx.doi.org/10.31718/2409-0255.2.2022.01.
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The aim of the study: to analyze the sources of scientific and metric information on the state of research on the strength of dental composites for tooth restoration.
It has been determined that the range of composite materials available on the dental market is very wide. They differ significantly in chemical, mechanical, physical, and biological characteristics, operating properties, techniques of their usage. All this requires special training to use the composites effectively and to get high quality restoration results. The optimal choice of material and suitable technique taking into account a particular clinical situation can increase the durability of restorations and prevent the development of complications that largely depends on the strength characteristics of composites.
At present, the problem of selecting and creating the perfect filling material has not been completely solved that is confirmed by the large number of new developments in materials science. At the same time, composite polymers are gaining ground in dental practice. The new concept of adhesive preparation of dental tissues before inserting filling material and improving the properties of the composite materials themselves contribute to the maximum preservation of healthy dental tissues, increase the aesthetics, durability and functionality of dental restorations.
It has been determined that the mechanical strength characteristics of composite materials play a significant role in the longevity/durability of restorations depending on different chewing force and occlusal loading. It is important to investigate factors, which may cause the destruction of dental composites during the functional loading.
The physical and mechanical properties of dental composites are impacted by a number of factors, including the type of polymer matrix, the amount of material takes, size and distribution of the filler, the state of the bond between the filler and the matrix, the degree of polymerization. The choice of a material also depends on a number of characteristics in terms of the combination of main components. Since the material parameters set by the material manufacturers can not be changes, the deep understanding of its properties will help to choose the best material in each clinical situation.
The main physical properties of dental composites include compressive and tensile strength, modulus of elasticity, coefficient of thermal expansion, wear resistance, polymerization shrinkage, X-ray contrast, density and thixotropy, optical effects (transparency, fluorescence, etc.).
The AE method based on the registration of elastic waves arising from the formation, change and destruction of the structure of various materials, is currently the most effective for studying the processes and stages of development of material defects. It enables in detecting initial changes in the material structure, the initial location of defects, the direction of their spreading and determining the maximum strength of the material. The advantages of this method include the ability to obtain information about the destruction in the early stages, its high accuracy and sensitivitys.
The AE method is commonly used to study the resistance to destruction of various composite materials, the study of the tooth / composite interface, the analysis of polymerization stresses and the degree of shrinkage.
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Hermansson, Leif, Lars Kraft, Karin Lindqvist, Nils Otto Ahnfelt i Hakan Engqvist. "Flexural Strength Measurement of Ceramic Dental Restorative Materials". Key Engineering Materials 361-363 (listopad 2007): 873–76. http://dx.doi.org/10.4028/www.scientific.net/kem.361-363.873.
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Flexural strength of a dental material reflects its ability to withstand tensile stresses and thus the fracture risk of a filling. The flexural strength of an experimental bioceramic Calcium aluminate-based (CA) dental restorative material was measured using three different methods with a composite (Tetric Ceram), a glass ionomer cement (Fuji II) and a phosphate cement (Harward) as references. The three test methods were: a) ISO 4049 for dental composites, 3-point bend test b) EN 843-1 for ceramic materials, 3-point bend test and c) ASTM F-394, biaxial ball-on-disc for ceramic materials. The strength of the CA-material, tested in the ball-on-disc method, is close to the theoretical strength based on the microstructure of the material (max. grain size of 15 μm). The composite material and the phosphate cement were rather insensitive to the test method, while the glass ionomer cement as the CA-material showed sensitivity towards the test method. A modified biaxial test method for evaluation of strength of dental materials in a close to real-life component is proposed.
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Tammaro, Loredana, Anna Di Salle, Anna Calarco, Ilenia De Luca, Francesco Riccitiello, Gianfranco Peluso, Vittoria Vittoria i Andrea Sorrentino. "Multifunctional Bioactive Resin for Dental Restorative Materials". Polymers 12, nr 2 (5.02.2020): 332. http://dx.doi.org/10.3390/polym12020332.
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Resin-based composites are widely used as dental restorative materials due to their excellent properties. They must have high modulus, high hardness, and be chemically inert while minimizing moisture uptake. To fulfill these higher standard prerequisites and properties, continuous improvements in each of their components are required. This study develops novel composites with multiple biofunctions. Light-cured Bis-GMA/TEGDMA dental resin (RK)/layered double hydroxide intercalated with fluoride ions (LDH-F)/calcium bentonite (Bt) hybrid composites were prepared. The loading ratio of LDH-F to Bt was varied, ranging from 2.5/2.5 to 10/10 parts per hundred RK and structural, mechanical, and biological properties were studied. The incorporation of even small mass fractions (e.g., 2.5 wt% of LDH-F and 2.5 wt% of Bt) in RK dental resin significantly improved the mechanical properties of the pristine resin. The synthetized materials showed antibacterial and antibiofilm effects against three bacterial strains isolated from healthy volunteers’ saliva (Streptococcus spp., Bacteroides fragilis, and Staphylococcus epidermidis) without affecting its ability to induce dental pulp stem cells differentiation into odontoblast-like cells. The capability to balance between the antibiofilm activity and dental pulp stem cells differentiation in addition with improved mechanical properties make these materials a promising strategy in preventive and restorative dentistry.
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Gönder, Hakan Yasin, Reza Mohammadi, Abdulkadir Harmankaya, İbrahim Burak Yüksel, Yasemin Derya Fidancıoğlu i Said Karabekiroğlu. "Teeth Restored with Bulk–Fill Composites and Conventional Resin Composites; Investigation of Stress Distribution and Fracture Lifespan on Enamel, Dentin, and Restorative Materials via Three-Dimensional Finite Element Analysis". Polymers 15, nr 7 (25.03.2023): 1637. http://dx.doi.org/10.3390/polym15071637.
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Objectives: the aim of this study was to examine the stress distribution of enamel, dentin, and restorative materials in sound first molar teeth with restored cavities with conventional resin composites and bulk–fill composites, as well as to determine their fracture lifetimes by using the three-dimensional finite element stress analysis method. Materials and Methods: an extracted sound number 26 tooth was scanned with a dental tomography device and recorded. Images were obtained as dicom files, and these files were transferred to the Mimics 12.00 program. In this program, different masks were created for each tooth tissue, and the density thresholds were adjusted manually to create a three-dimensional image of the tooth, and these were converted to a STL file. The obtained STL files were transferred to the Geomagic Design X program, and some necessary adjustments, such as smoothing, were made, and STP files were created. Cavity preparation and adhesive material layers were created by transferring STP files to the Solidworks program. Finally, a FE model was created in the ABAQUS program, and stress distributions were analyzed. Results: when the bulk–fill composite and conventional resin composite materials were used in the restoration of the cavity, the structures that were exposed to the most stress as a result of occlusal forces on the tooth were enamel, dentin, restorative material, and adhesive material. When the bulk–fill composite material was used in restoration, while the restorative material had the longest fracture life as a result of stresses, the enamel tissue had the shortest fracture life. When the conventional resin composite material was used as the restorative material, it had the longest fracture life, followed by dentin and enamel. Conclusion: when the bulk–fill composite material was used instead of the conventional resin composite material in the cavity, the stress values on enamel, dentin, and adhesive material increased as a result of occlusal forces, while the amount of stress on the restorative material decreased. In the fracture analysis, when the bulk–fill composite material was used instead of the conventional resin composite material, a decrease in the number of cycles required for the fracture of enamel, dentin, and restorative materials was observed as a result of the forces generated in the oral cavity.
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Li, Xiaoming, Wei Liu, Lianwen Sun, Katerina E. Aifantis, Bo Yu, Yubo Fan, Qingling Feng, Fuzhai Cui i Fumio Watari. "Resin Composites Reinforced by Nanoscaled Fibers or Tubes for Dental Regeneration". BioMed Research International 2014 (2014): 1–13. http://dx.doi.org/10.1155/2014/542958.
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It has been stated clearly that nanofillers could make an enhancement on the mechanical performances of dental composites. In order to address current shortage of traditional dental composites, fillers in forms of nanofibers or nanotubes are broadly regarded as ideal candidates to greatly increase mechanical performances of dental composites with low content of fillers. In this review, the efforts using nanofibers and nanotubes to reinforce mechanical performances of dental composites, including polymeric nanofibers, metallic nanofibers or nanotubes, and inorganic nanofibers or nanotubes, as well as their researches related, are demonstrated in sequence. The first purpose of current paper was to confirm the enhancement of nanofibers or nanotubes’ reinforcement on the mechanical performances of dental restorative composite. The second purpose was to make a general description about the reinforcement mechanism of nanofibers and nanotubes, especially, the impact of formation of interphase boundary interaction and nanofibers themselves on the advanced mechanical behaviors of the dental composites. By means of the formation of interface interaction and poststretching nanofibers, reinforced effect of dental composites by sorts of nanofibers/nanotubes has been successfully obtained.
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FURUKAWA, Taichi, Kazuo ARAKAWA, Yasuyuki MORITA i Masakazu UCHINO. "A101 Shrinkage analysis of Dental Restorative Resin Composites". Proceedings of the JSME Conference on Frontiers in Bioengineering 2007.18 (2007): 1–2. http://dx.doi.org/10.1299/jsmebiofro.2007.18.1.
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NAKAJIMA, Shinya, Noboru YAMAZAKI, Kimio KURITA i Eiichi WADA. "Elasticity of dental restorative composites containing whisker particles." KOBUNSHI RONBUNSHU 45, nr 5 (1988): 423–26. http://dx.doi.org/10.1295/koron.45.423.
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Boulden, Jordan E., Neil B. Cramer, Kathleen M. Schreck, Charles L. Couch, Cora Bracho-Troconis, Jeffrey W. Stansbury i Christopher N. Bowman. "Thiol–ene–methacrylate composites as dental restorative materials". Dental Materials 27, nr 3 (marzec 2011): 267–72. http://dx.doi.org/10.1016/j.dental.2010.11.001.
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LASSILA, Lippo, Filip KEULEMANS, Pekka K. VALLITTU i Sufyan GAROUSHI. "Characterization of restorative short-fiber reinforced dental composites". Dental Materials Journal 39, nr 6 (27.11.2020): 992–99. http://dx.doi.org/10.4012/dmj.2019-088.
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Pal, S. N., R. Vowles i D. F. Williams. "Curing of visible light-activated dental restorative composites". Bulletin of Materials Science 14, nr 1 (luty 1991): 77–85. http://dx.doi.org/10.1007/bf02745092.
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Poggio, Claudio, Carla R. Arciola, Federico Rosti, Andrea Scribante, Enrica Saino i Livia Visai. "Adhesion of Streptococcus Mutans to Different Restorative Materials". International Journal of Artificial Organs 32, nr 9 (wrzesień 2009): 671–77. http://dx.doi.org/10.1177/039139880903200917.
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Adherence of oral bacteria to the surface of dental restorative materials is considered an important step in the development of secondary caries and periodontal disease. The aim of this study was to investigate and compare the adherence of different restorative materials to Streptococcus mutans strain (CCUG35176) in order to ascertain possible differences. The materials tested ranged across different classes including: flowable composites (Gradia Direct LoFlo; Filtek Supreme XT Flowable), anterior composites (Gradia Direct Anterior), universal composites (Filtek Supreme XT), packable composites (Filtek Silorane; Filtek P60), glass-ionomers (Fuji IX Gp Extra; Equia) and a control reference material (Thermanox plastic coverlips). Bacterial suspension was deposited onto each material and the adhesion was evaluated trough the colony forming units (CFUs) determination. Packable silorane-based composite was found to be less adhesive than posterior packable composite P60, flowable composites and glass ionomers. The fluoride of glass ionomers did not prevent the attachment of S. mutans; furthermore, after roughness analysis and SEM investigations, the hypothesis that the difference in bacterial adhesion can be determined by the particular surface chemistry of the material itself as well as by different electrostatic forces between bacteria and restorative surfaces must be given serious consideration.
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Ikeda, Hiroshi, Yohei Kawajiri, Minako Kibune Sodeyama, Haruka Takesue Yano, Yuki Nagamatsu, Chihiro Masaki, Ryuji Hosokawa i Hiroshi Shimizu. "A SiO2/pHEMA-Based Polymer-Infiltrated Ceramic Network Composite for Dental Restorative Materials". Journal of Composites Science 6, nr 1 (5.01.2022): 17. http://dx.doi.org/10.3390/jcs6010017.
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SiO2-poly(2-hydroxyethyl methacrylate) (pHEMA)-based composites have been widely used as biomaterials owing to their biocompatibility. However, they have not yet been applied as tooth restorative materials because of their poor mechanical properties. In the present paper, we develop a novel SiO2/pHEMA-based composite with a polymer-infiltrated network (PICN) structure for use in dental restorative materials. A mixture of SiO2 nanoparticles and a poly(vinyl alcohol) binder was sintered at 950 °C to fabricate a porous SiO2 block. A monomer mixture containing 70 wt%-HEMA/30 wt%-ethylene glycol dimethacrylate and a benzoyl peroxide initiator was infiltrated into the porous SiO2 block and heat-polymerized to fabricate the SiO2/pHEMA-based composite with a PICN structure. The composite was characterized according to its mechanical properties, surface free energy, and bonding properties with a dental adhesive. The flexural strength was 112.5 ± 18.7 MPa, the flexural modulus was 13.6 ± 3.4 GPa, and the Vickers hardness was 168.2 ± 16.1, which are similar values to human teeth. The surface free energy of the polar component of the composite was 19.6 ± 2.5 mN/m, suggesting that this composite has an active surface for bonding with the adhesive. The composite bonded well to the adhesive, in the presence of a silane coupling agent. The SiO2/pHEMA-based composite was demonstrated to be a potential candidate for dental restorative materials.
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Ilie, N., i G. Furtos. "A Comparative Study of Light Transmission by Various Dental Restorative Materials and the Tooth Structure". Operative Dentistry 45, nr 4 (13.02.2019): 442–52. http://dx.doi.org/10.2341/19-037-l.
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Clinical Relevance Light transmission through dental materials and tooth structure has direct clinical implication on such factors as selecting an appropriate curing technique during a restorative process. SUMMARY Introduction: This study aims to quantify and compare the amount of light that passes through seven different types of direct and indirect restorative materials comprising light-cured resin based composites (regular and bulk-fill), computer-aided design/computer-aided manufacturing (CAD/CAM) restoratives such as resin based composites, poly(methyl methacrylate) (PMMA) resin, leucite glass-ceramic, lithium silicate glass-ceramic, feldspar ceramic, and the natural tooth structure. Methods and Materials: Individual sets (n=6) of plane-parallel test specimens (2 mm) of 32 restorative materials belonging to the aforementioned seven material types and the tooth structure were prepared. Within the analyzed materials, one leucite glass-ceramic and one lithium disilicate glass-ceramic were considered in two different translucencies. In addition, two light-cured resin composites, one CAD/CAM resin composite, and one lithium disilicate glass-ceramic were considered in two different shades. Optical properties (transmittance, T; absorbance, A; and opacity, O) of each material were calculated from the relationship between incident and transmitted irradiance [I(d)] using a violet-blue light-curing unit. Incident and transmitted irradiance were assessed in real time on a spectrophotometer. A multivariate analysis (general linear model) assessed the effects of various parameters on the optical properties. Results: A very strong influence of the parameter material was identified on I(d) (p<0.001; partial eta squared, ηP2=0.953), T (p<0.001; ηP2=0.951), A (p<0.001; ηP2=0.925), and O (p<0.001; ηP2=0.886), while the effect of the parameter material type was not significant (p=0.079, p=0.05, p=0.05, and p=0.051, respectively). Light attenuation differed significantly by material within each shade category and by shade category within the analyzed material. Conclusions: Attenuation of light through restorative materials and tooth structure is high (59.9% to 94.9%); thus, deficits in polymerization are difficult to compensate for by additional light exposure at the end of the restorative process.
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Shanitha Salim i Gautam Ranjit. "Recent advances in newer generation composites: An overview". World Journal of Advanced Research and Reviews 14, nr 2 (30.05.2022): 100–103. http://dx.doi.org/10.30574/wjarr.2022.14.2.0403.
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Composite restorative materials represent a class of unique modern biomaterials since they replace biological tissue in both appearance and function. The early formulations were characterized by problems such as polymerization shrinkage, improper marginal adaptation, inappropriate proximal contact, discoloration or staining and also secondary caries. The need to improve said properties and achieve adequate contact is necessary for dental composites and numerous attempts have been made to accomplish these aims. Newer generation composites have been produced in order to protect the healthy tooth structure, to reduce microleakage and secondary caries formation, increase fracture toughness and to reduce marginal pigmentation and postoperative sensitivity together with developments in technology. This article discusses the advances in resin restorative materials.
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AL-Rawas, Matheel, Yanti Johari, Nazrul M. Yusoff, Dasmawati Mohamad i Adam Husein. "The versatility of flowable composites. Part 2: clinical uses". Dental Update 49, nr 8 (2.09.2022): 633–36. http://dx.doi.org/10.12968/denu.2022.49.8.633.
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Flowable composite (FC) is a type of tooth-coloured restorative material with a lower viscosity compared to other types of resin composites. FC is considered as a versatile dental material, with a wide range of application. FCs have progressively gained importance in clinical dentistry. The increase in consumer demand has resulted in a gradual upsurge of dental professionals relying on composites in injectable form. Scientific and technological improvements in their properties and handling characteristics have not only seen FCs grow in popularity, but resulted in the development of different generations and types of dental FCs suitable for use in all cavity types, lining, core build-ups, and most recently, bulk-fill flowable composites. CPD/Clinical Relevance: To provide clinicians with an overview of the indications and clinical applications of the conventional FCs.
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Kawajiri, Yohei, Hiroshi Ikeda, Yuki Nagamatsu, Chihiro Masaki, Ryuji Hosokawa i Hiroshi Shimizu. "PICN Nanocomposite as Dental CAD/CAM Block Comparable to Human Tooth in Terms of Hardness and Flexural Modulus". Materials 14, nr 5 (3.03.2021): 1182. http://dx.doi.org/10.3390/ma14051182.
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Polymer infiltrated ceramic network (PICN) composites are an increasingly popular dental restorative material that offer mechanical biocompatibility with human enamel. This study aimed to develop a novel PICN composite as a computer-aided design and computer-aided manufacturing (CAD/CAM) block for dental applications. Several PICN composites were prepared under varying conditions via the sintering of a green body prepared from a silica-containing precursor solution, followed by resin infiltration. The flexural strength of the PICN composite block (107.8–153.7 MPa) was similar to a commercial resin-based composite, while the Vickers hardness (204.8–299.2) and flexural modulus (13.0–22.2 GPa) were similar to human enamel and dentin, respectively. The shear bond strength and surface free energy of the composite were higher than those of the commercial resin composites. Scanning electron microscopy and energy dispersive X-ray spectroscopic analysis revealed that the microstructure of the composite consisted of a nanosized silica skeleton and infiltrated resin. The PICN nanocomposite block was successfully used to fabricate a dental crown and core via the CAD/CAM milling process.
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Attar, Nuray, i Alev Önen. "Artificial formed caries-like lesions around esthetic restorative materials". Journal of Clinical Pediatric Dentistry 26, nr 3 (1.04.2002): 289–96. http://dx.doi.org/10.17796/jcpd.26.3.aun5413hm163g344.
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Dental restorations fail for a variety of reasons. Secondary caries is one of the primary causes of failure of dental restorations. One method for reducing frequency and severity of this problem is the use of fluoride containing restorative materials. The ability of a material to inhibit secondary caries formation is an important clinical therapeutic property. This investigation assessed the capacity of esthetic restorative materials to resist caries in vitro. Class V cavities were prepared in buccal and lingual surfaces of 50 extracted sound third molars. The occlusal and gingival cavosurface margin of each preparation was on enamel surface. The five materials were used: Conventional glass ionomer cement Ceramfil ß (PSP), two polyacid modified resin composites Compoglass (Vivadent) and Dyract (Dentsply/DeTrey), non fluoride releasing composite resin Valux Plus (3M) and fluoride releasing composite resin Tetric (Vivadent). After 10 weeks in an acid gel for caries-like lesion formation, the teeth were sectioned occluso-gingivally through the middle of the restorations and examined by polarized light microscopy, while immersed in water. The statistical analysis of the results showed that secondary caries initiation and progression might be reduced significantly when fluoride-containing materials were placed. The conventional glass ionomer cement (Ceramfil ß) provided the highest protection against caries attack and the non-fluoride releasing composite resin (Valux Plus) restoration provided the least (p<0.05).
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Suryawanshi, Abhijeet S., i Niranjana Behera. "Tribological behavior of dental restorative composites in chewable tobacco environment". Proceedings of the Institution of Mechanical Engineers, Part H: Journal of Engineering in Medicine 234, nr 10 (9.07.2020): 1106–12. http://dx.doi.org/10.1177/0954411920940829.
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This study investigates the effect of smokeless tobacco on the tribological properties of two commercially used dental composite materials: Tetric N-Ceram and Z350 Dentin shade. It is to evaluate the effect of smokeless tobacco on the wear properties of two dental composite materials after some stipulated period. The wear test was conducted on pin-on-disk tribometer in the presence of artificial saliva under different loading conditions of 10, 15 and 20 N. The pins of the dental composite material were immersed in tobacco solution. The tribological behavior was studied after 2 days, 3.5 days, 6 days, 15 days and 1 month which represented the real conditions for the contact of 1 week, 2 weeks, 1 month, 2 months and 5 months, respectively, between the dental material and the tobacco solution. Under different loading conditions, Z350 Dentin material exhibited much less wear than the Tetric N-Ceram material in the presence of synthetic saliva for the specimen with or without tobacco immersion. The microstructure of the pin surface was inspected using scanning electron microscopy.
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Gan, Xue-qi, Zhen-bing Cai, Bao-rong Zhang, Xue-dong Zhou i Hai-yang Yu. "Friction and Wear Behaviors of Indirect Dental Restorative Composites". Tribology Letters 46, nr 1 (10.02.2012): 75–86. http://dx.doi.org/10.1007/s11249-012-9921-z.
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Damasceno, Janaina Emanuela, Priscila Matos Pedreira, Thiago Ozi Bueno, Mariana Valerio Pallone, Thais Escobar Fava i Giselle Maria Marchi. "Conservative Esthetic Approach of Anterior Teeth Using Minimal Intervention and Preservation of all Sound Tooth Tissue: a Case Report". Journal of Health Sciences 21, nr 5 (20.12.2019): 489–93. http://dx.doi.org/10.17921/2447-8938.2019v21n5p489-493.
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AbstractThis clinical case report describes a conservative approach to a smile harmony rehabilitation performing a gingivoplasty, dental bleaching and resin-based composites to finalize the case. This clinical article describes the case report of a patient in need of an esthetic and corrective solution for the anterior teeth, which presented a disharmonic smile, in its shape and color, besides the gingival smile. As a result, gingivoplasty, dental bleaching and restoration with composite resin were done. Gingivoplasty with bone preservation was possible because there was a large volume of soft tissue, and a distance ≥ 2 mm from the bone crest to the junction cementum enamel was confirmed. Bleaching was performed with the use of associated techniques: office (Whiteness HP 35%) and supervised at-home (Whiteness Perfect 10%) bleaching were performed, and then the "buccolingual technique" using a nanocomposite resin IPS was used from a diagnostic wax-up to perform the restorative procedure for the anterior teeth. The use of minimally invasive techniques is an effective alternative for the anterior teeth rehabilitation. As in this case, the gingivoplasty, dental bleaching with associated techniques, and restorations with nanocomposites allowed satisfactory esthetic results, even more so in relation to dental preservation, mainly in young patients. Keywords: Tooth Bleaching. Gingivoplasty. Esthetic. Dental RestorationAbstractThis clinical case report describes a conservative approach to a smile harmony rehabilitation performing a gingivoplasty, dental bleaching and resin-based composites to finalize the case. This clinical article describes the case report of a patient in need of an esthetic and corrective solution for the anterior teeth, which presented a disharmonic smile, in its shape and color, besides the gingival smile. As a result, gingivoplasty, dental bleaching and restoration with composite resin were done. Gingivoplasty with bone preservation was possible because there was a large volume of soft tissue, and a distance ≥ 2 mm from the bone crest to the junction cementum enamel was confirmed. Bleaching was performed with the use of associated techniques: office (Whiteness HP 35%) and supervised at-home (Whiteness Perfect 10%) bleaching were performed, and then the "buccolingual technique" using a nanocomposite resin IPS was used from a diagnostic wax-up to perform the restorative procedure for the anterior teeth. The use of minimally invasive techniques is an effective alternative for the anterior teeth rehabilitation. As in this case, the gingivoplasty, dental bleaching with associated techniques, and restorations with nanocomposites allowed satisfactory esthetic results, even more so in relation to dental preservation, mainly in young patients. Keywords: Tooth Bleaching. Gingivoplasty. Esthetic. Dental Restoration
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Topcu, Fulya Toksoy, Gunes Sahinkesen, Kivanc Yamanel, Ugur Erdemir, Elif Aybala Oktay i Seyda Ersahan. "Influence of Different Drinks on the Colour Stability of Dental Resin Composites". European Journal of Dentistry 03, nr 01 (styczeń 2009): 50–56. http://dx.doi.org/10.1055/s-0039-1697405.
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ABSTRACTObjectives: The objective of this study was to evaluate the discolouration effects of artificial saliva, granule lemon juice, coffee (without sugar), coca cola, sour cherry juice, fresh carrot juice and red wine on resin-based composite materials that are commonly used in restorative dentistry.Methods: Colour of four brands of resin composites (Filtek Z 250 (3M Espe), Filtek Supreme (3M Espe), Quadrant (Cavex), Charisma (Heraeus-Kulzer)) of A2 shade was measured after one day of immersion in eight different solutions. Colour measurements were obtained by using a XL-20 Trismus Colourimeter and colour differences (�E) were estimated. For statistical evaluation, analysis of variance (ANOVA), Dunnett and Tukey tests were used at a significance level of 0.05.Results: For the four restorative materials tested, the lowest ΔE values were observed in the artificial saliva, while ΔE values were the highest in red wine group. When comparing the four different restorative materials, Filtek Supreme exhibited the least colour changes whereas Filtek Z250 was the least colour-stable.Conclusions: Dental resin composites and drinking solutions were significant factors that may affect the colour stability. After immersion for one day, all materials showed visible colour changes. The red wine solution exhibited more staining than others in three groups. Filtek Supreme showed significantly the least colour change due to its nano particle sizes. (Eur J Dent 2009;3:50-56)
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Ruyter, I. E. "Composites - Characterization of Composite Filling Materials: Reactor Response". Advances in Dental Research 2, nr 1 (sierpień 1988): 122–33. http://dx.doi.org/10.1177/08959374880020010401.
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Dental composite restorative materials consist of an organic matrix, ceramic fillers, and the interface between the inorganic fillers and the matrix. Marked variations in the composition of the composite materials, as well as different degrees of conversion after polymerization, have been observed. These circumstances lead to substantial differences in the properties of polymerized composite materials. The variations in clinical behavior of the different composite materials, e.g., discoloration or lack of wear resistance, may be explained on the basis of differences in composition. This review paper describes the composition, conversion, and properties of presently available composite materials.
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Dodo, R. M., Z. Musa, M. Abdulwahab, K. A. Bello, U. Abdullahi i A. Hamisu. "WEAR AND BIOCOMPATIBILITY PROPERTIES OF POLYPROPYLENE/PERIWINKLE SHELL PARTICULATES COMPOSITES FOR DENTAL IMPLANT APPLICATION". FUDMA JOURNAL OF SCIENCES 6, nr 5 (2.11.2022): 32–35. http://dx.doi.org/10.33003/fjs-2022-0605-1073.
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The present study explored wear and biocompatibility characteristics of polypropylene (PP)/ periwinkle shell particulates (PWS) composites for dental implant application. Wet-sliding the stainless steel ball against specimen disc revealed the abrasive wear behaviour of the composites under load and linear speed of 5 N and 10 cm/s respectively. In the wear tests, the specimens were wetted with simulated human saliva with and without sodium fluoride (NaF) additive. On the other hand, a mouse specimen was used to carry out a biocompatibility test. The composite demonstrated superb wear resistance at 40 and 50wt% reinforcement loading. Further, results showed that wear rate decreased considerably with increasing PWS content. Higher wear rate was noted on composites under condition of simulated human saliva with NaF addition. The biocompatibility test reveals that developed composite is harmless to the living tissues. Thus, PP/PWS composites could be recommended to be used as dental restorative material
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S, Madhumita, Dhanavel Chakravarthy i Viajayaraja S. "Evaluation of physico -mechanical properties of graphene nanoparticles modified nano hybrid composite resin after thermo mechanical loading cycle - An in vitro study". IP Indian Journal of Conservative and Endodontics 7, nr 2 (15.06.2022): 61–66. http://dx.doi.org/10.18231/j.ijce.2022.013.
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Composite restorative material is one of the most accomplished contemporary biomaterials because of its high aesthetic potential with satisfactory clinical durability. Although composites are favourable restorative material their polymerization shrinkage still remains a challenge. Recently, Science of Nanotechnology has invaded into the field of Dentistry in an attempt to offset the existing shortcomings of traditional dental composites and substantially improving its properties by adding nano sized filler particles like Silver, Titanium Dioxide, Zirconia and Silicone. Graphene Nanoparticles (GNP) are novel fillers that possess a high fracture strength, mechanical strength, chemical stability, flexibility, they are also biocompatible and non-cytotoxic. The objective of this study is to evaluate the Surface roughness, Microhardness and Flexural strength of Nano hybrid composite resin modified with Graphene nanoparticles after subjecting the specimens to Thermo Mechanical cyclic loading.
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Świderska, Jolanta, Zbigniew Czech, Waldemar Świderski i Agnieszka Kowalczyk. "Reducing of on Polymerization Shrinkage by Application of UV Curable Dental Restorative Composites". Polish Journal of Chemical Technology 16, nr 3 (1.09.2014): 51–55. http://dx.doi.org/10.2478/pjct-2014-0050.
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Abstract This manuscript describes dental compositions contain in-organic fillers, multifunctional methacrylates and photoinitiators. The main problem by application and UV curing process is the shrinkage of photoreactive dental materials during and after UV curing process. Total shrinkage of UV curable dental composites is a phenomenon of polymerization shrinkage, typical behavior for multifunctional methacrylates during polymerization process. The important factors by curing of dental composites are: kind and concentration of used methacrylates, their functionality, double bond concentration, kind and concentration of added photoinitiator and UV dose. They are investigated UV-curable dental compositions based on 2,2-bis-[4-(2-hydroxy-3-methacryxloyloxypropyl)phenyl]propane (Bis-GMA) and containing such multifunctional monomers as 1,3-butanediol dimethacrylate (1,3-BDDMA), diethylene glycol dimethacrylate (DEGDMA), tetraethylene glycol dimethacrylate (T3EGDMA), trimethylolpropane trimethacrylate (TMPTMA), polyethylene glycol 200 dimethacrylate (PEG200DA). Reduction of polymerization shrinkage of dental compositions is at the moment a major problem by dental technology.
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Bergenholtz, G. "Evidence for Bacterial Causation of Adverse Pulpal Responses in Resin-Based Dental Restorations". Critical Reviews in Oral Biology & Medicine 11, nr 4 (październik 2000): 467–80. http://dx.doi.org/10.1177/10454411000110040501.
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The widespread use of resin and resin-monomers for bonding of dental restorations to dentin has occurred because of a fundamental shift in the view that injury to the pulp is induced by restorative procedures. While, for many years, the toxic effects of restorative materials were thought to be of crucial importance in the development of adverse pulpal responses the key role of bacterial leakage at the restoration-tooth interface is now well-recognized. Consequently, if optimal conditions for the preservation of pulpal health are to be ensured, dental restorations should provide an impervious seal against the surrounding tooth structure. However, polymerization shrinkage and contraction stresses induced during setting, as well as a variety of technical difficulties encountered during the clinical operation, often produce less than perfect results. Therefore, modern restorative procedures involving resin and resin-bonded restoratives must still rely on the ability of the pulp to cope with the injurious elements to which it may be exposed during and after the procedure. This review examines factors that may govern the pulp's response to restorative procedures that involve adhesive technologies. An assessment is made of the risks involved as far as the continued vital function of the pulp is concerned. It is concluded that an intact, although thin, wall of primary dentin often enables the pulp to overcome both toxic material effects and the influences of bacterial leakage. In contrast, the pulp may not do equally well following capping of open exposures with resin composites. A dearth of controlled clinical studies in this area of dentistry calls for confirmation that pulpal health prevails over the long term following the use of total-etch and resin-bonding techniques.
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Wen, Xin, Rashed Almousa, Gregory G. Anderson i Dong Xie. "Developing a novel antibacterial dental resin composite with improved properties". Journal of Composite Materials 53, nr 22 (2.04.2019): 3085–92. http://dx.doi.org/10.1177/0021998319839134.
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A novel antibacterial resin composite has been developed and evaluated. Glycerol dimethacrylate was derivatized to have an antibacterial moiety attached and incorporated to a conventional resin composite formulation. Compressive strength and bacterial viability were used to evaluate the modified resin composites. Results showed that the modified resin composites showed a significantly enhanced antibacterial activity along with improved mechanical and physical properties. It was found that bromine-containing resin composite showed a higher antibacterial activity than its chlorine-containing counterpart. The modified resin composites showed an increase of 37–41% in yield strength, 23–27% in modulus, 9–15% in diametral tensile strength and 5–12% in flexural strength and a decrease of 35–69% in bacterial viability, 20–37% in water sorption, 7–12% in shrinkage and 7–10% in compressive strength, as compared to unmodified resin composite. Within the limitations of this study, the modified resin composite may potentially be developed into a clinically useful dental restorative since it demonstrated good mechanical strengths and potent antibacterial function.
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Czech, Zbigniew, Janina Kabatc, Marcin Bartkowiak, Karolina Mozelewska i Dominika Kwiatkowska. "Influence of an Alkoxylation Grade of Acrylates on Shrinkage of UV-Curable Compositions". Polymers 12, nr 11 (6.11.2020): 2617. http://dx.doi.org/10.3390/polym12112617.
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Commercially available UV curable restorative materials are composed of inorganic filler hydroxyapatite, multifunctional methacrylate, photoinitiator and alkoxylated acrylate. Especially, the application of alkoxylated monomers with different alkoxylation grade allows the reduction of polymerization shrinkage which plays the major role by application of low shrinkage composites as high quality restorative dental materials or other adhesive materials in the form of UV-polymerized self-adhesive acrylics layers (films). There are several ways to reduce polymerization shrinkage of restorative compositions, for example, by adjusting different alkoxylated acrylic monomers, which are integral part of investigated UV curable restorative composites. This article is focused on the studies of contraction-stress measured as shrinkage during UV-initiated curing of restorative composites containing various commercially available alkoxylated acrylates. Moreover, studies with experimental restorative materials and recent developments typical for UV curing technology using special photoreactive monomers are described.
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Van der Laan, H. L., S. L. Zajdowicz, K. Kuroda, B. J. Bielajew, T. A. Davidson, J. Gardinier, D. H. Kohn i in. "Biological and Mechanical Evaluation of Novel Prototype Dental Composites". Journal of Dental Research 98, nr 1 (6.09.2018): 91–97. http://dx.doi.org/10.1177/0022034518795673.
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The breakdown of the polymeric component of contemporary composite dental restorative materials compromises their longevity, while leachable compounds from these materials have cellular consequences. Thus, a new generation of composite materials needed to be designed to have a longer service life and ensure that any leachable compounds are not harmful to appropriate cell lines. To accomplish this, we have developed concurrent thiol-ene-based polymerization and allyl sulfide–based addition-fragmentation chain transfer chemistries to afford cross-linked polymeric resins that demonstrate low shrinkage and low shrinkage stress. In the past, the filler used in dental composites mainly consisted of glass, which is biologically inert. In several of our prototype composites, we introduced fluorapatite (FA) crystals, which resemble enamel crystals and are bioactive. These novel prototype composites were benchmarked against similarly filled methacrylate-based bisphenol A diglycidyl ether dimethacrylate / triethylene glycol dimethacrylate (bisGMA/TEGDMA) composite for their cytotoxicity, mechanical properties, biofilm formation, and fluoride release. The leachables at pH 7 from all the composites were nontoxic to dental pulp stem cells. There was a trend toward an increase in total toughness of the glass-only-filled prototype composites as compared with the similarly filled bisGMA/TEGDMA composite. Other mechanical properties of the glass-only-filled prototype composites were comparable to the similarly filled bisGMA/TEGDMA composite. Incorporation of the FA reduced the mechanical properties of the prototype and bisGMA/TEGDMA composite. Biofilm mass and colony-forming units per milliliter were reduced on the glass-only-filled prototype composites as compared with the glass-only-filled bisGMA/TEGDMA composite and were significantly reduced by the addition of FA to all composites. Fluoride release at pH 7 was greatest after 24 h for the bisGMA/TEGDMA glass + FA composite as compared with the similarly filled prototypes, but overall the F- release was marginal and not at a concentration to affect bacterial metabolism.
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Cândea, Andreea, Daniela Condor, Alexandra Roman, Cristina Micu i Andrada Şoancă. "Posterior composites – a challenge for practitioners". Romanian Journal of Stomatology 63, nr 1 (31.03.2017): 16–23. http://dx.doi.org/10.37897/rjs.2017.1.3.
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Presently, at least half of posterior direct restorations rely on resin composite materials. The resin composite market is highly competitive between manufacturers providing practitioners with a vast choice from an array of similar product types. The aim of the present article is to provide practitioners an updated view on the resin composites presently available, which could represent the theoretical basis for choosing this material type for different clinical purposes mainly focused on restoring posterior teeth. A significant progress in the composition of resin composites is represented by the improvement of the filler system in order to enhance mechanical properties and remineralizing potential, as well as to provide a cariostatic or anti-bacterial effects. Some clinical factors play an important role in restoration longevity and causes of failure such as: the tooth type, the number of restored teeth per patient, the type of the substrate on which the composite is placed, some demographic, socioeconomic and behavioural variables of the patient. It is generally acknowledged that the operator ability is probably the most important factor in the longevity of a dental restoration. Placement of direct composite restorations (mostly in class II cavities) on posterior teeth rests a highly demanding restorative procedure. Technique-related aspects of posterior restorations rely on the knowledge and sufficient skills of the operator.
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Naeimi Akbar, Homan, Keyvan Moharamzadeh, Duncan J. Wood i Richard Van Noort. "Relationship between Color and Translucency of Multishaded Dental Composite Resins". International Journal of Dentistry 2012 (2012): 1–5. http://dx.doi.org/10.1155/2012/708032.
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The aim of the present study was to compare the translucency of different shades of two highly aesthetic multilayered restorative composite resins. In total nine shades from Esthet.X and ten shades from Filtek Supreme composite resins were chosen. Discs of each shade were prepared (N=3) and light-cured. Total and diffuse transmittance values for each sample were measured. Statistical analysis showed that the opaque dentine shades of both composites were the least translucent and the enamel shades had the highest translucency. There was a significant decrease in translucency from A2 to C2 of regular body shades and also from A4 to C4 of opaque dentine shades of Esthet.X composite resin. Grey enamel shade had a significantly higher diffuse translucency compared to clear and yellow enamel shades. There was a significant decrease in translucency from A2B to D2B and also in diffuse translucency from A4D to C6D shades of Filtek Supreme composite resin. It can be concluded that the color of the composite resins tested in this study had a significant effect on their translucency. Information on the translucency of different shades of composite resins can be very useful for the clinicians in achieving optimal esthetic restorative outcome.
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Adilson Yoshio Furuse, Fabio Antonio Piola Rizzante, Rafael Francisco Lia Mondelli i Juliana Fraga Soares Bombonatti. "A simplified restorative technique of fractured maxillary anterior teeth". RSBO 13, nr 1 (25.03.2016): 60–06. http://dx.doi.org/10.21726/rsbo.v13i1.687.
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Fractures of the anterior teeth consists of a clinical condition that generates not only aesthetic and psychological problems, but may also cause dental pain. Thus, the affected teeth should be treated as urgencies in dental offices and their resolution whenever possible should be in a single session. Direct resin composite restorations should wherever possible be preferred due to the speed and possibility of obtaining good results. Objective: The objective of this case report is to describe the clinical sequence for restoration of a maxillary central incisor that presented a crown fracture using an immediate insert technique for resin composite (a "free hand" technique) with a modification to obtain dentin layer. Case report: A patient sought treatment after she fractured tooth #21. The restoration was performed with resin composite using the immediate technique. To facilitate the layering technique, the immediate insertion technique was changed for making the dentin lobes with the aid of a Teflon tape and the support with the index finger. Conclusion: The restoration of fractured anterior teeth can be performed quickly with the use of resin composites of different opacities and the use of the technique of immediate insertion proposed in this case report.
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Adeeb, Saja, Sanadra Adeeb i G. Chladek. "Influence of blenching agents on the mechanical properties and colour of dental restorative nanocomposite". Archives of Materials Science and Engineering 111, nr 2 (1.10.2021): 78–85. http://dx.doi.org/10.5604/01.3001.0015.5807.
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Purpose: Bleaching agents are commonly used to make the natural dentition look more attractive. Currently, in addition to products from reputable manufacturers, products of not fully known origin are available for purchase. The aim of the study was to investigate whether products of this type have a destructive influence on the mechanical and aesthetic properties of the dental restorative nanocomposite. Design/methodology/approach: Four bleaching agents were used, two recognized brands, and two products were purchased from Chinese websites (their manufacturer is unknown). Two gels and two types of whitening strips were used. One composite nanomaterial was used. Microhardness, diametral tensile strength,, compressive strength and colour measurements were tested. Findings: For some bleaching agents, studies have shown a relatively small effect on mechanical properties and an acceptable effect on colour changes. Regardless of the observed changes, the use of bleaching agents qualified for the experiment should be considered safe for composites. Research limitations/implications: The number of blenching agents used as well as dental composites in this study was limited. In future studies, increasing the number of cycles in the bleaching process should be considered. Practical implications: A popular method of improving the aesthetic properties of teeth is the use of a wide range of blenching agents. Most patients who use teeth whitening procedures are also users of composite fillings. The use of bleaching agents may have a different effect on the mechanical and aesthetic restorative composites. For economic reasons, many people decide to import cheap bleaching agents of unknown or dubious origin via Internet services to perform the bleaching process on their own. In this study, it was investigated whether products of this type have an influence on the mechanical and aesthetic properties of the dental restorative nanocomposite. Originality/value: Until now, no comparison of the safety of the use of bleaching agents of recognized manufacturers and of unknown origin in terms of the effect on composite materials has been presented, despite their high social importance.
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Yadav, Sukriti, i Swati Gangwar. "Long-term solubility and sorption characteristics of novel dental restoratives". International Journal of Engineering, Science and Technology 13, nr 1 (8.07.2021): 17–24. http://dx.doi.org/10.4314/ijest.v13i1.3s.
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Sorption and solubility are the unfavorable conditions for the dental restorative composites (DRCs). It can be precursor of various physical and chemical phenomenon that may lead to structural deterioration and minimizes the endurance of restorations. This study sought to evaluate the sorption and solubility features of MPTS (M)/APTES(A) treated n-HAPs filled dental composite in distilled water and artificial saliva medium. In this experiment, 7 different compositions of disc-shaped specimens of Φ15mm×1mm (n=3) of dental composites were prepared and tested under distilled water and artificial saliva medium for 35 days according to ISO 4049 method. The dental material shows relatively higher sorption and solubility in the artificial saliva medium as compared to distilled water. However, at higher wt.% (DRCs-12M & DRCs-12A), it shows minimum solubility (i.e.) and sorption characteristics. The results indicate that there was significant variation regarding storage medium and time to saturation but still these values are within the limit of the ISO 4049 standards, which is 40 μg/mm3 for sorption and 5μg/mm3 for Solubility.
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Ciocan, Lucian Toma, Elena Iuliana Biru, Vlad Gabriel Vasilescu, Jana Ghitman, Ana-Roxana Stefan, Horia Iovu i Roxana Ilici. "Influence of Air-Barrier and Curing Light Distance on Conversion and Micro-Hardness of Dental Polymeric Materials". Polymers 14, nr 24 (7.12.2022): 5346. http://dx.doi.org/10.3390/polym14245346.
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This study aims to assess the conversion degree and hardness behavior of two new commercial dental restorative composites that have been submitted to light curing in different environments (air and glycerin, respectively) at various distances from the light source (1 to 5 mm) and to better understand the influence of the preparation conditions of the restorative materials. Through FT-IR spectrometry, the crosslinking degree of the commercial restorative materials have been investigated and different conversion values were obtained (from ~17% to ~90%) but more importantly, it was shown that the polymerization environment exhibits a significant influence on the crosslinking degree of the resin-based composites especially for obtaining degrees of higher polymerization. Additionally, the mechanical properties of the restorative materials were studied using the nanoindentation technique showing that the nano-hardness behavior is strongly influenced not only by the polymerization lamp position, but also by the chemical structure of the materials and polymerization conditions. Thus, the nanoindentation results showed that the highest nano-hardness values (~0.86 GPa) were obtained in the case of the flowable C3 composite that contains BisEMA and UDMA as a polymerizable organic matrix when crosslinked at 1 mm distance from the curing lamp using glycerin as an oxygen-inhibitor layer.
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ZHANG, Yu, Yinyan CHEN, Yuntong HU, Fang HUANG i Yuhong XIAO. "Quaternary ammonium compounds in dental restorative materials". Dental Materials Journal 37, nr 2 (2018): 183–91. http://dx.doi.org/10.4012/dmj.2017-096.
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