Shaping ability of the profile 25/0.06 and protaper F2 in rotary motion, and reciproc in simulated canals

Background Since the introduction of nickel–titanium (Ni–Ti) instruments to dentistry, a wide variety of Ni–Ti instruments have become commercially available. These Ni–Ti instruments are expensive, which limits their usage in developing countries and forces practitioners to use instruments repeatedly. Another problem is the possible prion cross-contamination associated with the multiple usage of endodontic instruments. In addition, the use of these instruments requires new skills and experience. In this article, the shaping capacities of two conventional rotary file systems, ProFile 25/0.06 and ProTaper F2, were reviewed and compared with the Reciproc single-file system. Methods A total of 45 simulated canals with 40° curvature, in clear resin blocks, were prepared using conventional rotary systems consisting of ProFile orifice shaping (OS) #3 and final flaring #25/.06, Reciproc R25, and ProTaper shaping file SX and finishing file F2. Pre-and post-instrumentation images were analyzed at ten different levels, using AutoCAD 2007 software. The measurement positions were defined in 1-mm intervals: positions 0–3 established the apical part, positions 4–6 constituted the middle part, and positions 7–10 established the coronal part of the canal. The amount of removed resin, the transportation, instrumentation time, change in working length (WL), instrumentation fractures, and the presence of ledge were evaluated. Data were analyzed using ANOVA, Kruskal–Wallis and independent t-test (p < 0.001). Results ProFile removed the least resin (p < 0.001) and caused less transportation than Reciproc and ProTaper, in total (p < 0.001). ProTaper caused more transportation ProFile and Reciproc in the apical part (p < 0.000). Reciproc caused more transportation than ProTaper and ProFile (p < 0.001), and the transportation tendency toward the inner aspect of the curvature in the middle part. Reciproc caused the less transportation than ProFile and ProTaper in the coronal part. The transportations tended to occur toward the outside of the curvature, except the middle part with Reciproc and at points 5 and 6 with ProTaper. There were no significant differences among the groups in terms of maintaining the original WL. Reciproc was significantly faster than the others group (p < 0.001). Only one instrument fracture (25/0.06 ProFile) was noted. All groups showed one ledge each. Discussion The results of the present study showed that both ProFile 25/06 and ProTaper F2, combined with a file used for coronal enlargement (OS3 and SX), have the potential to create satisfactory canal shape in the curved root canals. Further studies using real human teeth are needed to confirm our results

On the Kirchhoff matrix, a new Kirchhoff index and the Kirchhoff energy

The main purpose of this paper is to define and investigate the Kirchhoff matrix, a new Kirchhoff index, the Kirchhoff energy and the Kirchhoff Estrada index of a graph. In addition, we establish upper and lower bounds for these new indexes and energy. In the final section, we point out a new possible application area for graphs by considering this new Kirchhoff matrix. Since graph theoretical studies (including graph parameters) consist of some fixed point techniques, they have been applied in the fields such as chemistry (in the meaning of atoms, molecules, energy etc.) and engineering (in the meaning of signal processing etc.), game theory, and physics

A Review of 2625 Isolated Hydrocele Cases in Children

Introduction: Inguinal hernias and hydroceles are the most frequently performed procedures in pediatric surgery departments. In this study, we aimed to define the spontaneous regression rate in different types of  hydroceles, the regression age, the timing of surgery, and the optimal treatment approaches for each hydrocele type in cases with isolated hydroceles in children.Material &amp;Methods: This historical cohort study included 2625 patients which were admitted between January 2004 and December 2012. The hydroceles were classified as: ‘non-communicating hydroceles’, ‘communicating hydroceles’, ‘spermatic cord hydroceles’ and ‘abdomino-scrotal hydroceles’ (ASH). Patients were divided into two groups with regard to their ages at diagnosis as follows: those presenting in the newborn period and before 24 months of age (Younger– Group 1) and those presenting after 24 months of age (Older – Group 2). Determining the type of isolated hydrocele, the decision making for follow-up or surgery, and the follow-up period were conducted by 7 attending pediatric surgeons and 6 residents. Results: In Group 1, 93% of 1086 non-communicating hydroceles, 40% of 158 cord hydroceles, and 15% of 34 communicating hydroceles resolved during the follow-up, and the remaining patients with each type of hydrocele underwent surgery. In Group 2, 8.7% of 183 non-communicating hydroceles resolved during the follow-up.Conclusion: The primary treatment of patients with isolated hydrocele should be decided regarding the type of hydrocele, along with age at admission, and accordingly, conservative or surgical treatment should be considered

A Constructivist Model Proposal For Speed Reading: Speed Reading And Constructing The Meaning

Hızla gelişen dünyada eğitim teknolojileri ve becerileri kendilerini bu düzene adapte edebilmek için değişirler. Temel dil becerilerinden okuma da çağın bu gereğine uygun olarak hızlı okuma becerisine dönüşmüştür. Hızlı okuma bireye, bilgiye hızla ulaşma ve kullanma imkanı veren bir beceridir. Çalışmamızda, hızlı okumayı tanıtmak, kavratmak ve öğretmek amacıyla hazırlanmış olan Hızlı Okuma ve Anlamı Yapılandırma adlı eser değerlendirilecektir.In rapidly evolving world, educational technologies and skills change for adapting themselves to this regulation. Reading, as one of the basic language arts, has been transformed into the skill of speed reading in accordance with the necessary of the modern world. Speed reading is a skill enabling to reach and use knowledge rapidly. In our study, it will be appreciated book of “SPEED READING AND STRUCTURING THE MEANING” which was prepared for the purpose of introducing, comprehending and teaching "speed reading"