scholarly journals Flexural strength and modulus of elasticity of different types of resin-based composites

2007 ◽  
Vol 21 (1) ◽  
pp. 16-21 ◽  
Author(s):  
Sinval Adalberto Rodrigues Junior ◽  
Cesar Henrique Zanchi ◽  
Rodrigo Varella de Carvalho ◽  
Flávio Fernando Demarco
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Modulus Of Elasticity ◽  
Filler Content ◽  
Hybrid Composites ◽  
In Vitro Study ◽  
Bending Test ◽  
Test Machine ◽  
Weight Content

The aim of the study was to test whether the filler composition of resin composites influences their flexural strength and modulus of elasticity. Flexural strength and modulus of elasticity were obtained through a three-point bending test. Twelve bar shaped specimens of 5 commercially available composites - Supreme (3M/ESPE), a universal nanofilled composite; Esthet-X (Dentsply), Z-250 (3M/ESPE), Charisma (Heraeus Kulzer), universal hybrid composites; and Helio Fill (Vigodent), a microfine composite - were confectioned according to the ISO 4049/2000 specifications. The test was performed after a 7-days storage time using a universal test machine with a crosshead speed of 1 mm/min. The filler weight content was determined by the ashing technique. The data obtained on the mechanical properties were submitted to ANOVA and Tukey test (p < 0.05). Pearson's correlation test was used to determine the correlation between the filler content and the mechanical properties. A weak but significant correlation between the mechanical properties evaluated and the filler weight content was observed (p < 0.000). The microfine composite presented the lowest filler weight and the lowest mechanical properties. Statistically different flexural strength and modulus of elasticity results were observed among the universal hybrid composites. The nanofilled composite presented intermediary results. Within the limitations of this in vitro study, it could be concluded that the filler content significantly interfered in the flexural strength and modulus of elasticity of the composites tested.

scholarly journals Effect of 5% Calcium Hypochlorite on Mechanical Properties of Root Dentin: An in vitro Study

2016 ◽  
Vol 1 (2) ◽  
pp. 56-59
Author(s):  
Natanasabapathy Velmurugan ◽  
Poornima Reddy ◽  
Suma Balla ◽  
Sandhya S Raghu ◽  
Garlapati T Gupta ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Modulus Of Elasticity ◽  
In Vitro Study ◽  
Chlorine Concentration ◽  
Control Group ◽  
Calcium Hypochlorite ◽  
Significant Difference ◽  
Root Dentin

ABSTRACT Introduction The aim of this study was to compare in vitro the effect of 5% calcium hypochlorite [Ca(OCl)2] and 5% sodium hypochlorite (NaOCl) on flexural strength and modulus of elasticity of root dentin. Materials and methods The available chlorine concentration of each solution was determined using iodometric titration. Standardized planoparallel dentin bars (n= 20) were divided into two test groups and one control group. The control, group 1, consisted of dentin bars stored in normal saline. The dentin bars in the two test groups were treated by exposure to following solutions: Group 2 to 5% Ca(OCl)2; and group 3 to 5% NaOCl. All the three test solutions were changed once in 15 minutes for 30 minutes. The dentin bars were then loaded to failure using three-point bend test. Results Available chlorine concentration was 64% in both the test solutions. There was a significant reduction in the flexural strength of 5% NaOCl group compared to 5% Ca(OCl)2-treated ones. A significant difference in modulus of elasticity was observed between the test groups and the control groups and also between the 5% Ca(OCl)2 and 5% NaOCl groups. Conclusion Within the limitations of this study, 5% NaOCl reduced the flexural strength and modulus of elasticity of root dentin bars more when compared to 5% Ca(OCl)2. How to cite this article Reddy P, Balla S, Raghu SS, Velmurugan N, Gupta GT, Sahoo HS. Effect of 5% Calcium Hypochlorite on Mechanical Properties of Root Dentin: An in vitro Study. J Oper Dent Endod 2016;1(2):56-59.

Effect of Filler Content and Waiting time Before Light-Curing on Mechanical Properties of Dual-Cured Cement

2020 ◽  
Vol 2 (1) ◽  
pp. 45-52
Author(s):  
Ana C. de Assunção Oliveira ◽  
Sandro Griza ◽  
Rafael R. de Moraes ◽  
André L. Faria-e-Silva
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Flexural Strength ◽  
Waiting Time ◽  
Filler Content ◽  
Bending Test ◽  
Resin Cements ◽  
Three Point Bending ◽  
Light Curing ◽  
Curing Procedure

Objective:: To investigate the effect of filler content and the time spent before light-curing on mechanical properties of dual-cured cement. Methods:: Experimental dual-cured resin cements were formulated with 60, 65 or 68wt% of filler. The viscosity of experimental cement was measured using a digital viscometer. Bar-shaped specimens (25 x 2 x 2 mm) were fabricated, while the light-curing was started immediately or 5 minutes after the insertion of cement into the mold (n = 7). A three-point bending test was performed and the values of flexural strength and elastic modulus were measured. The Vickers hardness of fractured specimens was measured on the surface of the cement. Data from viscosity were submitted to oneway ANOVA, while the data from mechanical properties were analyzed by two-way ANOVA. All pair-wise comparisons were performed using Tukey’s test (α = 0.05). Results:: The experimental cement with 68wt% of filler showed the highest viscosity and those with 60wt% showed the the lowest viscosity. Irrespective of the time spent before light-curing, the cement with 65wt% of filler presented the highest values of flexural strength and elastic modulus. The addition of 60wt% of filler resulted in the lowest elastic modulus, while 68wt% of filler resulted in lowest flexural strength. Regarding the hardness, the cement with 68wt% of filler showed the highest values, while there was no difference between 60 and 65wt% of filler. Conclusion:: Filler content affected the mechanical properties of the experimental cement and this effect did not depend on the waiting time before the light-curing procedure.

scholarly journals Assessment of Mineral Trioxide Aggregate Setting in Simulated Root Canal with Different Root Canal Wall Thickness: In Vitro Study

2021 ◽  
Vol 11 (4) ◽  
pp. 1727
Author(s):  
Radovan Žižka ◽  
Radim Čtvrtlík ◽  
Jan Tomáštík ◽  
Kamila Fačevicová ◽  
Ondřej Vencálek ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Wall Thickness ◽  
Modulus Of Elasticity ◽  
Root Canal ◽  
Interfacial Layer ◽  
Mineral Trioxide Aggregate ◽  
In Vitro Study ◽  
Canal Wall ◽  
Reduced Modulus

Setting of mineral trioxide aggregate (MTA) is affected by various factors. The purpose of this in vitro study was to evaluate the influence of root canal wall thickness on mechanical properties of MTA along the whole apical plug. Bovine bone mold tubes with internal diameter of 2 mm, height of 5 mm, and wall thickness of 0.8 mm, 1.2 mm, and 1.6 mm were filled with 3 mm ProRoot MTA and were kept in 37 °C and relative humidity of 100% for 7 days. The indentation hardness and reduced modulus of elasticity were measured in a large overview matrix and detailed matrix placed 1.5 mm from simulated apical foramen in order to obtain particularized information about gradient of altering mechanical properties. The uppermost layer of material in contact with simulated apical foramen had reduced mechanical properties irrespective of root canal wall thickness. The most distinct decrease of microhardness (32%) and reduced modulus of elasticity (27%) in interfacial layer were present in specimen with thinnest root canal wall. This effect could be observed in detailed measurement up to 190 µm in material. The interfacial layer of MTA, which was in contact during setting with root canal wall thinner than 1.2 mm, had reduced mechanical properties.

scholarly journals An in vitro Study to evaluate the Effects of Various Polymerizing Conditions on the Flexural Strength of Autopolymerizing Resins

2017 ◽  
Vol 8 (1) ◽  
pp. 15-19
Author(s):  
Sanjeev Singh, ◽  
Abid Z Hussain, ◽  
RU Thombare, ◽  
BK Motwani, ◽  
Shweta Singh,
Keyword(s):  
Flexural Strength ◽  
Constant Pressure ◽  
Testing Machine ◽  
In Vitro Study ◽  
Bending Test ◽  
Control Group ◽  
Time Interval ◽  
Time Intervals ◽  
Increased Strength

ABSTRACT Aim To investigate the effect of variation in temperature and time intervals on the flexural strength of two brands of autopolymerizing resins polymerized at constant pressure. Materials and methods Two autopolymerizing resins RR Cold Cure resin (DPI) and RR-Rapid Repair Powder (Dentsply) were used. A total of 20 samples were fabricated for each group. Samples were polymerized at temperature ranges of 40°, 50°, 60°, and 70°C and at time intervals of 5, 10, and 15 minutes in the customized curing pot, maintaining pressure of 30 psi. Results Flexural strength was verified using universal testing machine using three-point bending test and was then compared with all samples and also with the samples cured in open air (control group). The samples cured at higher temperature, i.e., 60° and 70°C, have shown increased strength than those at 40° and 50°C as well as control group. Time interval of 10 minutes is considered sufficient to increase the strength of the resin, as per the results of this study. Conclusion The samples cured under varied condition of time and temperature but under constant pressure showed increased strength than those cured in open air. Clinical significance The effect of pressure and temperature has been demonstrated, which could be utilized for enhancing the durability of the prosthesis fabricated from autopolymerized resins. How to cite this article Singh S, Hussain AZ, Thombare RU, Motwani BK, Singh S, Mangalekar SB. An in vitro Study to evaluate the Effects of Various Polymerizing Conditions on the Flexural Strength of Autopolymerizing Resins. J Health Sci Res 2017;8(1):15-19.

scholarly journals Comparative Evaluation of Flexural Strength and Flexural Modulus of Different Periodontal Splint Materials: An In Vitro Study

2019 ◽  
Vol 9 (19) ◽  
pp. 4197
Author(s):  
Shahabe Saquib ◽  
AlQarni Abdullah ◽  
Das Gotam ◽  
Naqash Talib ◽  
Sibghatullah Muhammad ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Flexural Modulus ◽  
In Vitro Study ◽  
Mean Value ◽  
Vitro Study ◽  
Bending Test ◽  
P Value ◽  
Significant Difference ◽  
Different Types

Splinting of the mobile teeth is a critical part of periodontal management to improve the prognosis and longevity of stable results of periodontally compromised teeth with increased mobility. Different types of splints are used in the dental field based on their mechanical and physical properties.The objective of the current in vitro study was to evaluate the flexure strength and flexural modulus of different types of splinting materials, such as: composite block, ligature wire, Ribbond®, InFibra®, and F-splint-Aid® bonded utilizing Flowable composites resin material. Seventy-five bar specimens were prepared with the dimensions of 25 × 4 × 2 mm, utilizing split metallic mold. Specimens were divided equally (n = 15) into five groups (one control group, four test groups). Different layers of splinting material were placed in between the layers of composite before curing. All the specimens were subjected to a three-point bending test by using a universal testing machine to calculate the flexural strength and flexural modulus. The entire data was subjected to statistical tests to evaluate the significance. Specimens from composite block groups showed the least mean value for flexural strength (89.15 ± 9.70 MPa) and flexural modulus (4.310 ± 0.912 GPa). Whereas, the highest mean value for flexural strength (168.04 ± 45.95 MPa) and flexural modulus (5.861 ± 0.501 GPa) were recorded by Ribbond® specimens. Inter group comparison of flexural strength showed statistically significant differences (P-value < 0.05), whereas comparison of flexural modulus showed non-significant difference among the groups (P-value > 0.05). Within the limitation of the present study, it was concluded that the Ribbond® exhibits maximum flexural strength and flexural modulus, whereas the composite blocks recorded the least values. Still, the decision making depends on the clinical scenario and the unique characteristic of each splint material.

scholarly journals Polymethylmethacrylate Incorporating Nanodiamonds for Denture Repair: In Vitro Study on the Mechanical Properties

2021 ◽  
Author(s):  
Mohammed Moustafa Ahmed Gad ◽  
Mohamed Saber Ali ◽  
Ahmad M. Al-Thobity ◽  
Yousif A. Al-Dulaijan ◽  
Mai El Zayat ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Impact Strength ◽  
Flexural Strength ◽  
In Vitro Study ◽  
Acrylic Resin ◽  
Bending Test ◽  
Control Group ◽  
Nd Addition ◽  
The Impact

Abstract Objective This study aimed to evaluate the effect of nanodiamond (ND) addition to repair resin with repair gap modifications on the flexural and impact strength of repaired polymethylmethacrylate denture base. Materials and Methods Heat-polymerized acrylic resin specimens (N = 100/test) were prepared and sectioned to half creating two repair gaps: 2.5- and 0 mm with 45 degrees beveling. They were further divided into subgroups (n = 20) according to ND concentration (control, 0.25%ND, and 0.50%ND), thermocycling (500 cycles) was done to half the specimens in each subgroup. Flexural strength was tested using 3-point bending test and impact strength was tested by Charpy's impact test. Analysis of variance and post-hoc Tukey's tests were performed for data analysis (α = 0.05). Scanning electron microscope was employed for fracture surface analysis and ND distribution. Results Before and after thermocycling, the addition of ND significantly increased the flexural strength and elastic modulus in comparison to control group (p ˂ 0.001), while 0 mm repair gap showed insignificant difference between ND-reinforced groups (p ˃ 0.05). Regarding impact strength, ND addition increased the impact strength with 0 mm gap in comparison to control and 2.5 mm with ND (p˂0.001), while later groups showed no significant in between (p ˃ 0.05). Comparing thermocycling effect per respective concentration and repair gap, thermocycling adversely affected all tested properties except elastic modulus with 0 mm–0.25 and 0 mm–0.5% and impact strength with 2.5 mm, 2.5 mm–0.25%, 2.5 mm– 0.5% (p ˃ 0.05). Conclusion ND addition combined with decreased repair gap improved the flexural strength, elastic modulus, and impact strength of repaired denture resin, while thermocycling has a negative effect on denture repair strength.

scholarly journals Mechanical properties of materials used for temporary fixed dentures – in vitro study

2017 ◽  
Vol 30 (2) ◽  
pp. 61-64
Author(s):  
Elzbieta Celej-Piszcz ◽  
Leszek Szalewski ◽  
Przemyslaw Kleinrok ◽  
Janusz Borowicz
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
In Vitro Study ◽  
Hardness Test ◽  
Micro Hardness ◽  
Hardness Testing ◽  
Filling Materials ◽  
Temporary Filling ◽  
Vickers Micro Hardness

Abstract Objectives. The objective of the research was to define the mechanical properties of currently marketed temporary filling materials. Methods. Eight temporary filling materials: Boston, Dentalon, Protemp II, Revotek LC, Structure 2, Structure 3, UniFast LC, UniFast Trad were used to make 5 samples each of measurements 2 × 2 × 25 mm, in order to define the flexural strength, and 10 rings each of measurements 2 × 5 mm, in order to carry out the Vickers micro-hardness test. After preparation, the samples were stored in distilled water of temperature of 370°C, for 7 days. Subsequently, flexural strength and Vickers hardness testing was undertaken. Results. Composite temporary materials showed considerably better mechanical properties, both in flexural strength and in Vickers micro-hardness testing. Conclusions. the best mechanical properties, both in terms of flexural strength, as well as Vickers micro-hardness test can be observe among composite materials.

scholarly journals Effect of Accelerated Aging on Some Mechanical Properties and Wear of Different Commercial Dental Resin Composites

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2769
Author(s):  
Jonne Oja ◽  
Lippo Lassila ◽  
Pekka K. Vallittu ◽  
Sufyan Garoushi
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Accelerated Aging ◽  
Wear Depth ◽  
Resin Composites ◽  
Expiration Date ◽  
Dental Resin ◽  
Hydrothermal Aging ◽  
Dental Resin Composites

The aim of current in vitro research was to determine the effect of hydrothermal accelerated aging on the mechanical properties and wear of different commercial dental resin composites (RCs). In addition, the effect of expiration date of the composite prior its use was also evaluated. Five commercially available RCs were studied: Conventional RCs (Filtek Supreme XTE, G-aenial Posterior, Denfil, and >3y expired Supreme XTE), bulk-fill RC (Filtek Bulk Fill), and short fiber-reinforced RC (everX Posterior). Three-point flexural test was used for determination of ultimate flexural strength (n = 8). A vickers indenter was used for testing surface microhardness. A wear test was conducted with 15,000 chewing cycles using a dual-axis chewing simulator. Wear pattern was analyzed by a three-dimensional (3D) noncontact optical profilometer. Degree of C=C bond conversion of monomers was determined by FTIR-spectrometry. The specimens were either dry stored for 48 h (37 °C) or boiled (100 °C) for 16 h before testing. Scanning electron microscopy (SEM) was used to evaluate the microstructure of each material. Data were analyzed using ANOVA (p = 0.05). Hydrothermal aging had no significant effects on the surface wear and microhardness of tested RCs (p > 0.05). While flexural strength significantly decreased after aging (p < 0.05), except for G-aenial Posterior, which showed no differences. The lowest average wear depth was found for Filtek Bulk Fill (29 µm) (p < 0.05), while everX Posterior and Denfil showed the highest wear depth values (40, 39 µm) in both conditions. Passing the expiration date for 40 months did not affect the flexural strength and wear of tested RC. SEM demonstrated a significant number of small pits on Denfil’s surface after aging. It was concluded that the effect of accelerated aging may have caused certain weakening of the RC of some brands, whereas no effect was found with one brand of RC. Thus, the accelerated aging appeared to be more dependent on material and tested material property.

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