Evaluation of surface energy and surface stability and adherence of Candida albicans to octa fluoro pentyl (meth) acrylate-coated PEEK using plasma spray.

Background: Polyetheretherketone (PEEK) has favorable properties that make it able to be used as a denture base material, but it is also susceptible to the adhesion of microorganisms. In this study, we applied Octafluoropentyl (meth) acrylate (OFPA) coating on the PEEK polymer surface by using plasma spray and investigated the functional groups present on the surface, changes in the surface energy and Candida albicans adhesion. Materials and Methods: In this experimental study, the samples were placed in a control group without surface preparation and three experimental groups that were subjected to plasma spray for 10, 30, and 60 s and then impregnated with degassed Octa fluoropentyl (meth) acrylate (Sigma-Aldrich, USA) monomer. Fourier transform infrared spectroscopy (FTIR) was used to identify the functional groups and new chemical bonds between PEEK and OFPA, and Sessile Drop Method was used to evaluate the surface's wettability. The surface morphology was checked using a LEXT OLS4000 (Olympus®-Japan) microscope, and the inhibition of C. albicans adhesion was also checked by counting the colonies in terms of colony forming unit/mL (CFU/mL). Kurskal-Wallis analysis was conducted to assess Candida adhesion, while wettability was evaluated using analysis of variance and post hoc analyses. The level of statistical significance was set at P < 0.05. Results: FTIR analysis confirmed that a chemical between OFPA and PEEK was established. The samples showed a significant increase in the contact angle after 30 s of plasma application (CA = 88.2 ± 7.3). The contact angle decreased again by increasing the surface modification to 60 s (CA = 64.33 ± 5.5). Examining the surface morphology of the samples shows an increase in surface roughness with increasing plasma time up to 60 s. The number of adherent colonies was the lowest in 30 s group, but it was not statistically significant (P = 0.658). Conclusion: No statistically significant difference in C. albicans CFU/mL count was found between groups. The contact angle of the 30 s group was significantly higher than the control group.

The role of current herbal extracts in bone regeneration through dental implants: in vitro/in vivo/clinical studies.

The quality and quantity of bone at the interface of an implant system are determining factors in the implant's stability. Alternative agents have been studied to augment implants and bone defects, including bone-conductive and bone-inducing agents. By modifying implant surface coatings on the nanoscale, one can enhance osseointegration by stimulating bone cell adhesion, bone matrix formation, and mineralization. Because alternative agents stimulate osteoblasts to mineralize and can control pectin structure, plant-derived silicone has been suggested as a potential candidate for surface nanocoatings on orthopedic and dental titanium implants. Inducing the differentiation of cells or accelerating bone regeneration is possible with the plant extract. Coating these extracts on implant devices can improve cell attachment, differentiation, and proliferation. This review article discusses the role of herbal materials in bone regeneration through dental implants.

The wound healing effect of collagen/adipose-derived stem cells (ADSCs) hydrogel: In vivo study.

BACKGROUND: The complex wound healing process involves activating and synchronizing intracellular, intercellular, and extracellular components. Adipose tissue is attracting attention to promote wound healing. Within subcutaneous adipose tissue, stromal vascular cells and their subsets release growth factors and cytokines critical for neovascularization and wound repair. OBJECTIVES: This study evaluated human placental collagen/adipose-derived stem cells (ADSCs) hydrogel for wound healing in rats. METHODS: In this study, ADSCs were harvested, cultured, and mixed with placental collagen. Twelve rats were used, and their backs were excised three times each. Group one received collagen/ADSCs, group two collagen, and group three non-filled (control) excisions. The healing processes were assessed by histological analysis, taking photographs, and calculating the percentage of wound contraction in mentioned times. RESULTS: Histopathological analysis revealed that the content of fibroblasts, follicles of the hair, and angiogenesis in group one was significantly more than in other groups. Group one had a significant result compared with the collagen and control groups. In group one, significant wound healing and wound contraction were observed with 52% and 80% wound contraction at 7 and 14 days, respectively. CONCLUSION: Collagen/ADSCs can be considered a suitable candidate hydrogel in wound healing with a high potential for enhancing wound repairing.

Dataset for classifying and estimating the position, orientation, and dimensions of a list of primitive objects.

OBJECTIVES: Robotic systems are moving toward more interaction with the environment, which requires improving environmental perception methods. The concept of primitive objects simplified the perception of the environment and is frequently used in various fields of robotics, significantly in the grasping challenge. After reviewing the related resources and datasets, we could not find a suitable dataset for our purpose, so we decided to create a dataset to train deep neural networks to classify a primitive object and estimate its position, orientation, and dimensions described in this report. DATA DESCRIPTION: This dataset contains 8000 virtual data for four primitive objects, including sphere, cylinder, cube, and rectangular sheet with dimensions between 10 to 150 mm, and 200 real data of these four types of objects. Real data are provided by Intel Realsense SR300 3D camera, and virtual data are generated using the Gazebo simulator. Raw data are generated in.pcd format in both virtual and real types. Data labels include values of the object type and its position, orientation, and dimensions.

Effect of Surfosept and Deconex® 53 Disinfectant Agents on the Accuracy and Dimensional Stability of Panasil Dental Impression Materials: An Experimental Study.

MATERIALS AND METHODS: This in vitro study was performed on 30 dental casts. The samples were divided into one control group and two experimental groups to be disinfected with Surfosept (1%) and Deconex® 53 (2%) using a sequential sampling method (10 per group). The impressions in the experimental groups (i.e., Surfosept and Deconex® 53) were rinsed and dried; then, the disinfectant was sprayed on the impressions and remained for 30 seconds before pouring with stone. In the control group, the impressions were only rinsed and dried and were poured in 10 minutes. Cast dimensions were measured by a profile projector device, and the mean values obtained from the experimental groups were compared with those of the control group. RESULTS: There were no significant differences among the groups regarding the height of the resulting dies without undercut (P=0.62). Moreover, there was no significant difference among the groups regarding the distance between the two dies (P=0.77). However, the diameter of the dies with undercut and without undercut was different significantly among the control and experimental groups (P < 0.005). CONCLUSION: In general, no significant difference was encountered between dimensional stability and accuracy of the dental impressions using Surfosept and Deconex® 53 in this study.

Design and control of a lower limb rehabilitation robot considering undesirable torques of the patient's limb.

This research introduces a new exoskeleton-type rehabilitation robot, which can be used in lower limb rehabilitation therapy for post-stroke patients. A novel design of a typical knee and ankle rehabilitation robot is proposed. The kinematic and dynamic models of the knee and ankle rehabilitation robot are derived. Furthermore, a super-twisting nonsingular terminal sliding mode control is developed to achieve the desired training missions and its results are compared with those of an adaptive sliding mode control. To reduce undesired interaction torques between knee and ankle rehabilitation robot and patient, an admittance control algorithm is added to the controller to guarantee a safe therapy session. The admittance super-twisting nonsingular terminal sliding mode control structure is considered as the novelty of this article. Taking into account the dynamic uncertainties, external disturbances, and the interaction torques, the validity of the admittance super-twisting nonsingular terminal sliding mode control controller is approved by various numerical simulations over the admittance adaptive sliding mode control.

Graphene nanosheets preparation using magnetic nanoparticle assisted liquid phase exfoliation of graphite: The coupled effect of ultrasound and wedging nanoparticles.

This study aims to investigate a novel technique to improve the yield of liquid phase exfoliation of graphite to graphene sheets. The method is based on the utilization of magnetic Fe3O4 nanoparticles as "particle wedge" to facilitate delamination of graphitic layers. Strong shear forces resulted from the collision of Fe3O4 particles with graphite particles, and intense ultrasonic waves lead to enhanced exfoliation of graphite. High quality of graphene sheets along with the ease of Fe3O4 particle separation from graphene solution which arises from the magnetic nature of Fe3O4 nanoparticles are the unique features of this approach. Initial graphite flakes and produced graphene sheets were characterized by various methods including field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), Raman spectroscopy, atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and Zeta potential analysis. Moreover, the effect of process factors comprising initial graphite concentration, Fe3O4 nanoparticles concentration, sonication time, and sonication power were investigated. Results revealed that graphene preparation yield and the number of layers could be manipulated by the presence of magnetic nanoparticles.

A new, simple implant-level impression technique for dental implants in limited interproximal space.

Making an implant-level impression when implants are placed in limited interproximal space or compromising angulations can be a time-consuming procedure. This article presents a new method for developing a master cast for two implants clinically placed convergent and very close to each other. The technique consists of making an implant-level impression using a transfer jig fabricated on dental abutments.