Dental Disorders and Salivary Changes in Patients with Laryngopharyngeal Reflux

Background: Laryngopharyngeal reflux (LPR) is a common inflammatory condition of the upper aerodigestive tract tissues related to the effects of gastroduodenal content reflux, characterized by a wide variety of clinical manifestations. The aim of our study was to evaluate the possible association between dental disorders and LRP, focusing on the role of salivary changes. Methods: Patient’s dental status was evaluated according to Schiff Index Sensitivity Scale (SISS), Basic Erosive Wear Examination (BEWE) and Decayed, Missing, and Filled Teeth (DMFT) scores. Reflux-associated symptoms were assessed according to Reflux symptom index (RSI). A qualitative and quantitative examination of saliva was performed. Results: Patients suffering from LPR had a higher incidence of dental disorders, regardless the presence of salivary pepsin, and thus, statistically significant higher scores of RSI (p = 0.0001), SISS (p = 0.001), BEWE (p < 0.001) and VAS (p < 0.001). Moreover, they had lower salivary flow compared with healthy patients. Conclusions: The finding of demineralization and dental caries on intraoral evaluation must raise the suspicion of LRP. Reflux treatments should also be aimed at correcting salivary alterations, in order to preserve the buffering capacity and salivary pH, thus preventing mucosal and dental damage.

CFD modeling of slurry flow erosion wear rate through mitre pipe bend

Erosive wear caused by particulates slurry is one of the major concerns in the pipe bend which may results in the failure of the pipe flow system. In the present work, erosion wear rate through mitre pipe bend caused by silica sand particulates slurry has been investigated using ANSYS Fluent code. The solid spherical particulates of size 125 µm and 250 µm having density of 2650 Kg/m3, were tracked to compute the erosion wear rate using Discrete Phase Method (DPM) model. The particulates were tracked using Eulerian-Lagrange approach along with k-ɛ turbulent model for continuous fluid phase. The silica particulates were injected at solid concentration of 5% and 10% (by weight) from the pipe inlet surface for wide range of velocities viz. 1–8 ms−1. The erosion wear rate was computed through four computational erosion models viz. Generic, Oka, Finnie and Mclaury. Furthermore, the outcomes obtained through Generic models are verified through existing experimental data in the literture. Moreover, the results of DPM concentration, turbulence intensity and particle tracking were predicted to analyze the secondary flow behaviour through the bend cross section. Finally, the effect of particulate size, solid concentration and flow velocity were discussed on erosion wear rate through bend cross section. The findings show that the locality of maximum erosive wear is positioned at the extrados of the bend outlet cross section. Additionally, it is found that Mclaury model offers higher erosion rate as compared to the other models and provides benchmark for designing the slurry pipeline system.

Abrasion and Erosion Resistance of Cermets: A Review

WC-based hardmetals are employed widely as wear-resistant ceramic–metal composites for tools and wear parts. Raw materials supply, environmental concerns and some limitations of hardmetals have directed efforts toward development of alternative wear-resistant composites–cermets. We present a current state of knowledge in the field of ceramic-rich (≥50 vol%) cermets behavior in abrasion and erosion conditions, which are the dominant types of wear in many industrial applications. Distinction is made between two-body and three-body abrasion, solid-particle erosion, and slurry erosion. Cermets, in particular TiC-, Ti(C,N)- and Cr3C2-based composites and hardmetals, are compared for their abrasive and erosive wear performance and mechanism. The review enabled formulation of tribological conditions in which cermets may be comparable or have potential to outperform WC-Co hardmetals. Hardmetals, in general, outperform cermets in abrasion and solid-particle erosion at room and moderate temperatures. However, cermets demonstrate their potential mainly in severe conditions—at elevated temperatures and corrosive (oxidation, electrochemical corrosion) environments.

Anorexia nervosa and purgative-type bulimia nervosa: a fundamental role of the dental surgeon in diagnosis and treatment

Introduction: In a world where appearance is considered above all by most people. It is in this unbridled search that some people end up acquiring eating disorders. Anorexia nervosa and purgative-type bulimia nervosa are diseases that are rarely taken into account in the first clinical assessment of the patient. Bulimia nervosa and Anorexia nervosa are eating disorder that causes serious physiological problems in the oral cavity, due to saliva calcification caused by frequent vomiting. Objective: it was to bring into discussion, through a literature review, the meticulous look that the dental surgeon must-have when performing the clinical examination and that he can be the first source in detecting signs of eating disorders and their clinical manifestations in the patient and so can forwards it to a multidisciplinary team for better diagnosis and treatment. Methods: This study followed an integrated literature review model and articles dating from 2001 to 2021 in English and Portuguese were selected. In virtual databases such as Scielo and PubMed. Results and Conclusion: The dental surgeon plays an important role in the team, controlling the development and progression of oral manifestations. Pass the oral hygiene guidelines, apply substances that can control the acids that are present in oral fluids; use salivary substitutes that can help reduce erosive wear. And always encourage this patient to come back for treatment. In extreme cases of damage to the dental structure, functional and anatomical, restorative or rehabilitative treatment is chosen. Recover form, function, esthetics and eliminate hypersensitivity and facilitate cleaning. The dental surgeon must be able to assess and diagnose the manifestations arising from eating disorders. Because it is the first professional to be able to detect and thus refer to a team of multi-professionals such as a psychologist, nutritionist, doctor and manage to perform the best possible treatment simultaneously and, through preventive and rehabilitative procedures, be able to return a better quality of life to the patient.

Erosion characteristics on surface texture of additively manufactured AlSi10Mg alloy in SiO2 quartz added slurry environment

Purpose The main purpose of this work is to explore the erosion wear characteristics of additively manufactured aluminium alloy. Additive manufacturing (AM), also known as three-dimensional (3D) manufacturing, is the process of manufacturing a part designed in a computer environment using different types of materials such as plastic, ceramic, metal or composite. Similar to other materials, aluminum alloys are also exposed to various wear types during operation. Production efficiency needs to be aware of its reactions to wearing mechanisms. Design/methodology/approach In this study, quartz sands (SiO2) assisted with oxide ceramics were used in the slurry erosion test setup and its abrasiveness on the AlSi10Mg aluminum alloy material produced by the 3D printer as selective laser melting (SLM) technology was investigated. Quartz was sieved with an average particle size of 302.5 µm, and a slurry environment containing 5, 10 and 15% quartz by weight was prepared. The experiments were carried out at the velocity of 1.88 (250 rpm), 3.76 (500 rpm) and 5.64 m/s (750 rpm) and the impact angles 15, 45 and 75°. Findings With these experimental studies, it has been determined that the abrasiveness of quartz sand prepared in certain particle sizes is directly related to the particle concentration and particle speed, and that the wear increases with the increase of the concentration and rotational speed. Also, the variation of weight loss and surface roughness of the alloy was investigated after different wear conditions. Surface roughness values at 750 rpm speed, 10% concentration and 75° impingement angle are 0.32 and 0.38 µm for 0 and 90° samples, respectively, with a difference of approximately 18%. Moreover, concerning a sample produced at 0°, the weight loss at 250 rpm at 10% concentration and 45° particle impact angle is 32.8 mg, while the weight loss at 500 rpm 44.4 mg, and weight loss at 750 rpm is 104 mg. Besides, the morphological structures of eroded surfaces were examined using the scanning electron microscope to understand the wear mechanisms. Originality/value The researchers verified that this specific coating condition increases the slurry wear resistance of the mentioned steel. There are many studies about slurry wear tests; however, there is no study in the literature about the quartz sand (SiO2) assisted slurry-erosive wear of AlSi10Mg alloy produced with AM by using SLM technology. This study is needed to fill this gap in the literature and to examine the erosive wear capability of this current material in different environments. The novelty of the study is the use of SiO2 quartz sands assisted by oxide ceramics in different concentrations for the slurry erosion test setup and the investigations on erosive wear resistance of AlSi10Mg alloy manufactured by AM.