Sumerianz Journal of Scientific Research

    
Online ISSN: 2617-6955
Print ISSN: 2617-765X

Quarterly Published (4 Issues Per Year)

Journal Website: https://www.sumerianz.com/?ic=journal-home&journal=29

Archive

Volume 1 Issue 4 (2018)

Fracture Resistance for Fatigue Cyclical Nickel - Titanium Endodontic Instruments – Literature Review

Authors : Sônia Sybelle de Mendonça Silva D. D. S. ; Luciano Barreto Silva ; Alexandrino Pereira dos Santos Neto M. D. ; Severino Alves Júnior ; Alessandra de Albuquerque Tavares Carvalho ; Jair Carneiro Leão ; Gerhilde Callou Sampaio
Abstract:
Background: rotary endodontic instrument fractures have been related as a major problem in Endodontics due to the complications that follow such incidents. Objective: The aim of this review was to evaluate, through traditional literature review, the factors that influence fracture resistance of endodontic NiTi instruments used in mechanical preparation and shaping of the root canals. Methods: The review was made by two independent reviewers and the following electronic databases were used: PUBMED Central, BVS/BIREME, Web of Science, Science Direct, Higher Level Personnel Improvement Coordinator (CAPES) Periodic Portal , The Cochrane Library and PROSPERO, from 1988 to 2014.Results: the number of cycles to which rotary NiTi instruments have been submitted showed that fracture resistance is directly related to fracture resistance; composition and thermomechanical processing of the alloy and transverse cross sections and dimensions. Conclusions: Fracture resistance seems to be related to the number of cycles that an instrument is able to resist after a given load conditions. Kinematic motion, alloy composition, different rotational angles and the speed used, as well as the shape and area of the cross section of the straight instrument, are the main fracture causes.

Pages: 88-94

Application of Grey Numbers to Assessment of Case-Based Reasoning Systems

Authors : Michael Gr. Voskoglou
Abstract:
Case-Based Reasoning (CBR) is the process of solving new problems (usually with the help of computers) by adapting the solutions of similar (analogous) problems solved in the past. The CBR approach has got a lot of attention over the last 30-40 years, because as an intelligent-systems method enables information managers to increase efficiency and reduce cost by substantially automating processes. In the present work a method is developed using Grey Numbers (GNs) as a tool for accessing the effectiveness of CBR systems and examples are provided illustrating it. This new assessment method is proved to be equivalent with an analogous method using Triangular Fuzzy Numbers that has been developed in earlier author’s works, but it has the advantage of reducing significantly the required computational burden. GNs, which are defined with the help of the closed intervals of real numbers, are indeterminate numbers whose range  is known, but not their exact value, and they have found nowadays many and important applications in science, engineering and in the everyday life for handling approximate data.

Pages: 80-87