Background and Objectives: This study aimed to evaluate the effects of advanced platelet-rich fibrin (A-PRF+) tissue regeneration therapy on clinical periodontal parameters in non-smokers and smoker patients. The anticipated biological mechanisms of A-PRF+ include stimulating angiogenesis, thereby promoting the formation of new blood vessels, which is essential for tissue healing. Additionally, A-PRF+ harnesses the regenerative properties of platelet-rich fibrin, contributing to the repair and regeneration of periodontal tissues. Materials and Methods: The study was conducted on 55 patients, divided into two groups: non-smoker patients (n = 29) and smoker patients (n = 26). A single operator conducted the surgical procedure. Following the administration of local anesthesia with articaine 4% with adrenaline 1:100,000 precise intracrevicular incisions were made, extending towards the adjacent teeth, until the interproximal spaces, with meticulous attention to conserving the interdental gingival tissue to the greatest extent possible. Extended, full-thickness vestibular and oral flaps were carefully lifted, and all granulation tissue was meticulously removed from the defect without altering the bone contour. After debridement of the defects, A-PRF+ was applied. BOP (bleeding on probing), PI (plaque index), CAL (clinical attachment loss), and probing depth (PD) were determined at baseline and six months post-surgery. Results: Significant reductions were observed in PD and CAL after six months. In the non-smokers group, PD decreased from 7.0 ± 1.0 mm to 3.1 ± 0.1 mm (p < 0.001), while in the smokers group, PD decreased from 6.9 ± 1.1 mm to 3.9 ± 0.3 mm (p < 0.001). CAL decreased in the non-smokers group from 5.8 ± 0.7 mm to 2.6 ± 0.2 mm and from 5.7 ± 0.9 mm to 3.2 ± 0.2 mm (p < 0.001) in smokers. Notably, the reductions in CAL and PD were statistically more significant in the non-smokers group. Conclusions: Even though the clinical periodontal improvements were considerable in smoker patients, they did not reach the level observed in non-smoker patients.
This paper presents a comprehensive analysis of recent advancements in the application of thermal spraying techniques to enhance the durability and wear resistance of agricultural machinery components, with a particular focus on disc harrow assemblies. Given the harsh conditions under which tillage tools operate—characterized by abrasive wear, impact stresses, and chemical exposure from various soil types—thermal sprayed coatings have emerged as a viable solution to extend the service life of these components. The study discusses various deposition methods, particularly Atmospheric Plasma Spraying (APS), and evaluates their effectiveness in creating high-performance surface layers that resist wear, corrosion, and mechanical degradation. The review also summarizes experimental and field test results for coatings based on materials such as NiCrBSi, WC-Co-Cr, TiO2, Al2O3, Cr2O3, and ceramic–metal composites, highlighting their significant improvements in hardness, friction reduction, and resistance to delamination and oxidation. The paper highlights research using thermal spraying techniques, especially APS for agricultural applications, with emphasis mostly on components intended for soil processing and requiring good resistance to abrasive wear.
Background: This study examined how the concentration of calcium (Ca) influences the microstructure, mechanical characteristics, and tribological attributes of Mg–Ca–Zn–RE–Zr alloys for orthopedic medicine. Materials and methods: Experimental alloys with 0.1 and 0.5 wt% Ca were prepared in a controlled atmosphere induction furnace. The microstructure of the alloys was investigated by scanning electron microscopy, the chemical composition by X-ray fluorescence and energy-dispersive spectroscopy, the mechanical properties by indentation and scratching, and the corrosion resistance by linear and cyclic potentiometry. Results: The alloy with 0.1% Ca exhibited greater fluctuations in the coefficient of friction, while the sample with 0.5% Ca showed a higher susceptibility to cracking. Regarding corrosion resistance, both samples exhibited a generalized corrosion trend with similar corrosion currents. At lower Ca concentrations (0.1%), the refined microstructure of the alloys provided an elastic modulus closer to that of human bone, minimizing the risk of excessive local stress and promoting uniform load distribution at the bone-implant interface. Conclusion: The 0.5% Ca alloy offered superior tribological stability and better shock absorption, making it suitable for applications requiring long-term stability. The study highlighted the potential of both compositions based on the specific requirements of biodegradable orthopedic implants.
The high yttria content of a stabilized zirconia (YSZ) (38 wt% Y2O3) coating was deposited by atmospheric plasma spraying (APS) from Metco 207 powders on an Inconel 718 (Ni-based superalloy) substrate. As a metal coating connection, a layer of cermet powder (Ni-20% Al—410NS) was used before the ceramic layer deposition. The electro-chemical corrosion resistance of these materials was tested using Inconel cylinders with a diameter of 10 mm and a thickness of 1 mm, with and without the ceramic layer. Linear and cyclic measurements were obtained in H2SO4 electrolyte media at pH = 2. Electro-impedance spectroscopy (EIS) experiments were performed on the sample covered with the ceramic layer to evaluate the interface behavior. Scanning electron microscopy (SEM), along with equipment to determine chemical composition, and an energy dispersive spectrometry (EDS) detector were used to characterize the material surface before and after corrosion tests. It was observed that the corrosion resistance of Inconel was influenced by the bonding layer and the ceramic coating.
Background and Objectives: This study aimed to evaluate the role of A-PRF (advanced platelet-rich fibrin) in the enhancement of wound healing and protecting the periodontal health of mandibular second molars after the extraction of mandibular third molars. Additionally, the study assessed the levels of pro-inflammatory cytokines in the gingival crevicular fluid (GCF) of mandibular second molars as markers of inflammation. Materials and Methods: Twenty-five systemically healthy adult patients with bilateral removal of impacted mandibular third molars were included. Each patient received A-PRF in one extraction site, while the contralateral site served as a control. Periodontal parameters of the adjacent second molar, including probing depth (PD) and clinical attachment level (CAL), were measured in distal–vestibular (DV) and distal–lingual (DL) sites. Pain, swelling, and overall healing were subjectively evaluated. Levels of tumor necrosis factor-alpha (TNF-α), interleukin 1 beta (IL-1β), and interleukin 6 (IL-6) in the GCF were analyzed. Evaluations occurred at baseline and three months post-surgery. Results: A-PRF significantly improved PD (from 4.69 ± 0.61 mm to 3.85 ± 0.34 mm in DV, and from 4.71 ± 0.65 mm to 3.79 ± 0.27 mm in DL, respectively) and CAL (from 2.41 ± 0.25 mm to 1.82 ± 0.21 mm in DV, and from 2.40 ± 0.36 mm to 1.75 ± 0.19 mm in DL, respectively) of the adjacent second molar, compared to control sites, three months post-surgery. Pain and swelling scores were notably lower on the 7th postoperative day in the A-PRF group. A-PRF also reduced pro-inflammatory cytokines in GCF, significantly more than in control sites, at three months post-surgery. Conclusions: A-PRF enhances the periodontal and inflammatory status of adjacent teeth and wound healing after the extraction of mandibular third molars.
Coatings deposited by the cold particle gas spray method have shown significant potential for enhancing the properties of metals. We investigated the wear characteristics and corrosion behavior of 52100 steel coated with a mixture of Ni/chromium carbide (Ni/CrC) particles. These coatings exhibited high density and were devoid of cracks, closely adhering to the substrate’s surface. Microscratch resistance testing revealed strong resilience, with the apparent friction coefficient exhibiting multiple peaks as the displacement varied. The determination of the friction coefficient, utilizing linear and rotational sliding tests, displayed a brief transition period. This occurred as the apparent contact area expanded until it reached an equilibrium state, with the large asperities being smoothed out and the remaining particles on the sliding track acting as an abrasive material, resulting in higher friction coefficient values. Electro-corrosion tests confirmed the near-intact condition of the deposited layer. Few compounds were detected in the electrolyte solution, resulting in significantly lower oxidation in the layer compared to the base material.