Background: The goal of a root canal treatment is three dimensional obturation with a complete seal of the root canal system. The aim of this study was to evaluate and compare the effect of two warm obturation techniques, warm vertical compaction (WVC) and, carrier based obturation technique Gutta Core (GC), versus two cold obturation techniques, cold lateral compaction (CLC) and, single cone (SC) on push-out bond strength of bioceramic sealer (Total Fill) at three different root levels. Materials and Methods: Forty extracted maxillary first molars teeth with a straight round palatal root canal and mature apices were selected for this study. After sectioning the palatal roots to 11 mm from the root apex, the canals were prepared with EDGEENDO X7 rotary system file from size 20 up to size 40 taper 04. The samples were then randomly separated into four groups based on obturation procedures (each group n = 10), with group A: obturated by WVC, group B: GC, group C: CLC, and group D: SC. Following obturation, the teeth were kept in an incubator at 37°C and 100% humidity for two weeks. Three slices of 2 mm thickness were cut horizontally at 2, 4.5, and 7 mm from the root apex in each of the three sections (apical, middle and coronal). The data were investigated using one-way ANOVA and Tukey's test with a significance level (p< 0.05). A digital microscope with a magnification of 60 X was used to establish the failure mode. Results: There was a significant increase in push-out bond strength following canal obturation with GC and WVC, particularly at the apical third (9.48, and 8.11 MPa, respectively) , compared to canals obturated with SC and CLC in all root levels except the middle third, at the (p< 0.05) significance level. The cohesive mode of failure was the most prevalent in all groups. Conclusio: BC (TotalFill) sealer showed higher bond strength when used in WVC and GC compared to other techniques. SC and CLC were showed comparable bond strength values.
Within this research, The problem of scheduling jobs on a single machine is the subject of study to minimize the multi-criteria and multi-objective functions. The first problem, minimizing the multi-criteria, which include Total Completion Time, Total Late Work, and Maximum Earliness Time (∑𝐶𝑗, ∑𝑉𝑗, 𝐸𝑚𝑎𝑥), and the second problem, minimizing the multi-objective functions ∑𝐶𝑗 + ∑𝑉𝑗 +𝐸𝑚𝑎𝑥 are the problems at hand in this paper. In this study, a mathematical model is created to address the research problems, and some rules provide efficient (optimal) solutions to these problems. It has also been proven that each optimal solution for ∑𝐶𝑗 + ∑𝑉𝑗 + 𝐸𝑚𝑎𝑥 is an effic
... Show MoreABSTRACT Background: Color changes that are detectable to human eye can affect the esthetic appearance of ceramic veneers. The purpose of this study was to evaluate and compare the effect of artificial accelerated aging on the color of ceramic veneers cemented with different resin cements. Materials and Methods: Sixty discs were prepared with 0.5 mm thickness, 30 discs made from IPS e.max press (Ivoclar Vivadent) and 30 discs were made from VITA Enamic (VITA Zahnfabrik). The discs were cemented with three resin cements: Variolink Veneer MV 0 shade (Ivoclar Vivadent), Rely X veneer Translucent shade (3M ESPE) and NX3 Nexus Clear shade (Kerr Corporation) with 0.1 mm thickness. The spectrophotometer Easyshade Advance was used to measure the co
... Show MoreWarm asphalt mixture (WMA) and reclaimed asphalt pavement (RAP) are the most memorable sustainable materials in world of asphalt concrete pavements . This research aims to study the warm asphalt mixture for different types of filler materials such as ordinary cement and limestone dust. Beside, this research focused on the test of emulsified asphalt properties by evaluating the performance of warm asphalt mixture by Marshall Stability properties as well as moisture sensitivity. The results of this experiment provided many important points. First, The cationic emulsified asphalt is suitable with RAP aggregate for production warm asphalt mixtures .Second, The effective mixing procedure for warm asphalt mixtures consists hea
... Show MoreObjective. This study aimed to evaluate and compare the force degradation of two types of elastomeric chains following different periods of immersion in zinc-containing mouthwashes. Materials and Methods. Four hundred and forty pieces of Elasto-Force and Super Elasto-Force elastomeric chains were divided into two control and eight experimental groups. The pieces were stretched to 25 mm on pins mounted on an acrylic block and stored in distilled water at 37°C. The experimental groups were immersed in four different types of mouthwash for one minute twice a day throughout the test period. Ten continuous thermocycles per day between cold and hot water baths (5–55°C) were carried out. Forces were measured at six-time intervals (in
... Show MoreBackground: White spot lesion considered as irreversible tooth demineralization presenting challenge to orthodontists during treatment schedules, fluoride was the most successfully used measure to overcome this challenge. Materials and method: A total of forty sound human permanent premolars were used in the present study and categorized into four groups, in one group the teeth were bonded with stainless steel brackets using Resin-modified glass ionomer cement (RMGIC) and the other three groups the teeth were bonded with light cured composite Resilience® (Ortho technology Co., USA). Group A; Acidulated phosphate fluoride (APF) topical gel (Mfg by DEEPAK PRODUCTS, INC, USA), fluoride ion 1.23% applied on examine area for four minute. Gro
... Show MoreA new pavement technology has been developed in Highway engineering: asphalt pavement production is less susceptible to oxidation and the consequent damages. The warm mix asphalt (WMA) is produced at a temperature of about (10-40) oC lower than the hot asphalt paving. This is done using one of the methods of producing a WMA. Although WMA's performance is rather good, according to previous studies, as it is less susceptible to oxidation, it is possible to modify some of its properties using different materials, including polymers. Waste tires of vehicles are one of the types of polymers because of their flexible properties. The production of HMA, WMA, and WMA modified with proportions of (1, 1.5, and 2%) of rub
... Show MoreObjectives: This study aims to assess and compare the micro-shear bond strength (μSBS) of a novel resin-modified glass-ionomer luting cement functionalized with a methacrylate co-monomer containing a phosphoric acid group, 30 wt% 2-(methacryloxy) ethyl phosphate (2-MEP), with different substrates (dentin, enamel, zirconia, and base metal alloy). This assessment is conducted in comparison with conventional resin-modified glass ionomer cement and self-adhesive resin cement. Materials and methods: In this in vitro study, ninety-six specimens were prepared and categorized into four groups: enamel (A), dentin (B), zirconia (C), and base metal alloys (D). Enamel (E) and dentin (D) specimens were obtained from 30 human maxillary first premolars e
... Show MoreThe In this experimental study, natural stone powder was utilized to improve a cohesive soil’s compaction and strength properties. According to the significant availability of limestone in the globe, it has been chosen for the purpose of the study, in addition to considering the existing rock industry massive waste. Stone powder was used in percentages of 4, 8, 12, 16% replaced from the soil weight in dry state. Some of cohesive soil’s consistency, shear, and compaction properties were depicted after improvement. The outcomes yielded in significant amendments in the experimented geotechnical properties after stone powder addition considering 60 days curing period. Cohesion and friction angle were notably increased by
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