Solid Core Materials Research Articles

Management of Silver Point Retrieval for Root canal Retreatment: A Case Report

The historical importance of the solid core material is decreasing. When greater, more precise preparation of the canal space was not possible due to inferior metallurgy and instrument design, it was frequently utilized in the past. Silver points were machined with a circular cross section and more frequently than not went into oval than round canals. Long-term success rates might not be as great, but some cases may defy the odds. The prognosis after treatment and follow up by phone five years after the completion of treatment. A 46-years-old Chinese female was referred from a general private practitioner for the endodontic management of 36. The tooth had been endodontically treated 30 years before; subsequently the patient complained of occasionally mild discomfort that last a few second without any stimulating factors at the lower left molar. Radiographic finding revealed that the tooth had been treated with silver points and associated with periapical radiolucency. Non-surgical root canal retreatment was performed for the tooth. Conclusions: Due to the nature of partially removal silver points, even though the prognosis is guarded at the time of obturation. After five years, it was considered favourable although it was extracted due to fracture.

AN OVERVIEW ON AQUASOMES : A NOVEL APPROACH FOR DELIVERING MACROMOLECULES

In recent blossoming era of research in nanobiotechnology, aquasomes are viewed as an effective and efficient carrier system for drug delivery or biochemically active long chain macromolecules like protein and peptide, different hormones, antigens, enzymes and gene delivery. Aquatones are spherical in shape and having particle size within 60- 300nm. Self-assembled structure of aquasome (due to its natural property) it generates a focus on nanobiotechnology research as a carrier system. Mainly, aquasomes contain three-layers, that is core material, coating material, drug layer attached by ionic or non-covalent bond. Aquasomes include mainly the core materials like , hydroxyapatite, solid phase nanocrystalline ceramic diamond (carbon) and calcium phosphate dihydrate(brushite) . The coating of core material is done with glassy polyhydroxyl oligomeric film such as cellobiose and trehalose, on which modification of biochemically active molecules are attached. Whereas, calcium phosphate used as a core material, because of it is naturally present in the body. Whether calcium phosphate is unstable in nature, due to prolong storage it converts into hydroxyapatite which is a better core than calcium phosphate to develop the aquasomes. The solid core material renders stability of structures, while the coating material stabilizes the biochemically active molecules and protects against dehydration. In this review, we tried to an overview of aquasomes, and about its advantages over conventional drug delivery system, shielding effect of aquasomes on desired drug and how its self-assembled structures, makes them an attractive carrier to deliver biochemically active molecules.

Experimental study of evaluation of dynamical utilization of a microencapsulated phase change material slurry based on temperature range matching analysis

Microencapsulated phase change material (MPCM) slurries are energy-carrier fluids. Their latent heat utilization has been investigated by a new method based on the temperature properties of the phase-change fluid, in which match of the working and phase-change temperature ranges is considered. Based on the working-temperature range (3–15 °C) in heat-exchange circulation, the dynamic heat-transfer characteristics and utilization of the MPCM slurry with the core material n-docosane (C22H46) are discussed. The experimental results indicate that the effects of the stirring rate and flow rate on the dynamic heat-transfer characteristics are similar to those of water, and they have little influence on utilization of the 10% MPCM slurry, whereas the corresponding effect of the concentration is relatively large. When investigating the effect of the concentration, it was found that a low phase-change ratio suppressed movement of the phase-change-temperature range owing to the residual solid core material acting as a crystal nucleus, while the heat-transfer performance and latent heat utilization of the MPCM slurry suppressed each other. The 10% MPCM slurry is the most suitable energy carrier fluid, but supercooling still needs to be resolved. The experimental results provide a reference for practical efficient application of MPCM slurries as energy carrier fluids.

Evaluation sealing ability of an epoxy resin based sealer

The main aim of root canal therapy is the removal of microbial contaminants in conjunction with the total closure of the root canal system. Root canal sealers along with solid core material plays a major role in achieving the three-dimensional sealing of the root canal system. These sealers are binding agents which are used to adapt the rigid gutta-percha to canal walls and to fill up the voids, accessory canals and irregularities within the canal. Root canal sealers, although used only as adjunctive materials in the obturation of root canals, have been shown to influence the outcome of endodontic treatment. A perfect combination of sealing ability and biocompatibility is what an ideal root canal sealer should possess. This article discusses the current concepts in the usage of different sealers in endodontic therapy and their comparison in order to draw some clinical inferences.

Evaluation sealing ability of a new polydimethyl siloxane sealer

The main aim of root canal therapy is the removal of microbial contaminants in conjunction with the total closure of the root canal system. Root canal sealers along with solid core material plays a major role in achieving the three-dimensional sealing of the root canal system. These sealers are binding agents which are used to adapt the rigid gutta-percha to canal walls and to fill up the voids, accessory canals and irregularities within the canal. Root canal sealers, although used only as adjunctive materials in the obturation of root canals, have been shown to influence the outcome of endodontic treatment. A perfect combination of sealing ability and biocompatibility is what an ideal root canal sealer should possess. This article discusses the current concepts in the usage of different sealers in endodontic therapy and their comparison in order to draw some clinical inferences.

Akışkan Yatak Kaplama ve Gıda Uygulamaları

Gıda maddelerinin çevresel etkenlerden korunması ve raf ömrünün arttırılması amacı ile çeşitli gıda işleme teknolojileri bulunmaktadır. Bunlardan biri de son zamanlarda artan bir ilgi ile kullanılan enkapsülasyon teknolojisidir. Enkapsülasyon için kullanılan fiziksel yöntemlerden biri olan akışkan yatak kaplama ile katı halde bulunan çekirdek materyaller, hava akımında akışkanlaştırılmakta ve kaplama materyali ile çekirdek materyalin yüzeyinde film tabakası oluşturulmaktadır. Akışkan yatak kaplama tekniğinin uygulanabilirliği, parçacık özelliklerinin yanı sıra; sistemde kullanılan işlem değişkenleri, çevre değişkenleri ve termodinamik faktörlerden önemli derecede etkilenmektedir. İşlem sonucunda oluşan kapsüllerin salınım karakteristikleri ise ısınma, çözünme, mekanik ya da kimyasal kırılma vd. çeşitli mekanizmalar ile değiştirilebilmekte ve kontrollü salınım sağlanabilmektedir. Akışkan yatak kaplama yöntemi ile kontrollü salınım avantajının yanı sıra homojen yapıda toz ürün oluşmakta, ince parçacıklar azalmakta, taşıma ve depolama özellikleri gelişmekte, reaktif bileşenler korunabilmekte ve istenmeyen tat ve koku engellenmektedir. Bu derlemede akışkan yatak kaplama mekanizması, akışkan yatak kaplama sistemleri ve bu sistemin gıda alanındaki uygulamaları üzerine yapılan çalışmalar incelenmiştir.

A Comparative Study of the Quality of Apical Seal in Resilon/Epiphany SE Following Intra canal Irrigation With 17% EDTA, 10% Citric Acid, And MTAD as Final Irrigants - A Dye Leakage Study Under Vacuum.

Adequate apical sealing ability of the root canal filling material is an essential requisite for a successful endodontic therapy. Various endodontic irrigants are used for the removal of smear layer before obturating with a solid core material, thereby, reducing microleakage and improving apical seal. Resilon, a synthetic material was developed as an alternative to replace the conventional gutta-percha (standard root canal filling material) and traditional sealers for the obturation of endodontically treated teeth. To evaluate and compare in-vitro, the post obturation apical seal obtained with Resilon /Epiphany SE (Self Etch) sealer following irrigation with 17% Ethylenediamine Tetra-Acetic Acid (EDTA), 10% citric acid, and MTAD (a mixture of doxycycline, citric acid, and a detergent, Tween 80), as final irrigants in combination with Sodium hypochlorite (NaOCl) using dye leakage under vacuum method. Fifty five single rooted human maxillary central incisors were subjected to root canal instrumentation. Based on the final irrigation solution, samples were divided into three experimental groups (n=15); (I) 17% EDTA + 1.3% NaOCl, (II) 10% citric acid + 1.3% NaOCl, (III) MTAD + 1.3% NaOCl and two control groups (positive and negative) with 0.9% normal saline as a final irrigant. The samples were obturated with resilon/epiphany SE sealer according to manufacturer instructions and placed in 2% rhodamine B dye solution under vacuum pressure for 30 minutes and allowed to remain in the dye for seven days. All samples were then longitudinally split and examined for dye leakage under stereomicroscope and the data were statistically analysed using one-way ANOVA and post hoc tukey test. Statistically significant difference (p=0.001) was observed in the mean apical leakage between the experimental and the control groups. However, there was no significant difference (p>0.05) observed in the mean apical leakage amongst the three experimental groups. 17% EDTA, 10% citric acid, and MTAD were equally effective in achieving the post-obturation apical seal with resilon/epiphany SE sealer when used as a final irrigant in combination with NaOCl.

“Endodontic Sealers”: Current Concepts and Comparative Analysis

The main aim of root canal therapy is the removal of microbial contaminants in conjunction with the total closure of the root canal system. Root canal sealers along with solid core material plays a major role in achieving the three dimensional sealing of the root canal system. These sealers are binding agents which are used to adapt the rigid gutta-percha to canal walls and to fill up the voids, accessory canals and irregularities within the canal. Root canal sealers, although used only as adjunctive materials in the obturation of root canals, have been shown to influence the outcome of endodontic treatment. A perfect combination of sealing ability and biocompatibility is what an ideal root canal sealer should possess. This article discusses the current concepts in the usage of different sealers in endodontic therapy and their comparison in order to draw some clinical inferences.

Ability of Gutta-Percha and Resilon to Fill Simulated Lateral Canals by Using the Obtura II System

IntroductionThe aim of this study was to evaluate the ability of Resilon (Resilon Research, LLC, North Branford, CT) and 2 types of gutta-percha to fill simulated lateral canals when using the Obtura II system (Model 823-700; Obtura Spartan, Fenton, MO). MethodsForty-five human single-rooted teeth were selected and subjected to root canal preparation. After that, simulated lateral canals were made at 2, 5, and 8 mm from the working length (WL). The specimens were divided into 3 groups (n = 15) according to the filling material used: Obtura Flow 150 gutta-percha (Obtura flow), Odous Endo Flow gutta-percha (Odous; Odous De Deus Ind e Com. Ltda Belo Horizonte, MG, Brazil), and Resilon pellets (Resilon). Root canals were filled using the Obtura II system with the tip inserted to 3 mm from the WL. No sealer was used for root canal obturation. Specimens were subjected to a tooth decalcification and clearing method, and filling of the lateral canals was analyzed by digital radiography and photographs. The measurement of lateral canal filling was done using Image Tool software (UTHSCSA Image Tool for Windows version 3.0, San Antonio, TX). Data were statistically analyzed with the Kruskal-Wallis test at 5% significance. ResultsAll materials showed an ability to penetrate into the simulated lateral canals, with a minimum percentage of 73% in all thirds of the root canal. ConclusionsIt was concluded that gutta-percha and Resilon are solid core materials with a lateral canal filling ability when used with the Obtura II system.

Operating conditions and microcapsules generated by in situ polymerization

Microencapsulation of glass beads was carried out by in situ polymerization with melamine and formaldehyde. Glass beads were chosen as a core material because of their narrow size distribution and spherical shape. The complicated influence of emulsion on microencapsulation was successfully excluded by the use of a solid core material with a narrow size distribution and in situ polymerization, where all reactants are supplied from outside of the cores. Glass beads were microencapsulated systematically under various experimental conditions, and the effects of dosages of initiator and dispersing agent, stirring rate, and concentration and ratio of melamine and formaldehyde on microcapsules were investigated.

Preparation and characterization of hollow microcapsules for use as ultrasound contrast agents

AbstractA laboratory‐scale method of producing micron‐sized hollow microscapsules from a biodegradable polymer such as 50/50 poly(D, L‐lactide‐co‐glycolide) (PLGA), for use as a diagnostic ultrasound contrast agent, was developed. The technique involved microencapsulation of a volatile solid core material, and subsequent sublimation of the core to leave a hollow microsphere. A core material, such as ammonium carbonate, was ground to a suitable size distribution and encapsulated by a modified solvent evaporation or coacervation technique. This study investigated process parameters to produce diagnostically viable microscapsules by these two en‐capsulation methods, such as polymer molecular weight (from 10,000 to 50,000), initial polymer concentration, agitation method, and stabilizer type. Polymer solution viscosity, polydispersity, and agitation rates significantly controlled the mean size of the microcapsules. Stabilizers were essential in solvent evaporation, but corrupted the morphology of spheres made by coacervation. Zeta potential values of microsphere dispersions revealed differences in surface characteristics between both encapsulation methods. Incubation of microcapsules with serum improved their dispersion in aqueous media. Preliminary in vivo ultrasound studies with the New Zealand white rabbit model, using color Doppler, showed that the microcapsules gave significant contrast in the right kidney.

Failure mode maps for foam core sandwich beams

Sandwich panels can fail in several ways. The faces and core can yield plastically or fracture depending on the nature of the materials from which they are made; the compressive face can buckle locally or “wrinkle”, and the bond between the faces and core can fracture, causing delamination. The critical failure mode, which occurs at the lowest load, depends in part on the properties of the face and core materials and, in part, on the design of the beam. Here, we develop equations describing the load at which failure occurs for each possible failure mode for a sandwich beam with face and core materials that yield plastically. We then develop a failure mode map, with axes of core relative density and the ratio of face thickness to span length, which, for a given loading configuration and set of face and unfoamed solid core materials, shows the dominant failure mode for every possible beam design. Tests on sandwich beams with aluminum faces and rigid polyurethane foam cores show that the equations and map describe failure well. The map can then be used to design the minimum-weight sandwich beam for a given strength. Similar failure mode maps can be developed for sandwich beams made from face and core materials that fracture and for sandwich plates.

Preparation of hollow spherical articles

A novel method for making hollow articles in spherical and other shapes is outlined. These spheres are prepared by dissolving a film-forming polymer in a sublimable core solvent, shaping the blend while molten, cooling to solidify, and subsequently removing the solid core material as a vapour. The film-forming solid migrates to form a shell having the original core shape and a honeycomb-like porous wall. Inorganic hollow objects can also be made by introducing sinterable solids to the hot solution, subsequently heating to remove the organic portion and further heating to effect sintering. Size, strength, wall thickness, bulk density and surface characteristics can be controlled to suit the end use.