Static and dynamic mechanical behavior of microcapsule-reinforced dental composite

2017 ◽  
Vol 233 (6) ◽  
pp. 1184-1190 ◽  
Author(s):  
Akhil Sharma ◽  
Sajid Alam ◽  
Chetan Sharma ◽  
Amar Patnaik ◽  
Shiv Ranjan Kumar
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Storage Modulus ◽  
Loss Modulus ◽  
Triethylene Glycol ◽  
Dental Composite ◽  
Dental Composites ◽  
Resin Matrix ◽  
Cole Plot ◽  
Dynamic Mechanical

Resin-based dental composites were prepared by the addition of four different weight percentages (0–9 wt% microcapsules) of silane-treated microcapsules. The resin matrix was prepared by adding 50 wt% BisGMA, 48 wt% triethylene glycol dimethylacrylate, 0.4 wt% camphorquinone, and 1.6 wt% ethyl 4 dimethyl amino benzoate, respectively. In this study, the static mechanical properties in terms of micro-hardness, compressive strength, flexural strength, and dynamic mechanical analysis, in terms of storage modulus (E′), loss modulus (E″), and Tan delta (δ) as a function of temperature were evaluated systematically as per specific standards. The mechanical results indicated that the addition of 3 wt% of microcapsules increased both the hardness and flexural strength by 38% and 6%, respectively. On the other hand, addition of 3 wt% of microcapsules on the same resin based dental composite decreased the compressive strength by 35%. The dynamic mechanical results indicated that the storage modulus, loss modulus and glass transition temperatures was initially decreased with the addition of micro-capsules from 0 to 6 wt% and increased on further increase of microcapsules up to 9 wt%. Finally, Cole–Cole plot has been drawn for identification of the nature of the proposed dental composites.

Comparative investigation of physical, mechanical and thermomechanical characterization of dental composite filled with nanohydroxyapatite and mineral trioxide aggregate

e-Polymers ◽  
2017 ◽  
Vol 17 (4) ◽  
pp. 311-319 ◽  
Author(s):  
Anoj Meena ◽  
Harlal Singh Mali ◽  
Amar Patnaik ◽  
Shiv Ranjan Kumar
Keyword(s):  
Compressive Strength ◽  
Dynamic Mechanical Analysis ◽  
Storage Modulus ◽  
Water Sorption ◽  
Mineral Trioxide Aggregate ◽  
Mechanical Analysis ◽  
Comparative Investigation ◽  
Dental Composite ◽  
Dynamic Mechanical

AbstractThis study presents comparative investigation of adding nanohydroxyapatite (HA) (5–20 wt.%) and mineral trioxide aggregate (MTA) (5–20 wt.%) on the physical, mechanical and thermomechanical characterization of dental composite. The performances of both experimental composites were assessed through various physical, mechanical and thermomechanical tests such as void content test, microhardness test, compressive strength test, dynamic mechanical analysis and thermogravimetric analysis. The result of experiment indicated that the addition of 5 wt.% of HA increased the water sorption, hardness and compressive strength by 50.47%, 13.46% and 62.35%, respectively, whereas the addition of 5 wt.% of MTA increased the water sorption, hardness and compressive strength by 19.23%, 100% and 5.44%, respectively. Dynamic mechanical analysis results revealed that the addition of 5 wt.% HA increased the storage modulus by 10.21%, whereas the addition of 5 wt.% of MTA decreased the storage modulus by 11.79%. The filler HA proved to be better choice in term of thermal stability behavior as compare to MTA filler.

scholarly journals “Effect of Hydroxyapatite Nanoparticles On Compressive strength and Flexural strength of Dental Composites Using Taguchi Method”

2022 ◽  
Vol 10 (1) ◽  
pp. 106-113
Author(s):  
Shubham Padmaker Thakur
Keyword(s):  
Compressive Strength ◽  
Composite Materials ◽  
Flexural Strength ◽  
Optimization Technique ◽  
Optimization Method ◽  
Dental Composite ◽  
Dental Composites ◽  
Hydroxyapatite Nanoparticles ◽  
Taguchi Optimization ◽  
Long Time

Abstract: Several composite materials are being used in biomedical and dental field with their immense applications to repair and transform various organs in human body. Recent advances suggest that Hydroxyapatite is one of the most reliable and widely used inorganic composite in dentistry. Desirable applications of Hydroxyapatite are achieved by utilizing variety of hydroxyapatite and their composites. This study was conducted to evaluate the compressive & flexural strength. Cylindrical specimens (n=9) for compressive strength & rectangular shaped specimens (n=9) for flexural strength were made according to manufacturer’s recommendations. Dental composite is using quartz, silica, and alumina glass as filler for a long time. Taguchi optimization technique keeps the experimentation within limit giving valid product in the calculating of compressive and flexural strength optimization. The goal of the work is to detect the best combination of composite materials. Keywords: Hydroxyapatite, Compressive Strength, Flexural Strength, Taguchi’s optimization method.

scholarly journals Dynamic mechanical behavior of nano-ZnO reinforced dental composite

2019 ◽  
Vol 8 (1) ◽  
pp. 90-99 ◽  
Author(s):  
Shubham Mahna ◽  
Hemraj Singh ◽  
Sumit Tomar ◽  
Deep Bhagat ◽  
Amar Patnaik ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Storage Modulus ◽  
Loss Modulus ◽  
Artificial Saliva ◽  
Dynamic Mechanical Properties ◽  
Dental Composite ◽  
Distilled Water ◽  
Nano Zno ◽  
Dynamic Mechanical ◽  
Cold Drink

Abstract In the present work, Bisphenol-A Glycidyl Methacrylate / Triethylene Glycol Dimethylacrylate based dental composites filled with 0-30 wt.% silane treated nano-ZnO were fabricated and tested for their dynamic mechanical properties. Samples were kept in each of three different mediums such as cold drink, distilled water and saliva for 7 days. The dynamic mechanical properties such as storage modulus, loss modulus and Tan delta were evaluated and compared for each composite under different conditions. The finding of results indicated that on adding 30 wt.% nano-ZnO, the storage modulus was increased by 109% in case of post cured, 120% in case of cold drink, 125% in case of artificial saliva but decreased by 70% in case of distilled water. The loss modulus was increased by 175% in case of post cured, 30% in case of cold drink, 50% in case of artificial saliva but decreased by 50% in case of distilled water. Further, minimum value of storage modulus was reported in case of distilled water medium followed by cold drink and then artificial saliva. Also, cold drink seems to be better medium than distilled water in terms of dynamic mechanical properties of dental composite. Graphical abstract Variation of storage modulus of sample kept in artificial saliva for 7 days Addition of 30 wt.% nano-ZnO increased the storage modulus by 109% in case of post cured, 120% in case of cold drink, 125% in case of artificial saliva but decreased by 70% in case of distilled water. Addition of 30 wt.% nano-ZnO increased the loss modulus by 175% in case of post cured, 30% in case of cold drink, 50% in case of artificial saliva but decreased by 50% in case of distilled water. Immersion of sample in each medium led to decrease in storage modulus but increase in Tan delta. Further, minimum value of storage modulus was reported in case of distilled water medium followed by cold drink and then artificial saliva. Cold drink seems to be better medium than distilled water in terms of dynamic mechanical properties of dental composite.

Mechanical Properties of Machinable Zirconia Dental Composites

2007 ◽  
Vol 336-338 ◽  
pp. 1587-1589
Author(s):  
Wen Xu Li ◽  
Hua Zhao ◽  
Ying Song ◽  
Bin Su ◽  
Fu Ping Wang
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Calcium Phosphate ◽  
Flexural Strength ◽  
Dental Composite ◽  
The Other ◽  
Dental Composites ◽  
Composite Ceramics ◽  
Cad Cam ◽  
The Common

Ca3(PO4)2/ZrO2 dental composite ceramics using for CAD/CAM system were prepared and the effects of weak phases on microstructures and mechanical properties were studied. The results showed that intergranular spreads happened with the increasing Ca3(PO4)2 contents due to the discontinuity of weak interfaces between Zirconia and Calcium phosphate in matrix. So the flexural strength and hardness of the Ca3(PO4)2/ZrO2 composite ceramics were decreased effectively, which improved the machinability of the composites. On the other hand, strong interfaces between Zirconias increased the integrality of the ceramic structures. ZrO2 composite Ceramics with 15% Ca3(PO4)2 were sintered at 1350°C. The flexural strength is 300.44MPa, fracture toughness is 4.36 MPam1/2, and hardness is 6.69 GPa. The cutting exponent of the Ca3(PO4)2/ZrO2 composite ceramics is obviously lower than that of the common commercial Vita Mark II and Dicor MGC ceramics, which shows good mechanical properties and machinability.

Applicability of time temperature superposition principle to an immiscible blend of polyphenyleneoxide and polyamide

2011 ◽  
Vol 31 (2-3) ◽  
Author(s):  
Narendra A. Hardikar ◽  
Somasekhar Bobba ◽  
Roshan Jha
Keyword(s):  
Storage Modulus ◽  
Master Curve ◽  
Loss Modulus ◽  
Superposition Principle ◽  
Strict Sense ◽  
Cole Plot ◽  
Temperature Superposition ◽  
Immiscible Blend ◽  
Thermorheological Behavior ◽  
Time Temperature Superposition

Abstract The immiscible blend of polyphenyleneoxide (PPO) and polyamide (PA) is used in several applications exposed to high temperature. The complexity of numerical modeling of such materials is dependent on their thermorheological behavior with significant simplification possibilities, if the material is found to follow the time temperature superposition (TTS) principle and show thermorheological simplicity (TRS). Hence as a precursor to selecting accurate constitutive modeling approach, the paper investigates the applicability of the TTS principle and the nature of thermorheological behavior to the blend. Dynamic mechanical analysis (DMA)frequency scans were performed in the range of 0.1–100 rad/s from 0°C to 210°C at 10°C intervals. Temperature dependency was observed on the Cole-Cole plot pointing to the thermorheological complexity and the need for vertical shift factors. 2-D minimization algorithm was used to shift the isotherms horizontally and vertically to obtain master curves. Except, in the vicinity of glass transition temperature T g , the isotherms overlap to form a master curve, but further analysis considering various conditions indicate that in a strict sense TTS is not applicable to the blend when both storage G′ and loss modulus G″ are considered. However, a continuous master curve of storage modulus spanning 31 decades of time is obtained using horizontal shifting alone when loss modulus is neglected. Further testing is required to ascertain if relaxation modulus can be approximated with storage modulus alone before taking recourse to characterization methods developed for thermorheologically complex (TRC) materials.

scholarly journals Effect of Short Fiber Reinforcement on Mechanical Properties of Hybrid Phenolic Composites

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Sembian Manoharan ◽  
Bhimappa Suresha ◽  
Govindarajulu Ramadoss ◽  
Basavaraj Bharath
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Loss Modulus ◽  
Basalt Fiber ◽  
Barium Sulphate ◽  
Dynamic Mechanical Properties ◽  
Damping Factor ◽  
X Ray ◽  
Weight Percentage ◽  
Dynamic Mechanical

Fiber plays an important role in determining the hardness, strength, and dynamic mechanical properties of composite material. In the present work, enhancement of viscoelastic behaviour of hybrid phenolic composites has been synergistically investigated. Five different phenolic composites, namely, C1, C2, C3, C4, and C5, were fabricated by varying the weight percentage of basalt and aramid fiber, namely, 25, 20, 15, 10, and 5% by compensating with barium sulphate (BaSO4) to keep the combined reinforcement concentration at 25 wt%. Hardness was measured to examine the resistance of composites to indentation. The hardness of phenolic composites increased from 72.2 to 85.2 with increase in basalt fiber loading. Composite C1 (25 wt% fiber) is 1.2 times harder than composite C5. Compression test was conducted to find out compressive strength of phenolic composites and compressive strength increased with increase in fiber content. Dynamic mechanical analysis (DMA) was carried out to assess the temperature dependence mechanical properties in terms of storage modulus (E′), loss modulus (E′′), and damping factor (tan δ). The results indicate great improvement of E′ values and decrease in damping behaviour of composite upon fiber addition. Further X-ray powder diffraction (XRD) and energy-dispersive X-ray (EDX) analysis were employed to characterize the friction composites.

REACTIVE COMPATIBILIZATION OF THE BLENDS OF THERMOPLASTIC POLYURETHANE AND POLYDIMETHYLSILOXANE RUBBER

2015 ◽  
Vol 88 (4) ◽  
pp. 584-603 ◽  
Author(s):  
Jineesh Ayippadath Gopi ◽  
Golok Bihari Nando
Keyword(s):  
Mechanical Properties ◽  
Storage Modulus ◽  
Loss Modulus ◽  
Thermoplastic Polyurethane ◽  
Domain Size ◽  
Damping Factor ◽  
Creep Tests ◽  
Dynamic Mechanical ◽  
Compatibilization Effect ◽  
Compatibilized Blends

ABSTRACT The effect of ethylene-co-methacrylate (EMA) as polymeric chemical compatibilizer on the mechanical, dynamic mechanical, phase morphology, adhesion, and rheological properties of the blends of thermoplastic polyurethane (TPU)–polydimethylsiloxane rubber (PDMS) was investigated at different blend ratios. Melt blending technique was used to prepare the compatibilized blends. Enhancement of the mechanical properties and the reduction of dispersed PDMS domain size in the alloy confirmed the compatibilization effect of EMA on TPU-PDMS blends. Dynamic mechanical properties such as storage modulus, loss modulus, and the damping factor were evaluated to assess the compatibilization effect of EMA on TPU-PDMS blends. Creep tests revealed that compatibilization led to better dimensional stability. Compatibilized blends with finer PDMS rubber domains showed relatively less reduction in storage modulus as compared with uncompatibilized blends during stress relaxation studies. Rheological analysis suggested that the incorporation of EMA decreased the interfacial slip between the blend constituents, and this also confirmed the compatibilization effect of EMA on TPU-PDMS rubber blends as a polymeric reactive compatibilizer.

scholarly journals Viscoelastic Properties of Contemporary Bulk-fill Restoratives: A Dynamic-mechanical Analysis

2018 ◽  
Vol 43 (3) ◽  
pp. 307-314 ◽  
Author(s):  
JEX Ong ◽  
AU Yap ◽  
JY Hong ◽  
AH Eweis ◽  
NA Yahya
Keyword(s):  
Dynamic Mechanical Analysis ◽  
Storage Modulus ◽  
Loss Tangent ◽  
Viscoelastic Properties ◽  
Loss Modulus ◽  
Artificial Saliva ◽  
Mechanical Analysis ◽  
Distilled Water ◽  
Glass Ionomer ◽  
Dynamic Mechanical

SUMMARY This study investigated the viscoelastic properties of contemporary bulk-fill restoratives in distilled water and artificial saliva using dynamic mechanical analysis. The materials evaluated included a conventional composite (Filtek Z350), two bulk-fill composites (Filtek Bulk-fill and Tetric N Ceram), a bulk-fill giomer (Beautifil-Bulk Restorative), and two novel reinforced glass ionomer cements (Zirconomer [ZR] and Equia Forte [EQ]). The glass ionomer materials were also assessed with and without resin coating (Equia Forte Coat). Test specimens 12 × 2 × 2 mm of the various materials were fabricated using customized stainless-steel molds. After light polymerization/initial set, the specimens were removed from the molds, finished, measured, and conditioned in distilled water or artificial saliva at 37°C for seven days. The materials (n=10) were then subjected to dynamic mechanical testing in flexure mode at 37°C and a frequency of 0.1 to 10 Hz. Storage modulus, loss modulus, and loss tangent data were subjected to normality testing and statistical analysis using one-way analysis of variance/Dunnett's test and t-test at a significance level of p < 0.05. Mean storage modulus ranged from 3.16 ± 0.25 to 8.98 ± 0.44 GPa, while mean loss modulus ranged from 0.24 ± 0.03 to 0.65 ± 0.12 GPa for distilled water and artificial saliva. Values for loss tangent ranged from 45.7 ± 7.33 to 134.2 ± 12.36 (10−3). Significant differences in storage/loss modulus and loss tangent were observed between the various bulk-fill restoratives and two conditioning mediums. Storage modulus was significantly improved when EQ and ZR was not coated with resin.

Synthesis and Characteristics of Dental Composites with Novel Bis-GMA Derivate as a Resin Base

2013 ◽  
Vol 745-746 ◽  
pp. 442-446 ◽  
Author(s):  
Rui Li Wang ◽  
Mo Zhu ◽  
Sheng Liu ◽  
Feng Wei Liu ◽  
Xiao Ze Jiang ◽  
...  
Keyword(s):  
Adverse Effects ◽  
Triethylene Glycol ◽  
High Viscosity ◽  
Dental Composites ◽  
Resin Matrix ◽  
Hydroxyl Groups ◽  
Acetyl Group ◽  
Matrix Differential ◽  
Dental Restorative ◽  
Kinetics Of

2,2-bis [4-(2-hydroxy-3-methacryloyloxypropoxy) pheny propane (Bis-GMA) and triethylene glycol dimethacrylate (TEGDMA) have been commonly used as a viscous monomer and a reactive diluent in the organic phase of dental restorative composites, respectively. The purpose of addition of TEGDMA is mainly to decrease the high viscosity of Bis-GMA caused by hydrogen bonding between hydroxyl groups. However, some adverse effects will accompany with increased amounts of the TEGDMA, such as higher values of polymerization shrinkage, which is not undesirable for the clinical application. Therefore, substituting hydroxyl groups of Bis-GMA might be an appropriate and effective way to reduce the amount of diluents and weaken the accompanied adverse effects. This work focuses on the synthesis of a novel Bis-GMA derivate, substituting acetyl groups for hydroxyl groups in Bis-GMA. The viscosity of Bis-GMA characterized with rotational rheometer was significantly decreased from 820 Pa.s to 11 Pa.s by substitution of acetyl group, leading to the low amount of TEGDMA in resin matrix. Differential Scanning Calorimeter (DSC) was used for investigating the reaction kinetics of this novel monomer with different mass ratios of TEGDMA. The results suggested that the maximum conversion of the Ac-Bis-GMA can reach 88% while the corresponding value for Bis-GMA is 75%. Dental composites were prepared from 2,2-bis [4-(2-acetyl-3-methacryloyloxypropoxy) pheny propane (Ac-Bis-GMA) or Bis-GMA resin mixtures with TEGDMA filled with 70 wt% silica co-fillers. The results presented that dental composites prepared from new resin matrixes exhibited adequate mechanical properties.

scholarly journals Development of an Innovative Urease-Aided Self-Healing Dental Composite

Catalysts ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 84
Author(s):  
Mostafa Seifan ◽  
Zahra Sarabadani ◽  
Aydin Berenjian
Keyword(s):  
Healing Process ◽  
Optical Microscope ◽  
Dental Restoration ◽  
Dental Composite ◽  
Dental Composites ◽  
Resin Matrix ◽  
Self Healing ◽  
Urease Enzyme ◽  
Near Future ◽  
Dental Restorative

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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