Absence Of Brushes Research Articles

Anti-biofilm effectiveness of protocols for cleaning complete dentures in hospitalized patients: a randomized controlled trial.

Denture biofilm acts as a potential reservoir for respiratory pathogens, considerably increasing the risk of lung infections, specifically aspiration pneumonia, mainly 48h after hospital admission. The establishment of a straightforward, affordable, and applicable hygiene protocol in a hospital environment for the effective control of denture biofilm can be particularly useful to prevent respiratory infections or reduce the course of established lung disease. To evaluate the anti-biofilm effectiveness of denture cleaning protocols in hospitalized patients. The maxillary complete dentures (MCDs) of 340 hospitalized participants were randomly cleaned once using one of the following 17 protocols (n=20): brushing with distilled water, toothpaste, or neutral liquid soap (controls); immersion in chemical solutions (1% sodium hypochlorite, alkaline peroxide, 0.12% or 2% chlorhexidine digluconate), or microwave irradiation (650 W for 3 min) combined or not with brushing. Before and after the application of the protocols, the biofilm of the intaglio surface of the MCDs was evaluated using two methods: denture biofilm coverage area (%) and microbiological quantitative cultures on blood agar and Sabouraud Dextrose Agar (CFU/mL). Data were subjected to the Wilcoxon and Kruskal-Wallis tests (α=0.05). All 17 protocols significantly reduced the percentage area of denture biofilm and microbial and fungal load (P<0.05). The highest percentage reductions in the area of denture biofilm were observed for 1% hypochlorite solution with or without brushing and for 2% chlorhexidine solution and microwave irradiation only in association with brushing (P<0.05). The greatest reductions in microbial and fungal load were found for the groups that used solutions of 2% chlorhexidine and 1% hypochlorite and microwave irradiation, regardless of the association with brushing (P<0.05). A single immersion for 10 min in 1% sodium hypochlorite, even in the absence of brushing, proved to be a straightforward, rapid, low-cost, and effective protocol for cleaning the dentures of hospitalized patients.

Oral health conditions of institutionalized older adults and associated factors

Introduction: The growth of the Brazilian older adult population has influenced the increased demand for institutionalization for this public, which usually has poor oral health conditions such as edentulism. Objective: To characterize the oral health conditions and verify the variables related to the edentulism of institutionalized older adults and verify the relation of the time of institutionalization with oral health. Methods: It was a cross-sectional study conducted with 512 institutionalized older adults in which the sociodemographic profile, general health conditions, and oral health care and conditions were evaluated by clinical exams, consultations of medical records, and structured questionnaires. The data were analyzed in the Statistical Package for Social Sciences using the Pearson Chi-square and Fisher's Exact tests and a logistic regression model using a 95% confidence level. Results: A high DMFT (29.4), high prevalence of complete edentulism (61.3%), high need for maxillary (73.6%), and mandibular oral rehabilitation (56.8%) were observed. Edentulism was associated with older age (p&lt;0.001), lower schooling (p&lt;0.001) and non-retirement (p=0.031). It was found that longer institutionalization time remained associated with edentulism even when adjusted by sociodemographic and general health variables (p=0.013). It was also associated with the absence of brushing (p=0.024) and a lower frequency of tooth, gum, and prosthesis brushing (p&lt;0.001). Conclusion: It is suggested to establish oral health care routines within long-term institutions for the effective maintenance of oral health throughout the institutionalization time.

The Effect of Mouthwash with Sambucus williamsii var. coreana Extract on Halitosis: A Randomised, Double-Blind, Placebo-Controlled Study.

To clinically assess the effects of a mouthwash containing an extract of Sambucus williamsii var. coreana, a natural ingredient, on halitosis and halitosis-causing bacteria. This randomised, double-blind, placebo-controlled study included 77 participants. The experiment was conducted at Misoplant Dental Clinic in Busan, South Korea. Participants were divided into two groups: a control group consisting of 38 participants, to who whom a saline gargle was administered 1x/day for 30 s, and an experimental group consisting of 39 participants, who used a mouthwash containing Sambucus williamsii var. coreana extract 1x/day for 30 s for 1 day or 5 days. Halitosis was measured for 30 s in the absence of brushing or moisture. A sterile #15 paper point was placed in the gingival sulcus for 10 s, after which it was analysed using the polymerase chain reaction (PCR) method. The measurement time points were defined as follows: 'baseline': before starting the gargling routine; '1 day of treatment': immediately after gargling once on day 1; '5 days of treatment ': after gargling once a day for 5 days. Clinical results were statistically analysed using SPSS 24.0 for Windows. Compared to the control group, halitosis clearly decreased in the experimental groups '5 days of treatment' and '1 day of treatment' (p < 0.05). There were statistically significant differences in the levels of halitosis-causing bacteria between the two groups; bacterial concentration in the experimental group decreased statistically significantly from day 1 to day 5 day of gargling with Sambucus williamsii var. coreana extract (p < 0.05). Accordingly, we clinically verified that Sambucus williamsii var. coreana has antibacterial effects against oral bacteria. The application of Sambucus williamsii var. coreana extracts effectively reduced halitosis and halitosis-causing bacteria. Therefore, mouthwashes containing Sambucus williamsii var. coreana extract can be used as an effective substitute for chemical formulations for treating halitosis.

Loss and Efficiency Analysis of BLDC Motor and Universal Motor by Mathematical Modelling in the Mixer Grinder

The typical mixer grinders are universal motor, which operates on alternating current supply because of the higher starting torque characteristics and easy speed control. The absence of brushes in the Brushless DC (BLDC) motor and noise reduction improves its life and makes it perfectly suited for mixer grinder. The mathematical modelling and experimental demonstration of a conventional universal motor and proposed simulated model of BLDC motor was analysed using the MATLAB/Simulink. The loss and efficiency analysis of the permanent magnet BLDC and universal motor in the application of a mixer grinder are presented in this paper.

The effectiveness of apple, sugar-free chewing gum and Rolly Brush® in the reduction of plaque index: crossover randomized clinical trial

Background: The implementation of the self-cleaning practice is of fundamental importance for the maintenance of oral health and to remove the human dental biofilm which is considered the main etiological factor for the development of caries and periodontal diseases. Objective: This study aimed to evaluate the use of chewing gum, Rolly Brush® and apples as forms of mechanical control and removal of the dental biofilm in the absence of brushing. Materials and Methods: Eighteen volunteers were submitted to plaque index evaluation after a period of 24 hours of no oral hygiene. Then, they would use one of the methods: chewing gum, Rolly Brush®, apple or tooth brushing, chosen by a draw, for one minute, and then, plaque index was evaluated again. This stage was repeated until all participants were submitted to all selected methods, in periods of 24 hours each. Results: Dental brushing was more effective when compared to each of the other methods applied and there was a statistically significant reduction of dental plaque index after apllying all methods of cleaning in all groups. Conclusion: Chewing gum, Rolly Brush® and apple may be used as auxiliary to dental brushing or when such method is impossible to be performed. Clinicaltrials.gov: number of protocol NCT 03.601.585.

Solar fed BLDC motor drive for mixer grinder using a boost converter

&lt;p&gt;The existing mixer grinder comprises of the universal motor operating in alternating current supply due to high starting torque characteristics and simple controlling of the speed. The absence of brushes and the reduction of noise in the Brushless DC (BLDC) extends its lifetime and makes it ideal in a mixer grinder. A novel solar-powered BLDC motor drive for mixer grinder is presented in this paper. A DC-DC boost converter has been utilised to operate a PV (photovoltaic) array at its highest power. The proposed hysteresis current control BLDC system has been developed in the MATLAB. A performance comparison is made using the commercially available mixer grinder along with the simulated proposed system.&lt;/p&gt;

Solar fed BLDC motor drive for mixer grinder using a buck-boost converter

In existing mixer grinders, the universal motor is used due to its high starting torque than the induction motor. To achieve higher speed for smaller devices, the implementation of the universal motor becomes cheaper. The absence of brushes and the reduction of noise in the BLDC extends its lifetime, making it ideal for a mixer grinder. The solar-powered BLDC motor drive for a mixer grinder is presented in this paper. A DC-DC buck boost (BB) converter is utilised to operate the PV (photovoltaic) array at its highest power. The proposed hysteresis current (HC) control BLDC system is developed in the MATLAB. A comparison performance is demonstrated between the commercially available mixer grinder and the simulated proposed system.

Biofilm composition and composite degradation during intra-oral wear

ObjectivesThe oral environment limits the longevity of composite-restorations due to degradation caused by chewing, salivary and biofilm-produced enzymes and acids. This study investigates degradation of two resin-composites in relation with biofilm composition in vitro and in vivo. MethodsSurface-chemical-composition of two Bis-GMA/TEGDMA composites was compared using X-ray-Photoelectron-Spectroscopy from which the number ester-linkages was derived. Composite-degradation was assessed through water contact angles, yielding surface-exposure of filler-particles. Degradation in vitro was achieved by composite immersion in a lipase solution. In order to evaluate in vivo degradation, composite samples were worn in palatal devices by 15 volunteers for 30-days periods in absence and presence of manually-brushing with water. PCR-DGGE analysis was applied to determine biofilm composition on the samples, while in addition to water contact angles, degradation of worn composites was assessed through surface-roughness and micro-hardness measurements. ResultsIn vitro degradation by lipase exposure was highest for the high ester-linkage composite and virtually absent for the low ester-linkage composite. Filler-particle surface-exposure, surface-roughness and micro-hardness of both resin-composites increased during intra-oral wear, but filler-particle surface-exposure was affected most. However, based on increased filler-particle surface-exposure, the high ester-linkage composite degraded most in volunteers harvesting composite biofilms comprising Streptococcus mutans, a known esterase and lactic acid producer. This occurred especially in absence of brushing. SignificanceDegradation during intra-oral wear of a low ester-linkage composite was smaller than of a high ester-linkage composite, amongst possible other differences between both composites. S. mutans herewith is not only a cariogenic, but also a composite-degradative member of the oral microbiome.

Preliminary Study of a New Topology Permanent Magnet Flux Switching Motor for Electric Buses

&lt;table width="593" border="1" cellspacing="0" cellpadding="0"&gt;&lt;tbody&gt;&lt;tr&gt;&lt;td valign="top" width="387"&gt;&lt;p&gt;Electric buses (EBs) as public transit that have been introduced in modern countries recently are an alternative effort to reduce climate change and environmental impacts of fossil fuels. One example of the successfully developed motor for EBs is interior permanent magnet synchronous motor (IPMSM) with merits of heat dissipating, high torque per frame size and reliability influence by absence of brushes. However, the three-phase armature windings are wounded in the form of distributed windings, results in much copper loss, high coil end length and reduced the efficiency. The embedded rectangular magnets inside the rotor make rotor less robust, increased rotor weight and reduced the torque and power density. The present IPMSM has a complex structure which is relatively difficult to manufacture and tough in optimization process. The 7.0 kg volume of PM used in IPMSM is very high, which increases the cost of the machine. Therefore, a new topology of permanent magnet flux switching motor using wedge-shaped PM and single stator structure with the advantages of simple stator design, robust rotor structure, high of torque and power, and high efficiency is proposed. The design, flux linkage, back-emf, cogging torque, average torque, speed, and power of this new topology are investigated by JMAG-Designer version 14.1 via a 2D-FEA. The initial design of proposed motor produces torque and power of 905.9 Nm and 57.75 kW, respectively.&lt;/p&gt;&lt;/td&gt;&lt;/tr&gt;&lt;/tbody&gt;&lt;/table&gt;

Design and Development of 5-HP BLDC Motor for Submersible Application

Pumps are the basic equipment needed for every sector they caterto a wide range of sectors from agriculture to nuclear power generation. Submersible pumps have a sealed motor like induction, brushed DC that is closely coupled to the pump. Brushless permanent magnet DC motor is increasingly getting admired in that its spectrum of applications is widening day by day. Nowadays BLDC motors are competing with other types of motors like induction, brushed DC in the submersible applications due to its recognized advantage such as high power density, higher efficiency, less maintenance, longer life, absence of brushes and Commutator, small in size and can operate at higher speeds than conventional motors. Replacing brushed DC, induction motor by energy efficient special machines like brushless permanent magnet DC motor, switched reluctance motor would prove to be a worthy measure to conserve energy. This paper deals with the design and analysis of 5-HP BLDC motors for submersible pump application of surface mounted permanent magnet. The machine performance determined analytically using Ansys/RMxprt. Finite Element Method (FEM) based 2D analysis is used to obtain the flux profile and magnet demagnetization study of the motor.

Effects of sugar‐free chewing gum sweetened with xylitol or maltitol on the development of gingivitis and plaque: a randomized clinical trial

The objective of this study was to test the effect of sugar-free chewing gum sweetened with xylitol or maltitol compared to the use of a gum base or no gum on gingivitis and plaque scores under both brushing and non-brushing circumstances. The design of the study was a four-group, double-blinded, randomized controlled study with a 3-week duration. In each group, the participants did not brush the teeth in the lower jaw designated to develop experimental gingivitis, while maintaining normal oral hygiene procedures in the upper jaw. After professional dental prophylaxis, the participants were allocated into one of four groups (xylitol, maltitol, gum base or no gum). Chewing gum was used five times a day for 10 min. 220 participants completed the study and provided evaluable data. The increase in bleeding on marginal probing (BOMP) and plaque scores (PS) in the non-brushed (lower) jaw with experimental gingivitis was significant in all groups (P < 0.001). As compared to the gum base, the increase in BOMP in the xylitol and maltitol group was significantly lower. In the brushed upper jaw, no significant changes for BOMP were observed from the baseline to the end point of the study, and there were no significant differences in BOMP and PS between the groups. In circumstances where regular brushing is performed, no effect of chewing gum was observed on bleeding and plaque scores. In the absence of brushing, chewing xylitol or maltitol gum provided a significant inhibitory effect on gingivitis scores compared to chewing gum base. The difference when compared to the group not using gum was not significant.

PREVALENCIA DE CARIES DE LA INFANCIA TEMPRANA Y FACTORES DE RIESGO ASOCIADOS EN NIÑOS DE 1 A 5 AÑOS EN LA CIUDAD DE SANTIAGO DE CALI

Objetivo: determinar la prevalencia de Caries de la Infancia Temprana (CIT) en niños de 1 a 5 años de la ciudad de Cali y describir los factores de riesgo asociados.Materiales y métodos: se realizó un estudio descriptivo transversal, de prevalencia con todas las instituciones educativas inscritas en la Secretaría de Educación. La muestra la constituyeron 929 menores a quienes se les indagó mediante un cuestionario dirigido a sus padres, acerca de los factores de riesgo asociados con caries dental. Se realizó un examen clínico intraoral para determinar el índice ceo-d según los criterios de la Organización Mundial de la Salud y se evaluó el índice de placa bacteriana de Sillness y Löe. Se realizó un análisis univariado para describir las variables y conocer la distribución de la variable de salida. Para el bivariado se utilizó la prueba Chi2 y la correlación de Spearman, según el tipo de variable. Para comparación del índice ceo-d según estrato socioeconómico y hábitos de higiene como el cepillado antes de acostarse, se utilizó la prueba de Kruskal-Wallis.Resultados: se encontró una prevalencia de CIT de 29,3%, siendo esta mayor en el estrato socioeconómico bajo. De los factores de riesgo analizados, se encontró una asociación significativa con no cepillar al niño antes de dormir con un OR de 1,50 [IC 95%: 1,09 - 2,07, p=0,008].Conclusiones: la prevalencia de caries dental fue mayor que la reportada para Cali en el ENSAB III a los 5 años. Se utilizó como índice para caries dental el ceo-d sin incluir lesiones precavitacionales, lo que podría subestimar la prevalencia de esta entidad en la población de estudio.[Arango MC, Jaramillo A, Cruz CA. Prevalencia de caries de la infancia temprana y factores de riesgo asociados en niños de 1 a 5 años en la ciudad de Santiago de Cali. Ustasalud 2013; 12: 108 - 115]

The effect of medicated, sugar‐free chewing gum on plaque and clinical parameters of gingival inflammation: a systematic review

This study aimed to systematically review the present literature to establish the clinical effect of medicated, sugar-free chewing gum on plaque indices and parameters of gingival inflammation. MEDLINE-PubMed, Cochrane CENTRAL and EMBASE databases were searched up to April 2012 to identify appropriate studies. Included studies used an intervention of medicated, sugar-free chewing gum containing antimicrobial agents or herbal extracts compared with a control gum. Plaque and gingivitis scores were selected as outcome variables. Independent screening of 594 unique titles and abstracts identified 10 non-brushing and four brushing studies that met the eligibility criteria. Means and standard deviations were extracted. A sufficient number of studies evaluated chlorhexidine gum to perform a meta-analysis. Although this review provides evidence for the comparative effectiveness of chewing gums containing various ingredients, the results must be weighed carefully against the methods that were used to assess their outcomes. Most of the chewing gums with antimicrobial agents or herbal extracts were shown to have a positive effect with respect to plaque and gingivitis scores. The most compelling evidence was provided for chewing gum containing chlorhexidine. Meta-analysis and individual results indicate a beneficial effect of chlorhexidine on plaque inhibition. However, GRADE evidence profile shows that the recommendation to use CHX-gum to reduce plaque scores in the absence of brushing is considered to be 'weak'. Other ingredients with positive outcomes on plaque scores are eucalyptus, acacia, funoran, Pycnogenol and mastic. Limited data with respect to gingivitis scores were available, and the following agents showed a positive effect: magnolia, eucalyptus and CHX.

Speed Control of Induction Motor Fed from Wind Turbine via Particle Swarm Optimization Based PI Controller

Three-phase Induction Motor (IM) is widely used in the industry because of its rugged construction and absence of brushes. However, speed control of IM is required depending on the desired speed and application. This study proposes a design of a Proportional Integral (PI) controller using Particle Swarm Optimization (PSO) algorithm to control the speed of an IM supplied from wind turbine. The wind turbine acts as a prime mover to a connected DC generator. Pulse Width Modulation (PWM) is used to obtain three phase AC voltage from the output of DC generator. The proposed design problem of speed controller is formulated as an optimization problem. PSO is employed to search for optimal controller parameters by minimizing the time domain objective function. The performance of the proposed technique has been evaluated with respect to the variation of load torque and speed wind turbine. Also the performance of the proposed controller has been evaluated with the performance of the PI controller tuned by Genetic Algorithm (GA) in order to demonstrate the superior efficiency of the proposed PSO in tuning PI controller. Simulation results emphasis on the better performance of the optimized PI controller based on PSO in compare to optimized PI controller based on GA over a wide range of load torque and speed wind turbine.

The effect of sugar‐free chewing gum on plaque and clinical parameters of gingival inflammation: a systematic review

The aim of this study was to systematically review the current literature on the clinical effects of sugar-free chewing gum on plaque indices and parameters of gingival inflammation. The MEDLINE-PubMed, Cochrane-CENTRAL and EMBASE databases were searched up to 20 April 2012 to identify any appropriate studies. Plaque indices and parameters of gingival inflammation were selected as outcome variables. An independent screening of the 594 unique titles and abstracts identified six non-brushing and four brushing studies that met the eligibility criteria. In the non-brushing studies, the use of chewing gum did not significantly affect the parameters of interest. In the descriptive analysis of the brushing studies, four of five comparisons showed a statistically significant effect in favour of the sugar-free chewing gum with respect to plaque scores. The meta-analysis for the Quigley & Hein (J Am Dent Assoc 1962; 65: 26) plaque index scores in the brushing studies also showed a significant difference (DiffM -0.24, 95% CI [-0.41; -0.08]). For bleeding tendency, the descriptive analysis showed that one of the two comparisons identified a significant difference in favour of chewing gum. The meta-analysis, however, did not substantiate this difference. Within the limitations of this systematic review, it may be concluded that the use of sugar-free chewing gum as an adjunct to toothbrushing provides a small but significant reduction in plaque scores. Chewing sugar-free gum showed no significant effect on gingivitis scores. In the absence of brushing, no effect on plaque and gingivitis scores could be established.

Performance Description of Brushless Doubly-Fed Induction Machine in Its Asynchronous and Variable Speed Synchronous Modes

Brushless Doubly-Fed Machine has attracted considerable attention in recent years due to its advantages. It has the robustness of the squirrel cage induction machine, and the speed and power factor controllability of the synchronous machine as well as the absence of brushes and slip rings, and using a fractionally rated frequency converter. Hence, there are considerable benefits over the conventional machines, when the machine is applied to applications such as a wind turbine generator or high power adjustable speed drive. However, these benefits are obtained in slightly more complex structure, higher cost and larger dimensions in comparison to the conventional induction machine. This paper presents fundamental aspects of the three modes of operation of brushless doubly fed machine, i.e. simple induction mode, cascade induction mode, and synchronous mode. The investigation is performed by analyzing the spatial harmonic contents of the rotor magnetic flux density. The direct cross couplings between stator and rotor fields as well as, indirect cross coupling between stator fields by the special rotor of this machine is described. Furthermore, loss analysis of the machine in various modes is presented and the torque-speed curves for asynchronous modes are obtained. A 2-D magnetodynamic finite element model based on the D-180 4/8 pole prototype machine is extracted and simulated to verify the results.

Reduced plaque accumulation on hydrocarbon thin film deposited on restorative acrylic polymers.

The deposition of a thin polymeric film from ethylene plasma was used to modify the surface properties of acrylic teeth, commonly used in the dental practice for crown and bridge restorations. The effects of the surface modification process on the surface composition, morphology, and energetics were evaluated by electron spectroscopy for chemical analysis, atomic force microscopy, and contact angle measurement respectively. Plaque accumulation on the plasma-coated and untreated material was evaluated in in vivo experiments, in which the same patient received conventional and plasma-coated restorations. The hydrocarbon-like surface of the plasma-coated restoration remained remarkably free from plaque, even in the absence of brushing. On the other hand, plaque accumulation was observed on the unmodified restoration. Results are discussed according to recent theories on bioadhesive phenomena.

Generalized Predictive Cascade Control (GPCC) for Machine Tools Drives

The use of self synchronous motors in the machine tools field has many advantages: The absence of brushes gives better accuracies in position and a small rotor inertia allows shorter time responses in speed and position. We propose in this paper n performant real time algorithm (GPCC) development this kind of performant motors. The use of predictive control algorithms instead of classical controllers is now possible due to the rapidity of numerical processors, and takes into account more informations about the future. According to this, a first part will develop the GPCC algorithm in a theoretical point of view. Then a second part will present the results obtained with this algorithm on a brushless motor used to drive machine tools axes.