Polyetheretherketone (PEEK) has been widely applied in fixed dental prostheses, comprising crowns, fixed partial dentures, and post-and-core. PEEK’s excellent mechanical properties facilitate better stress distribution than conventional materials, protecting the abutment teeth. However, the stiffness of PEEK is not sufficient, which can be improved via fiber reinforcement. PEEK is biocompatible. It is nonmutagenic, noncytotoxic, and nonallergenic. However, the chemical stability of PEEK is a double-edged sword. On the one hand, PEEK is nondegradable and intraoral corrosion is minimized. On the other hand, the inert surface makes adhesive bonding difficult. Numerous strategies for improving the adhesive properties of PEEK have been explored, including acid etching, plasma treatment, airborne particle abrasion, laser treatment, and adhesive systems.
1 January 2022 in Oxidative Medicine and Cellular Longevity
Traumatic brain injury (TBI) makes up a large proportion of acute brain injuries and is a major cause of disability globally. Its complicated etiology and pathogenesis mainly include primary injury and secondary injury over time, which can cause cognitive deficits, physical disabilities, mood changes, and impaired verbal communication. Recently, mesenchymal stromal cell‐ (MSC‐) based therapy has shown significant therapeutic potential to target TBI‐induced pathological processes, such as oxidative stress, neuroinflammation, apoptosis, and mitochondrial dysfunction. In this review, we discuss the main pathological processes of TBI and summarize the underlying mechanisms of MSC‐based TBI treatment. We also discuss research progress in the field of MSC therapy in TBI as well as major shortcomings and the great potential shown.
1 January 2020 in Evidence-Based Complementary and Alternative Medicine
Periodontitis is an infectious disease whereby the chronic inflammatory process of the periodontium stimulated by bacterial products induces specific host cell responses. The activation of the host cell immune system upregulates the production of inflammatory mediators, comprising cytokines and proteolytic enzymes, which contribute to inflammation and bone destruction. It has been well known that periodontitis is related to systemic inflammation which links to numerous systemic diseases, including diabetes and arteriosclerosis. Furthermore, periodontitis has been reported in association with neurodegenerative diseases such as Alzheimer’s disease (AD) in the brain. Regarding immune responses and inflammation, cathepsin B (CatB) plays pivotal role for the induction of IL‐1β, cathepsin K‐ (CatK‐) dependent active toll‐like receptor 9 (TLR9) signaling, and cathepsin S (CatS) which involves in regulating both TLR signaling and maturation of the MHC class II complex. Notably, both the production and proteolytic activities of cathepsins are upregulated in chronic inflammatory diseases, including periodontitis. In the present review, we focus on the roles of cathepsins in the innate and adaptive immune responses within periodontitis. We believe that understanding the roles of cathepsins in the immune responses in periodontitis would help to elucidate the therapeutic strategies of periodontitis, thus benefit for reduction of systemic diseases as well as neurodegenerative diseases in the global aging society.
Polyetheretherketone (PEEK) and its fiber-reinforced composites have been indicated as ideal post-and-cores materials due to its mechanical properties. However, the laboratory evidences of post-and-cores restored with fiber-reinforced PEEK are lacking. A total of 120 extracted mandibular premolars were treated endodontically and divided into six groups restored with different post-and-core materials (N = 20): (1) prefabricated quartz fiber-reinforced composite (QFRC), (2) polymer-infiltrated ceramic (PIC), (3) cobalt chromium (CoCr), (4) PEEK, (5) 30% glass fiber-reinforced PEEK (GFR-PEEK), and (6) 30% carbon fiber-reinforced PEEK (CFR-PEEK). Stress distribution was analyzed by finite element analysis (FEA). Then, each group was then divided into two subgroups (n = 10): static loading test and fatigue loading test. The static failure load (SFL) was analyzed by one-way analysis of variance (ANOVA) with least-significant difference (LSD) multiple comparison tests. The fatigue failure load (FFL) and cycles for failure (CFF) were evaluated by Kaplan-Meier survival analysis (P < 0.05). Groups PEEK, GFR-PEEK, and CFR-PEEK exhibited lower maximum peak principal stress and better stress distribution than Group CoCr. The SFL of Groups PEEK and QFRC did not differ from each other, and both were lower than those of Groups CoCr, GFR-PEEK, and CFR-PEEK. In the fatigue loading test, Group CoCr exhibited the best survival; however, with the progression of fatigue, the survival probabilities of Groups PEEK and its composites were close to that of Group CoCr. In all groups apart from Group CoCr, the rate of repairable failure modes was higher than that of irreparable ones. Customized post-and-cores manufactured with PEEK and its fiber-reinforced composites showed superior biomechanical performance, making them potential alternatives for the restoration of massive tooth defects. This study provides a theoretical basis for clinicians to select post-and-core materials for different root canal morphology residual roots and helps to reduce the occurrence of complications such as root fracture and post core debonding.
1 January 2020 in Evidence-Based Complementary and Alternative Medicine
Objective. To investigate the expression patterns and prognostic characteristics of inflammasome‐related genes (IRGs) across cancer types and develop a robust biomarker for the prognosis of KIRC. Methods. The differentially expressed IRGs and prognostic genes among 10 cancers were analyzed based on The Cancer Genome Atlas (TCGA) dataset. Subsequently, an IRGs risk signature was developed in KIRC. Its prognostic accuracy was evaluated by receiver operating characteristic (ROC) analysis. The independent predictive capacity was identified by stratification survival and multivariate Cox analyses. The gene ontology (GO) analysis and principal component analysis (PCA) were performed to explore biological functions of the IRGs signature in KIRC. Results. The expression patterns and prognostic association of IRGs varied from different cancers, while KIRC showed the most abundant survival‐related dysregulated IRGs. The IRG signature for KIRC was able to independently predict survival, and the signature genes were mainly involved inimmune‐related processes. Conclusions. The pan‐cancer analysis provided a comprehensive landscape of IRGs across cancer types and identified a strong association between IRGs and the prognosis of KIRC. Further IRGs signature represented a reliable prognostic predictor for KIRC and verified the prognostic value of inflammasomes in KIRC, contributing to our understanding of therapies targeting inflammasomes for human cancers.