Glass coatings to enhance the interfacial bond strength between veneering ceramic and zirconia.

The purpose of this study was to investigate the tensile bond strength (TBS) and shear bond strength (SBS) between a zirconia core and fluoroapatite-pressed ceramic after the application of glass 46SP6 and AP40 via the ISO-17095:2013 methodology. Sintered zirconia beams (n = 120) were divided into four groups: (a) control: no treatment; (b) ZirL: IPS-E max ceram ZirLiner coating; (c) glass AP40 coating; and (d) glass 46SP6 coating. A fluoroapatite ceramic (IPS e.max Zir Press, Ivoclar Vivadent) beam was injected perpendicularly on top of each zirconia (Zenostar, Wieland Dental) beam forming a cross-bonded specimen. All groups were sub-divided into two for tensile and shear bond strength tests using a universal testing machine. Data were analyzed using the Kruskal-Wallis, Pearson Chi2, and Mann-Whitney U test (α = 0.05). The failure modes were measured using a stereomicroscope for each group. Scanning electron and atomic force microscopy were also employed. Zirconia surface modification with glass AP40 showed higher TBS values followed by the ZirL group with statistical differences (p < 0.05). SBS values showed no statistical differences between the groups. AFM analysis showed higher roughness values (Ra) in the 46SP6 and AP40 groups (p < 0.05). Glass coating AP40 exhibited promising bond strength results between zirconia and fluorapatite veneering ceramic, making it better for chemical and mechanical interlocking which may improve bilayered restorations longevity.

Calcium sustained release, pH changes and cell viability induced by chitosan-based pastes for apexification.

We explored chitosan-based sustained release pastes for apexification. The study aimed to formulate chitosan-based pastes loaded with calcium hydroxide (CH) or with calcium chloride (CC), and to evaluate the sustained release of Ca2+ and pH changes in deionized water as well as the effect of the pastes on cell viability. The pastes were formulated by dissolution of the chitosan in 1% or 2% acetic acid (AAC) plus the addition of CH or CC, then were suspended in deionized water for 50 days; the released Ca(II) and pH were measured with an electrode probe. The effect of the pastes on viability of human dental pulp cells was evaluated with a MTS assay. The results showed that the pastes prepared with 1% and 2% AAC and loaded with CH released a 74.9% and a 76.1% of the Ca2+ content, respectively, while the pastes prepared with 1% and 2% AAC loaded with CC released a content of Ca2+ of 90.8% and 76.6%, respectively. A control paste (CH and polyethylene glycol) released a 95.4%; significant statistical differences were found between the percentage of the experimental pastes and the control. The CH-loaded pastes caused an alkaline pH at the starting of the study, but the pH became neutral at the ending. The pH of the CC-loaded pastes was neutral at the starting and was acid at the ending. The pastes no affected on the cell viability. The chitosan-based pastes showed a suitable sustained release profile and cytocompatibility.

Analgesic efficacy of preoperative dexketoprofen trometamol: A systematic review and meta-analysis.

Post-Market Research Clinical evidence supports the use of dexketoprofen trometamol (DEX) to manage acute postoperative pain. However, controversies surround the impact of the use of this drug in preoperative analgesic protocols. The aim of the present meta-analysis was to evaluate the effectiveness of the preoperative administration of DEX under postoperative pain conditions. Electronic and manual searches were conducted through diverse electronic databases. A systematic review and meta-analysis to evaluate the analgesic efficacy of the preoperative administration of DEX was performed including Randomized Clinical Trials (RCTs) published between 2002 and 2017. Suitable individual studies were evaluated through a quality system, and the data were extracted and analyzed. Fourteen RTCs were included (12 parallel trials and 2 cross-over trials), published in the English and Turkish languages. Follow-up periods ranged from 4, 6, 8, 24, and 48 hr. All trials measured the outcome result as Acute Pain Level (APL) (VAS, NRS, VRS), time to requiring a second dose of DEX or analgesic emergency and consumption of opioids via patient-controlled analgesia. When the comparators were other drugs - paracetamol, Lornoxicam or placebo during the preoperative time, preoperative administration of DEX was superior. When the comparison comprised preoperative and postoperative DEX, both alternatives exhibited comparable analgesic effects. The analgesic efficacy of the preoperative administration of DEX when compared to placebo, lornoxicam, and paracetamol on postoperative pain was evident. Preoperative administration of DEX compared to its immediate postoperative administration showed a similar analgesic effect.

Holotomography and atomic force microscopy: a powerful combination to enhance cancer, microbiology and nanotoxicology research.

Modern imaging strategies are paramount to studying living systems such as cells, bacteria, and fungi and their response to pathogens, toxicants, and nanomaterials (NMs) as modulated by exposure and environmental factors. The need to understand the processes and mechanisms of damage, healing, and cell survivability of living systems continues to motivate the development of alternative imaging strategies. Of particular interest is the use of label-free techniques (microscopy procedures that do not require sample staining) that minimize interference of biological processes by foreign marking substances and reduce intense light exposure and potential photo-toxicity effects. This review focuses on the synergic capabilities of atomic force microscopy (AFM) as a well-developed and robust imaging strategy with demonstrated applications to unravel intimate details in biomedical applications, with the label-free, fast, and enduring Holotomographic Microscopy (HTM) strategy. HTM is a technique that combines holography and tomography using a low intensity continuous illumination laser to investigate (quantitatively and non-invasively) cells, microorganisms, and thin tissue by generating three-dimensional (3D) images and monitoring in real-time inner morphological changes. We first review the operating principles that form the basis for the complementary details provided by these techniques regarding the surface and internal information provided by HTM and AFM, which are essential and complimentary for the development of several biomedical areas studying the interaction mechanisms of NMs with living organisms. First, AFM can provide superb resolution on surface morphology and biomechanical characterization. Second, the quantitative phase capabilities of HTM enable superb modeling and quantification of the volume, surface area, protein content, and mass density of the main components of cells and microorganisms, including the morphology of cells in microbiological systems. These capabilities result from directly quantifying refractive index changes without requiring fluorescent markers or chemicals. As such, HTM is ideal for long-term monitoring of living organisms in conditions close to their natural settings. We present a case-based review of the principal uses of both techniques and their essential contributions to nanomedicine and nanotoxicology (study of the harmful effects of NMs in living organisms), emphasizing cancer and infectious disease control. The synergic impact of the sequential use of these complementary strategies provides a clear drive for adopting these techniques as interdependent fundamental tools.

Aluminum enhances the oxidative damage of ZnO NMs in the human neuroblastoma SH-SY5Y cell line.

Bare and doped zinc oxide nanomaterials (ZnO NMs) are of great interest as multifunctional platforms for biomedical applications. In this study, we systematically investigate the physicochemical properties of Aluminum doped ZnO (AZO) and its bio-interactions with neuroblastoma (SH-SY5Y) and red blood (RBCs) cells. We provide a comprehensive chemical and structural characterization of the NMs. We also evaluated the biocompatibility of AZO NMs using traditional toxicity assays and advanced microscopy techniques. The toxicity of AZO NMs towards SH-SY5Y cells, decreases as a function of Al doping but is higher than the toxicity of ZnO NMs. Our results show that N-acetyl cysteine protects SH-SY5Y cells against reactive oxygen species toxicity induced by AZO NMs. ZnO and AZO NMs do not exert hemolysis in human RBCs at the doses that cause toxicity (IC50) in neuroblastoma cells. The Atomic force microscopy qualitative analysis of the interaction of SH-SY5Y cells with AZO NMs shows evidence that the affinity of the materials with the cells results in morphology changes and diminished interactions between neighboring cells. The holotomographic microscopy analysis demonstrates NMs' internalization in SH-SY5Y cells, changes in their chemical composition, and the role of lipid droplets in the clearance of toxicants.

Comparison of the analgesic efficacy of preoperative/postoperative oral dexketoprofen trometamol in third molar surgery: A randomized clinical trial.

The aim of this study was to compare the efficacy of preoperative and postoperative dexketoprofen trometamol for pain control after third molar surgery. Sixty subjects indicated for impacted mandibular third molar surgery were randomly assigned to two groups: preoperative (group 1, n = 30) and postoperative (group 2, n = 30) administration. Group 1 received 25 mg of dexketoprofen trometamol 30 min before surgery and 1 placebo capsule (same color and size with active drug) immediately after surgery. Group 2 received the placebo capsule 30 min before surgery and 25 mg of dexketoprofen trometamol immediately after surgery. Pain intensity was assessed using a numeric rating scale (NRS) during the first 8 h. The time of the need for a second dose of dexketoprofen trometamol, after the first administration, was recorded. The data were analyzed using mixed-model repeated-measures (MMRM), Wilcoxon rank-sum, and Kaplan-Meier analysis. After the 8 h period, no statistically significant difference was observed in the intensity of pain (MMRM, p = 0.41); and no significant difference in the time for a second dose (p = 0.956). In conclusion, preoperative administration of dexketoprofen trometamol is a reasonable clinical approach that is as effective as conventional postoperative pharmacological treatment, with the advantage of allowing early analgesia before pain develops. (ClinicalTrials.gov: NCT02380001).