Effect of different dentin adhesives and application modes on sealing ability of amalgam restorations

Purpose: The aim of the study was to evaluate the sealing ability of bonded amalgam restorations using different adhesive materials with different adhesive application methods including amalgam bonding application. Materials and methods: The prepared Class-V cavities were randomly assigned to four application groups of four tested dual-curing dentin adhesives (Scotchbond Multi-Purpose Plus, XP Bond, Xeno IV and Clearfil Liner Bond 2V), dual-curing resin-based cement (Panavia F2.0) and a control group (unlined amalgam). Group 1 adhesives were applied according to the instructions for direct light-curing, Group 2 chemical-curing mode was applied according to the manufacturer’s amalgam bonding instructions. Group 3 adhesives were first applied in light-curing mode, and then amalgam bonding adhesive was applied. Group 4 adhesives were first applied in chemical-curing mode, followed immediately by light-curing mode. After that, amalgam adhesive parts were applied; then, the amalgam was condensed and carved. After storage for 24 h in distilled water at 37 °C, restorations were finished and polished. The teeth were then thermocycled (500 cycles between 5 and 55 °C), and the specimens were examined for microleakage using methylene blue as a marker. Results: Compared to the control group, the adhesive application modes significantly reduced microleakage for both dentin and enamel margins (p < 0.05). In dentin margins of the adhesives tested, Group 4 showed the lowest leakage score. On the enamel margins for Scotchbond Multi-Purpose Plus and XP Bond, Group 1 showed the highest microleakage (p < 0.05). Conclusion: According to marginal sealing ability and ease of application, Group 2 was recommended for the etch and rinse systems, and Group 4 was also recommended for the self-etch systems under amalgam restorations.     

Effect of impression valve system on adhesion force of impression materials to edentulous maxillary jaw: a preliminary clinical study

Objective: The purpose of this preliminary clinical study was to evaluate the effect of novel impression valve system (IVS) on adhesion force of different impression materials to edentulous maxilla. Background data: Impression materials and techniques have an important role in complete denture success. During the functional impression with an individual impression tray (IIT), high adhesive forces exist between edentulous ridge and impression material. Removing the IIT from the mouth with minimal force provides the most accurate and non-deformed impression. Materials and methods: This study included twenty maxillary edentulous patients (n?=?20). Patients who had palatal torus, anatomic undercut, gagging reflex, and flabby ridges were excluded from the study. The age range of the participants was 55–70. All patients gave written informed consent. Two impression materials – zinc oxide eugenol (ZOE) and alginate – were used as experimental material. The digital dynamometer was used to determine the adhesion force of impression materials with and without IVS to edentulous maxilla. The mean values of the adhesion forces were analyzed using the Wilcoxon signed-ranks test (α = 0.05). Results: The effect of IVS on adhesion force was found to be statistically significant (p < 0.05). There were also statistical differences between the ZOE and alginate groups (p < 0.05). Conclusions: The IVS is useful to remove the functional impression from the mouth without any deformation and detaching in cases which high adhesive force occurs.     

The influence of retention hole and adhesive systems on the shear bond strengths of resin composite to amalgam

The aim of the study is to evaluate the influence of surface-treatment methods with and without the use of a retention hole on the shear bond strength of a resin composite adhered to amalgam using an adhesive system. Amalgam specimens were divided into six groups. Group 1 (Bur) specimens were roughened with a diamond bur, Group 2 (Al₂O₃) specimens were sandblasted with a 50?μm aluminum oxide powder, Group 3 (CoJet^®) specimens were sandblasted with 30?μm CoJet^® Sand, Group 4 (Bur?+?Rh) specimen surfaces were prepared with a retention hole 1?mm in diameter and 1?mm deep and roughened with a diamond bur, Group 5 (Al₂O₃?+?Rh) specimens were also prepared with a retention hole and sandblasted with 50?μm aluminum oxide powder, and Group 6 (CoJet^®?+?Rh) surfaces were prepared with a retention hole and sandblasted with 30?μm CoJet^® Sand. Resin composite cylinders were bonded onto the amalgam surfaces using Xeno^® IV, Optibond? All-In-One, Clearfil? SE Bond, Adper? Single Bond Plus, and Scotchbond? Multi-Purpose adhesive systems. In addition, silane (Monobond S) was used for Groups 5 and 6. The shear bond was determined and statistically analyzed using two-way analysis of variance and post hoc Tukey’s tests (p?≤?0.05). The surface treatment significantly affected the shear bond strengths of the adhesive systems. The shear bond strengths of Optibond? All-In-One (2.661?±?0.48?MPa) in Group 1 and Scotchbond Multi-Purpose (3.818?±?0.98) in Group 4 were significantly higher than those of the other adhesive systems. Silica coating of the amalgam surface significantly improved the shear bond strength of the resin composites. The addition of a retention hole on the amalgam affects the bonding strength of the composite adhesion.     

Drying of grape pomace with a double pass solar collector

This study aims to analyze the performance of a novel design of the double pass solar air collector (DPSAC)-assisted drying system and investigate the drying kinetics of grape pomace which is an agricultural by-product. The samples were dried to a moisture content of 0.01?g water/g dry matter between 100 and 250?min depending on the weather conditions. The average thermal efficiencies of DPSAC were calculated as 79.77, 79.85, and 69.46%. Average values of the coefficient of performance of DPSAC were determined as 5.32, 5.13, and 4.32. The highest specific moisture extraction rate value was achieved as 617.18?g water/kWh. Whereas the mass transfer coefficient (h_m) values ranged from 9.15E?11 to 1.04E?7?m/s, the effective moisture diffusivity (D_e) values were obtained between 3.04E?13 and 1.02E?10?m²/s. The qualitative analysis showed that the drying using DPSAC may be an alternative for drying applications in terms of short drying time and energy usage. Nevertheless, these results clearly suggest a complex and effective interplay between thermal performance and drying kinetics.     

Hydrogen release from aqueous hydrazine bisborane

Aqueous hydrazine bisborane H₃BN₂H₄BH₃ (HBB) might be a possible liquid-state chemical H storage material at the conditions that the compound totally dehydrogenates in mild conditions. Herein we demonstrate such a potential. We report for the first time a work about the dehydrogenation of aqueous HBB. The compound is not stable in water. Its stability is even lower in alkaline conditions because of the likely formation of the unstable intermediate [H₃BOH]^?. The use of a metal-based catalyst accelerates the hydrolysis of the BH₃ groups but the bimetallic NiPt catalyst is more active, being also able to decompose the N₂H₄ moiety. The best kinetics is observed at 70 °C and in alkaline conditions. However, the dehydrogenation is not total, reaching a limit of 80% of conversion. Unfortunately the reason of that is not understood yet. As things stand, there are some challenges ahead, but HBB has shown to be a possible liquid-state chemical H storage material.     

Aqueous hydrazine borane N2H4BH3 and nickel-based catalyst: An effective couple for the release of hydrogen in near-ambient conditions

Nickel-based bimetallic catalysts were screened using the sodium borohydride NaBH₄ hydrolysis and the aqueous hydrazine borane N₂H₄BH₃ dehydrogenation. A total of 22 bimetallic catalysts were synthesized according to an easy process while focusing on metals like Fe, Co, Ni, Cu, Rh, Pd, Ag, Ir, Pt and Au. In the end, the bimetallic candidate Ni_87.5Pt_12.5 showed to be the most active and the most selective for the dehydrogenation of N₂H₄BH₃. At 70?°C, it is able to decompose N₂H₄BH₃ into 5.8 equivalents of H₂+N₂ in less than 12?min such as: N₂H₄BH₃?+?3H₂O?→?0.95 N₂?+?0.1 NH₃?+?B(OH)₃?+?4.85H₂. Durability and stability tests were also performed. In our conditions, Ni_87.5Pt_12.5 was found to suffer from small loss of performance because of an electronic evolution of the catalytic surface leading to modified sorption properties of the catalytic sites. Our main results are reported and discussed herein.     

Some compositional properties of main Malatya apricot (Prunus armeniaca L.) varieties

Malatya apricot (Prunus armeniaca L.) varieties are among the most important agricultural products of Turkey and protected as a geographical indication. In this research, it was aimed to determine some important analytical properties (dry matter, soluble solid content, a_w, ash, titratable acidity, pH, color, total phenolics, total carotenoids, β-carotene, sugars, organic acids, and mineral content) of Malatya apricots and to reveal the characteristic properties that differ these products from the similar ones. The apricot varieties, namely Hac?halilo?lu, Hasanbey, So?anc?, Kabaa??, Çatalo?lu, Çölo?lu, and Hac?k?z that are widely cultivated in Malatya region and other regions (Ere?li, ?zmir, I?d?r, and Bursa) of Turkey were involved in the study. All analytical properties were found to be significantly different (p < 0.05) among different apricot varieties. The results have shown that dry matter and sugar content of Malatya apricot varieties are considerably higher than the other apricot varieties investigated in this study, as well as the data of other researches on apricots. All apricot varieties were found to be a good source of phenolic compounds (4233.70–8180.49 mg of gallic acid equiv/100 g of dry weight), carotenoids (14.83–91.89 mg of β-carotene equiv/100 g of dry weight), and β-carotene (5.74–48.69 mg/100 g of dry weight). Sucrose, glucose, and fructose were determined as the major sugars in all apricot varieties. In addition, sorbitol contents (16.91–26.84 mg/100 g of dry weight) of Malatya apricots were remarkably higher than the other apricot varieties. This was considered to be the one of the unique properties of Malatya apricots. Malic acid was the predominant organic acid in all Malatya apricot varieties. The results have also shown that the potassium content of Malatya apricots was significantly high and these apricots were important sources of Mg, Zn, and Se. This study has revealed that Malatya apricot contains functional food components with high nutritional value.     

Regulation of Molecular Targets in Osteosarcoma Treatment

The most prevalent malignant bone tumor, osteosarcoma, affects the growth plates of long bones in adolescents and young adults. Standard chemotherapeutic methods showed poor response rates in patients with recurrent and metastatic phases. Therefore, it is critical to develop novel and efficient targeted therapies to address relapse cases. In this regard, RNA interference technologies are encouraging options in cancer treatment, in which small interfering RNAs regulate the gene expression following RNA interference pathways. The determination of target tissue is as important as the selection of tissue-specific promoters. Moreover, small interfering RNAs should be delivered effectively into the cytoplasm. Lentiviral vectors could encapsulate and deliver the desired gene into the cell and integrate it into the genome, providing long-term regulation of targeted genes. Silencing overexpressed genes promote the tumor cells to lose invasiveness, prevents their proliferation, and triggers their apoptosis. The uniqueness of cancer cells among patients requires novel therapeutic methods that treat patients based on their unique mutations. Several studies showed the effectiveness of different approaches such as microRNA, drug- or chemotherapy-related methods in treating the disease; however, identifying various targets was challenging to understanding disease progression. In this regard, the patient-specific abnormal gene might be targeted using genomics and molecular advancements such as RNA interference approaches. Here, we review potential therapeutic targets for the RNA interference approach, which is applicable as a therapeutic option for osteosarcoma patients, and we point out how the small interfering RNA method becomes a promising approach for the unmet challenge.