Investigating the influence of titanium particle size and concentration on osteogenic response of human osteoblasts - in vitro study.

Purpose: The purpose of this study was to investigate the correlation between the size and concentration of titanium particles and the osteogenic response of human osteoblasts (HOB). Materials and Methods: Different concentrations of titanium dioxide nano- and micro-particles were prepared and their biocompatibility on HOBs was analyzed using XTT assay. The changes in the actin cytoskeletal organization were studied by confocal laser scanning microscopy. The generation of intracellular reactive oxygen species (ROS) by HOBs after exposure to titanium dioxide particles was analyzed using ROS assay. Besides, the osteogenic potential represented by alkaline phosphatase activity, osteoprotegerin, macrophage colony stimulating factor levels, and biomineralization were analyzed. Results: Short-term interaction of titanium dioxide nano- and micro-particles did not induce toxicity to HOBs. However, cells treated with 100 µg/mL titanium dioxide nano- and micro-particles demonstrated higher ROS generation compared to control. Besides, cells treated with 100 µg/mL titanium dioxide nanoparticles showed higher alkaline phosphatase activity, osteoprotegerin, macrophage colony stimulating factor levels and biomineralization compared to titanium dioxide microparticles. Conclusion: Collectively, the study found titanium dioxide nanoparticles to be more biocompatible than microparticles providing an insight into the capability of nanostructures in supporting osteoblast differentiation and its plausibility in biomedical applications.

Evaluation of the effectiveness of sleep hygiene education and FITBIT devices on quality of sleep and psychological worry: a pilot quasi-experimental study among first-year college students.

Background: College students report disturbed sleep patterns that can negatively impact their wellbeing and academic performance. Objectives: This study examined the effect of a 4-week sleep hygiene program that included sleep education and actigraph sleep trackers (FITBITs) on improving sleep quality and reducing psychological worry without control group. Design settings and participants: A pilot quasi-experimental design, participants were randomly selected medical and health sciences from a university students in the United-Arab-Emirates. Methods: Students were asked to wear FITBITs and log their daily sleep data and completed the Pittsburgh Sleep Quality Index (PSQI) and Penn State Worry Questionnaire (PSWQ). Extensive sleep hygiene education was delivered via lectures, a WhatsApp group, and the Blackboard platform. In total, 50 students completed pre-and post-assessments and returned FITBIT data. Results: There was a significant difference in the prevalence of good sleep postintervention compared with pre-intervention (46% vs. 28%; p = 0.0126). The mean PSQI score was significantly lower post-intervention compared with pre-intervention (6.17 ± 3.16 vs. 7.12.87; p = 0.04, Cohen's d 0.33). After the intervention, subjective sleep quality, sleep latency, and daytime dysfunction were significantly improved compared with pre-intervention (p < 0.05). In addition, FITBIT data showed total sleep time and the number of restless episodes per night were significantly improved postintervention compared with pre-intervention (p = 0.013). The mean PSWQ score significantly decreased from pre-intervention to p = 0.049, Cohen' d = 0.25. The correlation between PSQI and PSWQ scores was significant post-intervention (ß = 0.40, p = 0.02). Conclusion: Our results may inform university educational policy and curricular reform to incorporate sleep hygiene awareness programs to empower students and improve their sleep habits.

Titanium dioxide dental implants surfaces related oxidative stress in bone remodeling: a systematic review.

Background: Titanium dioxide dental implants have a controversial effect on reactive oxygen species (ROS) production. ROS is necessary for cellular signal transmission and proper metabolism, but also has the ability to cause cell death as well as DNA, RNA, and proteins damage by excessive oxidative stress. This study aimed to systematically review the effect of titanium dioxide dental implant-induced oxidative stress and its role on the osteogenesis-angiogenesis coupling in bone remodeling. Methods: This systematic review was performed conforming to preferred reporting items for systematic review and meta-analysis (PRISMA) model. Four different databases (PubMed, Science Direct, Scopus and Medline databases) as well as manual searching were adopted. Relevant studies from January 2000 till September 2021 were retrieved. Critical Appraisal Skills Programme (CASP) was used to assess the quality of the selected studies. Results: Out of 755 articles, only 14 which met the eligibility criteria were included. Six studies found that titanium dioxide nanotube (TNT) reduced oxidative stress and promoted osteoblastic activity through its effect on Wnt, mitogen-activated protein kinase (MAPK) and forkhead box protein O1 (FoxO1) signaling pathways. On the other hand, three studies confirmed that titanium dioxide nanoparticles (TiO2NPs) induce oxidative stress, reduce ostegenesis and impair antioxidant defense system as a significant negative correlation was found between decreased SIR3 protein level and increased superoxide (O2 •-). Moreover, five studies proved that titanium implant alloy enhances the generation of ROS and induces cytotoxicity of osteoblast cells via its effect on NOX pathway. Conclusion: TiO2NPs stimulate a wide array of oxidative stress related pathways. Scientific evidence are in favor to support the use of TiO2 nanotube-coated titanium implants to reduce oxidative stress and promote osteogenesis in bone remodeling. To validate the cellular and molecular cross talk in bone remodeling of the present review, well-controlled clinical trials with a large sample size are required.

Post COVID-19 lockdown: measures and practices for dental institutes.

Resuming regular clinical activities at dental premises after the COVID-19 lockdown period or post COVID-19 is likely to be a challenge for all dental institutes. When returning to the dental practice or training, staff and students alike should abide by the new rules and regulations. In the process of controlling viral spread, clinical dental facilities face a higher risk of disease transmission among patients as well as clinical and non-clinical staff. Aerosols formation and diffusion into the surrounding air can be a real concern of viral transmission, if no protective measures are established. We aim in this review to present the currently implemented measures and propose changes in clinical dental facilities to minimize the risk of transmission. Dental professionals should be prepared to treat every patient as a suspected COVID-19 carrier and be ready to receive and manage an overwhelming number of patients. We suggest that dental practices establish a sensible workforce shift schedule, improve ventilation levels, reduce dental aerosol generating procedures, and develop a comprehensive guidance to Healthcare Workers to reduce the risk of COVID-19 transmission.

Nanoscale Thermosensitive Hydrogel Scaffolds Promote the Chondrogenic Differentiation of Dental Pulp Stem and Progenitor Cells: A Minimally Invasive Approach for Cartilage Regeneration.

PURPOSE: Several scaffolds and cell sources are being investigated for cartilage regeneration. The aim of the study was to prepare nanocellulose-based thermosensitive injectable hydrogel scaffolds and assess their potential as 3D scaffolds allowing the chondrogenic differentiation of embedded human dental pulp stem and progenitor cells (hDPSCs). MATERIALS AND METHODS: The hydrogel-forming solutions were prepared by adding ß-glycerophosphate (GP) to chitosan (CS) at different ratios. Nanocellulose (NC) suspension was produced from hemp hurd then added dropwise to the CS/GP mixture. In vitro characterization of the prepared hydrogels involved optimizing gelation and degradation time, mass-swelling ratio, and rheological properties. The hydrogel with optimal characteristics, NC-CS/GP-21, was selected for further investigation including assessment of biocompatibility. The chondrogenesis ability of hDPSCs embedded in NC-CS/GP-21 hydrogel was investigated in vitro and compared to that of bone marrow-derived mesenchymal stem cells (BMSCs), then was confirmed in vivo in 12 adult Sprague Dawley rats. RESULTS: The selected hydrogel showed stability in culture media, had a gelation time of 2.8 minutes, showed a highly porous microstructure by scanning electron microscope, and was morphologically intact in vivo for 14 days after injection. Histological and immunohistochemical analyses and real-time PCR confirmed the chondrogenesis ability of hDPSCs embedded in NC-CS/GP-21 hydrogel. CONCLUSION: Our results suggest that nanocellulose-chitosan thermosensitive hydrogel is a biocompatible, injectable, mechanically stable and slowly degradable scaffold. hDPSCs embedded in NC-CS/GP-21 hydrogel is a promising, minimally invasive, stem cell-based strategy for cartilage regeneration.

Morning and evening salivary melatonin, sleepiness and chronotype: A comparative study of nurses on fixed day and rotating night shifts.

AIMS: To compare morning and evening salivary melatonin levels, sleep quality and chronotype between nurses working fixed day shifts and those working rotating night shifts. BACKGROUND: Rotating night shift work is an inevitable part of nursing and is a major reason for disrupted sleep. DESIGN: Cross-sectional comparative design. PARTICIPANTS AND SETTINGS: We used cluster sampling to recruit 520 female nurses working fixed day and rotating night shifts in the United Arab Emirates. METHODS: Morning and evening melatonin were measured from corresponding saliva samples. The Pittsburgh Sleep Quality Index used to evaluate sleep quality and self-assessment of preferred circadian times was used to assess participants' chronotypes. Data were collected between October 2017-December 2018. RESULTS: Rotating night shift nurses had significantly lower evening melatonin compared with the fixed day shift group. No significant difference was found in sleep quality between the groups, although more participants in the rotating night shift group (N = 110, 42.31%) expressed better sleep quality than those in the fixed day group (N = 90, 36.00). Participants in the rotating night shift group expressed better subjective sleep, longer sleep duration, less disturbed sleep and better daily function (p > .05) than the fixed day group. Rotating night shift participants were more likely to have evening or intermediate chronotypes and more likely to report alignment of shift work to their chronotype compared with fixed day shift participants (p = .001). Longer shift duration, marital status and city location were associated with reduced evening melatonin among nurses on rotating night shifts. CONCLUSION: Rotating night shift nurses showed evidence of better sleep than those from the fixed day shift. Proper shift assignment, chronotype and alignment with shift work appeared to produce better sleep quality. IMPACT: Organizational policy must consider a novel model for work schedules that allow adequate off-duty days for sleep recovery among nurses.

A Comparative Clinical Study between Concentrated Growth Factor and Low-Level Laser Therapy in the Management of Dry Socket.

OBJECTIVE: A dry socket is a well-recognized complication of wound healing following tooth extraction. Its etiology is poorly understood and commonly occur among healthy patients. As such, management strategies for dry socket has always been empirical rather than scientific with varying outcome. The aim of this study is to investigate the efficacy of concentrated growth factor (CGF) and low-level laser therapy (LLLT) and compared them to the conventional treatment in the management of dry socket. MATERIALS AND METHODS: Sixty patients with one dry socket each, at University Dental Hospital Sharjah, were divided into three treatment groups based on their choice. In group I (n = 30), conventional treatment comprising of gentle socket curettage and saline irrigation was done. Group II (n = 15) dry sockets were treated with CGF and group III (n = 15) sockets were lased with LLLT. All dry socket patients were seen at day 0 for treatment and subsequently followed-up at 4, 7, 14, and 21 days. Pain score, perisocket inflammation, perisocket tenderness, and amount of granulation tissue formation were noted. STATISTICAL ANALYSIS: Data were analyzed as mean values for each treatment group. Comparisons were made for statistical analysis within the group and among the three groups to rank the efficacy of treatment using one-way analysis of variance (ANOVA). Statistically significant difference is kept at p < 0.05. RESULTS: Conventional treatment group I took more than 7 days to match the healing phase of group II CGF treated socket and group III LLLT irradiated socket (p = 0.001). When healing rate between CGF and LLLT are compared, LLLT group III showed a delay of 4 days compared with CGF in granulation tissue formation and pain control. CONCLUSION: CGF treated socket was superior to LLLT in its ability to generate 75% granulation tissue and eliminate pain symptom by day 7 (p = 0.001).