Study on the Surface of Cobalt-Chromium Dental Alloys and Their Behavior in Oral Cavity as Cast Materials.

This study presents the correct processing of Co-Cr alloys as a method of preserving the properties of the materials as-cast, and therefore they can be safely placed in contact with the oral cavity tissues as resistance frameworks. The basic materials analyzed in this study were five commercial Co-Cr dental alloys with different components obtained in three processing steps. The analysis of the electrochemical behavior at the surface of the Co-Cr alloys was performed by electrochemical measurements: impedance spectroscopy (EIS), open circuit electrical potential (OCP), and linear polarization (LP). In terms of validation, all five alloys had a tendency to generate a stable oxide layer at the surface. After the measurements and the graphical representation, the alloy that had a higher percentage of tungsten (W) and iron (Fe) in composition showed a higher tendency of anodizing. After the application of the heat treatment, the disappearance of the hexagonal phase was observed, with the appearance of new phases of type (A,B)2O3 corresponding to some oxide compounds, such as Fe2O3, Cr2O3, (Cr,Fe)2O3, and CoMnO3. In conclusion, the processing of Co-Cr alloys by melting and casting in refractory molds remains a viable method that can support innovation, in the context of technology advance in recent years towards digitalization of the manufacturing process, i.e., the construction of prosthetic frameworks conducted by additive methods using Co-Cr powder alloy.

High-Frequency Ultrasound Assessment of Skin and Oral Mucosa in Metabolic Syndrome Patients-A Cross-Sectional Study.

BACKGROUND: Exogenous factors (such as sun exposure, smoking habits, and diet) and endogenous (inflammatory status, general diseases) have a direct influence on skin and soft tissue characteristics. The study's objective was to assess the impact of metabolic syndrome (MS) on characteristics of skin layers in sun-exposed and non-exposed maxillofacial tissues evaluated by high-frequency ultrasound (HFU), as a potential diagnosis and monitoring tool for the aging process. MATERIAL AND METHODS: The present study included 102 subjects (24 with MS; 78 without MS). Anthropometric parameters and disease history were recorded, and blood samples were harvested in order to assess biochemical parameters of MS. Sun-exposed skin (zygomatic region) and non-exposed oral mucosa of the lower lip were assessed using HFU (DUB® cutis, Taberna Pro Medicum) with a 22 MHz probe. RESULTS: Patients with cardiac disease had significantly lower values for epidermis density (p = 0.002). Gender was independently linked to the aged dermis depth (p < 0.001), aged dermis no. of px (pixels) (p < 0.001), dermis depth (p < 0.001), dermis no. of px (p < 0.001), and subcutaneous tissue density (p < 0.001). Patients with MS had thinner epidermis (p = 0.008) and thinner aged dermis (p = 0.037) when compared to non-MS subjects. CONCLUSION: Patients with MS had thinner epidermis and a lower epidermis number of pixels in sun-exposed skin. Women had lower epidermis density and thicker dermis in sun-exposed skin. Our study showed that HFU, as a non-invasive investigation approach, is useful to diagnose and monitor the aging process in skin and oral mucosa, correlated with skin phenotype pathological conditions.

Impact of COVID-19 Pandemic on Healthcare Professionals and Oral Care Operational Services: A Systemic Review.

The unprecedented climate of the COVID-19 pandemic has some restrictions on oral care operational services, which heavily impacted the delivery of aerosol generating procedures (AGPs). This led the health authorities to set up guidelines and policies that should be followed to minimize the virus spread and ensure safe and effective dental care delivery. This systemic review aimed to evaluate the current guidelines and strategies in providing safe dental services and ensuring efficacy of the current universal personal preventive and protective measures, as well the impact that this outbreak might have on practicing the dental profession in full scope. The review focus questions were as follows: are the current guidelines and measures in literature mitigated enough to ensure safe and effective oral care delivery to patients during the COVID-19 pandemic? Is it possible to highlight the essential and fundamental cross-infection control measures and policies? Twenty articles were chosen out of 180,248 after the inclusion and exclusion criteria were applied in the period between January 1st and August 1st 2020. Our results highlighted effective safety measures that can be implanted in protecting healthcare professionals and patients and ensuring optimal dental care delivery in a safe and healthy environment, taking into consideration the risk assessment and management of AGPs. In conclusion, informative updated standardized policies and protocols are required when more knowledge on the virus behavior keeps evolving. Moreover, there is a need for evidence-based protective measures to be modified on a regular basis to be followed, until a safe vaccine is produced.

Oral appliance therapy in obstructive sleep apnea and snoring - systematic review and new directions of development.

Objective: Oral appliance therapy is a non-invasive treatment that offers a wide variety of oral devices for the treatment of obstructive sleep apnea (OSA). The present review focuses on the effectiveness of mandibular advancement devices for the treatment of OSA.Methods: A systematic review based on the PRISMA checklist was carried out. A detailed electronic database search was conducted using "Obstructive sleep apnea" AND "Oral appliance" AND "Dentistry" as keywords.Results: The initial search in the electronic databases resulted in a total of 262 papers. After the title and abstract analysis and full-text review, the number of eligible papers was reduced to 15.Conclusion: The mandibular advancement device is an effective treatment, improving the Apnea Hypopnea Index and the symptoms of patients with OSA in 92% of the subjects from all the investigated studies. The future may include the integration of a biosensor for the diagnosis and follow-up.Abbreviations: OSA: Obstructive sleep apnea; MADs: Mandibular advancement devices; CPAP: Continuous positive airway pressure; OAT: Oral appliance therapy; MRD: Mandibular repositioning devices; MAS: Mandibular advancement splints; MAA: Mandibular advancement appliances; OA: Oral appliances; AASM: American Academy of Sleep Medicine; AHI: Apnea-hypopnea index; EEG: Sleep-related breathing disorder SRBD; Electroencephalogram; EOG: Electrooculogram; ECG: Electrocardiogram; QOL: Quality of life; TMJ: Temporomandibular joint.

Saliva, a Magic Biofluid Available for Multilevel Assessment and a Mirror of General Health-A Systematic Review.

BACKGROUND: Saliva has been recently proposed as an alternative to classic biofluid analyses due to both availability and reliability regarding the evaluation of various biomarkers. Biosensors have been designed for the assessment of a wide spectrum of compounds, aiding in the screening, diagnosis, and monitoring of pathologies and treatment efficiency. This literature review aims to present the development in the biosensors research and their utility using salivary assessment. METHODS: a comprehensive literature search has been conducted in the PubMed database, using the keywords "saliva" and "sensor". A two-step paper selection algorithm was devised and applied. RESULTS: The 49 papers selected for the present review focused on assessing the salivary biomarkers used in general diseases, oral pathologies, and pharmacology. The biosensors proved to be reliable tools for measuring the salivary levels of biochemical metabolic compounds such as glucose, proteinases and proteins, heavy metals and various chemical compounds, microorganisms, oncology markers, drugs, and neurotransmitters. CONCLUSIONS: Saliva is a biofluid with a significant clinical applicability for the evaluation and monitoring of a patient's general health. Biosensors designed for assessing a wide range of salivary biomarkers are emerging as promising diagnostic or screening tools for improving the patients' quality of life.

Osseointegration of titanium scaffolds manufactured by selective laser melting in rabbit femur defect model.

The aim of this study was to assess the osseointegration of two series of titanium (Ti) scaffolds with 0.8 and 1 mm cell size obtained by Selective Laser Melting (SLM) technique. One of the series had the Ti surface unmodified, while the other had the Ti surface coated with silicon-substituted nano-hydroxyapatite (nano-HapSi). The scaffolds were implanted in the femur bone defects of 6 White Californian male rabbits: three animals were implanted with 0.8 mm cell size scaffolds and three animals with 1 mm cell size scaffolds, respectively. The bone fragments and scaffolds harvested at 2, 4 and 6 months were histologically analyzed using conventional light microscopy (LM) and scanning electron microscopy (SEM) for the qualitative evaluation of the bone tissue formed in contact with the scaffold. Both LM and SEM images indicated a better osseointegration for nano-HapSi coated Ti scaffolds. LM revealed that the compact bone formed in the proximity of nano-HapSi-coated scaffolds was better organized than spongy bone associated with unmodified scaffolds. Moreover, Ti scaffolds with meshes of 0.8 mm showed higher osseointegration compared with 1 mm. SEM images at 6 months revealed that the bone developed not only in contact with the scaffolds, but also proliferated inside the meshes. Nano-HapSi-coated Ti implants with 0.8 mm meshes were completely covered and filled with new bone. Ti scaffolds osseointegration depended on the mesh size and the surface properties. Due to the biocompatibility and favorable osseointegration in bone defects, nano-HapSi-coated Ti scaffolds could be useful for anatomical reconstructions.