Novel antimicrobial and self-healing dental resin to combat secondary caries and restoration fracture.

OBJECTIVE: Dental resin composites have been the most popular materials for repairing tooth decay in recent years. However, secondary caries and bulk fracture are the major hurdles that affect the lifetime of dental resin composites. This current study synthesized a novel antimicrobial and self-healing dental resin containing nanoparticle-modified self-healing microcapsules to combat secondary caries and restoration fracture. METHODS: Multifunctional dental resins containing 0-20% nanoparticle-modified self-healing microcapsules were prepared. The water contact angle, antimicrobial properties, mechanical properties, cell toxicity, and self-healing capability of the dental resins were tested. RESULTS: A novel multifunctional dental resin was synthesized. When the microcapsule mass fraction was 10%, the resin presented a strong bacteriostasis rate (80.3%) and excellent self-healing efficiency (66.1%), while the hydrophilicity, mechanical properties, and cell toxicity were not affected. SIGNIFICANCE: The novel antimicrobial self-healing dental resin is a promising candidate for use in clinical practice, which provides a simple and highly efficient strategy to combat secondary caries and restoration fracture. This novel dental resin also gives the inspiration to prolong the service life of dental restorations.

Bioinspired fluorescent molecules realize super bright blue luminescence under sunlight.

In recent years, non-aromatic fluorescent materials have attracted widespread attention, but achieving a high quantum yield (QY) in their dilute solutions still remains a challenge. In this work, inspired by the Clustering-triggered emission (CTE) phenomenon of non-aromatic amino acids and poly(amino acids), we successfully designed a bioinspired molecule with a dipeptide-like structure and active silanol groups. The as-prepared bioinspired molecule can be hydrolyzed by simple heating to obtain the hydrolysate h-PDs, which can emit strong blue fluorescence in dilute solution. And this was the first time to realize the emission behavior of non-aromatic fluorescent materials under sunlight. The QY of h-PDs in aqueous solution and solid state were as high as 98.2% and 96.3%, respectively, which were attributed to the condensation of active silanol groups at the end of the molecule, and the existence of hydrogen bonds and N â†’ Si coordination bonds that made small molecules cross-linked and aggregated into dense clusters. Finally, the application of h-PDs in the detection of intracellular and exogenous Hg2+ and Cys and luminescent films were also explored. Significantly, this work provides a design strategy for synthesizing high-fluorescence QY non-aromatic fluorescent materials, and verifies their potential application value in the fields of environment, biology and light-emitting devices.

Research progress of dental self-healing microcapsule materials / 口腔医学

@#The self-healing microcapsule material is one of the smart materials that can self-identify and self-heal microcracks. Adding microcapsules to dental resin composites can resist generation of microcracks and prolong service life of resin restorations. In this literature, the overview of self-healing microcapsule materials, the combined application of self-healing microcapsule materials and other modified materials, the silanization treatment of dental self-healing microcapsules, the dynamic mechanics, fatigue and aging studies on self-healing dental resins were comprehensively presented and reviewed. In addition, prospects of dental self-healing microcapsule materials were also discussed.

Novel antibacterial dental resin containing silanized hydroxyapatite nanofibers with remineralization capability.

OBJECTIVES: Secondary caries is the primary issue that causes restoration failure. The objectives of this study were to: (1) synthesize silanized hydroxyapatite nanofibers loaded with erythromycin (s-HAFs@EM); (2) evaluate the mechanical property, antibacterial activity, and remineralization capability of the novel dental resin containing s-HAFs@EM. METHODS: s-HAFs were prepared by the solvothermal approach and loaded with EM. Characterization and antibacterial activity were evaluated. Subsequently, s-HAFs@EM were incorporated into dental resin at different mass fractions (5 %, 10 %, 15 %, and 20 %), and then they were submitted to characterization, including mechanical property, antibacterial activity, remineralization capability, and cytotoxicity. RESULTS: s-HAFs@EM were successfully synthesized, and they exhibited excellent antibacterial activity. Resin containing 15 % s-HAFs@EM exhibited the best flexural strength (118.67 ± 15.71 MPa) and elastic modulus (2.02 ± 0.30 GPa) (P < 0.05), which were increased by 65.43 % and 90.7 %, compared to those of neat resin, respectively. Resin with 15-20 % s-HAFs@EM showed high antibacterial rate (>85 %) when compared control group (P < 0.05). Furthermore, resin also exhibited a definite remineralization capability and good biosafety in vitro. SIGNIFICANCE: This novel multifunctional resin with improved mechanical property, desirable antibacterial activity and remineralization capability is promising to combat secondary caries.

Novel nanoparticle-modified multifunctional microcapsules with self-healing and antibacterial activities for dental applications.

OBJECTIVE: Although microcapsules (MCs) have been used for dental resins to achieve self-healing capabilities, the fragile organic shell and single healing event functions during the service period limit their use. Herein, a novel nanoparticle-modified MC with a nano-antibacterial inorganic filler (NIF) containing a quaternary ammonium salt was synthesized to address these issues. METHODS: MCs with 0 %-30 % NIFs were prepared via an in situ polymerization method and characterized their morphology, chemical composition, thermal stability, roughness, mechanical properties, and antibacterial effect. Subsequently, M-10 MCs were mixed into the resin matrix at a mass fraction of 7.5 %. The self-healing capability and cytotoxicity were evaluated. RESULTS: The introduction of nanomaterials enhances the shell of the MCs and endows them with an antibacterial effect. With the addition of NIFs, the roughness, modulus, and hardness values of MCs all increased (p < 0.05). The presence of M-10 MCs reduced the CFU by 2-3 orders of magnitude compared to the control group. The dental resin containing 7.5 % M-10 MCs obtained almost 69 % self-healing efficiency, without significantly compromising cell viability (p < 0.05). SIGNIFICANCE: Self-healing MCs with NIFs were prepared for the first time with strong antibacterial properties, a substantial self-healing capability, and low toxicity. This multifunctional MC is a promising candidate for use in dental resins to extend the service life and resolve the problem of bulk fracture and secondary caries.

Review on Development and Dental Applications of Polyetheretherketone-Based Biomaterials and Restorations.

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.

Group 2 Innate Lymphoid Cells Participate in Renal Fibrosis in Diabetic Kidney Disease Partly via TGF-ß1 Signal Pathway.

AIM: To explore the role of group 2 innate lymphoid cells (ILC2s) in the pathogenesis of renal fibrosis in diabetic kidney disease (DKD). METHODS: The proportion of ILC2s and the levels of Th2 cytokines (IL-4, IL-5, and IL-13) in the peripheral blood of normal control subjects (NC) or patients with type 2 diabetes mellitus (DM), early diabetic kidney disease (DKD1), or late diabetic kidney disease (DKD2) were analyzed by flow cytometry and ELISA. The expression of transforming growth factor-ß1 (TGF-ß1), fibronectin (FN), collagen1, IL-4Rα, and IL-13Rα1 in renal tubular epithelial cells (HK-2) induced by IL-4, IL-13, or high glucose was analyzed by ELISA or qPCR. RESULTS: The proportion of ILC2s and the levels of IL-4, IL-5, and IL-13 were significantly increased in DKD patients and were positively correlated with the severity of DKD (P < 0.05). The expression of TGF-ß1, FN, and collagen1 was significantly upregulated in HK-2 cells induced by IL-4 or IL-13 (P < 0.05). Moreover, the IL-4Rα and IL-13Rα1 mRNA in HK2 cells were increased followed by high glucose alone or combined with IL-4 or IL-13, but the differences were not statistically significant (P > 0.05). However, compared with high-glucose stimulation alone, the expression of TGF-ß1, FN, and collagen1 was significantly increased in HK-2 cells induced by high glucose combined with IL-4 or IL-13 (P < 0.05). CONCLUSIONS: ILC2s may participate in renal fibrosis in DKD partly via TGF-ß1 signal pathway.

Sweet Taste Receptors Mediated ROS-NLRP3 Inflammasome Signaling Activation: Implications for Diabetic Nephropathy.

Previous studies demonstrated that ROS-NLRP3 inflammasome signaling activation was involved in the pathogenesis of diabetic nephropathy (DN). Recent research has shown that sweet taste receptors (STRs) are important sentinels of innate immunity. Whether high glucose primes ROS-NLRP3 inflammasome signaling via STRs is unclear. In this study, diabetic mouse model was induced by streptozotocin (STZ) in vivo; mouse glomerular mesangial cells (GMCs) and human proximal tubular cells were stimulated by high glucose (10, 20, and 30 mmol/L) in vitro; STR inhibitor lactisole was used as an intervention reagent to evaluate the role and mechanism of the STRs in the pathogenesis of DN. Our results showed that the expression of STRs and associated signaling components (Gα-gustducin, PLCß2, and TRPM5) was obviously downregulated under the condition of diabetes in vivo and in vitro. Furthermore, lactisole significantly mitigated the production of intracellular ROS and reversed the high glucose-induced decrease of Ca2+ and the activation of NLRP3 inflammasome signaling in vitro (p < 0.05). These combined results support the hypothesis that STRs could be involved in the activation of ROS-NLRP3 inflammasome signaling in the pathogenesis of DN, suggesting that STRs may act as new therapeutic targets of DN.