Heterogeneity Challenges in Multiple-Element-Modified Lead-Free Piezoelectric Ceramics

We report on a heterogeneity study, down to the atomic scale, on a representative multiple-element-modified ceramic based on potassium sodium niobate (KNN): 0.95(Na0.49K0.49Li0.02)(Nb0.8Ta0.2)O3–0.05CaZrO3 with 2 wt % MnO2. We show that different routes for incorporating the MnO2 (either before or after the calcination step) affect the phase composition and finally the functionality of the material. According to X-ray diffraction and scanning electron microscopy analyses, the ceramics consist of orthorhombic and tetragonal perovskite phases together with a small amount of Mn-rich secondary phase. The addition of MnO2 after the calcination results in better piezoelectric properties, corresponding to a ratio between the orthorhombic and tetragonal perovskite phases that is closer to unity. We also show, using microscopy techniques combined with analytical tools, that Zr-rich, Ta-rich and Mn-rich segregations are present on the nano and atomic levels. With this multi-scale analysis approach, we demonstrate that the functional properties are sensitive to minor modifications in the synthesis route, and consequently to different material properties on all scales. We believe that detecting and learning how to control these modifications will be a step forward in overcoming the irreproducibility problems with KNN-based materials

Magnetic contributions in multiferroic gadolinium modified bismuth ferrite ceramics

Bi0.88Gd0.12FeO3 multiferroics are of interest for next-generation electronics and are shown with a remnant magnetization 0.2 emu·g−1, coercive field 8 kOe, Curie temperature 370 °C and magnetization of 0.7 emu·g−1 at magnetic fields 30 kOe. Scanning probe microscopy confirmed the intrinsic multiferroicity in the perovskite phase with coexistence of ferroelectric/ferroelastic and ferromagnetic domain structures. Strong magnetic hysteresis was produced by thermal cycling to 1000 °C due to degeneration of the perovskite phase into iron oxide inclusions, highlighting the importance of processing, thermal history and thermodynamic stability for minimizing the amount of parasitic magnetic secondary phases

THE IMPACT OF SYSTEMIC CORTICOSTEROID THERAPY ON ORAL HEALTH: COMPLICATIONS AND MANAGEMENT STRATEGIES

Corticosteroids, including glucocorticoids, mineralocorticoids, and androgenic hormones, are hormonal mediators produced by the adrenal glands and are widely used in the treatment of various conditions, including dental diseases. While systemic corticosteroid therapy offers significant therapeutic benefits, it is crucial to understand the potential adverse effects on oral health. This paper aims to highlight the impact of systemic corticosteroid therapy on oral health, focusing particularly on the associated complications and management strategies. The paper emphasizes specific complications that may occur in the oral cavity as a result of corticosteroid use, the most important being an increased susceptibility to oral infections such as candidiasis and impaired bone metabolism, with a significant reduction in the mineral density of the mandibular bone (BMD), as well as delayed wound healing, the occurrence of oral ulcers, and changes in the oral microbiome. Furthermore, the importance of rigorous oral care and regular dental monitoring for patients undergoing systemic corticosteroid therapy is underlined. The role of oral health specialists in the early detection and efficient management of oral complications, as well as patient education regarding proper oral hygiene practices and possible side effects, is of crucial importance. In conclusion, it is essential for healthcare providers to be vigilant regarding the potential oral health complications associated with systemic corticosteroid therapy, and early detection, prevention, and the implementation of appropriate management strategies are fundamental for optimizing oral health outcomes in patients undergoing corticosteroid treatment

ANGULAR CHEILITIS: A MULTIDISCIPLINARY APPROACH TO DIAGNOSIS AND MANAGEMENT

Angular Cheilitis (AC) represents a multifaceted oral pathology characterized by erythematous lesions at the labial commissures. Despite its prevalence, AC is often inadequately addressed due to its polymorphic etiology, which can encompass infectious agents, nutritional deficits, and systemic conditions. This article provides a systematic review of the pathophysiology, clinical presentation, and etiological factors of AC, including nutritional deficiencies, infectious agents, and systemic diseases. Emphasizing a multidisciplinary strategy, we discuss the collaborative roles of dental, medical, and dermatological expertise in the accurate diagnosis and effective management of AC. We outline diagnostic criteria, appropriate laboratory tests, and imaging techniques tailored to address the multifaceted nature of the condition. Management strategies encompass a range of options from topical treatments and medications to dietary modifications and preventative measures, with an emphasis on evidence-based practices. This review advocates for integrated care models to optimize treatment efficacy, patient compliance, and to mitigate the recurrence of AC. Our analysis aims to enhance the understanding of AC and to provide a framework for its management, contributing to better patient care and opening avenues for future research

ORAL MANIFESTATIONS OF VIRAL INFECTIONS IN IMMUNOCOMPROMISED CANCER PATIENTS

Immunodeficiencies induced by chemotherapy make cancer patients vulnerable to to reactivation of latent viruses and to primary viral infections caused by exposure to environmental factors, such as air, water, microbial flora and debris. Patients with hematological cancers are more prone than patients with solid tumors to develop viral infections that affect the oral cavity due to high-dose chemotherapy regimens and prolonged immunosuppression. Viruses of the Herpetoviridae family (herpes simplex, varicella, cytomegalovirus, Epstein-Barr) and human papillomavirus cause mouth pain with difficulties in eating and oral ulcerations that can spread, leading to life-threatening systemic infection. Therapeutic approaches for the more severe and atypical oral manifestations seen in cancer immunosuppressed patients include inhibitors of virus replication, antivirals, surgical excision and analgesics, but the painful oral lesions are associated with longer healing times. The differential diagnosis of a oral ulcers in cancer patients is broad, but it should include various viral infections