Core Build Research Articles

Comparative evaluation of the fracture resistance of different core build up materials – An ex vivo study

Comparative evaluation of the fracture resistance of different core build up materials – An ex vivo study

Comparison of the Flexural Strength of Four Core Built up Materials

The aim of this study is to compare the flexural strength of 4 commonly used core build up materials in clinics. Four core built up materials, a cermet cement (ketac silver), a light cure composite, conventional silver amalgam (control group) and zirconomer (zirconia reinforced GIC) were used and were divided into Group A, B and C and D respectively. The root canal of 90 extracted mandibular molars with similar anatomy and morphology were selected. Highest flexural strength was shown by Group A followed by group C, group B and then group D.

Comparative evaluation of the tensile and compressive strength of three light cured bulk-filled composite core build up material

Introduction- The loss of a considerable amount of tooth structure makes retention of subsequent restorations more problematic and increases likelihood of fracture during functional loading. Different clinical techniques are there, one such technique is post and core. An ideal core build- up material must present excellent mechanical properties to resist the stresses that may be produced during function, providing equitable stress distributions of forces and reducing probability of tensile and compressive failures. Recent developments in flowable and restorative composite resins have resulted in a greater total depth of cure—between 4 and 5 mm for some materials. Materials and Methods: study was conducted in the department of prosthodontics and crown and bridge, including implantology along with external laboratory support and molds for tensile and compressive strength were made. Result- Based on strength, Photocore and Multicore HB may be used as alternatives to Kerr Herculite Precise; however, other physical qualities should also be considered. Conclusion-Within limited data available on recent bulk fill material that is PLT, Kerr Herculite Precis more in vitro and in vivo studies should be held for long term success of the material.

Comparative evaluation of compressive strength of three different core build up materials on fiber reinforced composite post after 24 hours and 1 week- an in vitro UTM study

Background: A core build-up is a restoration placed in a badly broken down tooth to restore the coronal portion of the tooth. This facilitates subsequent restoration of the broken down tooth by means of extra-coronal restoration. Compressive strength of core materials is thought to be important because core usually replaces the large bulk of the tooth structure and must resist multidirectional forces. In this study compressive strength of three different core materials was investigated on Fiber Reinforced Composite post at different time intervals. Objective: The purpose of the study undertaken was to determine the compressive strength of self-cured, photo cured and dual cured core build up materials on Fiber Reinforced Composite post after 24 hours and 1 week. Methodology: Cylindrical specimens measuring 6mm in height and 4mm in diameter were prepared using a machined plexiglass mold and core build up was done around the fiber post. Ten specimens were prepared in each group (n=30); Group A: Restorative Glass lonomer Cement-GC Gold, Japan; Group B: Light-cured composite-Magma NT, Prevest Denpro, USA and Group C: Dual-cure core-build up composite resin-Para Core, Coltene whaledent, USA, which were further subdivided into five specimens per group according to the time intervals of 24 hours and 1 week. Compressive strength was determined using a universal testing machine. The maximum load applied to fracture the specimens was recorded and compressive strength calculated in MPA. The data obtained was analyzed using parametric one way ANOVA test and Bonferroni post-hoc procedure. Results: The mean compressive strength was significantly higher (p

Comparison of Retention between Two Dental Root Canal Core Build Up Materials and Silanized and Non-Silanized Glass Fibre Posts: An Invitro Study

Background: Various resin-based core builds up materials are commercially available in market but their clinical use should follow recommendations of bond strength measurement studies. Objective: to evaluate the retention between two commercially available core build up materials and silanized and non-silanized glass fibre posts. Methodology: The retention between two commercially available core build up materials (Core X Flow and Light Core) and Silanized and Non- Silanized glass fiber posts with ten samples in each group were assessed using ‘pull out test’ in universal testing machine. Student’s unpaired ‘t’ test was used for inter group comparison by fixing significance level at p ≤ 0.05. Results: The retention force was higher in silanized fibre post group compared to non-silanized posts (p=0.02). Among the silanized posts, the retention force was significantly higher in CORE X FLOW group compared to LIGHT CORE group (p=0.03). Conclusion: The retention of posts improved with silanization. With silanization, the retention force was significantly higher with ‘CORE X FLOW’ compared to ‘LIGHT CORE’ core build up material.

Comparison of Retention between Two Dental Root Canal Core Build Up Materials and Silanized and Non-Silanized Glass Fibre Posts: An Invitro Study

Comparison of Retention between Two Dental Root Canal Core Build Up Materials and Silanized and Non-Silanized Glass Fibre Posts: An Invitro Study

Comparison of Retention between Two Dental Root Canal Core Build Up Materials and Silanized and Non-Silanized Glass Fibre Posts: An Invitro Study

Comparison of Retention between Two Dental Root Canal Core Build Up Materials and Silanized and Non-Silanized Glass Fibre Posts: An Invitro Study

DIRACOS: a cross platform solution for grid tools

DIRACOS is a project aimed to provide a stable base layer of dependencies on top of which the DIRAC middleware is running. The goal was to produce a coherent environment for grid interaction and streamline the operational overhead. Historically the DIRAC dependencies were grouped in two bundles; Externals containing Python and standard binary libraries, and the LCGBundle which contained all grid-related libraries (gfal, arc, etc). Such a setup proved difficult to test and hindered agile development. DIRACOS solves the binary incompatibility that was caused by using a python version newer than the native system one (SLC6). It is spawned from a single list of required packages from where we pull all dependencies down to the level of glibc using SRPMs. With such an approach we can provide a uniform set of packages for our clients, servers, and several platforms. It is an extendible setup with a DevOps development cycle in mind. The core build functionality of DIRACOS is based on Fedora Mock. DIRACOS introduces its own grammar to handle specific cases, and it also allows patching (some SRPMs require tweaking, which the user can do by providing a diff) as well as routines for pre/post/instead actions of compilation. With this approach DIRAC was able to provide a single bundle for clients and servers that is reliable, flexible, easy to test and relatively small (250 MB). It allows for a smooth transition from SLC6 to CC7 and provides a clear roadmap for possible extensions of DIRAC to a wide variety of platforms.

Resin based core bguild up materials - A review

A core build up is a restoration placed in a severely damaged tooth in order to restore the structural balance, functional efficiency and aesthetic harmony of the dentition (including oro-facial structures). In order to achieve these criteria, certain factors should be kept into consideration such as: it should protect the remaining tooth from fracture, it should have sufficient compressive strength to resist intra-oral forces, sufficient flexural strength to prevent core dislodgement during function, biocompatibility with the surrounding tissues, ease of manipulation, ability to bond to tooth structure, pins and posts, dimensional stability. To compensate its drawbacks and to enhance its durability, certain materials have been introduced in order to fulfil most of its criteria. Certain materials such as amalgam, resin based core build up materials, glass ionomer cements and others have been introduced. These resin based core build up materials met most of its demands which is required in order to fulfil its criteria for an ideal core build up materials. Most of the resin based core build-up materials placed in increments in order to cure completely but now a days few of its materials can be placed in bulk such as Bulk Flow materials and some materials releases fluoride such as Fluorocore, Absolute dentin core build up composite, Pulpdent Hardcore. Therefore the review of this literature could be a helpful for dentists to use these new promising restorative materials with long term clinical outcome. Keywords: Microhardness, Flowcore, Biocompatibility.

Post & Core Build up “Support for a Final Success”

Post & Core Build up “Support for a Final Success”

REVIEW OF LITERATURE ON TURNAROUND STRATEGY IN BANKING

Purpose of the study: The business cycle always occur in banking activities. For that reason, banks often prepare a turnaround strategy to keep banking growing during changes of business cycles during which often happen during changes in the economic situation or changes in the regulation of a country. This article reviews study on banking turnaround strategy (in conventional and Islamic banks) regarding to the model turnaround strategy by Schoenberg, Collier, and Bowman (2013) from January 1990 to December 2017, in order to identify the current state of study and research gap. The publications were classified into process-orientated strategies and content-orientated strategies. The process-orientated strategies were divided into cost efficiencies, asset retrenchment, focus on core activities and build the activities. Meanwhile, the content-orientated strategies were classified into the changes of organisational structure and culture change.
 Methodology: This paper focuses on peer-reviewed Economy journal, excluding book and book chapters. The keywords included ‘turnaround strategy in banking’ and ‘business cycle’. Articles were only selected if they directly addressed into turnaround banking and the business cycle. The sample was generated by applying a keyword search on Mendeley database.
 Main Findings: There were 122 out of 250 in the sample analysed on the banking turnaround strategy. The majority of studies were concerned with the process-oriented strategies (such as the focus on core activities and build of the activities).
 Applications of this study: This study can be useful for strategic management of banking
 Novelty/Originality of this study: The implementation of turnaround model strategy by Schoenberg, Collier, and Bowman (2013) as the management strategies during the recovery process in banking.

Comparative Evaluation of Flexural Strength of Four Recent Core Build up Materials: An in Vitro Study

Comparative Evaluation of Flexural Strength of Four Recent Core Build up Materials: An in Vitro Study

Tensile Strength of Core Build up Material to Glass Fiber Post with Different Surface Treatment

Aims: The purpose of this study was to investigate the effects of different surface treatments on the tensile retentive force of fiber reinforced posts (FRPs) to composite core material buildup. Materials and methods: A total of fifty FRPs were randomly divided into five groups (n = 10), the first group was the untreated control group, second group immersion in 24% hydrogen peroxide; third group immersion in 4% hydrofluoric acid gel; fourth group sandblasting with 50um Al2O3 powder, fifth group surface preparation with an Er:YAG laser under power setting (300m), at 2 Hz and 100 uS) for 10 seconds. A cylindrical polyethylene mold was used to surround the treated posts, and the mold was filled with dual cure composite core material buildup. All samples were light cured for 40 seconds through the top of the mold. After 24 hours of storage in water, the post was then grasped with Jacobs chuck attached to the upper member of testing machine and produced tensile loading. Tensile tests were performed at a cross, head speed of 0.5 mm/minute using a universal testing machine. Data were analyzed by One-Way Analysis of Variance followed by Duncan Multiple Range Test at significant difference (p < 0.05). Results: The post core tensile retentive force achieved following pretreatment with hydrogen peroxide and sandblast (Groups 2 and 4) were comparable to each other, and significantly higher than those of other groups in which the post surface had been treated with hydrofluoric acid gel, control group and laser, respectively. Conclusions: surface pretreatment of FRP has significance effect on the tensile retentive force. Sandblasting and hydrogen peroxide are increasing tensile retentive force of FRPs to composite core material buildup greater than those of hydrofluoric acid gel, control and laser group, respectively.

Mechanical, antibacterial and bond strength properties of nano-titanium-enriched glass ionomer cement

The use of nanoparticles (NPs) has become a significant area of research in Dentistry. Objective The aim of this study was to investigate the physical, antibacterial activity and bond strength properties of conventional base, core build and restorative of glass ionomer cement (GIC) compared to GIC supplemented with titanium dioxide (TiO2) nanopowder at 3% and 5% (w/w).Material and Methods Vickers microhardness was estimated with diamond indenter. Compressive and flexural strengths were analyzed in a universal testing machine. Specimens were bonded to enamel and dentine, and tested for shear bond strength in a universal testing machine. Specimens were incubated with S. mutans suspension for evaluating antibacterial activity. Surface analysis of restorative conventional and modified GIC was performed with SEM and EDS. The analyses were carried out with Kolmogorov-Smirnov, ANOVA (post-hoc), Tukey test, Kruskal-Wallis, and Mann Whitney.Results Conventional GIC and GIC modified with TiO2 nanopowder for the base/liner cement and core build showed no differences for mechanical, antibacterial, and shear bond properties (p>0.05). In contrast, the supplementation of TiO2 NPs to restorative GIC significantly improved Vickers microhardness (p<0.05), flexural and compressive strength (p<0.05), and antibacterial activity (p<0.001), without interfering with adhesion to enamel and dentin.Conclusion GIC supplemented with TiO2 NPs (FX-II) is a promising material for restoration because of its potential antibacterial activity and durable restoration to withstand the mastication force.

Comparative evaluation of compressive strength and flexural strength of conventional core materials with nanohybrid composite resin core material an in vitro study.

Several dental materials have been used for core build-up procedures. Most of these materials were not specifically developed for this purpose, but as a consequence of their properties, have found application in core build-up procedures. Improvements in composites and the development of nanocomposites have led to their use as a core build up material due to their superior mechanical properties, optical properties and ease of handling. However it is not clear if they have better mechanical properties than the conventional core build up materials like amalgam, GIC and dual cure composite core build up material. The strength of the core material is very important and this study was undertaken to compare the mechanical properties of materials used for direct core foundations. The differences between the compressive strength and flexural strength of Filtek Z350 nanocomposite with conventional core build up materials like Amalgam, Vitremer GIC and Fluorocore were tested. Cylindrical plexi glass split molds of dimension 6±1mm [height] x4±1mm [diameter] were used to fabricate 15 samples of each core material for testing the compressive strength and rectangular plexi glass split molds of dimension 25±1mm [length] x 2±1mm[height] x2±1mm [width] used for fabricating samples for flexural strength. The samples were stored a water bath at 250°C for 24h before testing. The samples were tested using a Universal Instron testing machine. The results of the study showed that Fluorocore had the highest compressive strength and flexural strength followed by Filtek Z350 [nanocomposite] Amalgam had the least flexural strength and Vitremer GIC had the least compressive strength. Thus flurocore and nanocomposite are stronger than other core build up materials and hence should be preferred over other conventional core build up materials in extensively damaged teeth.

Comparative Evaluation of Bond Strengths of Different Core Materials with Various Luting Agents Used for Cast Crown Restorations

The coronal cast restoration continues to be used commonly to restore mutilated, endodontically treated teeth. The tensile bond strength of luting cements is of critical importance as many of failures are at the core and the crown interface. An invitro study with aim to evaluate and compare bond strengths of luting cements between different core materials and cast crowns. A total of 45 extracted identical mandibular second premolars were endodontically treated and divided into 3 groups of 15 each. Specimens in first group were restored with cast post and core (Group C), and specimens in second group were restored with stainless steel parapost and composite core material (Group B) and specimens in third group were restored with stainless steel parapost and glass ionomer core build (Group G). Standardized crown preparation was done for all the specimens to receive cast crowns. Each group was further divided into 3 subgroups and were cemented using 3 different luting cements namely, resin cement, polycarboxylate cement, glass ionomer cement (Type I). The samples of each subgroup (n=5) were subjected to tensile testing using Universal Testing Machine at a crosshead speed of 2mm/min till the dislodgement of crown from the core surface was observed. The bond strengths were significantly different according one way ANOVA (F-150.76 and p<0.0000). The results of the study showed that the specimens cemented with resin cement in cast core, composite core and glass ionomer core exhibited significantly higher bond strengths as compared to specimens cemented with glass ionomer and polycarboxylate cement. Composite resin core and resin cement combinations were superior to all other cement and core combinations tested.

Restoration Of A Severely Damaged Crown With Chopped Glass Fibers And Core Build-Ups : A Clinical Report

This article aims to describe a technique using glass fiber post with an interpenetrating polymer network (IPN) polymer matrix, and chopped the same as glass fibers core build-up material to restore a tooth with a significant loss of crown structure. Following the root canal therapy, the post was bonded into the canal and the core 4mm of chopped glass fiber bundles were used tothe core of build up a block on the bonding surface of the glass fiber post so as to strengthen the post and core assembly. Prefabric core build ups were used to shape the core form easily. Zirconia full ceramic crown was fabricated and the patient was satisfied with the treatment. Restoration was examined to remain succesful after 1 year.

Self-Assembling Peptide−Polymer Conjugates Comprising (d-alt-l)-Cyclopeptides as Aggregator Domains

The synthesis of peptide−polymer conjugates comprising (d-alt-l)-cyclopeptides as aggregator domains and their self-assembly into tubelike structures is described. By coupling two well-defined poly(n-butyl acrylate) blocks to opposite sides of a preformed cyclic (d-alt-l)-α-octapeptide, a coil−ring−coil bioconjugate was accessed. The applied solution-phase coupling route allowed a multigram scale synthesis of the conjugate and assured both a controlled synthesis and ease of analysis. The controlled self-assembly of the conjugate leads to uniform tube structures. Atomic force microscopy (AFM) of these aggregates deposited on mica revealed a height of 1.4 ± 0.2 nm, a width of 5 nm, and roughly estimated lengths of up to 200−300 nm. A model is proposed, explaining the structure dimensions. This includes the formation of a tubular peptide core build via stacking of the cyclopeptides and a poly(n-butyl acrylate) shell wrapping around the peptide tube. The model is consistent with infrared spectroscopy and elec...

Bonding of Resin Cement to Resin Composite for Core Build Up

Bonding of Resin Cement to Resin Composite for Core Build Up