scholarly journals The Effect of Heating on Surface Microhardness of Resin-based Materials for Direct Restoration

2018 ◽  
Vol 55 (4) ◽  
pp. 584-589
Author(s):  
Simona Stoleriu ◽  
Gianina Iovan ◽  
Irina Nica ◽  
Galina Pancu ◽  
Andrei Victor Sandu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Vickers Microhardness ◽  
Composite Resin ◽  
Heating Temperature ◽  
Surface Hardness ◽  
Mean Value ◽  
Direct Restoration ◽  
Different Temperatures ◽  
Materials Used ◽  
Hardness Values

The aim of this study was to evaluate and to compare the surface hardness of three types of resin-based materials used for direct restoration after heating at different temperatures. A giomer (Beautifil II, Shofu Dental), a compomer (Dyract eXtra, Dentsply Sirona) and a hybrid composite resin (Gaenial Posterior, GC Corporation) were selected for this study. Twenty disk-shaped specimens of each material were heated at room temperature (21�C), at 37�C, at 50�C and at 60�C. Vickers microhardness test was performed on top and bottom surfaces using digital microhardness tester (Micro-Vickers Hardness System CV- 400DMTM, CV Instruments Namicon). The top and bottom surfaces VHN was calculated as a mean value of five determinations. Also, the microhardness ratio was calculated by dividing the top mean VHN value by bottom mean VHN value. Increased mean hardness values were recorded after heating, irrespective of resin-based tested materials. The highest hardness values were recorded after heating all three materials at 60�C, followed by the hardness recorded at 50�C, 37�C and 21�C. For top surfaces, the lowest hardness value was recorded in Dyract eXtra group when samples were warmed at room temperature and the highest hardness value was obtained in Beautifil II group when samples where heated at 60�C. For the bottom surfaces, Dyract eXtra specimens heated at 21�C presented the lowest hardness values and Beautifil II samples heated at 60�C presented the highest hardness values. On top and on bottom surfaces Dyract eXtra showed the lowest hardness values, followed by G-aenial Posterior and Beautifil II, irrespective the heating temperature.

scholarly journals Evaluation of Pre-heating Effects on Marginal Adaptation of Resin-based Materials

2018 ◽  
Vol 55 (2) ◽  
pp. 238-242 ◽  
Author(s):  
Ionut Taraboanta ◽  
Simona Stoleriu ◽  
Gianina Iovan ◽  
Antonia Moldovanu ◽  
Andrei Georgescu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Composite Resin ◽  
Optical Microscope ◽  
Marginal Adaptation ◽  
Gap Formation ◽  
Solution Ph ◽  
Filling Materials ◽  
Heating Effects ◽  
Direct Restoration ◽  
Materials Used

The aim of the study was to compare the marginal adaptation of three different resin-based materials used for direct restoration: hybrid composite resin (Gaenial Posterio, GC Corporation), a compomer (Dyract eXtra, Dentsply Sirona), and a giomer (Beautifil II, Shofu Dental) applied at room temperature or after preheated at preheating 50 and 60oC. Class II cavities were prepared on proximal surfaces of extracted teeth and randomly divided in 3 groups according to the material used for restoration. In each group five cavities were restored using the materials at room temperature (subgroup 1), five cavities were restored using preheated materials at 50şC (subgroup 2), and five cavities were restored using preheated materials at 60şC (subgroup 3). The teeth were stored in distilled water for 14 days and then were immersed in 2% methylene blue buffered dye solution (pH = 7) for 4 hours. The teeth were transversally cut and the sections were examined using optical microscope (Carl-Zeiss AXIO Imager A1m) at 50x magnification and the dye penetration was evaluated according to 4 scores. Decreased microleakage and fewer gap formation were recorded for all filling materials after they have been heated at 50 or 60oC. Pre-warming of resin-based materials improves the adaptation of these materials to tooth structures.

scholarly journals The effects of food simulating liquids on surface roughness, hardness, and solubility of bulk fill composites

2019 ◽  
Author(s):  
Özge Gizem Cabadağ ◽  
NİHAN GÖNÜLOL
Keyword(s):  
Surface Roughness ◽  
Citric Acid ◽  
Vickers Microhardness ◽  
Surface Hardness ◽  
High Viscosity ◽  
Constant Mass ◽  
Measuring Device ◽  
Hardness Values ◽  
Roughness Measurements ◽  
Scanning Electron

Abstract BackgroundThe aim of this study was to compare the effects of food simulating liquids (FSLs) on the surface roughness, surface hardness and solubility of bulk fill composites. MethodsTwo-hundred samples were prepared from four high viscosity bulk fill composites (SonicFillTM, Tetric® EvoCeram Bulk Fill, Beautifil-Bulk Restorative, FiltekTM Bulk Fill Posterior Restorative) and a microhybrid composite (FiltekTM Z250). After the initial weights of the samples were recorded (m1), surface roughness measurements were evaluated with a profilometer. The samples were stored in 4 different FSLs for 7 days, then the second surface roughness values were recorded. Then the samples were stored in a desiccator to reach the constant mass and the values were recorded as m2. The solubility levels were calculated according to the ISO 4049: 2009 specification. The surface hardness values of the samples were determined by using the Vickers microhardness measuring device. Twenty specimens from each group were evaluated in terms of surface morphology with scanning electron microscope (SEM).ResultsBeautifil Bulk Restorative was the most affected group in terms of surface roughness after storage in FSLs and citric acid caused the highest values in this group (p<0,005). Beautifil Bulk Restorative and Filtek Z250 groups showed the highest surface hardness values, while the Tetric EvoCeram group had the lowest. The highest solubility values were detected in Beautifil Bulk Restorative group, and citric acid and ethanol caused the highest solubility values on all the tested composites. ConclusionsBeautifil Bulk Restorative group showed significant differences from the other groups in all tested parameters.

scholarly journals Effect of Precuring Warming on Mechanical Properties of Restorative Composites

2011 ◽  
Vol 2011 ◽  
pp. 1-5 ◽  
Author(s):  
Kareem Nada ◽  
Omar El-Mowafy
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Room Temperature ◽  
Surface Hardness ◽  
Mean Value ◽  
Test Surface ◽  
Bulk Properties ◽  
Mean Values ◽  
Enhanced Surface ◽  
Diametral Tensile Strength

To investigate the effect of prepolymerization warming on composites' mechanical properties, three composites were evaluated: Clearfil Majesty (CM) (Kuraray), Z-100 (3M/ESPE), and Light-Core (LC) (Bisco). Specimens were prepared from each composite at room temperature as control and 2 higher temperatures (37∘Cand54∘C) to test surface hardness (SH), compressive strength (CS), and diametral tensile strength (DTS). Data were statistically analyzed using ANOVA and Fisher's LSD tests. Results revealed that prewarming CM and Z100 specimens significantly improved their SH mean values (P<0.05). Prewarming also improved mean CS values of Z100 specimens (P<0.05). Furthermore, DTS mean value of CM prepared at52∘was significantly higher than that of room temperature specimens (P<0.05). KHN, CS, and DTS mean values varied significantly among the three composites. In conclusion, Prewarming significantly enhanced surface hardness of 2 composites. Prewarming also improved bulk properties of the composites; however, this improvement was significant in only some of the tested materials.

scholarly journals Effect of Drying Processes on Stability of Anthocyanin Extracts from Saffron Petal

2014 ◽  
Vol 2 ◽  
pp. 13-18 ◽  
Author(s):  
Somayeh Heydari ◽  
Roya Rezaei ◽  
Gholam Hossein Haghayegh
Keyword(s):  
Room Temperature ◽  
Heating Temperature ◽  
Heating Time ◽  
Crocus Sativus ◽  
The Sun ◽  
Processing Treatment ◽  
Different Temperatures ◽  
The Stability ◽  
Synthetic Pigments ◽  
Good Substitute

Saffron (Crocus sativus) has cyanic color flowers with major colorant of anthocyanin. Attractive color and functional properties of anthocyanins make them a good substitute for synthetic pigments in the food industry. These natural soluble water colorants are rather unstable and influenced by final processing treatment. The drying process is critical to the stability of saffron petals anthocyanins. Four different dehydration methods were evaluated: traditional method (at room temperature and under the sun); dehydration with electrical oven at different temperatures; and dehydration with microwave at different powers. The results showed that the highest amount of anthocyanin was obtained when saffron petals treated by traditional methods (at room temperature and under the sun). According to the results, the stability of saffron petals anthocyanins gradually accessed with increase of the heating temperature and decrement of heating time until 100 °C. However, heated at 120 and 140 °C, the anthocyanins could break down, and their residual amounts declined within 20 min and 10 min, respectively. The results suggested that saffron petals anthocyanins tended to degrade at high temperatures (>100 °C). Between these methods, drying at room temperature and drying with microwave at 900 W obtained the highest and the lowest results respectively.

Analysis of Volatile Organic Compounds in Disposable Food Packages at Three types of Temperature

2012 ◽  
Vol 476-478 ◽  
pp. 2625-2629
Author(s):  
Li Xie ◽  
Jiang Yu ◽  
Shuang Li ◽  
Sha Sha Diao
Keyword(s):  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Room Temperature ◽  
Heating Temperature ◽  
Food Packages ◽  
External Standard Method ◽  
Volatile Organic ◽  
Different Temperatures ◽  
Black Plastic ◽  
Method Show

Eight volatile organic compounds (VOCs) in the four disposable food packages at refrigeration temperature, room temperature and heating temperature have been analyzed by a headspace gas chromatography and mass spectrometry method. The results of external standard method show that the amount of VOCs in the four disposable packages at different temperatures are arranged in the following order: black plastic lunch box, white plastic lunch box, paper cup, paper bowl. Under the three types of temperature for an hour, the amount of VOCs in the black plastic lunch box at heating temperatures is higher (1.2382 mg/m2at 90 °C), room temperature has smaller content (0.6682 mg/m2and 0.9105 mg/m2at 20 °C and 30 °C, repectively). Content of VOCs in the white plastic lunch box increases gradually with temperature rising.

The Influence of Plasma Nitrocarburizing Process Temperature to Commercially Pure Titanium Surface Hardness

2013 ◽  
Vol 315 ◽  
pp. 700-704 ◽  
Author(s):  
Agung Setyo Darmawan ◽  
Waluyo Adi Siswanto ◽  
Tjipto Sujitno
Keyword(s):  
Pure Titanium ◽  
Surface Hardness ◽  
Process Time ◽  
Commercially Pure Titanium ◽  
Process Duration ◽  
Hardness Tester ◽  
Commercially Pure ◽  
Different Temperatures ◽  
Plasma Nitrocarburizing ◽  
Hardness Values

Commercially pure (cp) titanium is a relative soft metal and easily broken on friction-wear applications. To improve the hardness of the surface while maintaining the original properties, plasma nitrocarburizing process has been conducted. The effects of the treatment in different temperatures to the surface harness are then studied. In this study, cp titanium plasma nitrocarburizing process is conducted at different temperatures with different process time, i.e. at 350 °C for 3, 4, and 5 hours, and at 450 °C for 2, 3, and 4 hours respectively. Hardness tests are then performed on each specimen by using Micro Vickers Hardness Tester. The hardness values for the plasma specimens nitrocarburizing processes at temperature of 350 °C for process duration of 3 hours, 4 hours, and 5 hours are 74.16 HV, 92.25 HV and 94.41 HV, respectively, while for processes at temperature of 450 °C, the hardness values are 103.70 HV, 121.31 HV, and 126.17 HV for process duration of 2 hours, 3 hours, and 4 hours respectively. Hardness value of specimens which are resulted from the plasma nitrocarburizing process at temperature of 450 °C is higher compared with specimens that are processed at temperature of 350 °C.

scholarly journals Effects of Temperature on Bending Properties of Three-Dimensional and Five-Directional Braided Composite

Molecules ◽  
2019 ◽  
Vol 24 (21) ◽  
pp. 3977
Author(s):  
Li ◽  
Jia ◽  
Pei ◽  
Wan ◽  
Li ◽  
...  
Keyword(s):  
Epoxy Resin ◽  
Room Temperature ◽  
Bending Strength ◽  
Heating Temperature ◽  
Three Dimensional ◽  
Heating Time ◽  
Resin Composites ◽  
Bending Properties ◽  
Different Temperatures ◽  
Epoxy Resin Composites

The bending properties of three-dimensional (3Dim) and five-directional (5Dir) braided/epoxy resin composites at room temperature, 90 °C, 110 °C, and 150 °C and heating for 0.25 h, 10 h, and 30 h, respectively, were studied. The effect of different temperatures and heating times on the bending property of these composites was discussed. The results showed that the bending strength of these composites at 90 °C, 110 °C, and 150 °C and heating time of 0.25 h is 33.86%, 46.27%, and 83.94% lower, respectively, than that at room temperature. In addition, 3Dim–5Dir braided composites exhibit different damage modes at different temperatures, revealing different failure mechanisms. Heating temperature has greater influence on the bending properties of these composites than heating time. The results provided a basis for the application of resin-based 3Dim–5Dir braided/epoxy resin composites at different temperatures.

scholarly journals Comparison of time-dependent changes in the surface hardness of different composite resins

2013 ◽  
Vol 07 (S 01) ◽  
pp. S020-S025 ◽  
Author(s):  
Suat Ozcan ◽  
Ihsan Yikilgan ◽  
Mine Betul Uctasli ◽  
Oya Bala ◽  
Zeliha Gonca Bek Kurklu
Keyword(s):  
Composite Resin ◽  
Surface Hardness ◽  
Multiple Comparisons ◽  
Composite Resins ◽  
Time Dependent ◽  
Bottom Surface ◽  
Significance Level ◽  
Hardness Tester ◽  
Significant Difference ◽  
Hardness Values

ABSTRACT Objective: The aim of this study was to evaluate the change in surface hardness of silorane-based composite resin (Filtek Silorane) in time and compare the results with the surface hardness of two methacrylate-based resins (Filtek Supreme and Majesty Posterior). Materials and Methods: From each composite material, 18 wheel-shaped samples (5-mm diameter and 2-mm depth) were prepared. Top and bottom surface hardness of these samples was measured using a Vicker′s hardness tester. The samples were then stored at 37°C and 100% humidity. After 24 h and 7, 30 and 90 days, the top and bottom surface hardness of the samples was measured. In each measurement, the rate between the hardness of the top and bottom surfaces were recorded as the hardness rate. Statistical analysis was performed by one-way analysis of variance, multiple comparisons by Tukey′s test and binary comparisons by t-test with a significance level of P = 0.05. Results: The highest hardness values were obtained from each two surfaces of Majesty Posterior and the lowest from Filtek Silorane. Both the top and bottom surface hardness of the methacrylate based composite resins was high and there was a statistically significant difference between the top and bottom hardness values of only the silorane-based composite, Filtek Silorane (p < 0.05). The lowest was obtained with Filtek Silorane. The hardness values of all test groups increased after 24 h (p < 0.05). Conclusions: Although silorane-based composite resin Filtek Silorane showed adequate hardness ratio, the use of incremental technic during application is more important than methacrylate based composites.

Effect of Cerium and Lanthanum Addition on Mechanical Properties of Bismuth Titanate Ceramics

2009 ◽  
Vol 409 ◽  
pp. 330-333
Author(s):  
Nina Pavlovic ◽  
Dragan Rajnovic ◽  
L. Sidjanin ◽  
Vladimir V. Srdic
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Room Temperature ◽  
Bismuth Titanate ◽  
Vickers Microhardness ◽  
Grain Morphology ◽  
Sintering Behaviour ◽  
Titanate Ceramics ◽  
Hardness Values ◽  
Microhardness Tester

Cerium- and lanthanum- substituted bismuth titanate (Bi4-xAxTi3O12; where A=La or Ce, and x=0, 0.5 and 1) ceramics were prepared from nanopowders synthesized by coprecipitation method. The as-synthesized powders were calcined, uniaxially pressed and finally sintered at 1050°C. It was shown that sintering behaviour, phase composition and grain morphology of the obtained ceramics were influenced by the presence of lanthanum and especially cerium ions in the titanate structure. Mechanical properties (hardness and fracture toughness) were measured at room temperature on polished sample surfaces using a Vickers microhardness tester. The hardness values for of bismuth titanate based ceramics were in the range for some other important perovskite titanate, whereas their fracture toughness was somewhat higher.

scholarly journals Penatalaksanaan Perawatan Saluran Akar pada Fraktur Gigi 21 disertai Perforasi

2019 ◽  
Vol 7 (1) ◽  
pp. 27-32
Author(s):  
Zieta Sakinah Emdi ◽  
Reni Nofika
Keyword(s):  
Root Canal ◽  
Composite Resin ◽  
Mineral Trioxide Aggregate ◽  
Root Canal Treatment ◽  
Tooth Structure ◽  
Anterior Teeth ◽  
Direct Restoration ◽  
Procedural Error ◽  
Horizontal Pressure ◽  
Materials Used

Root canal treatment aims to maintain the condition of the teeth in order to keep them functioning. In practice, the treatment procedure does not always run smoothly, the operator can face undesirable conditions that can affect the prognosis of treatment. A common procedural error during root canal treatment is a lateral root perforation which must be treated immediately to avoid further damage. The success of the perforation treatment is determined by the materials used. One of the bicompatible materials to seal lateral perforations using MTA (mineral trioxide aggregate). Successful root canal treatment affects treatment outcomes, so proper restoration is required to reduce the risk of marginal leakage. The choice of final restoration in post-root canal treatment depends on the amount of remaining tooth structure, horizontal pressure and chewing load. For post-root canal treatment anterior teeth with intact marginal edges, direct restoration can be performed using composite resin

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