Brush Type Research Articles

THE IMPACT OF ORAL HYGIENE MAINTENANCE ON THE GINGIVAL HEALTH OF PATIENTS HAVING FIXED ORTHODONTIC APPLIANCES

Abstract 
 Objective: to evaluate the oral hygiene habits among patients experiencing fixed orthodontic treatment
 Material and method: The study was conducted in the orthodontic department of Multan medical and dental college, Multan. One hundred and five patients undergoing fixed orthodontic treatment were included in the study. Duration of study was 5months and 12 days. Patients were asked to fill out a questionnaire about the reason for undergoing treatment, the importance of orthodontic treatment in life, and oral hygiene practice after having fixed orthodontic treatment. Statistical data were analyzed by SPSS version 22 to determine the frequency distribution and percentage ratio for each variable. A Chi-square test was applied to compare gingivitis and frequency of brushing and a p-value ≤ 0.05 was considered significant.
 Results: The mean age of participants was 20± 4.7 years, with females predominant (71%). Most of the patients were undergoing treatment due to a friend’s suggestion (32%) and a dentist’s suggestion (17%). Most patients brushed twice daily (25%) or after every meal (24.4%) and still have gingivitis which represents brushing alone is not enough. Chi- square test was utilized between frequency of brushing and gingivitis and p- value was > 0.05 which is considered insignificant. The most preferred toothbrush was the general toothbrush (28%) and unspecified brush (23%). Which means proper knowledge of the type of brush was lacking. Only 41% of patients were sure about using fluoridated toothpaste which again shows a lack of awareness. 35% of patients were using a toothpick and 22% were using pins to clean their teeth in absence of a brush which again shows a lack of proper knowledge. 37% of patients were using their mouth wash and 24% were using interdental brushes occasionally.
 Conclusion: orthodontic treatment itself causes plaque retention and gingivitis so in order to maintain good oral hygiene self-motivation and proper knowledge given by the care provider is very necessary to improve gingival outcomes.

A Study on the Particle Removal Efficiency and Durability According to the Material of the Ionizer of the Fiber Brush Type Electric Precipitator

In this study, we investigated the particulate matter (PM) removal efficiency and durability of the two-stage electrostatic precipitator (ESP) different materials of brush-typed ionizers (non-metal: carbon fiber/metal: stainless steel (SUS) fiber). The PM removal efficiency was reduced when the average diameter and number of fibers of the brush-typed ionizer increased due to thin and multi-edge in a large number of fibers, which decreased the average electric field, resulting in lower PM removal efficiencies. In contrast with the carbon fiber ionizer, when the SUS fiber ionizer was used, the PM removal efficiency was maintained for a long time, due to its lower electrical resistivity (∼6.9 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−7</sup> Ω * m) of the SUS fiber compared with the carbon fiber (∼5 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">−4</sup> Ω * m), which prevents the positive ions to be stacked on the fiber. Therefore, the present research showed the potential use to apply SUS fiber ionizers as two-stage ESPs for a future air pollution control technology with high PM removal efficiency and durability without ozone emission and additional maintenance.

Efficacy of a new sonic powered toothbrush versus a manual toothbrush in a young population. A randomized cross-over clinical trial.

To compare the effectiveness of dental plaque removal between a new sonic toothbrush and a manual toothbrush. In total, 75 healthy dental students participated in this randomized double-blind crossover clinical trial. Subjects were randomly assigned to one of the two groups (manual or sonic toothbrush) and underwent a single toothbrushing exercise. Seven days after, patients were asked to repeat the same procedure with the other toothbrush. Plaque scores were recorded before and after brushing. A significant mean reduction in the full-mouth plaque index was observed after the use of both type of brushes: 46.2% ± 0.28% (p=0.000) and 50.5% ± 0.24% (p=0.000) for the manual and sonic toothbrush, respectively. However, there were no statistically significant differences between the two types of brushes (p=0.277). Regarding plaque reduction on the distinct tooth surfaces, differences between the groups reached statistical significance in favour of the sonic toothbrush only on the buccal sites (p=0.003). Both devices lead to similar plaque score reduction after a single tooth brushing.

An Evaluation of Immobilized Poly-(S)-N-(1-phenylethyl)acrylamide Chiral Stationary Phases

In this study, brush type and polymer type stationary phases were prepared based on (S)-N-(1-phenylethyl) acrylamide, and the polymeric stationary phase demonstrated superior chiral recognition ability. The two polymeric stationary phases were synthesized by two strategies, one was the “grafting from” method, which obtained polymer CSP by initiating monomer polymerization on the surface of 3-methacrylatepropyl silica gel, and the other was “grafting to”, which fixed the copolymer of (S)-N-(1-phenylethyl) acrylamide and trimethoxysilylpropyl methacrylate on silica gel. A comparison of these two bonding modes revealed that the stationary phase produced by “grafting to” had higher chiral recognition ability. Further improvement can be achieved by the end-capping of silanol groups with trimethylchlorosilane to reduce non-enantioselective retention caused by residual silanol groups and improve the peak shape of enantiomers. Chiral separation in subcritical fluid chromatography was also studied. Similar enantioselectivity results with higher resolution were observed due to the improvement of peak shape.

Brushing Characteristics and Dietary Patterns of Orthodontic Patients with Fixed Appliances

Background: Proper brushing practices are required to maintain good oral hygiene. This is of utmost importance in patients with fixed orthodontic appliances as these appliances can facilitate plaque accumulation and make cleaning process difficult. Hence if good oral hygiene is not maintained with these appliances then deterioration of gingival and periodontal health will result. Frequent intake of acidic drinks and sweet food can further harm the teeth. Aim: To determine tooth brushing characteristics of orthodontic patients with fixed appliances. Determine dietary patterns of such patients. Determine other oral hygiene measures used by them. Study Design: Cross sectional study Duration of the study: 6 months Methodology: Questionnaires were conveniently distributed among 104 orthodontic patients who met the inclusion criteria and provided consent to provide the information. Data collected was analyzed using SPSS 2020. Results: Most (70%) of the responding patients brush two times daily. Correct brush type (soft) is in use by 77% of the individuals. Approximately 64-66% of individuals combine vertical and horizontal technique of tooth brushing, use interdental toothbrush and report that they hardly intake fizzy drinks. However, only 55% patients have reported brushing for total duration of 2 minutes. Around 30% of the respondents have frequent intake of junk food and sugary food. Practical Implication: According to our knowledge, this study is the first study to date to evaluate the brushing habits and dietary patterns in Pakistani orthodontic patients with fixed appliances. Conclusions: The present study shows that majority of the patients show good brushing practices but need to improve their total duration of brushing. Frequent intake of junk food, sweets and fizzy drinks are also avoided by most patients. Use of fluoride mouthwashes and floss was seen in lesser proportion of surveyed patients. Keywords: Brushing characteristics, oral hygiene measures, dietary patterns, orthodontic patients with fixed appliances.

Efficiency evaluation of satellite detumbling using a brush type contactor based on flexible multibody dynamics

Detumbling manipulation to capture a noncooperative space satellite using a brush type contactor is getting more and more attention due to its lower cost and easy implementation. It is important to evaluate the effects of various modal parameters on the detumbling efficiency, including the design of the brush contactor and the manipulation schemes. In this study, a simplified planar multibody dynamic model is established to estimate the detumbling efficiency. An analytical formula is proposed based on some assumptions from the aspect of energy. Several model parameters are considered in the formula including the brush&apos;s bending stiffness and length, the contact position and angle. Concerning the numerical strategies, the planar corotational beam element is adopted to discretize the brush contactor undergoing large displacement and large rotations while the motion of the solar panel undergoing small deformation is modelled by the floating frame of reference formulation. The contact force between the brush contactor and the solar panel is described by the Hertz contact law. The results show that the analytical formula can give a rough estimation to the reduced kinetic energy even if dumping forces are considered. It can be found that a short brush contactor with high bending stiffness can improve the detumbling efficiency. Moreover, touching the solar panel near the root of the brush contactor and maintaining a small contact angle are both efficient manipulations.

Dental hygiene students' participation as subjects in a randomized controlled trial: A full evidence-based dentistry experience.

Demonstrate that dental hygiene students' participation in a randomized controlled trial comparing the plaque-removing capability of two toothbrushes provides a fuller understanding of the factors affecting the potential application of research to practice. All students (N=18) in a baccalaureate dental hygiene class were engaged in the design of a randomized controlled trial using the Consolidated Standards of Reporting Trials (CONSORT) standard and then participated as subjects in a staggered, repeated measures trial using plaque removal as the dependent variable and brush type, brush head wear, and time in study as independent variables. A debriefing of student participation and lessons learned from analyzing the results was conducted. The study found statistically significant differences in plaque removal capability. Brush type accounted for only 4% of the variance, while measures of brush head wear were inconsistent, and time in the study ("experimental fatigue") accounted for the most variance (9%). Students recognized and confirmed by their personal experiences that research that fails to focus on variance can create an overly optimistic impression of research effectiveness. There was strong agreement that subjects/patients vary widely and that performance depends on multiple factors. Dental hygiene students who participated as subjects in a randomized controlled trial comparing toothbrushes for plaque removal capacity felt that full analysis to account for all sources of variance and estimate the magnitude of measures of effect add to the value of reported research. Variation across patients is important in practice, if often overlooked as an "error" in the literature.

Knowledge, attitude, and awareness of parents regarding their children’s oral health in Bathinda, Punjab

Objective: The objective of this study was to determine the knowledge, attitude, and practical behavior of parents regarding their children’s oral health in Bathinda, Punjab. Methodology: A cross sectional study was conducted among 500 parents who reported in outpatient department of All India Institute of Medical Sciences, Bathinda, Punjab. Data were collected through a self‑administered questionnaire. The statistical analysis was performed using the Statistical Package for Social Sciences software (21.0 version; Inc., Chicago IL, USA) for descriptive and multivariate analysis, and the level of statistical significance used in this study was chosen at P &lt; 0.005. Results: The results showed that parents have satisfactory knowledge regarding the oral hygiene maintenance of their children. Lack of knowledge regarding fluoridated tooth paste were found. Moreover, many people don’t have any idea about ideal time for first dental visit. Otherwise, parents knew well about different type of brushes, importance of brushing, and food substances that may cause tooth decay etc. Conclusion: The present study indicates satisfactory results regarding knowledge of parents regarding their child’s oral health in Bathinda. Even though the knowledge and awareness is good, the caries status in children are found to be high in this region.

Third-party toothbrushing is associated with a positive patient experience: randomized, single-blind, patient-centered analysis

BackgroundAs the need for care increases with higher age, so does the need for assistance with oral hygiene. A recent study analyzed the clinical effectiveness of oral hygiene assistance provided by caregivers. The current secondary analysis of this study aimed to assess pleasant and unpleasant perceptions of patients while being brushed and to investigate whether these perceptions depend on the qualification of the person brushing and the type of toothbrush used (manual vs. powered).MethodsFirst, a qualitative study was conducted. This aimed at developing the questionnaire. Items were extracted on the basis of qualitative interviews with a sample of 6. A delphi process ensured the content validity of the final instrument. The main study comprised 39 periodontitis patients with reduced oral hygiene capability randomized to one of four groups: brushing carried out by trained laypeople or dental professionals, each using a manual or powered toothbrush at three different time points during anti-infective periodontal therapy. Patient perceptions of the third-party toothbrushing were assessed immediately after brushing.ResultsPatients reported mainly positive feelings regarding being brushed by a third person and the interaction with this person during brushing. Neither the professional background of the brushing person nor the type of brush had a significant influence on pleasant and unpleasant perceptions (all F < 3.30, all p > 0.07, all η2 < 0.10).ConclusionsPatient perceptions of third-party toothbrushing are mainly positive regarding wellbeing and interactions with the toothbrushing person, and do not depend on the qualification of the brushing person or the toothbrush used (manual versus powered).Trial registrationhttps://www.germanctr.de, No. DRKS00018779 (04/11/2019).

Grooming of fouling-release coatings to control marine fouling and determining how grooming affects the surface

Grooming may be an effective technique to control marine biofouling without damaging the coating or discharging active ingredients into the environment. This study assessed the grooming performance of three experimental biocide-free siloxane polyurethane (SiPU) fouling-release coatings. Coatings were statically immersed in Port Canaveral, Florida, and groomed every two weeks for five months using three different brush types. The ungroomed panels became heavily fouled with biofilm, tubeworms, barnacles, and bryozoans. Two of the brushes were able to control the fouling with a coverage of <5%. The commercial silicone elastomer coating was damaged from grooming procedures, while the SiPU coatings were not. Laboratory biological assays were carried out and mirrored the grooming results. Through surface characterization techniques, it was concluded that the coatings were unaffected by the grooming procedures. This study shows that marine fouling on durable SiPU fouling-release coatings can be controlled via grooming without damage or changing the surface properties.

Infection Resistant Surface Coatings by Polymer Brushes: Strategies to Construct and Applications.

Bacteria-assisted infections on biomaterials used inside a body as an implant/device are one of the major threats to human health. Microbial-resistant coatings on biomaterials can potentially be considered to mitigate the biomaterial-associated infections. Usually biomaterials with leachable antimicrobial coatings, though economically attractive, provide only short-term protection of the surface against bacteria. Therefore, a stable, nonfouling or bactericidal, and biocompatible polymeric coating is highly desirable. In this regard, polymer brushes, defined as polymer chains tethered to a surface by one end, with suitable anti-infective functionality, represent a useful class of stable coatings which are covalently connected to the underlying surface, thus prolonging the infection resistance of the coated surface. Surface-initiated atom transfer radical polymerization (SI-ATRP) is a versatile technique for the generation of polymeric brushes via "grafting from" way. In this review, we have attempted to give a brief overview about the recent developments of surface coatings by infection-resistant polymer brushes synthesized via SI-ATRP and their applications in the biomedical field. On the basis of their charges, these anti-infective brushes can be classified into five different categories such as neutral, cationic, anionic, zwitterionic, and mixed brushes. The working mechanism of each type of brush in repelling (nonfouling/bacteriostatic) and/or killing (bactericidal) the bacteria has also been discussed. A brief summary of their future scope is also highlighted.

A Test Method to Evaluate the Adhesive Property between Asphalt and Aggregate Based on Simulating Actual Working Conditions

The adhesive property between asphalt and aggregate is a crucial factor that affects the resistance of asphalt pavement to moisture damage. In this study, by simulating the actual working conditions of asphalt–aggregate bonding characteristics, test equipment was developed and a method for evaluating the adhesive properties between asphalt and aggregate—the brush damage test—was proposed. A steel-wire brush as the brush type, a total of 0.5 kg/m2 asphalt content, 70 °C as the maintenance temperature, and 4 h as the maintenance time, as well as mass loss rate (ML) of specimens before and after brushing, were used as the evaluation index. The brush damage test was conducted on five commonly used asphalt binders and two commonly used aggregates. Finally, the results of the brush damage test were analyzed in comparison with those of a binder bond strength (BBS) test. It was indicated that the evaluation results for the adhesive properties between asphalt and aggregate were not consistent under the two test methods. The pull-off tensile strength under dry conditions (POTSdry) and under wet conditions (POTSwet) when ignoring the influence of the texture of aggregate did not reflect the adhesive properties. ΔPOTS, representing the ability of asphalt to resist the loss of adhesion strength due to moisture damage, can be used to evaluate the adhesion properties between asphalt and aggregate. Under appropriate conditions, the brush damage test has the advantages of simple operation, high credibility, and good discrimination.

Multiple Attributed Parametric Review Study on Mechanical Cotton (Gossypium hirsutum L.) Harvesters

Crop characteristics of cotton are crucial to identify the important crop attributes like plant height, canopy width, sympods and monopods distribution, row spacing which affects the performance of mechanical harvesters. The activity and effectiveness of most harvest aids, including desiccants is reduced by low temperature conditions. Trash content was observed to be lesser in cotton harvested by cotton picker than cotton harvested by cotton stripper. It was found that a maximum cotton yield of 1000 kg acre-1 was obtained for a cotton plant population ranging between 45,000 and 90,000 plants acre-1. Likewise, a minimum of 700 to 740 kg acre-1 was observed for a cotton plant population of 33,000 plants acre-1. In higher yielding cotton, cotton pickers recorded higher picking rate than cotton strippers. Picking/harvesting efficiency of cotton stripper with both finger and brush type mechanism was higher than the spindle type cotton picker. Picking efficiency of pneumatic picker was higher than the other types of picking mechanisms, but with lesser rate of picking capacity. Gin turnout of cotton was higher with cotton picker when compared with cotton stripper due to lesser trash content in picker harvested cotton. The horsepower requirement of cotton stripper ranged from &amp;frac12; to &amp;frac14; horsepower and cost is about two-thirds of the price as compared with cotton picker. The scheduling and monitoring of various activities involved in cotton picking by using a suitable software model can increase the benefits of both growers and harvesting companies. The reduction in uniformity with roller gin-type lint cleaners ranged between 0.2 to 0.8%, which was lesser as compared with saw-type lint cleaners. Introducing mechanical harvesting has always been a decades-long process. In Turkey, it took 20 years and in Greece, this process took place very gradually over a 15-year period. Top cotton producing countries like India, Pakistan, China, Uzbekistan and other developing countries like Iran Paraguay are still not using machine harvesting. The introduction of mechanical cotton picker or stripper can help improve quality and quantity of cotton picking thereby giving more benefit to growers in developing countries and improving their socio-economic status. The most controversial issue raised by the introduction of the mechanical cotton harvester is great migration as the machines eliminated jobs and forced poor families to leave their homes and farms in search for urban jobs. Therefore Government policies towards cotton harvesting mechanization must include the alternative jobs, packages for dependent manual cotton pickers and their families.

Development of descriptive mathematical models for different domains of gingival recession using multiple linear regression analysis

Context:Gingival recession (GR) is a common finding seen in the periodontics clinic. It has a significant functional and esthetic impact on the patient's dentition and quality of life.Aims:The current study aimed to develop the descriptive mathematical models for different domains of GR based on the data obtained from the North Indian population.Settings and Design:Cross-sectional observational study.Materials and Methods:Consecutive 130 participants were enrolled between June and August 2019. Complete case history and thorough oral examination were carried out including assessment of periodontal variables, for example, pocket depth (PD), gingival marginal level, clinical attachment level (CAL), simplified oral hygiene index, and gingival index. Prediction models for different domains of GR, namely Miller's class, severity, extent, and distribution of recession were made, and further, the best-fitted model on the basis of “coefficient of determination (R2)” was analyzed.Statistical Analysis Used:Multiple linear regression.Results:Nine factors, i.e., mean CAL, mean PD, tooth mobility, abrasion, width of attached gingiva, number of teeth present, age, type of brush, and socioeconomic status showed a significant association with different domains of the GR. In addition, a high degree of overlap was observed among factors associated with different domains of the GR.Conclusion:Diverse clinical (mean CAL, mean PD, tooth mobility, and abrasion), biological (width of attached gingiva, number of teeth present, and age), and environmental factors (type of brush and socioeconomic status) were found to have a significant association with the occurrence of GR in the North Indian population. Owing to the multifactorial etiology of GR, the identification of susceptible patients based on the presence of risk factors is an essential step in developing action plans for the prevention of the disease.

Effects of iRGD conjugation density on the in vitro and in vivo properties of cylindrical polymer brushes.

iRGD can significantly improve the tumor accumulation and tumor penetration of nanomaterials. However, it still remains unclear how far iRGD can enhance the properties of nanomaterials when its conjugation density is maximized. Herein, we synthesized three types of cylindrical polymer brushes (CPBs) with 0%, 50% and 100% of side chains terminated by iRGD, which were named CPBs-1, CPBs-2 and CPBs-3, respectively, and studied the effects of iRGD density on their cellular uptake, and tumor targeting ability and tumor permeability. It was demonstrated that compared with the iRGD-free CPBs-1, the cellular uptake of CPBs-3 was enhanced 5 times and their tumor accumulation was enhanced twice. The penetration depth of CPBs-3 in three-dimensional multicellular spheroids was larger than 100 μm. Our results provide useful information for the design of active tumor targeting nanomaterials as therapeutics or contrast agents.

Dynamic modeling and analysis of satellite detumbling using a brush type contactor based on flexible multibody dynamics

A brush type contactor has been proposed to detumble non-cooperative space targets. Current researches mainly focused on the control schemes and their validations, whereas the dynamic modeling is rarely investigated. In this paper, both the analytical formulation and the numerical approach are employed to establish the dynamic model of the detumbling system. An analytical formula is proposed to evaluate the detumbling efficiency from the aspect of energy. The numerical simulation is conducted using flexible multibody dynamics and the contact theory. The analytical results and the numerical results are compared and the influence of various model parameters on dynamic behaviors is studied. It shows that the detumbling efficiency can be significantly affected by several factors, including the stiffness and length of the brush, the end velocity of the contactor, the contact angle, and the contact position. The detachment phenomenon of the brush from the solar panel is investigated. A criterion for the detachment is proposed and verified by numerical simulations.

(Invited) Synergistic Effect of Polyvinyl Alcohol (PVA) Brush Type and Cleaning Chemistry Formulation for Copper (Cu) Post-Chemical Mechanical Planarization (p-CMP) Cleaning

Chemical Mechanical Planarization (CMP) is a critical process step in extending Moore’s Law and must be understood at a deeper, mechanistic level to limit defects that are detrimental to shrinking feature size. Specifically, Cu CMP utilizes a nanoparticle dispersion (slurry) composed of SiO2 abrasive nanoparticles, complexing agent, oxidizer, and a corrosion inhibitor. Slurry components must work in synergy to chemically modify the Cu surface while unwanted topography is removed by mechanical abrasion. The CMP process can cause various defects, and they can be classified as mechanical (i.e., scratching), chemical (i.e., corrosion), or physiochemical (i.e., adsorbed contaminants) according to the mechanism of formation. Adsorbed particles, polish residues, pad debris, and other foreign materials can have catastrophic impacts on device performance as line width decreases to the atomic scale. Upon the completion of the CMP process, removal of unwanted particle residue/organic contaminants is achieved using oxidation/reduction reactions, etching, or encapsulation chemistry coupled with ultrasonic methods or polyvinyl alcohol (PVA) brush cleaning. The nature of the current cleaning techniques has been known to provide insufficient cleaning capacity for next generation devices. This presentation will explore two fundamentally different approaches to post-CMP cleaning for Cu processes. First, the implementation of supramolecular cleaning chemistries to traditional PVA brush scrubbing was explored for the removal of SiO2 nanoparticles from a Cu surface. This work explored a structure activity relationship between the type of supramolecular cleaning chemistry used and its ability to effectively “encapsulate” nanoparticle contaminants. Initial results indicate that the anionic and non-ionic micelle show some corrosive behavior due to non-uniform passivation layers formed at the Cu surface during cleaning. This behavior is not seen with the cationic micelle suggesting its effective surface adsorption to the contaminant particle which can ultimately be removed via brush contact. Secondly, current cleaning chemistries typically utilize an undercutting mechanism to remove organic residues (i.e., BTA), however, this requires harsh oxidation and can result in scratches/erosion. Therefore, an approach to chemically activate the residue in an “overcutting” mechanism can improve cleaning performance with reduced defectivity. More specifically, this work will explore the use of α-β-unsaturated ketones as cleaning agents to initiate the nucleophilic attack and subsequent removal of BTA via a Michael’s Addition reaction. This mechanism will be evaluated via dynamic Tafel analysis, contact angle, atomic force microscopy, and cleaning performance to correlate interfacial interactions/reactions to p-CMP performance.

Modelling and stability analysis of a longitudinal wheel dynamics control loop with feedback delay

Vehicle safety is an important field of today's engineering practice and the scientific research as well. One of the basics of the modern vehicle system dynamics control systems is braking or driving torque control. Ensuring proper connection between the tyre and the road surface is essential for safety and good handling behaviour. Fundamental questions may arise about the details of the model, such as feedback delay, sampling effect, numerical differentiation in the control algorithm or the dynamical characteristics of the tyre model. In this article, a connected dynamical system is presented which contains a wheel model and a PID type traction controller. Steady state and dynamical brush type tyre models are presented and compared. Two different ways are described to model the feedback delay. The fully continuous time model contains constant time delay, while there is another case, where the sampling effect and the numerical differentiation methods of the control algorithm are presented. Finally, stability analysis of the delayed system is performed. The stability and performance characteristics and different bifurcations are presented using stability charts. The type of the tyre model has significant effect on the stability characteristics.

The use of medium bristle toothbrushes is associated with the incidence of gingival fissures.

The objective of this study was to compare the incidence of gingival fissures (GF) associated with the use of soft and medium bristle toothbrushes over three months. A blind randomized crossover clinical trial was conducted with 20 high school students (14 females, 14-24years old) using both toothbrushes type (soft and medium bristle) during 3months each. Periodontal examinations and photographs of premolars and molars were recorded on days 0, 30, 60, and 90 of 1st phase. Following a 10-day washout period, the 2nd phase was carried out with the participants changing the assigned brush type. Toothbrushing perception was evaluated at the end of study through a questionnaire. A calibrated and blind examiner analyzed the photographs for GF presence. Differences in the GF incidence between toothbrushes type were analyzed by McNemar test, while factors associated with GF incidence were investigated by Poisson regression. Sixty-five percent (n = 13) of participants had at least one GF throughout the study, with 40% (n = 8) of them while using medium brushes only (p = 0.039). GF occurrence was significantly associated with medium brushes (IRR, 3.582; 95% CI 1.459-8.795; p = 0.005). 58.8% of participants reported gingival soreness or bleeding with medium brushes. Both toothbrushes led to the GF occurrence. Nonetheless, medium bristles toothbrushes determined a 3.58 times greater risk of developing these lesions. Clinical relevance The use of medium bristle brush is associated with greater incidence of gingival fissures. The presence of gingival fissures should be considered by the clinician when evaluating the toothbrushing habits of patients.

Rheological properties of polymer chains at a copper oxide surface: Impact of the chain length, surface coverage, and grafted polymer shape.

We employ a recently derived semirealistic set of coarse-grained interactions to simulate polymer brushes of cis-1,4-polybutadiene grafted on a cuprous-oxide surface within the framework of dissipative particle dynamics. We consider two types of brushes, I and Y, that differ in the way they are connected to the surface. Our model explores the impact of free polymer chain length, grafting density of the brush, and imposed shear rate on the structural and dynamic properties of complex metal oxide polymer interfaces.