Metallurgical Tests in Endodontics: A Narrative Review

Since there are no reviews of the literature on this theme, the aim of this narrative review is to summarize the metallurgical tests used in endodontics, pointing out their functional use and their pros and cons and giving readers a user-friendly guide to serve as an orientation aid in the plethora of metallurgical tests. With this purpose, a literature search for articles published between January 2001 and December 2021 was conducted, using the electronic database PubMed to collect all published articles regarding the metallurgical tests used in endodontics for the evaluation of NiTi rotary instruments. The search was conducted using the following keywords: “metallurgy”, “differential scanning calorimetry” (DSC), “X-ray diffraction” (XRD), “atomic force microscopy” (AFM), “energy-dispersive X-ray spectroscopy” (EDS), “focused ion beam analysis” (FIB) and “Auger electron spectroscopy” (AES) combined with the term “endodontics” or “NiTi rotary instruments”. Considering the inclusion and exclusion criteria, of the 248 articles found, only 81 were included in the narrative review. According to the results, more than 50% of the selected articles were published in one of the two most relevant journals in endodontics: International Endodontic Journal (22.2%) and Journal of Endodontics (29.6%). The most popular metallurgical test was DSC, with 43 related articles, followed by EDS (33 articles), AFM (22 articles) and XRD (21 articles). Few studies were conducted using other tests such as FIB (2 articles), micro-Raman spectroscopy (4 articles), metallographic analysis (7 articles) and Auger electron spectroscopy (2 articles).

Поверхностное соединение при адсорбции Be на W(100): определение абсолютной концентрации и свойства

Be adsorption and T = 900 - 1100 K results in formation of a stable adsorption state; it drops the activation energy of atomic Be dissolution in the substrate bulk, and all newly deposited Be dissolves in the substrate. The absolute concentration of atomic Be has been measured by Auger electron spectroscopy using specially designed ultra high vacuum getter Be source. The concentration is (1 ± 0.1)•1015 сm-2 , and corresponds to WBe stoichiometry relative to W surface concentration. The layer is destroyed at T > 1100 K, the atomic Be dissolves in the bulk with the activation energy ~ 3,5 eV.