The Effect of Elastic Moduli of Restorative Materials on the Stress of Non-Carious Cervical Lesion

Author(s):  
W. Kwon ◽  
K. H. Kim ◽  
K. Son ◽  
J. K. Park
2019 ◽  
Vol 4 (1) ◽  
pp. 19-24
Author(s):  
Gabriela Beresescu ◽  
Emanuela Tegla ◽  
Despina Temistocle ◽  
Alina Ormenisan ◽  
Alina Baldean

Abstract Background: Cervical lesions appear on the cervical surface of the lingual or buccal side of the tooth and are classified into carious and non-carious lesions. Aim: The present study evaluates the performance of three different types of aesthetic restorative materials, used for the restoration of carious or non-carious cervical lesions. Materials and methods: The study comprised 195 cervical lesions in 45 patients. The restorations were carried out for non-carious cervical lesions in 34.62% of the cases, for primary carious lesions in 40.00% of the cases, and to replace a previous restoration in 25.38% of the cases. The restorations were evaluated at 2 weeks (the reference line), and then at 1 and 2 years after placement. The following have been assessed: restoration retention, color harmonization, surface texture, margin discoloration, anatomical contour, margin integrity, and the presence of secondary caries. The characteristics were registered in conformity with the modified USPHS criteria. Results: At the one-year evaluation, we noticed the loss of 12 restorations, and after 2 years, the loss of 19 restorations. The results showed significant differences between restorative materials regarding color, margin adaptation, margin coloration, surface texture, as well as criteria regarding the anatomical contour (p <0.05). Conclusions: The evaluation of the success of restorative material retention must consider the location of the cervical lesion. A successful treatment depends particularly on a full understanding of the factors that caused the lesions and on the method of their treatment.


2002 ◽  
Vol 715 ◽  
Author(s):  
Zhi-Feng Huang ◽  
Rashmi C. Desai

AbstractThe morphological and compositional instabilities in the heteroepitaxial strained alloy films have attracted intense interest from both experimentalists and theorists. To understand the mechanisms and properties for the generation of instabilities, we have developed a nonequilibrium, continuum model for the dislocation-free and coherent film systems. The early evolution processes of surface pro.les for both growing and postdeposition (non-growing) thin alloy films are studied through a linear stability analysis. We consider the coupling between top surface of the film and the underlying bulk, as well as the combination and interplay of different elastic effects. These e.ects are caused by filmsubstrate lattice misfit, composition dependence of film lattice constant (compositional stress), and composition dependence of both Young's and shear elastic moduli. The interplay of these factors as well as the growth temperature and deposition rate leads to rich and complicated stability results. For both the growing.lm and non-growing alloy free surface, we determine the stability conditions and diagrams for the system. These show the joint stability or instability for film morphology and compositional pro.les, as well as the asymmetry between tensile and compressive layers. The kinetic critical thickness for the onset of instability during.lm growth is also calculated, and its scaling behavior with respect to misfit strain and deposition rate determined. Our results have implications for real alloy growth systems such as SiGe and InGaAs, which agree with qualitative trends seen in recent experimental observations.


1983 ◽  
Vol 11 (1) ◽  
pp. 3-19
Author(s):  
T. Akasaka ◽  
S. Yamazaki ◽  
K. Asano

Abstract The buckled wave length and the critical in-plane bending moment of laminated long composite strips of cord-reinforced rubber sheets on an elastic foundation is analyzed by Galerkin's method, with consideration of interlaminar shear deformation. An approximate formula for the wave length is given in terms of cord angle, elastic moduli of the constituent rubber and steel cord, and several structural dimensions. The calculated wave length for a 165SR13 automobile tire with steel breakers (belts) was very close to experimental results. An additional study was then conducted on the post-buckling behavior of a laminated biased composite beam on an elastic foundation. This beam is subjected to axial compression. The calculated relationship between the buckled wave rise and the compressive membrane force also agreed well with experimental results.


2015 ◽  
Vol 10 (2) ◽  
pp. 2663-2681
Author(s):  
Rizk El- Sayed ◽  
Mustafa Kamal ◽  
Abu-Bakr El-Bediwi ◽  
Qutaiba Rasheed Solaiman

The structure of a series of AlSb alloys prepared by melt spinning have been studied in the as melt–spun ribbons  as a function of antimony content .The stability  of these structures has  been  related to that of the transport and mechanical properties of the alloy ribbons. Microstructural analysis was performed and it was found that only Al and AlSb phases formed for different composition.  The electrical, thermal and the stability of the mechanical properties are related indirectly through the influence of the antimony content. The results are interpreted in terms of the phase change occurring to alloy system. Electrical resistivity, thermal conductivity, elastic moduli and the values of microhardness are found to be more sensitive than the internal friction to the phase changes. 


2019 ◽  
Vol 4 (1) ◽  
pp. 87-91
Author(s):  
Leandro COSTA ◽  
Larissa SOARES-SILVA ◽  
Paulini Malfei De C. COSTA ◽  
Adrielle MANGABEIRA ◽  
Maristela PORTELA ◽  
...  

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