Tooth Surface Roughness Research Articles

An Advanced DEM-FEM Method for Herringbone Gear in Shot Peening

Introduction: The complex geometry of herringbone gear can lead to uneven surface strengthening, which affects the overall effect of treatment. Methods: A discrete element model (DEM) of shot peening for herringbone gears was developed, incorporating accurate gear surface parameters to study impact characteristics along the tooth profile. A finite element model (FEM) was created for small local units of the gear surface to calculate the residual stress and roughness. Results: There are a large number of low-velocity shots at the root of the gear, and the closer to the top of the gear, the higher the impact velocity of the shots, but the number of impacts also decreases. The surface roughness Sa near the root of the tooth is the smallest, the Sa at the pitch circle is the largest, and the Sa at the top of the tooth is intermediate. However, the residual stress levels at different positions of the tooth surface are not significantly different. Conclusion: The difference in tooth surface roughness of herringbone gear is the synergistic effect of shot impact velocity and shot frequency, but this synergistic effect has no significant effect on the stress after shot peening.

Predictive Model for Scuffing Temperature Field Rise of Spiral Bevel Gears under Different Machining Conditions

Spiral bevel gears are extensively employed in mechanical transmissions; however, they are prone to adhesive wear when operating under high-speed and heavy-load conditions. Research indicates that the tooth surface roughness of gears significantly influences the friction and wear of the meshing gears. The present study delves into the origins of tooth surface roughness through the integration of the W-M function and fractal theory. Utilizing an involute helical gear with surface roughness for tooth cutting, a three-dimensional model is established with roughened tooth surfaces. This paper introduces an approach to developing three-dimensional gear models with roughness and applies the finite element method to perform thermodynamic analysis on gears exhibiting diverse levels of surface roughness. The thermal analysis of gears with varying degrees of roughness was conducted using the finite element method. Comparative analysis of the results under specific operating conditions elucidated the impact of roughness on tooth surface temperature rise. In order to validate the simulation model, an experimental test platform for spiral bevel gears of identical size was established. This model integrates tooth surface roughness with thermodynamic analysis, allowing for the rapid assessment of tooth surface temperature rise under different machining conditions, and reducing the cost of validating predicted tooth surface load-carrying capacity.

Evaluation of nanohardness, elastic modulus, and surface roughness of fluoride-releasing tooth colored restorative materials.

Recently, interest in tooth-colored fluoride-releasing dental materials has increased. Although physical and mechanical properties such as surface hardness, elastic modulus and surface roughness of the restorative materials have been investigated, the effect of different immersion media on these properties is still controversial. The aim of this study was to evaluate the nanohardness, elastic modulus and surface roughness of the fluoride release of tooth-colored restorative materials after immersion in acidic beverages. Prepared samples of three restorative materials (a highly viscous glass ionomer (EQUIA Forte; GC, Tokyo, Japan), a compomer (Dyract XP; Dentsply, Weybridge, UK), and a bioactive restorative material (Activa BioACTIVE; Pulpdent, MA, USA)) were randomly divided and immersed in distilled water, a cola and an orange juice for one week. The HYSITRON T1 950 TriboIndenter device (Hysitron, USA) with the Berkovich diamond indenter tip was used for all measurements. The nanohardness and elastic modulus of the samples were measured by applying a force of 6000 μN to five different points on the sample surface. Surface roughness measurements were evaluated on random samples by scanning five random 40 × 40 μm areas. The properties were measured at the initial and one week after immersion. The values of nanohardness, elastic modulus and surface roughness were tested for significant differences using a two-way analysis of variance (ANOVA) with repeated measures (p < 0.05). Tukey's honest significant difference (HSD) test was used for multiple comparisons. AB (Activa BioACTIVE) had the highest initial mean values for nanohardness. After post-immersion, the highest mean value for elastic modulus was the initial AB value. The lowest mean value for roughness of 100.36 nm was obtained for the initial DX (Dyract XP) measurement. Acidic beverages had a negative effect on the nanohardness, elastic modulus and surface roughness of the restorative materials.

Prediction model of grinding roughness for worm with complicated space tooth surface

Optimum grinding parameters are crucial for achieving high-quality grinding of helical tooth surfaces for worm drives. The complex coupling motion relationship and formation mechanism between the worm blank and the grinding head make it difficult to predict the effect of grinding parameters on tooth surface roughness. Therefore, we developed a prediction model for the worm tooth surface roughness under conjugate grinding and applied it to the Roller Enveloping Worm Reducer (REWR). The forming process of the theoretical worm tooth surface during the grinding process was modeled by using the conjugate meshing principle. Considering the plowing and cutting effects of grinding particles on the tooth surface at different design parameters, feed speeds, and rotational speeds of the grinding head, the roughness prediction equation was established based on the theory of the maximum depth of valley bottom. Through the coupling analysis of the theoretical tooth surface model and the roughness prediction model, the prediction of the worm tooth surface roughness is realized. Based on the validated model, the influences of grinding parameters on the worm tooth surface roughness of REWR were quantitatively discussed. This study is of great significance for optimizing process parameters in the grinding of complex spatial surface transmissions.

Analysis of the Surface Roughness of Different Denture Teeth Materials: A Quantitative In-Vitro Study.

The surface roughness of denture teeth materials significantly influences their clinical performance and patient satisfaction. Understanding the variations in surface roughness among different materials is crucial for optimizing denture fabrication processes. In this quantitative in-vitro study, three commonly used denture teeth materials, namely acrylic resin, composite resin, and porcelain, were evaluated for surface roughness. Twenty samples of each material were prepared and subjected to profilometric analysis. The surface roughness parameters Ra and Rz were measured using a contact profilometer. Statistical analysis was performed to compare the surface roughness among the different materials. The mean surface roughness (Ra) values were found to be 0.32 μm for acrylic resin, 0.25 μm for composite resin, and 0.18 μm for porcelain. Similarly, the mean Rz values were 2.45 μm for acrylic resin, 1.98 μm for composite resin, and 1.62 μm for porcelain. Statistical analysis revealed significant differences in surface roughness among the three materials (P < 0.05). Porcelain denture teeth exhibited the smoothest surface, followed by composite resin and acrylic resin. These findings suggest that material selection plays a crucial role in determining the surface roughness of denture teeth. Porcelain may offer superior aesthetics and reduced plaque accumulation compared with acrylic and composite resin materials. Clinicians should consider these differences when choosing denture materials to achieve optimal clinical outcomes and patient satisfaction.

PENGARUH PERENDAMAN AIR PDAM BANDARMASIH TERHADAP KEKASARAN PERMUKAAN GIGI PASCA PENGAPLIKASIAN KARBAMID PEROKSIDA 20%

Background: One of the treatments to overcome the problem of discolored teeth is to do tooth whitening or bleaching. The tooth whitening agent that is often used is carbamide peroxide which is applied directly to the tooth enamel surface. Several factors that can affect tooth enamel are the degree of acidity or potential hydrogen (pH), acid concentration, dissolving time and the presence of calcium-like ions, and the level of water hardness. Most of the people in Banjarmasin City still frequently use PDAM water as drinking water and for daily use Objective: To analyze the effect of immersing PDAM water and distilled water on tooth surface roughness after application of 20% carbamide peroxide. Methods: Using a pure experimental design with the Posttest Only With Control Group Design and simple random sampling technique. The total sample was 16 maxillary first premolars which were divided into 3 treatment groups and 1 control group. Results: analysis of the One Way Anova test with Bonferroni's Post-Hoc showed no difference in roughness between the PDAM water immersion and distilled water groups with or without the application of 20% carbamide peroxide (p&gt;0.05). There was a difference in roughness between the group that was given carbamide peroxide and the group that was not given carbamide peroxide 20% (p&lt;0.05). Conclusion: There is an effect of PDAM water immersion on tooth surface roughness after application of 20% carbamide peroxide, but the resulting roughness is not significant.Keywords: PDAM water, Tooth Surface Roughness, 20% Carbamide Peroxide

Effects of a new magnetostrictive ultrasonic scaler and a traditional piezoelectric ultrasonic scaler on root surfaces and patient complaints

Tooth wear and pain are the primary concerns of patients undergoing periodontal scaling. The aims of this study were to compare the effects of a new magnetostrictive ultrasonic scaler and a traditional piezoelectric ultrasonic scaler on tooth surface roughness and calculus removal and to determine their impacts on patient discomfort during supragingival cleaning. This article had two parts: an in vitro study and a clinical study. In the in vitro study, thirty teeth with subgingival calculus were randomly assigned to two scaling treatment groups: magnetostrictive scalers (n = 15) and piezoelectric scalers (n = 15). Surface roughness measurements were taken at baseline and after scaling, and the root samples were visualised by SEM after scaling. Additionally, a single-centre randomised split-mouth clinical trial was conducted. Eighty-five participants diagnosed with chronic gingivitis or periodontitis were randomly assigned to receive supragingival scaling. The magnetostrictive scaler was used in half of the mouths (n = 85), and the piezoelectric scaler was used in the other half of the mouths (n = 85). Data on pain, noise, and vibration were collected using a VAS questionnaire, and the operating time was recorded. In both in vitro and clinical studies, magnetostrictive scalers were reported to be more effective than piezoelectric scalers in removing dental deposits (P < 0.05). Additionally, the root surface after scaling with the magnetostrictive scaler was smoother than that after scaling with the piezoelectric scaler in the in vitro study (P = 0.02). SEM examination also revealed that fewer dental materials were lost after instrumentation with the magnetostrictive scaler than after instrumentation with the piezoelectric scaler. Piezoelectric scalers caused less discomfort to patients in terms of pain, noise, and vibration than magnetostrictive scalers (P < 0.05). According to this clinical study, the magnetostrictive scaler caused more discomfort during supragingival scaling than the piezoelectric scaler. Moreover, the magnetostrictive scaler was also more efficient and produced a smoother root surface with less material loss after scaling than the piezoelectric scaler, as demonstrated in the in vitro study.

Comparative study on the effects of different polishing methods on tooth surface microstructure and roughness following initial periodontal treatment.

To investigate the effects of different polishing methods on the surface microstructure and roughness of teeth following initial periodontal treatment. Teeth were divided into three groups (silica onegloss, polishing disc, and polishing strip) in vitro. Tooth surface microstructure was characterized via scanning electron microscopy. Roughness was measured by profilometry and laser scanning confocal microscopy (LSCM). According to the in vitro results, one group was chosen for further clinical trials. Effects of the chosen polishing method on patient plaque control and satisfaction were assessed via plaque staining and visual analog scale (VAS). Electron microscopy results revealed that the polishing disc group had smoother roots and crowns than did the other two groups. Roughness analysis revealed that the crown roughness with the polishing disc and silica onegloss was lower, and the root roughness with the polishing disc was the lowest (p < .05) The LSCM results showed that the pigment deposition depth with the polishing disc and silicon onegloss in the crowns and roots were significantly lower than those with the other two methods (p = .000). The polishing effect of the polishing disc was best among the three groups. Clinical trials were performed to verify the polishing disc effects. Plaque staining results showed that the decrease in plaque in the polishing disc group was greater than that ofthe rubber cup group (p = .020), which was similar to the results of LSCM. The VAS results showed that the polishing disc made teeth feel smoother, similar to the results of the roughness detection, and the procedure was more comfortable (p < .05). However, there was no significant difference between the two groups regarding foreign body sensation during pronunciation (p = .178). Combining in vitro and in vivo evaluations, the use of a polishing disc following periodontal treatment yielded superior polishing effects on teeth and was better accepted by patients.

Dynamics characteristics of wind turbine gear pairs considering lubrication and tooth surface roughness

Dynamics characteristics of wind turbine gear pairs considering lubrication and tooth surface roughness

EFFECT OF DIFFERENT WHITENING TOOTHPASTES ON SURFACE ROUGHNESS OF YOUNG HUMAN ENAMEL

Purpose: The purpose of this study was to determine the whitening toothpastes effect of surface roughness in young permanent human enamel. Methods: In this in vitro study, 100 premolars were sectioned, mounted and stored. All teeth were divided into 10 experimental groups (n=10). The specimens were brushed 3600 cycles (equivalent 12-week brushing) with a brushing machine using 25 g of each toothpaste mixed with 40 ml of distilled water. The surface profile of the teeth was measured a profilometric device before and after brushing, respectively. Each teeth surface roughness measured three times and averaged. Results: In five groups which toothpastes containing bromelain, nano hydroxyapatite, silica, blue covarine and charcoal the decrease in surface roughness was found statistically significant (p&lt;0.05), except toothpastes groups containing hydrogen peroxide, sodium hydroxide, microbeads, hydroxyapatite and water. In toothpastes groups containing hydrogen peroxide, sodium hydroxide and microbeads group’s surface roughness values were increased but not statistically significant difference between the groups in terms of initial and after brushing surface roughness values. Conclusion: According to the results of this in vitro study, it can be concluded that, hydrogen peroxide, sodium hydroxide and microbeads based whitening toothpastes increased the surface roughness of young permanent human tooth; had not provide smoother surface on tooth after 3600 cycles brushing. This study emphasizes the need for healthcare professionals to be aware of the whitening products usage for teenagers and make evidence-based decisions when recommending the product to patients.

The Effect of Strawberries as a Natural Teeth Whitening Agent on Tooth Surface Roughness: In Vitro Study

Teeth whitening due to discoloration can be achieved by methods of bleaching. The material used in bleaching conventional methods can have effects on hard tooth tissue, such as increasing tooth surface roughness. Strawberries (Fragaria x ananassa) have long been known for being effective in whitening teeth. The aim of the research was to determine the effect of strawberries as a natural teeth whitening agent on tooth surface roughness in vitro. This research is an in vitro experiment. The samples were 24 first premolars of the upper jaw and lower jaw, which were divided into two groups. Group 1 (strawberry juice 100%) and group 2 (carbamide peroxide 10%). Testing tooth surface roughness using tools surface roughness tester, then the data was analyzed using statistical test paired t-test and Mann-Whitney. The results of the study showed that the mean and standard deviation of tooth surface roughness before and after application of strawberry fruit juice was 0.37 ± 0.156 and 0.22 ± 0.129, while the 10% carbamide peroxide group obtained the value of tooth surface roughness before and after application was 0.36 ± 0.118 and 0.37 ± 0.263.

The bending-torsional vibration characteristics of gear transmission under the effect of tooth surface roughness

The bending-torsional vibration characteristics of gear transmission under the effect of tooth surface roughness

Dental wear in a marine economy: A case study from Philistine Ashkelon

AbstractIn the Iron Age IIA Philistine cemetery at Ashkelon (modern Israel), roughly 11% of individuals exhibit severe and highly variable dental wear, which we explore here at two timescales: wear that accumulates over days and weeks (microwear) and wear that accumulates over months and years (macrowear). Using teeth from both adult and nonadult individuals, we first established categories of dental macrowear patterns and sorted individuals within them. We then made replicas of the teeth from 27 individuals having both typical and atypical dental wear and performed metrology by noncontact profilometry on a reflected light microscope. We then calculated each tooth's surface roughness (Sa) and collected qualitative observations of teeth within each macrowear category. Our findings show no macrowear or microwear pattern exclusive to sex or age group. Likewise, there are no statistically significant differences (p &lt; 0.05) in Sa between adult males and females, and sampled nonadults fall within two standard deviations of the pooled adult means. The microscopic surfaces of all teeth show a wide variety of textures on the occlusal surfaces, including wavy striations, deep parallel striations, globular pitting, and newly described rectangular pits. These results indicate that individuals used their teeth as a third hand while manipulating objects and that children also participated in these activities. Due to the similarities in dental wear between Ashkelon and other coastal populations, we conclude that the observed wear patterns arose from the performance of specialized tasks for a marine‐based economy.

Effect of whitening toothpastes on the surface roughness and microhardness of human teeth—an in vitro study

ObjectiveTo determine the effect of whitening toothpastes on the surface roughness and microhardness of human teeth.MethodologySurface roughness was estimated using the Talysurf instrument, and microhardness was estimated using the Vickers hardness tester before and after the application of whitening toothpastes on mounted extracted human teeth.ResultsIn the activated charcoal group, there was a reduction in the surface roughness from 1.21 at baseline to 1.09 at 1 month and a further reduction to 1.02 at 3 months, which was found to be statistically significant. However, no statistically significant difference in surface roughness was found in the other toothpaste groups. With respect to microhardness, all 4 whitening toothpastes showed a statistically significant reduction in microhardness after 3 months of brushing. However, the reduction was significantly higher in group 2 and in group 4 compared to the others.ConclusionThis study showed that whitening toothpaste containing activated charcoal significantly reduced the surface roughness, whereas toothpastes with blue covarine and toothpastes containing activated charcoal significantly reduced the microhardness of the tooth.Clinical relevanceThis study emphasizes the need for healthcare professionals to be aware of the potential disadvantages of whitening toothpastes and make evidence-based decisions when recommending the product to patients.

Effect of Hand and Ultrasonic Scaling-Root Planing Methods on Tooth Surface Topography: An In-Vitro Atomic Force Microscopy Study.

Any instrumentation on the tooth surface for plaque or calculus removal will cause some amount of roughness on the tooth surface. Hence, this study was proposed to investigate the effects of hand and ultrasonic scaling and root planing on enamel and cementum, respectively. Forty tooth samples were prepared from extracted maxillary and mandibular first pre-molars and were divided randomly into four groups of 10 samples each. Group l: received ultrasonic scaling on enamel; Group II: received hand scaling on enamel surface; Group III: root planing with an ultrasonic unit on the cementum samples; and Group IV: root planing using hand curettes on cementum surface. The amount of roughness produced on the surface of each sample of all four groups was evaluated using atomic force microscopy (AFM) and statistically analyzed using Chi-square, ANOVA, and Wilcoxon tests. The results suggested that the surface roughness produced on both crown and root after scaling and root planing (SRP) using a hand instrument is lower than that of an ultrasonic unit. The roughness of the crown was found to be lower than that of the root after SRP using both a hand instrument and an ultrasonic unit and was also statistically significant (P= 0.034). In contrast, there is not enough evidence to conclude a significant difference (P=0.13) between root planing using hand instruments and ultrasonic scaler groups. The combined p-value using the Chi-square test (P=0.026) suggests a statistically significant overall difference between crown and root groups. From the present study, the authors concluded that scaling as well as root planing using an ultrasonic unit cause more tooth (enamel and cementum) surface roughness as compared to hand scaling and root planing. While there is no significant difference in the surface roughness of root-cementum produced due to the root planing in both groups, crown-enamel exhibits a significant difference after scaling in both groups. Clinical significance of the study: Rough, uneven tooth surfaces negatively influence the anticipated healing of the periodontium by providing retention areas for microbial dental plaque.

Influence of tooth profile and surface roughness on wear of spur gears considering temperature

Influence of tooth profile and surface roughness on wear of spur gears considering temperature

Effectiveness of Silver Diamine Fluoride, Bioactive Glass and Casein Phosphopeptide Amorphous Calcium Phosphate in Comparison with Sodium Fluoride on Tooth Surface Roughness (An in Vitro Study)

Effectiveness of Silver Diamine Fluoride, Bioactive Glass and Casein Phosphopeptide Amorphous Calcium Phosphate in Comparison with Sodium Fluoride on Tooth Surface Roughness (An in Vitro Study)

Model of Surface Texture for Honed Gear Considering Motion Path and Geometrical Shape of Abrasive Particle

Gear power-honing is mainly applied to finish small and medium-sized automotive gears, especially in new energy vehicles. The distinctive curved surface texture greatly improves the noise emission and service life of honed gears. The surface texture for honed gear considering the motion path and geometrical shape of abrasive particles has not been investigated. In this paper, the kinematics of the gear honing process is analyzed, and the machining marks produced by the abrasive particles of honing wheel scratching abrasive particles against the workpiece gear are calculated. The tooth surface roughness is modeled considering abrasive particle shapes and material plastic pile-ups. This results in a mathematical model that characterizes the structure of the tooth surface and the orientation of the machining marks. Experiments were used to verify the model, with a maximum relative error of less than 10% when abrasive particles are spherical. Based on this model, the effects of process parameters on the speeds of discrete points on the tooth flank, orientations of machining marks and roughness are discussed. The results show that the shaft angle between the workpiece gear and the honing wheel and the speed of the honing wheel is the main process parameters affecting the surface texture. This research proposes a surface texture model for honed gear, which can provide a theoretical basis for optimizing process parameters for gear power-honing.

Surface roughness assessment with fluoride varnish application: An in vitro study

Background: The cause of cavities is initially due to roughness on the tooth surface, requiring fluoride varnish to prevent caries, as the varnish applies a fluoride compound to the tooth surface. Fluoride varnish reacts with the tooth enamel surface to form calcium fluoride and fluorapatite, thus making the enamel surface more resistant to demineralization and damage. Purpose: This study aims to compare the roughness of tooth enamel surfaces among three fluoride varnishes under acidic conditions. Methods: The research method uses three fluoride varnish materials: sodium fluoride 5% + tricalcium phosphate, calcium fluoride, and sodium fluoride 5% + casein phosphopeptide-amorphous calcium phosphate 2%. Samples of 81 teeth were divided into three groups (Group 1 without fluoride varnish application, Group 2 application of fluoride varnish with pH 3, and Group 3 application of fluoride varnish with pH 5). The teeth were tested before and after application of the varnishes using the scanning electron microscope and surface roughness tests. Results: The results showed a significant difference in the mean surface roughness of the enamel of the anterior deciduous teeth tested with fluoride varnish. The before and after comparisons in the pH 3 and pH 5 groups were very significant (p-value 0.000). The comparison results in each pH group after fluoride varnish administration showed no significant difference (pH 3 p-value 0.074 and pH 5 p-value 0.196). The tooth surfaces appear to be rougher after administration of an all-acid solution. Conclusion: There is a difference in surface roughness of primary teeth after being given fluoride varnish in low pH 3 immersion for 24 hours.

Air polishing therapy in supportive periodontal treatment: a systematic review

The aim of this study was to analyze tooth surface roughness and clinical parameters by a systematic review of the literature to compare the efficacy of air polishing with hand or ultrasonic instrumentation during supportive periodontal therapy (SPT). This study used a research question based on the PICO method. Bibliographic research was performed using four different databases. For the search of the articles, the work was divided into two parts: the first part analyzed the clinical parameters of air polishing in supportive periodontal therapy, and the second part analyzed the effects of air polishing on hard tissues. Of 164 articles concerning clinical parameters, 49 met the inclusion criteria; from 64 articles concerning hard tissues, it reached 4. Excluding these doubles, 12 were chosen for the literature review: eight RCTs, one retrospective cohort study, and three in vitro studies. The scientific literature has shown that air polishing, scaling, and root planing in supportive periodontal therapy give similar clinical results. However, air polishing seems to preserve the hard tissues of the tooth more than the traditional treatment with ultrasonic or manual instrumentation.