فهرست مطالب mohsen shahmoradi

Management of patients with high risk of bleeding during oral and dental procedures faces many challenges. The aim of this study was review strategies for facing high risk of bleeding patients taking dabigatran under dental procedure.

Articles and scientific texts will be searched in the six main databases, such as PubMed, Scopus, Web of Science, Science Direct, Google Scholar and Cochrane Library from 2007 to 2022, with keywords “dabigatran” AND “bleeding” AND “dental procedures” OR “dental care”. The inclusion criteria for articles included in the study were papers published about treatment patients with dabigatran and undergoing a dental procedure, English language and design of case reports, case series, quasi-experimental studies and clinical trials. This study was performed using PRISMA.

At first, 43 references included and finally 8 articles that met the inclusion criteria were select. CASP and STORBE checklists used for quality evaluation. Two reviewers checked eligibility of the selected articles, separately. Challenging Controversial results were found in selected studies. 4 studies demonstrated that Dabigatran should be interrupted at least 12 hours before invasive dental procedures. Some studies highlight that discontinuing Dabigatran depends on the patient's renal function. Also, it showed that deciding whether to stop Dabigatran or not by cardiologists determine based on elective or emergency high-risk patients.

Based on the results of the included studies, it is better to decide to stop or continue dabigatran before any dental treatment based on the type of intervention, the risk of bleeding and the patient's clinical situation. However, is preferred to discontinue taking this drug in high risk of bleeding dental procedures.

The literature on the effect of bleaching on stainability and color stability of any composites is scarce and controversial. In the case of some composites and/or bleaching agents or staining solutions, there is no previous study. Therefore, this rather large study was conducted for the first time to examine simultaneously the effects of bleaching and 3 staining solutions on 3 composite types.

This 3‑phase experimental in vitro study was performed on 18 groups of 5 specimens each: 90 composite discs with 10 mm diameter and 1 mm thickness were fabricated from 3 resin composites (microhybrid, nanohybrid, and nanofilled). Forty‑five discs underwent bleaching with 15% carbamide peroxide, and the remaining 45 were immersed in distilled water at room temperature. The color assessment was performed before and after this step, and ∆a, ∆b, and ∆L color parameters were calculated for each specimen. The specimens were then immersed in coffee, cola, and red grape juice for 2 weeks, and underwent colorimetry again. The simultaneous effects of bleaching and staining agents and composite types on ΔE (color changes) of composite specimens were analyzed using an independent‑samples t‑test, a Mann–Whitney U‑test, and two‑way and one‑way analysis of variances followed by a Tukey and a Dunnett’s T3 tests ( = 0.05).

Bleaching had no significant effect on color changes of microhybrid, nanohybrid, or nanofilled composites (P > 0.05). The stainability of composites did not increase after bleaching (P > 0.05). Regardless of the composite type and the presence of bleaching, coffee had the worst effect on color of composite specimens, while cola had the smallest staining effect (P < 0.05).

Stainability of microhybrid/nanohybrid/nanofilled composites did not increase after bleaching with 15% carbamide peroxide. Coffee should be consumed with care, as far as composite coloring is a concern, regardless of the type of composite in use or its bleaching history. Cola was the weakest stainer. Coffee always caused perceptible staining (ΔE >3.7), regardless of the composite in use or its bleaching history. Red grape juice caused such perceptible colorations in most cases. Cola did not cause any perceptible discoloration in most cases.

In CNG steel cylinders produced by the hot spinning method from seamless tubes, homogeneity of the material in the closed-end region is a significant factor. Therefore, in the production process, the produced cups are immediately under a hot heavy press, and in addition to forming the bottom shape, the heterogeneous area is driven out, finally, this region is eliminated via machining. Ideally, the depth of this milled area should be to the extent that the heterogeneous region is completely removed, also according to the designing standards, the minimum bottom thickness shall be more than that of wall thickness. However, the problem is that controlling this parameter is impossible in the machining process, and in some cases, it may become more than the specified limit. In this research, the minimum allowed remained thickness after bottom milling has been obtained by analysis and also compared with real results acquired from static and fatigue tests. Deducing the results of the FEM analysis, it can be seen that the remained bottom thickness up to 6mm has no limitation for the endurance hydrostatic pressure, and that was supported by experimental burst tests. Considering this amount for the bottom thickness, the percentage of rejected products declined considerably from 4% to 2% in the factory.