Search Results (24)

Background: Dental erosion is the irreversible loss of tooth structure from acid exposure. Its prevalence is rising globally, making it an important oral health concern. However, longitudinal data from Eastern Europe are scarce, especially in Romania. This pilot study aimed to assess the 10-year incidence of dental erosion in Romanian young adults and to compare clinical index scoring with digital scanning. Methods: A 10-year prospective study followed 540 Romanian adults (aged 18–30) selected with no erosive lesions at baseline (Basic Erosive Wear Examination BEWE = 0). Erosive wear was assessed at the 10-year follow-up using BEWE, with 40 participants also undergoing digital intraoral scanning to measure enamel loss (μm). Gender differences were analyzed. Chi-square tests, relative risk, and correlation analyses were performed. Results: After 10 years, 23.2% of participants developed dental erosion. Males exhibited a higher incidence than females (29.9% vs. 17.2%; RR = 1.74, p < 0.001). Among the scanned subset (n = 40), the mean enamel loss was 137 ± 79 µm, with greater wear on palatal vs. buccal surfaces (p = 0.002). BEWE scores were moderately correlated with digital enamel loss (r = 0.58, p < 0.001). Conclusions: Erosion progressed over time in this cohort, with males at higher risk. Digital scanning detected subtle enamel loss not captured by BEWE, indicating greater sensitivity to early changes. BEWE and digital methods provided complementary information; their combined use offers a more comprehensive assessment. Full article

Background: In recent years, thanks to the improvement of adhesive techniques, patients affected by tooth wear, related to erosion and/or parafunctional habits, can undergo restoration by adding only what has been lost of their dentition (additive approach). However, since not all clinicians are convinced that dental rehabilitation should be proposed in the early stages of exposed dentin, several treatments are often postponed. It is important to emphasize that, in the early stages, the clinical approach should remain conservative, focusing on dietary counseling, the modification of harmful habits, fluoride application, and risk factor management. Only when these preventive and non-invasive strategies prove insufficient, and the condition continues to progress, should invasive restorative treatments be considered. Unfortunately, epidemiological studies are reporting an increase in the number of young patients affected by erosive tooth wear, and not intercepting these cases earlier could lead to a severe degradation of the affected dentition. In addition, parafunctional habits are also becoming more frequent among patients. The combination of erosion and attrition can be very destructive, and may progress rapidly once dentin is exposed and the risk factors remain unaddressed. The aim of this report was to present a conservative full-mouth rehabilitation approach for severe erosive lesions and to provide a 10-year follow-up assessing the biological, functional, and esthetic outcomes. Methods: In this article, the postponed restorative treatment of a patient, suffering from severe tooth wear, is illustrated. The patient had sought dental treatment in the past; however, due to the already very compromised dentition, a conventional but very aggressive treatment was proposed and refused. Four years later, when the patient finally accepted an alternative conservative therapy, the tooth degradation was very severe, especially at the level of the maxillary anterior teeth. The combination of three different approaches, Speed-Up Therapy, BOPT (Biologically-Oriented Preparation Technique), and the 3 Step Technique, however, improved the capacity to successfully complete the difficult therapeutic task. Results: The biological goals (maintenance of the pulp vitality of all of the teeth and the minimal removal of healthy tooth structure) were accomplished, relying only on adhesive techniques. Conclusions: The overall treatment was very comfortable for the patient and less complicated for the clinician. At 10-year follow-up, biological, functional, and esthetic success was still confirmed. Full article

Valve leakage mainly comes from worn sealing surfaces caused by abrasive particles. This study uses plasma beam spraying to create Fe55 alloy coatings with CeO₂ and TiN added to improve microstructure and wear resistance. Five coatings were prepared: Fe55 with 0.02% CeO₂ (FC2), 0.04% CeO₂ (FC4), 1% TiN (FT1), 2% TiN (FT2), and 2% TiN/0.02% CeO₂ (FC2T2). These coatings were tested for wear and erosion using wet sand and slurry experiments. Results showed that FC2T2 had the most uniform microstructure with fully equiaxed grains (20.32 μm size) and no columnar grains. This was due to CeO₂ and TiN co-working effect: CeO₂ was adsorbed onto TiN surfaces, reducing TiN decomposition and acting as nucleation sites. The FC2T2 coating also showed the highest hardness uniformity (no large changes with depth) and the lowest surface roughness after wear (41% lower than pure Fe55). In wear tests, FC2T2’s Cr₇C₃ hard phases blocked abrasive cutting, while the γ-Fe matrix prevented Cr₇C₃ from breaking off. Erosion tests confirmed FC2T2’s superior performance, as its uniform structure limited deep grooves. Adding both CeO₂ and TiN improved wear resistance by providing a balanced microstructure, reducing leakage risks in valve sealing surfaces. Full article

Background/Objectives: Tooth wear is a progressive and multifactorial condition influenced by mechanical and chemical factors. Saliva plays a crucial role in modulating erosive wear through its buffering capacity and remineralization potential. This study aimed to assess the prevalence and severity of erosive tooth wear among dental students and explore its correlation with salivary factors such as flow rate and pH. Methods: A cross-sectional study was conducted on 96 individuals from the Egas Moniz School of Health & Science. Erosive wear was evaluated using the Basic Erosive Wear Examination (BEWE) index. Unstimulated and stimulated saliva samples were collected to measure salivary flow rate and pH. Statistical analyses included Spearman’s correlation and multinomial logistic regression. Results: All individuals were classified as no risk (BEWE Score 0–2) or low risk (BEWE Score 3–8). The most affected teeth were the lower first molars and the 4th and 6th sextants. Salivary analysis showed a mean unstimulated flow rate of 0.5 mL/min and stimulated flow of 1.7 mL/min. A significant negative correlation (rho = −0.224, p = 0.029) was found between stimulated salivary pH and BEWE score, indicating that higher acidity contributes to greater erosive wear. Conclusions: This study highlights the impact of salivary properties on erosive tooth wear, emphasizing the protective role of higher salivary pH. Regular monitoring of saliva and preventive strategies should be integrated into early diagnosis and management of erosive wear in young adults. Full article

Background/Objectives: Early tooth wear (TW) assessment prevents challenging and costly dental treatments. Knowledge of data on the prevalence and risk factors is crucial for developing preventive guidelines. This retrospective cross-sectional study aims to study the prevalence of TW in a sample of patients seeking a Screening and Emergency appointment at Egas Moniz Dental Clinic (EMDC) and its associated risk factors. Methods: Descriptive and logistic regression analysis were applied to data from a sample of 2266 patients, collected between 2021 and 2023, to ascertain the presence of tooth wear, its different types and its correlation with potential risk factors. Results: The prevalence of dental wear was found to be 54.7%, with attrition (24.1%) being the most prevalent lesion and erosion (2.7%) the least prevalent. Concerning the risk predictors for tooth wear, age (OR = 1.01–1.05, p < 0.05), decreased DVO (OR = 2.16, p = 0.028), antacids (OR = 7.07, p = 0.003), mastication difficulties (OR = 1.87, p = 0.039), drugs (OR = 2.38, p = 0.032) and use of mouthwash (OR = 1.47, p = 0.008) were positively associated. Gender (OR = 0.7, p = 0.015) was negatively associated, with females showing a 30% less risk than males. Conclusions: It was concluded that TW is prevalent and increases with age, underscoring the necessity for timely and accurate diagnosis to minimize its progression. Additionally, it is crucial to conduct a thorough evaluation of the risk factors involved to implement effective preventive measures and treatment strategies. Full article

The geometry of the ladle bottom and the position of stirring paddles during hot metal stirring significantly influence hydrodynamic characteristics, thereby affecting desulfurization efficiency. Water model experiments and hydrodynamic simulations were conducted to investigate the effects of ladle structures and stirrer positions on the flow field and mixing characteristics in hot metal desulfurization. The results indicate that ladles with a spherical-bottom structure effectively reduced the “dead zone” volume in the hot metal flow. In the water model tests, the mixing time for the spherical-bottom ladle was reduced by 22.5% and 20% at different stirring paddle speeds compared to the flat-bottom ladle, facilitating the better dispersion of the desulfurization agents. The hot metal flow velocities in all directions were also superior in spherical-bottom ladles. Under identical conditions, eccentric stirring generated shallower and broader vortices, with the vortex center offset from the stirring shaft axis, thereby minimizing the risk of “air entrainment” associated with high-speed central stirring. During eccentric stirring, the flow-field distribution was uneven, and the polarization of the stirrer was observed in the water model, whereas central stirring revealed a more uniform and stable flow field, reducing the risk of paddle wear and ladle wall erosion. Central stirring exhibits distinct advantages in the desulfurization process, whereas eccentric stirring is exclusively applicable to metallurgical modes requiring a rapid enhancement of bottom flow and localized rapid dispersion of desulfurizing agents. Full article

The combination of future changes in sea levels and wave climate in coastal areas represents one of the greatest threats to the preservation of underwater cultural heritage (UCH). This study presents a new methodology to assess climate change’s impacts on UCH preservation in shallow waters, focusing on wave-induced hazards like decontextualization, scouring, and wear erosion. The approach uses hybrid downscaling of bias-corrected wave fields from the RCP4.5 and RCP8.5 CMIP5 scenarios. The methodology was applied in the Bay of Cadiz, where an overall reduction in wave energy flux was observed. However, local increases were detected in rocky outcrops and coastal areas with high UCH density. As a result, the shallow zones exhibited significant changes in decontextualization and scouring hazards. However, the most relevant risk changes were linked to wear erosion, particularly at sites on rocky outcrops near Cadiz. The methodology proposed in this study is essential for identifying areas with higher risk and for evaluating UCH preservation under future climate conditions. It offers an effective tool for discriminating sites at risk and for conducting a long-term assessment of these risks in coastal environments affected by climate change. Full article

Background and Objective: Limited access to health services and low educational levels are factors in the rural population that are associated with the development of oral pathologies. However, the specific risk indicators contributing to erosive tooth wear (ETW) in these populations remain unclear. The objective of this study was to identify risk indicators associated with the prevalence of erosive tooth wear (ETW) in schoolchildren aged 8–12 years from rural and urban areas in the State of Mexico. Methods: A cross-sectional study was carried out in public schools in rural and urban areas. The prevalence of ETW was evaluated using the Basic Erosive Wear Examination (BEWE). The risk indicators studied were gastroesophageal reflux, vomiting, vitamin C, food, beverages, dental hygiene, bruxism, and hyposalivation. Logistic regression models were used to calculate odds ratios (OR) and 95% confidence intervals (CI). Results: The prevalence of ETW was higher in the rural area (77.3%) compared to the urban area (51.2%) (p = 0.001). The odds of presenting ETW were more than twice in schoolchildren from rural areas compared to those from urban areas (OR: 2.25, 95% CI: 1.11–3.98). Risk indicators varied between rural and urban populations, with different factors such as the consumption of fresh tomato sauce, orange, tangerine, atole (artisanal corn-based drink), and teeth grinding in the rural area, and lemon, soft drink, fruit juice consumption, and the simplified oral hygiene index in the urban area (p < 0.05). Conclusions: To prevent ETW, strategies offering tailored dietary and hygiene advice should be proposed, considering the specific conditions of each geographic area. Full article

Ice accumulation on lift-generating surfaces, such as rotor blades or wings, degrades aerodynamic performance and increases various risks. Active measures to counteract surface icing are energy-consuming and should be replaced by passive anti-icing surfaces. Two major categories of surface treatments—coating and structuring—already show promising results in the laboratory, but none fulfill the current industry requirements for performance and durability. In this paper, we show how femtosecond laser structuring of stainless steel (1.4301) combined with a hydrocarbon surface treatment or a vacuum treatment leads to superhydrophobic properties. The anti-ice performance was investigated in an icing wind tunnel under glaze ice conditions. Therefore, flexible steel foils were laser-structured, wettability treated and attached to NACA 0012 air foil sections. In the icing wind tunnel, hydrocarbon treated surfaces showed a 50 s ice build-up delay on the leading edge as well as a smoother ice surface compared to the reference. To demonstrate the erosion resistance of these surfaces, long-term field tests on a small-scale wind turbine were performed under alpine operating conditions. The results showed only minor erosion wear of micro- and nano-structures after a period of six winter months. Full article

The wind–sand climate prevalent in the central and western regions of Inner Mongolia results in significant damage to wind turbine blade coatings due to sand erosion. This not only leads to a decline in power generation but also poses safety risks. This study replicated the wind–sand environment of Alashan and numerically simulated the erosion and wear process of the blade coatings of a 1.5 MW horizontal axis wind turbine under rotational conditions using the DPM model. Additionally, erosion tests were conducted on the operating wind rotor in a wind tunnel. The simulation results demonstrate that sand particle trajectories in the rotating domain are influenced by vortex, incoming wind speed, and sand particle size. For small-sized sand particles, variations in wind speed do not substantially alter the number of particles in contact with the wind turbine blades. However, alterations in the momentum of these particles lead to changes in the impact force on the coating surface. Conversely, the change of wind speed will not only alter the number of large-size sand particles in contact with the wind rotor but also modify the impact force on the coating surface. Furthermore, after impacting the blade, small sand particles continue to move along an approximate helical trajectory with the airflow, while large-size sand particles swiftly rebound. Through statistical analysis of erosion pits on the blade surface after the erosion experiments, it was observed that, in comparison among the leading edge, windward side, trailing edge, and leeward side, the leading edge presents the greatest number of erosion pits, whereas the leeward side has the fewest. Along the spanwise direction, the 0.7R-blade tip segment exhibits the highest count, while the blade root-0.3R section displays the fewest number of pits. The wear morphology of the blade coating was observed from the blade root to tip. The leading edge coating exhibits a range from shallow pits to coating flaking and deeper gouge pits. On the windward side, the coating displays wear patterns varying from tiny cutting pits to cutting marks, and then to gouge pits and coating flaking. Erosion morphology of the trailing edge evolves from only minor scratches to spalling pits, further deepening and enlarging. These research findings provide a basis for the study of zoning-adapted coating materials for wind turbine blades in wind–sand environments. Full article

In underground coal gasification, as a choke regulating the formation gas lift pressure, the throttling tool can effectively reduce the production cost, the number of ground heating and insertion equipment, and gas consumption. Because in this process, the coal is transformed into composite synthetic gas through a series of technical treatments, the throttling tool is in a working environment with high temperature and pressure. In the process of transportation of combined synthetic gas, the pulverized coal parts produced by incomplete coal combination move with the gas in the throttling tool. The high temperature and high-pressure gas carrying large-diameter pressed coal parts will cause serial erosion and wear to the throttling device, resulting in failure and well-controlled safety risks. Therefore, according to the Joule–Thomson effect, this paper independently designs downhole throttling tools with single- and double-hole structures. According to actual field conditions, the erosion wear of throttling tools with different systems in high-temperature gas–solid two-phase flow was simulated and predicted, and the internal flow field characteristics of throttling means were analyzed. The difference between the wall wear distribution, wall collision position, and wall erosion effect of different structure throttling mechanisms with the change in gas velocity was investigated, which guides the practical use of the subsequent throttling tools. Full article

Background: Chronic stomach regurgitation associated with eating disorders (EDs) poses a high risk for tooth erosion. This study investigated oral health conditions, behavioral patterns, and tooth erosion in women with EDs. Methods: 16 ED and 13 healthy women were enrolled; 14 ED and 10 healthy control subjects completed the study. Subjects completed demographic, medical, oral, and behavioral health history questionnaires. Dental caries status was recorded as Decayed, Missing and Filled Teeth (DMFT)index and the severity of tooth erosion as Basic Erosive Wear Examination (BEWE) scores. Saliva was collected for flow rate, pH, and buffering capacity analysis. Results: The ED group had a lower stimulated saliva flow rate and higher DMFT index but no significant difference in BEWE scores compared to the controls (t-test, significance level 0.05). Five of the fourteen ED subjects exhibited extensive tooth erosion, which may have been exacerbated by their tooth-brushing behavior. Conclusions: Although some ED subjects showed extensive tooth erosion in this pilot study, the average BEWE score of the ED group was not significantly different from the controls. Extensive tooth erosion in ED may relate to the low stimulated salivary flow. A larger-scale clinical study is necessary to validate these results. Full article

Background: The aim of this study was to analyse the relationship between the type and amount of fluid intake and the incidence of erosive tooth wear in a group of healthy children and children with disabilities. Methods: This study was conducted among children aged 6–17 years, patients of the Dental Clinic in Kraków. The research included 86 children: 44 healthy children and 42 children with disabilities. The prevalence of erosive tooth wear using the Basic Erosive Wear Examination (BEWE) index was assessed by the dentist, who also determined the prevalence of dry mouth using a mirror test. A qualitative-quantitative questionnaire on the frequency of consumption of specific liquids and foods related to the occurrence of erosive tooth wear, completed by the children’s parents, was used to assess dietary habits. Results: The occurrence of erosive tooth wear was determined for 26% of the total number of children studied, and these were mostly lesions of minor severity. The mean value of the sum of the BEWE index was significantly higher (p = 0.0003) in the group of children with disabilities. In contrast, the risk of erosive tooth wear was non-significantly higher in children with disabilities (31.0%) than in healthy children (20.5%). Dry mouth was significantly more frequently identified among children with disabilities (57.1%). Erosive tooth wear was also significantly more common (p = 0.02) in children whose parents declared the presence of eating disorders. Children with disabilities consumed flavoured water or water with added syrup/juice and fruit teas with significantly higher frequency, while there were no differences in quantitative fluid intake between groups. The frequency and quantity of drinking flavoured waters or water with added syrup/juice, sweetened carbonated, and non-carbonated drinks were associated with the occurrence of erosive tooth wear for all children studied. Conclusions: The group of studied children presents inappropriate drinking behaviours regarding the frequency and amount of beverages consumed, which, especially in a group of children with disabilities, may contribute to the formation of erosive cavities. Full article

The purpose of this study was to report a rare case of an aggressive nasopalatine cyst with nasal involvement in an edentulous patient. A 61-year-old edentulous Caucasian male presented with an anterior maxillary lesion that prevented him from wearing his complete upper denture. Clinical examination showed vestibular and palatal swelling around the edentulous sites of teeth #11, 12 and 13. Radiological examination revealed a well-limited cyst of the anterior maxilla that was aggressive in nature because of its size, erosion of the palatal and buccal cortical bone, and extension to the nasal floor. The provisional diagnosis was an aggressive nasopalatine duct cyst, but because the patient had been edentulous for years, the differential diagnosis also included a residual cyst. To remove the lesion, we used a slightly modified surgical procedure compared with the conventional approach: a flap was raised on the palatal side and another on the vestibular side instead of the classical palatal approach. The diagnosis of a nasopalatine duct cyst was confirmed after a histopathological examination. Large destructive nasopalatine duct cysts involving the nasal cavity are rare. In an edentulous patient, this lesion may be misdiagnosed as a residual cyst. In this case, the surgical risk was the inadvertent creation of a naso-antral communication. The lesion was completely enucleated without complications and healing was uneventful. Full article

People performing regular physical activity are at high risk of dental erosion especially in cases of high sport drinks intake. Biomimetic hydroxyapatite-based oral hygiene products, like toothpastes and mouthwashes, have been investigated in recent years for their remineralizing activity on the teeth. The aim of the present study was to evaluate the efficacy of two different oral hygiene protocols, respectively consisting of the combination of a hydroxyapatite-based toothpaste plus mouthwash (Trial group) or toothpaste alone (Control Group). At baseline (T0), as well as at 15 days (T1), 30 days (T2) and 90 days (T3), the following clinical indexes were assessed: Basic Erosive Wear Examination (BEWE), Schiff Air Index (SAI), Visual Analogue Scale (VAS), Plaque Index (PI) and Bleeding Index (BI). In general, for all the indexes assessed, a progressive intragroup reduction was noticed from the baseline to the subsequent timepoints, with no intergroup differences. Accordingly, the use of the hydroxyapatite-based toothpaste, alone or in combination with the mouthwash containing hydroxyapatite as well, is an effective method for the domiciliary management of dental erosion in physically active individuals like rugby players. Full article