română DORINEL TĂLPEANU, LAURA ELENA GEAMBAZU, ALINA IULIA DUMITRU, FLORENTINA CLICINSCHI, VIOLETA TSAKIRIS, ANDREI CUCOȘ, VIRGIL MARINESCU
Abstract
The main objectives of this work are represented by both the development of hydroxyapatite (HAP) and the technique of casting it into plaster forms order to develop of ceramic structures with complex shapes for applications in neurosurgery. The tested models were made from ceramic powders based on HAP and, shaped by the casting technique in plaster molds. In order for the process of casting ceramic suspensions to be more efficient, specific techniques were performed such as: rheological curves of shear stress variation depending on the speed gradient and the dependence of the viscosity of the HAP suspensions on the speed gradient. Experimental models of cranial prostheses were developed in the form of a skull cap with an average thickness of ~3.5 mm, rods with a diameter of 5 mm, length of 50 mm. The samples were sintered at temperatures of 1275˚C and 1350˚C, for 2 hours. The variation of density and porosity with sintering temperature were determined by Archimedes method and the mechanical properties were investigated by bending and compression tests. The average values for the bending strength, for the two obtained models, are in the range of 32.64-36.68 MPa and for the compression strength they range from 44.54 to 50.10 MPa. Furthermore, the obtained samples were characterized by scanning electron microscopy (SEM) and the X-ray diffraction data for the HAP powder were confirmed by FT-IR spectra and thermogravimetric measurements. In order to establish the biocompatibile character, a first set of bacteriological and sterility determinations was performed. The novelty of this work consists in the fact that both the rheological characteristics have been optimized (ceramic suspensions with a solid phase content of min. 60%) as well as the technique of casting ceramic suspensions in plaster molds through ultrasonic and degassing processes/deaeration, obtaining shaped products with a raw density of min. 50% of roth.
Keywords
hydroxyapatite, biomaterials, casting in plaster forms, viscosity curves
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Year
2023
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Issue
53 (1)
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Pages
3-12
ALEXANDRU BURCEA, TALAAT GABRIEL REZK-GAVRILĂ, EDWIN SEVER BECHIR BOGDAN CONSTANTIN COSTĂCHEL, LAURENȚA LELIA MIHAI
Abstract
A cervical abrasion lesion is represented by a concave surface, situated at the gum line area. The aim of this study was to compare the efficiency of three composite resins used for the rehabilitation of cervical abrasions. Cervical abrasion lesions were rehabilitated with Estelite Asterıa - Tokuyama, GrandioSO x-tra Bulk Fill - Voco, and Tetric EvoCeram Bulk Fill - Ivoclar Vivadent) composite resins. 111 abrasion cervical lesions were restored with the three aesthetic dental composites in the assessed patients (26). The assessments were realized at 6 days after the insertion of the restoration material (baseline), and then 6, 12 and 18 months after, according to the modified USPHS criteria regarding the colour stability, anatomical contour, surface texture, marginal adaptation and integrity, marginal discoloration, apparition of secondary caries, postoperative sensitivity, and retention of the restoration. The restored teeth with abrasion lesions were distributed in three groups divided by the used restorative material: group G1 (EA, abrasion lesions restored with Estelite Asterıa composite), group G2 (GSOx, restoration with GrandioSO x-tra Bulk Fill composite), and group G3 (TEC, restoration made with Tetric EvoCeram Bulk Fill composite). The comparative study was a split-mouth study. All three restorative dental materials presented good clinical results after 18 months, in all studied criterion, without significant differences.
Keywords
dental non-carious cervical abrasion, direct restorations, composites, modified USPHS criteria
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Year
2023
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Issue
53 (1)
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Pages
13-22
G. VIGNESH KUMAR, S. UDHAYAKUMAR
Abstract
Increasing threads of the global warming and issues in disposals in municipal solid waste without compromising the mechanical properties the existing composite materials requires some additional materials. The traditional glass fiber, basalt fiber and epoxy based hybrid composite material is accommodate with bio waste tamarind seed polysaccharides and cashew nut frictional dust with different mesh with that the mechanical properties are improved based on the results of tensile, impact and flexural tests. The biodegradable test confirms the biodegradation of the fabricated samples with frictional dust.
Keywords
Frictional Dust, Hybrid biocomposite, biodegradation, tensile property, Tamarind seed polysaccharides
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Year
2023
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Issue
53 (2)
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Pages
103-110
MUSA AYRAN, ZEKIYE AKDAG, SONGUL ULAG, OGUZHAN GUNDUZ
Abstract
Diabetic wounds pose a significant challenge in clinical settings, primarily due to uncontrolled blood sugar levels and compromised immune systems observed in diabetes mellitus. Curcumin (CUR), a well-known anti-inflammatory and antioxidant agent, has shown potential for wound regeneration. However, its limited bioavailability and stability necessitate the development of a novel scaffold to overcome these limitations. In this study, we investigated the wound-healing properties of extracted CUR from Curcuma longa rhizomes and their combination with organic polymers by developing and evaluating a biomimetic composite 3D scaffold specifically designed for diabetic wounds. Incorporating CUR and Ethyl cellulose (EC) nanoparticles onto Alginate and Chitosan (SA/CS) scaffolds was achieved through the electrospraying method, resulting in an average particle size of 784±35.1 nm for CUR/EC nanoparticles. The interaction between different concentrations of CUR1 and CUR3 (1mg/1ml and 3mg/1ml) with EC on scaffolds was analyzed using FTIR spectroscopy, providing insights into the chemical composition of the scaffolds. The structural properties of the scaffolds and nanoparticles were examined to assess their morphological characteristics. Furthermore, the swelling and degradation behaviors of the scaffolds were investigated under in vitro conditions. The release profile of CUR was determined, and cytotoxicity testing was performed on the L929 cell line using an MTT assay to evaluate the biocompatibility of CUR/EC-coated scaffolds, as indicated by viable and proliferating cells in vitro study. In addition, the potential of CUR/EC-coated scaffolds to support tissue regeneration was evaluated using a DAPI staining assay and scanning electron microscopy (SEM).
Keywords
alginate, chitosan, curcumin, electrospraying, wound healing, 3D printing
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Year
2023
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Issue
53 (3)
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Pages
189-204
ȘTEFAN GEORGE CĂLINOIU, CORNELIA BÎCLEȘANU, ANAMARIA FLORESCU, CĂTĂLIN CONSTANTIN DUMITRU, MIHAI EFTIMIE, ANTON FICAI
Abstract
The aim of this study is to compare the mechanical strength in compression, tension and FTIR microscopy of 2 types of dental adhesives: 4th generation, considered the "gold standard" and the latest generation adhesives called universal adhesives.
In the dental community, I have noticed that opinions regarding the two adhesives are divided. More comfortable and younger doctors prefer universal adhesive because it gives them easier and faster working times. And the experienced doctors who used the 4th generation adhesive claim that after using the universal adhesive they returned to the "gold standard".
We compared the two adhesives regarding the adhesion they achieve through compressive forces and tensile forces. The compression was carried out with the help of a press and on blocks of Gradia Direct Posterior filling material, which after the first test, the blocks were reformed with the help of the 2 adhesives and retested. After the traction that was performed on extracted teeth on which fillings were made similar to clinical situations, the detachment area was studied under the FTIR microscope.
In tests, All-Bond 3® Bisco adhesive had higher bond strength and compressive strength than CLEARFIL™ Universal Bond Quick Kuraray. Following the tensile tests, the values obtained showed a higher adhesion to the 4th generation adhesive. Also, the interface area where debonding occurred showed that the 4th generation adhesive is superior in terms of adhesion to dental tissues.
Keywords
universal, 4th generation adhesives. compressive, tensile, adhesion
SEBASTIAN VÂLCEA, BOGDAN DUMITRIU, VALENTIN NIȚESCU, MIRCEA BEURAN, MIHAI ȘTEFAN
Abstract
Postoperative pancreatic fistula is the leading cause of morbidity and mortality in patients undergoing pancreatic resection. The pancreatic duct stenting technique during pancreatic anastomosis does not reduce the incidence of postoperative pancreatic fistula after cephalic pancreatoduodenectomy. The drainage method includes the use of an external or internal stent . The current literature suggests that the use of an internal pancreatic duct stent does not help to reduce the leakage rate of pancreatic anastomosis after pancreatic resection, and it may increase the risk of pancreatic fistulas in soft pancreases [1].
We report here the case of a 74-year-old patient, who 15 years ago underwent a Whipple-type cephalic duodenopancreatectomy, the operative indication being a Vaterian ampulla, for which the anastomosis prosthesis was performed with a plastic stent placed intraoperatively at the level of the Wirsung canal later, in 2022, he developed a late pancreatic fistula through the migration of the transparietal stent to the skin level.
Pancreatic postoperative fistula represents a major cause of morbidity and mortality in pancreatic surgery. Therefore, many surgical techniques have been undertaken and tested to prevent the occurrence of pancreatic fistula and its related complications, also useful for decreasing mortality rates among these patients.
Keywords
stent, fistula, pancreas, morbidity
BENOUIS ALI, AIT KACI DJAFAR,ZAHI RACHID, MOULGADA ABDELMADJIDÉ, ZAGANE MOHAMMED EL SALLAH,MOHAMMED BENTAHAR, BOUTABOUT BENALI
Abstract
This study represents an in-depth exploration of stress distribution within polymethylmethacrylate (PMMA) orthopedic cement, a critical material used in hip prostheses. Focusing on the inherent fragility of the cement and its intricate interface with implants, our research meticulously investigates stress patterns surrounding individual cavities. What sets this study apart is its nuanced examination of interactions between multiple cavities and their consequential effects on both stress intensity and distribution. The findings from this research offer nuanced and illuminating insights into the interconnected nature of cavities, aligning closely with observations derived from real-world experiments. This study significantly advances our understanding of potential damage phenomena within total hip prostheses. Moreover, it establishes a robust foundation for potential advancements in the design and performance of prostheses, taking into account the complex interplay within orthopedic cement. These insights pave the way for more targeted improvements in the mechanical behavior of hip prostheses, thereby contributing to the ongoing evolution of orthopedic implant technology.
Keywords
Cement, implant, stress, bone, defect, rupture