Fractionation and Molecular Weight of Rubber and Gutta-Percha

Kemp, A. R.; Peters, H.

doi:10.1021/ie50383a014

Cited by 9 publications

(5 citation statements)

References 7 publications

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“…Gutta-percha is a trans -1,4-polyisoprene based nanocomposite, where the average molecular weight of the PI matrix was found to be 42,000 [ 19 ]. Because of the low glass transition temperature of PI, T g = −40 °C, inorganic fillers are added to reinforce the mechanical properties [ 20 , 21 ].…”

Section: Introductionmentioning

confidence: 99%

Differentiation of Dental Pulp Stem Cells on Gutta-Percha Scaffolds

Zhang

Joubert

et al. 2016

Polymers

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Advances in treatment of tooth injury have shown that tooth regeneration from the pulp was a viable alternative of root canal therapy. In this study, we demonstrated that Gutta-percha, nanocomposites primarily used for obturation of the canal, are not cytotoxic and can induce differentiation of dental pulp stem cells (DPSC) in the absence of soluble mediators. Flat scaffolds were obtained by spin coating Si wafers with three Gutta-percha compounds: GuttaCore™, ProTaper™, and Lexicon™. The images of annealed surfaces showed that the nanoparticles were encapsulated, forming surfaces with root mean square (RMS) roughness of 136-211 nm. Then, by culturing DPSC on these substrates we found that after some initial difficulty in adhesion, confluent tissues were formed after 21 days. Imaging of the polyisoprene (PI) surfaces showed that biomineral deposition only occurred when dexamethasone was present in the media. Spectra obtained from the minerals was consistent with that of hydroxyapatite (HA). In contrast, HA deposition was observed on all Gutta-percha scaffolds regardless of the presence or absence of dexamethasone, implying that surface roughness may be an enabling factor in the differentiation process. These results indicate that Gutta-percha nanocomposites may be good candidates for pulp regeneration therapy.

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Section: Introductionmentioning

confidence: 99%

Differentiation of Dental Pulp Stem Cells on Gutta-Percha Scaffolds

Zhang

Joubert

et al. 2016

Polymers

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“…1 (regular Buna S gum) 2 (regular Buna S-Statex)3 (high-mol.-wt. fraction Buna S gum)4 (high-mol.-wt. fraction Buna S-Statex)5 (natural rubber gum) Acetone Chloroform Ext., % Ext., % 0-24 hr.…”

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confidence: 99%

Structural Features of Buna S

Kemp¹,

Straitiff²

1944

Ind. Eng. Chem.

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“…Pummerer (17,18) termed the ether-soluble part the "sol" fraction and the ether-insoluble part, the "gel" fraction. More recently Kemp and Peters (9,10,11) and Bloomfield and portions depends on the type of solvent used and other conditions of extraction. Although the method of Pummerer produces only a rough separation, it was chosen as a convenient starting point for the electron microscope examination of rubber fractions, and the terms "sol" and "gel" will refer here to fractions obtained by this method.…”

Section: Unvulcanized Rubbermentioning

confidence: 99%