Mechanical Properties of Bisacryl-, Composite-, and Ceramic-resin Restorative Materials

2022 ◽  
Author(s):  
TA Sulaiman ◽  
AA Suliman ◽  
EA Mohamed ◽  
B Rodgers ◽  
A Altak ◽  
...  

SUMMARY Objective: Resin-based materials used in restorative dentistry are introduced at a fast pace with limited knowledge about their properties. Comparing properties of these materials from different restorative categories is lacking but can help the clinician in material selection. This study aimed to compare mechanical properties and wear resistance of bis-acryl-, composite-, and ceramic-resin restorative materials. Methods and Materials: Bisacryl-resin (Bis-R, LuxaCrown, DMG), composite-resin (Com-R, Filtek Supreme Ultra, 3M Oral Care), and ceramic-resin (Cer-R, Enamic, VITA Zahnfabrik) specimens were prepared for mechanical tests: fracture toughness (FT) with and without initial thermomechanical loading using a mastication simulator, flexural strength (FS), and flexural modulus (FM), compressive strength (CS), and volumetric wear loss measurement. The datasets for FT and wear resistance were each analyzed using two-way ANOVA followed by pairwise comparisons or Tukey testing as appropriate. The datasets for FS, FM, and CS were analyzed using one-way ANOVA followed by the Tukey test. Results: Analysis of FS, FM, and CS showed significant differences between materials, with all pairwise comparisons between materials showing significance. Analysis of FT resulted in a significant interaction between the material and treatment, with analysis of wear loss showing a significant interaction between the material and the number of cycles. Conclusions: Cer-R demonstrated superior FT, CS, and wear resistance compared to Bis-R and Comp-R materials. Fracture toughness of Bis-R increased after thermomechanical loading.

2020 ◽  
Vol 993 ◽  
pp. 492-496
Author(s):  
Peng Xiao Zhu ◽  
Yi Li ◽  
Bo Chen ◽  
Kun Feng

The effects of different zero-holding quenching temperatures on the tempering microstructure, mechanical properties and wear resistance of 40Cr were studied. The results showed that the microstructure of 40Cr was tempered sorbite and a small amount of unmelted ferrite after quenching at 850 °C and tempering at 550 °C for 2 h. Tempered sorbite was obtained after quenching at 880 °C~910 °C and tempering at 550 °C for 2 h. With the increasing of quenching temperature at zero holding temperature, the tensile strength and yield strength of 40Cr increased, while the elongation and impact toughness decreased. With the decreasing of impact test temperature, the ballistic work of 40Cr decreased gradually, and decreased fastest between 0 °C~-20 °C. 40Cr had the best impact performance after quenching at 850 °C and tempering at 550 °C for 2 h. 40Cr had the smallest wear loss after quenching at 880 °C and tempering at 550 °C for 2 h. Its wear marks were smooth, and had the shallowest furrows and ridges.


2012 ◽  
Vol 727-728 ◽  
pp. 1085-1091
Author(s):  
José Vitor C. Souza ◽  
O.M.M. Silva ◽  
E.A. Raymundo ◽  
João Paulo Barros Machado

Si3N4based ceramics are widely researched because of their low density, high hardness, toughness and wear resistance. Post-sintering heat treatments can enhance their properties. Thus, the objective of the present paper was the development of a Si3N4based ceramic, suitable for structural applications, by sintering in nitrogen gas pressure, using AlN, Al2O3, and Y2O3as additives and post-sintering heat treatment. The green bodies were fabricated by uniaxial pressing at 80 MPa with subsequent isostatic pressing at 300 MPa. The samples were sintered at 1900°C for 1 h under N2gas pressure of 0.1 MPa. Post-sintering heat treatment was performed at 1500°C for 48 h under N2gas pressure of 1.0 MPa. From the results, it was observed that after post-sintering heat treatment there was a reduction of α-SiAlON phase and increase of β-Si3N4phase, with consequent changing in grain size, decrease of fracture toughness and increase of the Vickers hardness.


2021 ◽  
Author(s):  
Abay Namen ◽  
Radu Iovita ◽  
Klaus G. Nickel ◽  
Aristeidis Varis ◽  
Zhaken Taimagambetov ◽  
...  

The study of lithic raw material quality has become one of the major interpretive tools to investigate the raw material selection behaviour and its influence to the knapping technology. In order to make objective assessments of raw material quality, their mechanical properties (e.g., fracture resistance, hardness, modulus of elasticity) should be measured. However, such comprehensive investigations are lacking for the Palaeolithic of Kazakhstan. In this work, we investigate geological and archaeological lithic raw material samples of chert, porphyry, and shale collected from the Inner Asian Mountain Corridor (henceforth IAMC). Selected samples of aforementioned rocks were tested by means of Vickers and Knoop indentation methods to determine one aspect of their mechanical properties: their indentation fracture resistance (a value closely related to fracture toughness). These tests were complemented by traditional petrographic studies to characterise the mineralogical composition and evaluate the level of impurities that could have potentially affected the mechanical properties. The results show that materials, such as porphyry, previously thought to be of lower quality due to the anisotropic composition and coarse feldspar and quartz phenocrysts embedded in a silica rich matrix, possess fracture toughness values that can be compared to those of chert. Thus, it appears that different raw materials cannot be distinguished from the point of view of indentation fracture resistance, calling for detailed supplementary analyses of different fracture properties. This work also offers first insight into the quality of archaeological porphyry that was utilised as a primary raw material at various Middle and Upper Palaeolithic sites in the IAMC.


2022 ◽  
Vol 6 (1) ◽  
pp. 17
Author(s):  
Hiroshi Ikeda ◽  
Yohei Kawajiri ◽  
Minako Kibune Sodeyama ◽  
Haruka Takesue Yano ◽  
Yuki Nagamatsu ◽  
...  

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.


Materials ◽  
2019 ◽  
Vol 12 (8) ◽  
pp. 1344 ◽  
Author(s):  
Saleh Zidan ◽  
Nikolaos Silikas ◽  
Abdulaziz Alhotan ◽  
Julfikar Haider ◽  
Julian Yates

Acrylic resin PMMA (poly-methyl methacrylate) is used in the manufacture of denture bases but its mechanical properties can be deficient in this role. This study investigated the mechanical properties (flexural strength, fracture toughness, impact strength, and hardness) and fracture behavior of a commercial, high impact (HI), heat-cured denture base acrylic resin impregnated with different concentrations of yttria-stabilized zirconia (ZrO2) nanoparticles. Six groups were prepared having different wt% concentrations of ZrO2 nanoparticles: 0% (control), 1.5%, 3%, 5%, 7%, and 10%, respectively. Flexural strength and flexural modulus were measured using a three-point bending test and surface hardness was evaluated using the Vickers hardness test. Fracture toughness and impact strength were evaluated using a single edge bending test and Charpy impact instrument. The fractured surfaces of impact test specimens were also observed using a scanning electron microscope (SEM). Statistical analyses were conducted on the data obtained from the experiments. The mean flexural strength of ZrO2/PMMA nanocomposites (84 ± 6 MPa) at 3 wt% zirconia was significantly greater than that of the control group (72 ± 9 MPa) (p < 0.05). The mean flexural modulus was also significantly improved with different concentrations of zirconia when compared to the control group, with 5 wt% zirconia demonstrating the largest (23%) improvement. The mean fracture toughness increased in the group containing 5 wt% zirconia compared to the control group, but it was not significant. However, the median impact strength for all groups containing zirconia generally decreased when compared to the control group. Vickers hardness (HV) values significantly increased with an increase in ZrO2 content, with the highest values obtained at 10 wt%, at 0 day (22.9 HV0.05) in dry conditions when compared to the values obtained after immersing the specimens for seven days (18.4 HV0.05) and 45 days (16.3 HV0.05) in distilled water. Incorporation of ZrO2 nanoparticles into high impact PMMA resin significantly improved flexural strength, flexural modulus, fracture toughness and surface hardness, with an optimum concentration of 3–5 wt% zirconia. However, the impact strength of the nanocomposites decreased, apart from the 5 wt% zirconia group.


2011 ◽  
Vol 474-476 ◽  
pp. 1881-1886 ◽  
Author(s):  
Lian Wei Yang ◽  
Jin Hui Li ◽  
Rui Jie Wang

To improve the wear and mechanical properties, SiCand Si3N4whiskers reinforced Si3N4composites were sintered by hot press sintering technique at 1800 and 1900°C for 1 h. The Friction and wear behaviors of Si3N4-SiC whisker reinforced Si3N4composites have been studied by using a reciprocating sliding apparatus. The results show that Si3N4-SiC whisker can greatly improve the hardness, fracture toughness and wear resistance of Si3N4. Lower sintering temperature can make both the grain dimension and interface area of the whiskers with the matrix decrease, resulting in relatively uneasy fracture of the whiskers. This uneasy fracture of the whiskers is the main reason for improvement in fracture toughness, and thus, the decrease in wear rate compared with those of the samples sintered at higher temperature and Si3N4material.


2015 ◽  
Vol 817 ◽  
pp. 493-497 ◽  
Author(s):  
Qin Shi ◽  
Wan Chang Sun ◽  
Jun Gao ◽  
Ying Wang ◽  
Miao Miao Tian

Ni-P-CNT nanocomposite coating was successfully co-deposited by electroless plating and the heat treatment was carried out at 200°C, 400°C, 600°C in nitrogen atmosphere respectively for a holding period of 1 h. The effects of heat treatment on the microstructure and mechanical properties of Ni-P-CNT composite coating were investigated. The results indicate that the heat treatment at 400°C can greatly improve the hardness and wear resistance of the composite coating. The reason is that Ni3P hard phase is greatly precipitated after the heat treatment, which played a strengthening effect. On the other hand, the precipitated Ni, Ni3P crystalline phases in the coating result in an increase of the amount of grain boundary. The increased amount of grain boundary broke the spread of shear force during friction process, and reduced the wear loss caused by friction pair. Compared with as-deposited coating, the coatings after heat treatment possess higher microhardness and wear resistance.


2021 ◽  
pp. 37-45
Author(s):  
Jamal Moammar ALDABIB

In removable prosthodontics, poly(methyl methacrylate) (PMMA) is the most suitable for the construction of denture bases. Intra-orally, the subjected stress intensity during the function accelerate the fracture of acrylic resin denture bases. Extra-orally, fracture occurs when dentures are accidentally dropped on a hard surface. The aim of the current study was to investigate the effect of coupling agent concentration on the mechanical properties of Hydroxyapatite/Poly(methyl methacrylate) (HA/PMMA) denture base composite. The Hydroxyapatite (HA) treated with four different ratios (i.e. 0, 5, 7 and 10 wt%) of 3-(trimethoxysily) propyl methacrylate (γMPS) silane coupling agent was added into the PMMA matrix. The mechanical performance of the composite was evaluated by conducting fracture toughness, flexural and tensile tests. An improvement of 13.83% and 9.62% in the tensile and flexural strength respectively, was achieved. The tensile and flexural modulus of the composite increased by 19.04% and 12.5% respectively. A significant improvement of 29.26% in the fracture toughness was observed at 10 wt% of γ-MPS. 10 wt% of γ-MPS is the optimum amount of coupling agent for obtaining balanced mechanical properties.


2006 ◽  
Vol 312 ◽  
pp. 179-186
Author(s):  
Jang Kyo Kim ◽  
Naveed A. Siddiqui ◽  
Ricky S.C. Woo ◽  
Christopher K.Y. Leung ◽  
Arshad Munir

The fracture resistance and mechanical properties of carbon fiber reinforced composites (CFRPs) containing organoclay-filled epoxy resin are studied. The XRD analysis and TEM examination revealed well-dispersed organoclay in the epoxy matrix displaying a mixture of exfoliation and intercalation. There was a significant improvement in flexural modulus and a marginal reduction in flexural strength of epoxy matrix due to the incorporation of organoclay. The quasi-static fracture toughness of epoxy increased nearly 60% with the addition of 3wt% clay, but there was a 45% drop in impact fracture toughness with 1wt% clay. When CFRPs were fabricated with the clay-modified epoxy resin, both the flexural modulus and strength of the hybrid composites showed negligible changes due to a few wt% of organoclay in the matrix. The interlaminar crack growth stability and the corresponding mode I interlaminar fracture toughness of the hybrid composites with organoclay improved substantially compared to those with carbon fibres only. The hybrid composites typically presented rough matrix surface associated with pinning and crack tip bifurcation, whereas the composite made from neat epoxy showed a smooth river line structure which is characteristic of brittle epoxy. The correlation between the composite interlaminar fracture properties and the toughness of modified matrix is discussed.


2008 ◽  
Vol 403 ◽  
pp. 189-192
Author(s):  
Jow Lay Huang ◽  
Horng Hwa Lu

Ti3SiC2 has been a spectacular material, as it combines many of the best properties of metals and ceramics. This new material has potential applications for fabrication of jet engines and in bonding phases. Microstructure can further enhance the mechanical properties, such as strength, wear resistance and chemical stability. In the current research the different starting powder systems were used to synthesize Ti3SiC2 by hot pressing. The contents of Si were controlled appropriately to obtain Ti3SiC2/TiC ceramic composites. Preliminary results indicated that the fracture toughness and strength were improved. The influences of TiC contents on the microstructure and mechanical properties were investigated and the fracture mechanisms of Ti3SiC2/TiC ceramic composites are discussed qualitatively.


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