Introduction: Carrier-based gutta-percha is an effective method of root canal obturation creating a 3-dimensional filling; however, retrieval of the plastic carrier is relatively difficult, particularly with smaller sizes. The purpose of this study was to develop composite carriers consisting of polyethylene (PE), hydroxyapatite (HA), and strontium oxide (SrO) for carrier-based root canal obturation. Methods: Composite fibers of HA, PE, and SrO were fabricated in the shape of a carrier for delivering gutta-percha (GP) using a melt-extrusion process. The fibers were characterized using infrared spectroscopy and the thermal properties determined using differential scanning calorimetry. The elastic modulus and tensile strength tests were determined using a universal testing machine. The radiographic appearance was established using digital periapical radiographs. Results: The composite core carrier exhibited a melting point of 111°C to 112°C, which would facilitate removal by heat application. The elastic modulus and the tensile strength were found to be lower than those of Thermafil carriers (Dentsply Tulsa Dental, Tulsa, OK). The preliminary radiographic evaluation showed that the novel composite core carrier is sufficiently radiopaque and can be distinguished from gutta-percha. Conclusions: The PE-HA-SrO composites were successfully melt processed into composite core carriers for delivering gutta-percha into the root canal space.
The current research aims to identify measure classroom flexibility for kindergartens children, identify the correlation between the classroom flexibility of kindergartens children and the gender of the child, and identify the correlation between the classroom flexibility of kindergartens children and their classroom. The current research sample consisted of (200) boys and girls selected randomly from the governmental Riyadh affiliated with the six directorates of education of Baghdad on both sides (al-karkh - al-rasafa). in order to achieve the objectives of the current research, this required including two tools, one is the scale of classroom flexibility for the kindergartens' children, which was constructed by the researcher based on
... Show MoreThe following list comprises sixty-one species and subspecies of coccine¬llid beetles belonging to twenty-two genera distributed among six tribes in three subfamilies. All the species and subspecies have been recorded for Iraq. The categories have been arranged systematically according to Korschefsky's (1931) catalogue.
Many critics suggest that Beckett’s early plays are comic because they focus their analyses on the use comic elements. Waiting for Godot is one of Beckett’s early plays, and it has been heavily analyzed and read as a comic text partly because its subtitle is “a tragicomedy in two acts” and also because of the comic techniques used in the play. The present paper, however, attempts to read the play as a piece in which comedy fails to produce any effects on the characters who remain apparently very desperate and frustrated throughout the play. The characters perform different comic acts, but they do not really feel amused or entertained. The paper suggests that the acts these characters put on stage are only means to pass t
... Show MoreFamily social institution mission in the community, if and repaired Magistrate society and often lead that institution a positive role in the socialization, but a variety of factors ailing infect system family Vtfkdh role effective and influential in society and stands at the forefront of those factors disintegration family, whether caused by the death of one or both parents, divorce or separation, or whether the result of domestic weakness and poor family behavioral practices. And gaining the study of great importance and that the scarcity of studies that address the problem of delinquency female, is no secret that stand on the fact the role of disintegration family in the events of that problem will help and a large degree in the devel
... Show MoreAThe Bridge Maintenance Management System (BMMS) is an application system that uses existing data from a Bridge Management System database for monitoring and analysis of current bridges performance, as well as for estimating the current and future maintenance and rehabilitation needs of the bridges. In a transportation context, the maintenance management is described as a cost-effective process to operate, construct, and maintain physical money. This needs analytical tools to support the allocation of resources, materials, equipment, including personnel, and supplies. Therefore, Geographic Information System (GIS) can be considered as one tool to develop the road and bridge maintenanc
Recently, complementary perfect corona domination in graphs was introduced. A dominating set S of a graph G is said to be a complementary perfect corona dominating set (CPCD – set) if each vertex in is either a pendent vertex or a support vertex and has a perfect matching. The minimum cardinality of a complementary perfect corona dominating set is called the complementary perfect corona domination number and is denoted by . In this paper, our parameter hasbeen discussed for power graphs of path and cycle.