Thermal expansion and filler content of composite resins

Hashinger, D.T.; Fairhurst, Carl W.

doi:10.1016/0022-3913(84)90334-2

Cited by 28 publications

(13 citation statements)

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“…(The reported coefficients of thermal expansion of enamel and dentin were approximately 17×10 -6 /°C and 11×10 -6 /×C respectively 26) .) In general, the coefficients for dental composites reportedly ranged between 20×10 -6 /°C and 80×10 -6 /°C 27,28) . A lower coefficient of thermal expansion under a higher energy density could be ascribed to sufficient polymerization.…”

Section: Discussionmentioning

confidence: 99%

The Effects of Light Intensity and Light-curing Time on the Degree of Polymerization of Dental Composite Resins

Baek¹,

Hyun²,

Lee³

et al. 2008

Dent. Mater. J.

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The aim of this study was to investigate the effects of light intensity and light-curing time on the polymerization of composite resins. Four composite resins were light-cured with different light-curing conditions. In the non-thermocycled case, specimens showed almost the same or similar microhardness values if energy density was identical or similar. As the energy density decreased, maximum polymerization shrinkage decreased. At higher energy densities, specimens had a lower coefficient of thermal expansion than at lower energy densities. At the same or similar energy density, most resin products showed coefficient values which were not statistically different. After 10,000 thermocycles, specimens showed decreases of 2.4 -16.5% and 4.6 -25.2% in microhardness and coefficient of thermal expansion respectively. Within the limitations of the present study, it was found that light-curing composite resins with higher energy density was beneficial to acquiring higher microhardness values and lower coefficients of thermal expansion.

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Section: Discussionmentioning

confidence: 99%

The Effects of Light Intensity and Light-curing Time on the Degree of Polymerization of Dental Composite Resins

Baek¹,

Hyun²,

Lee³

et al. 2008

Dent. Mater. J.

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“…It is for this reason that ideally restorative materials should have similar coefficients of thermal expansion to enamel and dentine of tooth. For some commercial pit and fissure sealants this coefficient was found to range from 70.9 to 93.7 Â 10 À6 / C [4], while for various commercial resin composites from 26 to 35 Â 10 À6 / C [2,4], or from 26 to 83.5 Â 10 À6 / C [5], or from 20 to 80 Â 10 À6 / C [6]; all for the temperature range 0-60 C. For the enamel and dentin it is 17 Â 10 À6 / C and about 11 Â 10 À6 / C, respectively [7]. The most widely used resin in dental composites is that based on the copolymer network prepared from a combination of bisphenol A glycol dimethacrylate (Bis-GMA) and triethylene glycol dimethacrylate (TEGD-MA).…”

Section: Introductionmentioning

confidence: 98%

“…In the literature there is a controversy about this view. Some researchers observed that there is an inverse linear relationship between the coefficient of linear thermal expansion and the filler volume fraction of the composite [6,[17][18][19] while, others did not find any significant correlation between these parameters and suggest that the thermal expansion is also affected by some other potential factors, such as the thermal characteristics of the filler particles, the condition of silanate bonding between filler and matrix and composition of the matrix resin [5].…”

Section: Introductionmentioning

confidence: 99%

Thermal expansion characteristics of light-cured dental resins and resin composites

2004

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“…No micromechanics algorithm has been devised to determine the thermal coefficients of dental FRCs according to their varying fiber orientation. A number of different experimental methods are in use to determine the coefficient of thermal expansion of FRC materials, such as the TMA [15], differential dilatometer [16,17] and strain gages [18]. The TMA method for measurement of linear CTE is relatively fast, easy, and suitable for the measurement of small sized specimens, e.g.…”

Section: Industrial Application Of the Algorithmmentioning

confidence: 99%

“…For anisotropic materials, shear strains will also be developed due to temperature change. The compliance matrix in the above formulation can be written in terms of the conventional engineering constants (Young's modulus and Poisson's ratio) and by introduction of the shear coupling parameter in general if required [16].…”

Section: Micromechanics Analysis Techniquementioning

confidence: 99%

Thermoelastic Characterization and Evaluation of Residual Stresses in Bi-Directional Fibrous Composites

et al. 2008

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The thermoelastic behavior of bi-directional fibrous composites will be studied through the use of a finite element-based micromechanical model. The model is used to study the effect of the crossing angle of the fibers on the composite's coefficient of thermal expansion (CTE) and the residual thermal stresses that develop after a temperature change. The effect of the fiber volume fraction (V f ) on the same results is also studied. For anisotropic materials, one can see that in addition to normal strains, shear strains will also be developed due to temperature change. This method will lend itself to evaluate the coefficients of thermal expansions not only due to normal expansion, but also due to shear expansion for composites with no principal directions. In this micromechanical model, parallelepiped unit cells incorporating the fibers at different cross angles are created to represent the periodic microstructure of the angular bi-directional composite. The volume averaged stresses per unit temperature of the individual constituents are used to study the residual thermal stresses that develop. Two different sets of materials are used to test this model. Results show that when the fiber's cross angle is not 0 o or 90 o , shear strains are created. Also, residual stresses in the unit cell are functions of the cross angle between the fibers.

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Thermal expansion and filler content of composite resins

Cited by 28 publications

References 1 publication

The Effects of Light Intensity and Light-curing Time on the Degree of Polymerization of Dental Composite Resins

The Effects of Light Intensity and Light-curing Time on the Degree of Polymerization of Dental Composite Resins

Thermal expansion characteristics of light-cured dental resins and resin composites

Thermoelastic Characterization and Evaluation of Residual Stresses in Bi-Directional Fibrous Composites

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