Synthesis of antibacterial methacrylate monomer derived from thiazole and its application in dental resin

Polyetheretherketone (PEEK) is an important high-performance thermoplastic. Its excellent strength, stiffness, toughness, fatigue resistance, biocompatibility, chemical stability and radiolucency have made PEEK attractive in dental and orthopedic applications. However, PEEK has an inherently hydrophobic and chemically inert surface, which has restricted its widespread use in clinical applications, especially in bonding with dental resin composites. Cutting edge research on novel methods to improve PEEK applications in dentistry, including oral implant, prosthodontics and orthodontics, is reviewed in this article. In addition, this article also discusses innovative surface modifications of PEEK, which are a focus area of active investigations. Furthermore, this article also discusses the necessary future studies and clinical trials for the use of PEEK in the human oral environment to investigate its feasibility and long-term performance.

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Enhancing Toughness and Reducing Volumetric Shrinkage for Bis-GMA/TEGDMA Resin Systems by Using Hyperbranched Thiol Oligomer HMDI-6SH

Materials ◽

10.3390/ma14112817 ◽

2021 ◽

Vol 14 (11) ◽

pp. 2817

Author(s):

Biao Yu ◽

Jingwei He ◽

Sufyan Garoushi ◽

Pekka K. Vallittu ◽

Lippo Lassila

Keyword(s):

Water Sorption ◽

Water Solubility ◽

Click Reaction ◽

Raw Materials ◽

Triethylene Glycol ◽

Bending Test ◽

Volumetric Shrinkage ◽

Dental Resin ◽

System A ◽

Double Bond Conversion

In order to improve the toughness and reduce polymerization shrinkage of traditional bisphenol A-glycidyl methacrylate (Bis-GMA)/triethylene glycol dimethacrylate (TEGDMA) based dental resin system, a hyperbranched thiol oligomer (HMDI-6SH) was synthesized via thiol-isocyanate click reaction using pentaerythritol tetra(3-mercaptopropionate (PETA) and dicyclohexylmethane 4,4′-diisocyanate (HMDI) as raw materials. Then HMDI-6SH was mixed with 1,3,5-Triallyl-1,3,5-Triazine-2,4,6(1H,3H,5H)-Trione (TTT) to prepare thiol-ene monomer systems, which were added into Bis-GMA/TEGDMA resins with different mass ratio from 10 wt% to 40 wt% to serve as anti-shrinking and toughening agent. The physicochemical properties of these thiol-ene-methacrylate ternary resins including functional groups conversion, volumetric shrinkage, flexural properties, water sorption, and water solubility were evaluated. The results showed that the incorporation of HMDI/TTT monomer systems into Bis-GMA/TEGDMA based resin could improve C=C double bond conversion from 62.1% to 82.8% and reduced volumetric shrinkage from 8.53% to 4.92%. When the mass fraction of HMDI/TTT monomer systems in the resins was no more than 20 wt%, the flexural strength of the resin was higher or comparable to Bis-GMA/TEGDMA based resins (p > 0.05). The toughness (it was measured from the stress–strain curves of three-point bending test) of the resins was improved. Water sorption and water solubility tests showed that the hydrophobicity of resin was enhanced with increasing the content of thioester moiety in resin.

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A Low-Viscosity BisGMA Derivative for Resin Composites: Synthesis, Characterization, and Evaluation of Its Rheological Properties

Materials ◽

10.3390/ma14020338 ◽

2021 ◽

Vol 14 (2) ◽

pp. 338

Author(s):

Ali Alrahlah ◽

Abdel-Basit Al-Odayni ◽

Haifa Fahad Al-Mutairi ◽

Bashaer Mousa Almousa ◽

Faisal S. Alsubaie ◽

...

Keyword(s):

Substantial Reduction ◽

Triethylene Glycol ◽

High Viscosity ◽

Resin Matrix ◽

Resonance Spectroscopy ◽

Dental Resin ◽

Triethylene Glycol Dimethacrylate ◽

Oh Groups ◽

Low Viscosity ◽

13C Nuclear Magnetic Resonance

This study aimed to synthesize new bisphenol A-glycidyl methacrylate (BisGMA) derivatives, targeting a reduction in its viscosity by substituting one of its OH groups, the leading cause of its high viscosity, with a chlorine atom. Hence, this monochloro-BisGMA (mCl-BisGMA) monomer was synthesized by Appel reaction procedure, and its structure was confirmed using Fourier transform infrared spectroscopy, 1H and 13C-nuclear magnetic resonance spectroscopy, and mass spectroscopy. The viscosity of mCl-BisGMA (8.3 Pa·s) was measured under rheometry conditions, and it was found to be more than 65-fold lower than that of BisGMA (566.1 Pa·s) at 25 °C. For the assessment of the viscosity changes of model resins in the presence of mCl-BisGMA, a series of resin matrices, in which, besides BisGMA, 50 wt % was triethylene glycol dimethacrylate, were prepared and evaluated at 20, 25, and 35 °C. Thus, BisGMA was incrementally replaced by 25% mCl-BisGMA to obtain TBC0, TBC25, TBC50, TBC75, and TBC100 blends. The viscosity decreased with temperature, and the mCl-BisGMA content in the resin mixture increased. The substantial reduction in the viscosity value of mCl-BisGMA compared with that of BisGMA may imply its potential use as a dental resin matrix, either alone or in combination with traditional monomers. However, the various properties of mCl-BisGMA-containing matrices should be evaluated.

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Viscosity and stickiness of dental resin composites at elevated temperatures

Dental Materials ◽

10.1016/j.dental.2020.11.024 ◽

2021 ◽

Vol 37 (3) ◽

pp. 413-422

Author(s):

Nikolaos Loumprinis ◽

Eva Maier ◽

Renan Belli ◽

Anselm Petschelt ◽

George Eliades ◽

...

Keyword(s):

Elevated Temperatures ◽

Resin Composites ◽

Dental Resin ◽

Dental Resin Composites

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Effect of Accelerated Aging on Some Mechanical Properties and Wear of Different Commercial Dental Resin Composites

Materials ◽

10.3390/ma14112769 ◽

2021 ◽

Vol 14 (11) ◽

pp. 2769

Author(s):

Jonne Oja ◽

Lippo Lassila ◽

Pekka K. Vallittu ◽

Sufyan Garoushi

Keyword(s):

Mechanical Properties ◽

Flexural Strength ◽

Accelerated Aging ◽

Wear Depth ◽

Resin Composites ◽

Expiration Date ◽

Dental Resin ◽

Hydrothermal Aging ◽

Dental Resin Composites

The aim of current in vitro research was to determine the effect of hydrothermal accelerated aging on the mechanical properties and wear of different commercial dental resin composites (RCs). In addition, the effect of expiration date of the composite prior its use was also evaluated. Five commercially available RCs were studied: Conventional RCs (Filtek Supreme XTE, G-aenial Posterior, Denfil, and >3y expired Supreme XTE), bulk-fill RC (Filtek Bulk Fill), and short fiber-reinforced RC (everX Posterior). Three-point flexural test was used for determination of ultimate flexural strength (n = 8). A vickers indenter was used for testing surface microhardness. A wear test was conducted with 15,000 chewing cycles using a dual-axis chewing simulator. Wear pattern was analyzed by a three-dimensional (3D) noncontact optical profilometer. Degree of C=C bond conversion of monomers was determined by FTIR-spectrometry. The specimens were either dry stored for 48 h (37 °C) or boiled (100 °C) for 16 h before testing. Scanning electron microscopy (SEM) was used to evaluate the microstructure of each material. Data were analyzed using ANOVA (p = 0.05). Hydrothermal aging had no significant effects on the surface wear and microhardness of tested RCs (p > 0.05). While flexural strength significantly decreased after aging (p < 0.05), except for G-aenial Posterior, which showed no differences. The lowest average wear depth was found for Filtek Bulk Fill (29 µm) (p < 0.05), while everX Posterior and Denfil showed the highest wear depth values (40, 39 µm) in both conditions. Passing the expiration date for 40 months did not affect the flexural strength and wear of tested RC. SEM demonstrated a significant number of small pits on Denfil’s surface after aging. It was concluded that the effect of accelerated aging may have caused certain weakening of the RC of some brands, whereas no effect was found with one brand of RC. Thus, the accelerated aging appeared to be more dependent on material and tested material property.

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