The physical characterization of a thermoplastic polymer for endodontic obturation

Elzubair, Amal; Elias, Carlos Nelson; Suarez, João Carlos Miguez; Lopes, Hélio Pereira; Vieira, Márcia Valéria Boussada

doi:10.1016/j.jdent.2006.03.002

Cited by 120 publications

(87 citation statements)

References 22 publications

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“…The peak at 1731 cm À 1 is associated to carbonyl stretching vibration and at 1293 cm À 1 is related to CÀ O and CÀ C stretching in crystalline phase. The asymmetric and symmetric C-O-C stretching vibration bands are observed at 1240 cm À 1 and 1160 cm À 1 [55][56][57][58]. The peak at 1160 cm À 1 is ascribed to CÀ O and CÀ C stretching in the amorphous phase [55][56][57].…”

Section: Characterization Of Mc-pcl Gelsmentioning

confidence: 94%

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Magnetic field responsive methylcellulose-polycaprolactone nanocomposite gels for targeted and controlled release of 5-fluorouracil

Nikjoo

Aroguz

2015

International Journal of Polymeric Materials and Polymeric Biom

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ABSTRACT5-Fluorouracil loaded magnetic field sensitive methylcellulose and polycaprolactone gels were prepared and characterized by FTIR, XRD, TGA, SEM, and VSM. Swelling analysis supplied important information on drug diffusion properties. The release profile of gels was investigated in different buffer solutions and the highest release values were observed at pH ¼ 7.2. Release kinetic was analyzed using an empirical equation to clarify the transport properties of drug. The effects of nanoparticle concentration and applying external magnetic field were investigated on release profile. The results indicated that the drug release decreased by both, applying external magnetic field and increasing the concentration of Fe 3 O 4 nanoparticles. GRAPHICAL ABSTRACT ARTICLE HISTORY

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Section: Characterization Of Mc-pcl Gelsmentioning

confidence: 94%

“…Figure 5 shows the spectra of pure PCL film. There is a sharp peak at 2h ¼ 21.9°indicating highly ordered chain folding characteristics, related to the semi crystalline structure of PCL [55,58]. X-ray diffraction pattern of blends containing MC-PCL are given in Figure 5.…”

Section: Characterization Of Mc-pcl Gelsmentioning

confidence: 99%

Magnetic field responsive methylcellulose-polycaprolactone nanocomposite gels for targeted and controlled release of 5-fluorouracil

Nikjoo

Aroguz

2015

International Journal of Polymeric Materials and Polymeric Biom

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“…24,25 To check the influence of thermal grease on the thermal wave response, under absorbing conditions for an optically opaque layer, grease were put on top of two different substrates (grade American Iron and Steel Institute-AISI), AISI 304 or AISI 316 stainless steel and glass soda lime. Grease thicknesses were (38,90,166, and 343) lm on glass and (10, 60, 100, 170, and 340) lm on stainless steel. PTR scans were done using light on the grease surface for both substrates, by means of three different sources of radiation, the xenon arc lamp emitting polychromatic white light with a power 800 W, the argon laser with k ¼ 514 nm (model Innova 90-Plus Coherent TEM 00 -6 W, multiline mode), with power applied to the experiment 675 mW, and, finally, the laser diode/Transistor-transistor logic modulated (TTL) (model DHMO-M), k ¼ 532 nm and power 500 mW.…”

Section: A Thermal Coupling Analysismentioning

confidence: 98%

“…This negative slope can be explained by calling the composition of the emulsifier gel, used in preparing CER samples. Since the volume emulsion is mainly constituted by polymeric materials, which present thermal diffusivity at least 1 order of magnitude lower than cements, 23,[36][37][38] it could be expected. For thermal effusivity, the slope was (0.0023 6 0.0026) and for heat capacity (0.016 6 0.031), these values are in agreement with that for MTA with dispersion at most about 11% for both "e" and for "qc p. " Again, recalling the definition of thermal diffusivity a ¼ K/qc p and observing that slope of "qc p " is positive, the immediate consequence on "a" is its reduction, agreeing with the reducing or negative slope of "a.…”

Section: Influence Of Emulsion Volumementioning

confidence: 99%

Non-destructive thermal wave method applied to study thermal properties of fast setting time endodontic cement

Picolloto

Mariucci

Szpak

et al. 2013

Journal of Applied Physics

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The thermal wave method is applied for thermal properties measurement in fast endodontic cement (CER). This new formula is developed upon using Portland cement in gel and it was successfully tested in mice with good biocompatibility and stimulated mineralization. Recently, thermal expansion and setting time were measured, conferring to this material twice faster hardening than the well known Angelus Mineral trioxide aggregate (MTA) the feature of fast hardening (∼7 min) and with similar thermal expansion (∼12 μstrain/ °C). Therefore, it is important the knowledge of thermal properties like thermal diffusivity, conductivity, effusivity in order to match thermally the tissue environment upon its application in filling cavities of teeth. Photothermal radiometry technique based on Xe illumination was applied in CER disks 600 μm thick for heating, with prepared in four particle sizes (25, 38, 45, and 53) μm, which were added microemulsion gel with variation volumes (140, 150, 160, and 170) μl. The behavior of the thermal diffusivity CER disks shows linear decay for increase emulsion volume, and in contrast, thermal diffusivity increases with particles sizes. Aiming to compare to MTA, thermal properties of CER were averaged to get the figure of merit for thermal diffusivity as (44.2 ± 3.6) × 10−3 cm2/s, for thermal conductivity (228 ± 32) mW/cm K, the thermal effusivity (1.09 ± 0.06) W s0.5/cm2 K and volume heat capacity (5.2 ± 0.7) J/cm3 K, which are in excellent agreement with results of a disk prepared from commercial MTA-Angelus (grain size < 10 μm using 57 μl of distilled water).

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“…Both materials have also been shown to have the same melting point (60℃). 1,4,5 However, in the comparison of specific heat capacities of the two materials, Resilon revealed significantly more heat absorption for melting compared to gutta percha. 1 Resilon allowed deeper penetration with a spreader than gutta percha when using the same controlled pressure during compaction.…”

Section: Introductionmentioning

confidence: 97%

Rheological characterization of thermoplasticized injectable gutta percha and resilon

Chang

Baek

Lee

2011

J Korean Acad Conserv Dent

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Objectives:The purpose of this study was to observe the change in the viscoelastic properties of thermoplasticized injectable root canal filling materials as a function of temperature and to compare the handling characteristics of these materials. Materials and Methods: Three commercial gutta perchas and Resilon (Pentron Clinical Technologies) in a pellet form were heated in the Obtura-II system (Obtura Spartan) at 140℃ and 200℃, and the extrusion temperature of the thermoplasticized materials was measured. The viscoelastic properties of the materials as a function of temperature were evaluated using a rheometer. The elastic modulus G', viscous modulus G'', loss tangent tan δ , and complex viscosity η * were determined. The phase transition temperature was determined by both the rheometer and a differential scanning calorimeter (DSC). The consistency of the materials was compared under compacting pressure at 60℃ and 40℃ by a squeeze test. Results: The three gutta perchas had dissimilar profiles in viscoelastic properties with varying temperature. The phase transition of softened materials into solidification occurred at 40℃ to 50℃, and the onset temperatures obtained by a rheometer and a DSC were similar to each other. The onset temperature of phase transition and the consistency upon compaction pressure were different among the materials (p < 0.05). Resilon had a rheologically similar pattern to the gutta perchas, and was featured between high and low-flow gutta perchas. Conclusions:The rheological characteristics of the thermoplasticized root canal filling materials changed under a cooling process. The dissimilar viscoelastic properties among the materials require different handling characteristics during an injecting and compacting procedure.

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The physical characterization of a thermoplastic polymer for endodontic obturation

Cited by 120 publications

References 22 publications

Magnetic field responsive methylcellulose-polycaprolactone nanocomposite gels for targeted and controlled release of 5-fluorouracil

Magnetic field responsive methylcellulose-polycaprolactone nanocomposite gels for targeted and controlled release of 5-fluorouracil

Non-destructive thermal wave method applied to study thermal properties of fast setting time endodontic cement

Rheological characterization of thermoplasticized injectable gutta percha and resilon

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