Accuracy of Kubelka–Munk reflectance theory for dental resin composite material

2012 ◽  
Vol 28 (7) ◽  
pp. 729-735 ◽  
Author(s):  
Sarah S. Mikhail ◽  
Shereen S. Azer ◽  
William M. Johnston
Keyword(s):  
Composite Material ◽  
Resin Composite ◽  
Dental Resin

scholarly journals Effect of ethanol in mouthwashes on the surface hardness of a dental resin composite material

2009 ◽  
Vol 21 (1) ◽  
Author(s):  
Decky J. Indrani ◽  
S. Triaminingsih ◽  
N. Nurvanita ◽  
A. Andhesti ◽  
N. Noviana
Keyword(s):  
Composite Material ◽  
Similar Pattern ◽  
Resin Composite ◽  
Surface Hardness ◽  
Time Dependent ◽  
Alcoholic Beverages ◽  
Dental Resin ◽  
Dental Resins ◽  
Microhardness Tester

The previous study has shown that dental resins exhibited changes in the surface hardness when soaked in alcoholic beverages. As ethanol was one of the components contained in some commercial mouthwashes, therefore, the present study aimed at the effect of ethanol in some mouthwashes on the surface hardness of a dental resin composite. Specimens were prepared from a light cured dental resin composite. The specimens were then immersed in some commercial mouthwashes for periods up to 14 days. The surface hardness of the specimens was then measured using a Microhardness tester. The results displayed reductions in surface hardness (p<0,01), upon one day of immersing the specimens in Bactidol®, Listerine® or Minosepe® mouthwash, respectively. The surface hardness curves from each mouthwash demonstrated a similar pattern which approached a plateau near 2 weeks. It can be concluded that the ethanol-containing mouthwashes appeared to have more implication on surface hardness of the dental resin composite and the effect of immersing in the mouthwashes was time-dependent; it decreased sharply on the first day of immersion, however, further changes, did not exist.

The Analysis of Reinforcing the Bottom Chord around the Tapped Holes Based on the Thermosetting Resin Composite Materials

2012 ◽  
Vol 531 ◽  
pp. 609-612
Author(s):  
Xue Dong Han ◽  
Li Wei ◽  
Gang Luo ◽  
Li Ping Chang
Keyword(s):  
Composite Material ◽  
Resin Composite ◽  
Steel Bridge ◽  
Stress Distributions ◽  
Element Analysis ◽  
Steel Truss Bridge ◽  
The Finite Element Analysis ◽  
Before And After ◽  
Truss Bridge

The intensity of the joint in the bottom chord would affect the quality of the whole bridge because that the force of the bottom-through bridge is transferred mainly through the bottom chord, and the members of the truss connect each other by using the thread. In this paper, the bottom chord around the tapped holes is reinforced by composite material , and the stress on the bottom chord is analyzed before and after the reinforcement using the finite element analysis method, and the stress distributions in the directions of X,Y and Z on every layer of the composite material under the bilateral reinforcing condition are extracted and compared. The results show that: Reinforcing the bottom chord around the tapped holes using the composite material can change the stress level of the bottom chord effectively, helping to improve the quality of the construction of the steel bridge and the effect of the bilateral reinforcing is better than the unilateral reinforcing and providing certain reference for the security of the steel truss bridge

Characterization of Nano- and Micro-Filled Resin Composites Used as Dental Restorative Materials

2008 ◽  
Author(s):  
Dalia Abdel Hamid ◽  
Amal Esawi ◽  
Inas Sami ◽  
Randa Elsalawy
Keyword(s):  
Resin Composite ◽  
Physical And Mechanical Properties ◽  
Sem Analysis ◽  
Indentation Modulus ◽  
Resin Composites ◽  
Adhesively Bonded ◽  
Dental Resin ◽  
Tooth Structure ◽  
Dental Restorative

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.

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