Nanocomposites-A review (original) (raw)
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Characterization of Nano- and Micro-Filled Resin Composites Used as Dental Restorative Materials
ASME 2008 2nd Multifunctional Nanocomposites and Nanomaterials, 2008
Adhesively-bonded resin composites have the advantage of conserving sound tooth structure with the potential for tooth reinforcement, while at the same time providing an aesthetically acceptable restoration. However, no composite material has been able to meet both the functional needs of posterior restorations and the superior aesthetics required for anterior restoration. In an attempt to develop a dental resin composite that had the mechanical strength of hybrid composite materials and the superior polish and gloss retention associated with microfilled materials, nanofilled resin composites have been introduced in the market. Although nanofillers are the most popular fillers utilized in current visible light-activated dental resin composites and are claimed to be the solution for the most challenging material limitations as a universal restorative material, the mechanisms by which these fillers influence the resin composite properties are not well explained. In this study, some physical and mechanical properties of a nanofilled resin composite containing 60 vol. % zirconia and silica fillers were evaluated and compared to those of a microhybrid resin composite of the same composition. The nanofilled resin composite was found to have equivalent polymerization shrinkage and depth of cure to the microhybrid material but a slightly lower degree of conversion and density. Regarding mechanical behaviour, although the nanocomposite was found to exhibit significantly higher wear resistance, and equivalent flexural strength, its indentation modulus and nanohardness were slightly lower. Field-emission scanning electron microscopy (FE-SEM) analysis was conducted in order to evaluate the microstructure and to obtain a better understanding of the effect of the nanofillers on the behaviour of the nanocomposite.
Nanocomposites for Restorative Dentistry
2007
In the present investigation a new method is described for modification of dental resins with reactive polymeric nanoparticles (RPNPs) as organofillers. Nanoparticles (NPs) as model compounds indicate clearly that the RPNPs significantly influence the mechanical and shrinkage properties of the matrix and composite. Nanoparticles were prepared by free radical non-linear copolymerization of a mixture of mono (styrene, ST) and bifunctional (ethylene glycol dimethacrylate, EGDM) comonomers in homogeneous solution. The EGDM monomer is a commonly used component of several dental filling composites. The size, reactivity and distribution of nanoparticles are influenced by the mole ratio of the monomers in the feed. Size of nanoparticles was determined by Scanning Electron Microscopy (SEM). Reactivity of nanoparticles was measured by Nuclear Magnetic Resonance (NMR).
Investigating Some Properties of Nanocomposites for Dental Restoration Materials
Journal of Applied Sciences and Nanotechnology, 2022
In this work, it was evaluated the wear resistance, hardness, and surface roughness values of resin-based composites that applied in dentistry as restorative materials. The resin composites were made from six types of resin matrixes (A, B, C, D, E, and F) and each one of them has contained different types and ratios of monomers as well as the inorganic nanofillers (SiO2, ZrO2, HA, and Al2O3). For each test, thirty specimens were prepared, which were classified into six groups depending on the types of the resin matrix and fillers used in the composites. The results prove that the nanocomposites that have the lowest rate of wear were the group E which was derived from the resin matrix of the group E that has monomers are (BIS-GMA, meth acrylamide, methacrylic acid, and 1-6 hexanediol methacrylate) with values range from 8.11 to 6.11 mm 3 /mm depending on the filler type material. All prepared composites resin materials (A to F) showed an increase in their hardness values as regards the reference, group D showed the highest hardness value followed by group B while group C was the lowest. The highest mean roughness was shown in groups A and F with 0.82 and 0.79 μm respectively, while the smoother surfaces among all groups were groups B and D which had significantly fewer roughness values of 0.16 and 0.19 μm respectively.
DENTAL RESIN-BASED COMPOSITES: A TRANSITION FROM MACROFILLED TO NANOFILLED
JPDA , 2012
The invention of dental resin based-composites (RBCs) has provided a broad range of materials for the restoration of load-bearing posterior teeth with excellent clinical results and adequate longevity. A variety of RBCs, namely “microhybrid”, “nanohybrid” and “nanofilled” have been marketed with bold claims of a technological advancement. Although “microhybrid”, “nanohybrid” and “nanofilled” RBCs have exhibited a degree of clinical and experimental success compared with their predecessors, however, it is difficult to justify which RBC is superior as a result of slight variations in filler size and associated interchangeable mechanical and physical properties of RBCs. The objective of the current review article is to highlight the development of various filler particles of dental RBCs and resultant variation in mechanical and physical properties which may ultimately provide directions for future research on the RBCs. KEYWORDS: Filler particles; Nanotechnology; Resin composites; Resin monomers How to cite this article:
Fabrication and Characterization of Experimental Nanocomposites for Dental Restoration
2013
s | Abstracts of theses approved for the MSc and PhD at the School of Dental Sciences www.mjms.usm.my 183 Conclusion: There is no significant association between LOH with gender, tumour stage and differentiation grades. However, there is a significant association between tumour stage and differentiation grades with MSI status in OSCC in Malaysian population with P values of 0.002 and 0.035. There is also a significant association between MA and differentiation grades with a P value of 0.041. Supervisor: Associate Professor Dr TP Kannan Co-supervisor: Associate Professor Dr Venkatesh R Naik
Operative Dentistry, 2013
Under clinical conditions, posterior direct nanofilled composites and indirect composite inlay systems have the potential to present a high success rate and were clinically satisfactory at five years postplacement. SUMMARY Aim: To assess the clinical efficacy of posterior composite resin restorations placed directly and indirectly in posterior teeth after five years. Materials and Methods: A total of 108 cavities in 54 patients were restored with three direct composite resins (Filtek SupremeXT [FSXT], Tetric Evo Ceram [TEC], AELITE Aesthetic [AA]) and two indirect composite resins (Estenia [E] and Tescera ATL [TATL]). All restorations were evaluated by two examiners using the United States Public Health Service criteria at baseline and five years after placement. Statistical analysis was completed with Fisher exact and McNemar v 2 tests. Results: At baseline, 4% (five) of the restored teeth presented postoperative sensitivity; however, only one of them (a member of the E group) required canal treatment and replacement after two years. At the five-year evaluation, all restorations were retained, with Alpha ratings at 100%. Only one tooth (in the TEC group) required replacement after three years due to secondary caries. Color match, surface texture, and marginal integrity were predominantly scored as Alpha after five years for all
Dental Materials Journal, 2009
The aim of this study was to assess the clinical performance of three direct composite resins and two indirect inlay systems in posterior teeth using the modified USPHS criteria. A total of 100 restorations were placed in the molars of 54 patients by one operator. All restorations were directly evaluated by two examiners at baseline, 6 months, and 12 months. Statistical analysis was conducted using McNemar chi-square test at a significance level of 5% (p<0.05). Recall rate was 100% at 6 and 12 months, and all the restorations evaluated (i.e., 100%) received Alpha rating for the criteria of retention and gingival adaptation. At 12 months for the surface texture criterion, 80% of Filtek Supreme XT received Alpha rating while it was 95% for Tetric EvoCeram and AELITE Aesthetic. For marginal discoloration, 85% of Tescera ATL and Filtek Supreme XT received Alpha rating while it was 95% for Tetric EvoCeram and AELITE Aesthetic. Further, none of the restorative systems received a Charlie rating for any of the criteria at all evaluation periods. In summary, all the restorations demonstrated clinically satisfactory performance with no significant differences detected among them.
Preparation and characterization of a nanostructured dental composite
Physica Status Solidi (a), 2008
One of the major objectives of dental medicine that should be mentioned is the use of increasingly powerful materials of coronary restoration, as regards to their biomechanical, biofunctional and bio-prophylactic characteristics. Nanotechnologies often provide the techniques used in the field of filler particles. Solutions to obtain a first generation of composite material with nanoparticles with dimensions between 5–75 nm have been successfully tested. It has been important to also obtain conglomerates with dimensions between 0.2–0.6 mm, that should be present. The present paper describes the preparation through sol–gel methods and aims to characterize ceramic nanoparticles used as filling inorganic materials for dental composites for esthetical restorations. We have obtained nanometric powders of silica and zirconia/silica. Thermal treatments were conducted at temperatures between 700 °C and 1200 °C for 2 hours. The powders had been analyzed as regards to their mineralogical composition, granulometric distribution and microstructure. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Yeditepe Dental Journal, 2016
This study evaluated the clinical performance of a nanofill resin composite in Class III and IV cavities. Materials and Methods: One hundred and seven Class III and Class IV restorations were performed with a nanofill resin composite. Restorations were evaluated using the modified USPHS/FDI criteria. The changes were analyzed using McNemar and Marginal Homogeneity and Kaplan-Meier tests. Results: Fourteen absolute failures were encountered resulting in a survival rate of 86.8% (Kaplan-Meier). Nanofill resin composite showed acceptable clinical performance up to 32 months of service. Conclusion: However color stability and retention decreased at the end of two year follow up instead of fractures.
Microleakage of Nanofilled Composite Resin Restorative Material
Journal of Biomaterials and Nanobiotechnology, 2011
The role of nanofillers in reducing the microleakage of dental composite resins has not been previously investigated. So this study was designed to evaluate microleakage of nanofilled composite resin in comparison to the conventional hybrid composite. Twenty extracted sound molars were selected. Class II cavities were prepared. All cavities were etched (enamel and dentin) with 37% phosphoric acid. Dentin bonding agents were applied to etched tooth surfaces and restored with nanofilled and hybrid composite restorative materials. The restored teeth were thermocycled. Specimens were immersed in 2% methylene blue dye, sectioned along the mesio-distal direction; dye penetration of occlusal and gingival margins of each section was evaluated using a stereo-microscope. No significant difference was found between the microleakage of nanofilled and hybrid composite restorations at occlusal/enamel and at gingival/dentin margins. Also, there were no significant differences for nanofilled composite restorations at occlusal/enamel margins and gingival/dentin margins. On the other hand, there were a significant differences for hybrid composite restorations at occlusal/enamel margins and gingival/dentin margins.