Ring Molds Research Articles

Design and simulation of internal planetary wheel plunger-type ring molding machine for biomass pellets

Key components of the existing external meshing dorsal spine plunger-type molding machine were modeled in three dimensions, and the fatigue life analysis of the molding machine spindle was carried out by using Ansys software. Due to the nonlinear mechanical behavior of the material ring mold, and pressure roller in the granulation process, there are a lot of contacts and collisions. Using the linear mechanics model is difficult to analyze. To achieve more accurate and realistic results, an Edem-Ansys joint coupled simulation was carried out for the pressure roller and ring mold engagement process. The results showed that the stress concentration point and fatigue weak region of the spindle occurred at the shaft cross-section, where the stress value should be less than 0.75 F. The maximum stresses and strains in the engagement process of the pressure roller and the ring die body occurred at the engagement point. The maximum values of deformation, stress, and strain were 0.039 mm, 412 MPa, and 0.002 mm/mm, respectively, which are all within the reasonable range and meet the design requirements.

Physicochemical characteristics and discolouration potentials of Pulpine mineral® and Pulpine NE®

ABSTRACT Aim: To compare the physicochemical properties (solubility, pH, radiopacity and crown discoloration) of Pulpine mineral (PMIN) and Pulpine NE (PNE) with the conventional material, mineral trioxide aggregate (MTA). Methodology: Specimens of the tested materials were prepared according to the manufacturer’s instructions using split Teflon ring molds. Solubility was evaluated by the percentage of material mass loss over 24 h and one week. The alkalinity was measured after each evaluation period using a pH meter. Other specimens were digitally radiographed on a size 2 sensor plate along with an aluminum step wedge to analyze the radiopacity by the Image J software. Finally, crown discoloration was assessed after applying the tested materials in the pulp chamber of sound human premolars using spectrophotometer. All data were statistically analyzed. Results: Compared to MTA, both materials had significantly higher solubility and lower radiopacity (P<0.05). The alkalinity of PMIN was higher than that of MTA and PNE. Unlike PMIN, PNE and MTA caused crown discoloration. Conclusions: PMIN exhibits promising results related to high alkalinity and adequate color stability but it needs modifications for radiopacity and solubility.

Real-time straw moisture content detection system for mobile straw granulator

In order to improve the molding rate of biomass particles extruded by ring mold of the mobile straw granulator, a real-time straw moisture content detection system based on frequency was designed in this paper. The detection system comprised the frequency based acquisition devices and the supporting circuits, and support vector regression (SVR) based calculation method. The acquisition device contained a soil separation cylinder and a signal detection chamfer. The soil separation cylinder was used to remove the soil from the straw. The moisture of the straw was transformed into the relatively stable frequency for detection, but the temperature can affect the Brownian movement of free water. Hence, the designed signal detection chamfer mainly contained a frequency sensor and a temperature sensor. The proposed calculation method blended the frequency and temperature to acquire the accurate moisture of the straw. A water replenishment module was also designed to verify the effectiveness of the detection system, and it was used to supply water to the straw when it becomes too dry. The system was verified in the experimental plots and field. The actual moisture content was obtained by 105℃ drying method. The results obtained in the experiment plots showed that the detectable moisture content range was between 9.09% to 46.68%, the maximum detection error was less than 0.44%, and the average absolute error was less than 0.33%, and the molding rate could reach approximately 94%. The results obtained in the fieldd showed that the average molding rate achieved was 93.57% and 89.76% for straws with moisture content of about 20% and 15%, respectively. The detection system comprehensively takes into account the influence of temperature and soil on moisture content and can effectively improve the working efficiency of the mobile straw granulator.

PEMBUATAN RAK PADA CV. AYUNA SILVER UNTUK MEMBANTU MENGATUR LETAK CETAKAN CINCIN

The ring mold storage rack created is equipped with a ring mold search system as an alternative for the automatic ring mold search process. This system is built with several supporting components such as ESP32 microcontroller, Servo Motor, L9110 Motor Driver, DC Gearbox Motor, 16x2 LED. The result of this service activity is the creation of an automatic ring mold storage rack which is able to simplify and reduce the time of the ring mold searching process at CV. Ayuna Silver. The final results obtained from several testing processes carried out contained 3 invalid results from 10 system tests, this shows that the system has a system success percentage of up to 70%. The time needed to search for rubber molds before the automatic ring mold storage rack was around 20 minutes, after the automatic ring mold storage rack was installed using a mobile system, it was only take 0.20 minutes or 12 seconds.

Effect of Fluorohydroxyapatite on Biological and Physical Properties of MTA Angelus.

This study aimed to assess the effect of addition of fluorohydroxyapatite (FHI) on biological and physical properties of mineral trioxide aggregate (MTA) Angelus. In this in vitro, experimental study, nano-FHI powder was first synthesized, and the morphology and chemical structure of particles were evaluated by scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). Three groups were evaluated in this study: MTA Angelus, MTA modified with 10% FHA, and MTA modified with 15% FHA. After mixing, the materials were applied to ring molds (10 mm diameter, 1 mm height), and the setting time of the three groups was evaluated according to ISO6876 and ASTMC266-03 with a Gillmore needle. The pH was measured using a pH meter at 24 and 48 hours and 7 days after mixing. The cytotoxicity of the materials was assessed in freshly mixed form and after 1 and 7 days using the methyl thiazolyl tetrazolium (MTT) assay according to ISO10993-5. Data were analyzed by one-way and repeated measures ANOVA and Tukey's test (alpha = 0.05). The addition of FHA to MTA significantly decreased the initial setting time (P < 0.05) and had no significant effect on cell viability (compared with pure MTA Angelus) at 1 and 7 days. However, modified MTA groups in freshly mixed form showed significantly lower cell viability (P < 0.05). The pH remained alkaline at all time points. Addition of 15% FHA to MTA Angelus decreased its setting time with no adverse effect on cell viability (except for fresh form) or pH.

Evaluation of the effect of mechanical alteration of enamel surface on shear bond strength of self-adhering composites utilizing different adhesive modalities

Abstract Background: Self-adhering flowable composite (SAC), which has currently been launched, is said to be postoperatively responsive and less technique-reactive than previous materials. Clinical demands for bonding to undamaged, modified, or prepared enamel surfaces—which may attach differently with adhesive resins—often accompany restorative demands. Very little information was available for SAC. Aim: This study was carried out to determine the impact of mechanical enamel surface modification on shear strength properties in various bonding procedures. Materials and Methods: The three groups of prepared enamel surfaces (group A, n = 60), unprepared enamel surfaces (group B, n = 60), and prepared enamel surfaces plus etch-and-rinse (group C, n = 20), which served as the control group, were randomly assigned to the 140 constructed samples. Subgroups A1, B1 (nanohybrid composite + self-etch), A2, B2 (self-adhering composite), and A3, B3 (self-adhering composite + self-etch) were created from groups A and B, respectively (n = 40). Composite resin cylinders with the unique bonding protocols of each group were created using Teflon ring molds. Testing for shear bond strength was done, and information was examined. Results: The control group C was found to have the highest mean shear bond strength (29.77 MPa), whereas subgroup B2 had the lowest mean shear bond strength (8.4 MPa). For all adhesive techniques, shear bond strength values for prepared enamel surfaces were considerably greater than those for unprepared enamel surfaces (P &lt; 0.01). The following were the mean shear bond strength values: C &gt; A1 &gt; A3 &gt; A2 &gt; B1 &gt; B3 &gt; B2. Conclusions: Shear bond tensile properties on prepared enamel surfaces were higher than those of unprepared enamel surfaces. Higher shear bond strength values of the self-adhering composite in prepared and unprepared enamel surfaces were produced by using a self-etch agent first.

Shear bond strength of porcelain to milled and stereolithography additively manufactured zirconia with and without surface treatment: An in vitro study

Statement of problemDelamination of veneering ceramic is one of the most common challenges relating to veneered zirconia restorations. Additive manufacturing (AM) is a fast-expanding technology that has gained widespread acceptance in dentistry and is increasingly being used to produce dental restorations. However, information about bonding of porcelain to AM zirconia is lacking. PurposeThe purpose of this in vitro study was to investigate the shear bond strength (SBS) of porcelain to milled and additively manufactured zirconia, and the effect of surface treatment on bond strength. Material and methodsA Ø12×5-mm disk was designed virtually to fabricate all specimens, which were divided into 2 groups according to the manufacturing technique: additively manufactured or milled zirconia. The effect of airborne-particle abrasion and a zirconia liner before porcelain application was investigated in both groups. Veneering porcelain was fired into an alumina ring mold on the zirconia surface. SBS was measured by using a universal testing machine at a crosshead speed of 1 mm/min before and after aging (n=10). SBS data were analyzed with 3-way ANOVA (α=.05) ResultsA significant difference was found between milled and AM zirconia. The SBS of porcelain to milled zirconia was significantly higher (1.38 MPa) than to AM zirconia (0.68 MPa) (P<.001). The surface treatment of zirconia had no significant effect on porcelain SBS in either group (P=.254), whereas thermocycling significantly reduced the SBS of porcelain to zirconia in both milled and AM groups (P=.001). ConclusionsPorcelain bonding to milled zirconia was better than to AM zirconia. Pretreating the zirconia substrate before porcelain application did not improve the porcelain bond.

Evaluation the Solubility and the Porosity of the Nano Fast Cement Comparing to the Mineral Trioxide Aggregate: An in vitro Study.

New calcium silicate base cements are introduced as root repair materials in order to defeat the problems of early root repair materials. Their mechanical properties such as solubility and porosity should be concerned. This study was conducted to evaluate the solubility and porosity of the NanoFastCement (NFC) as a new calcium silicate base cement comparing to mineral trioxide aggregate (MTA). In this in vitro study, scanning electron microscope (SEM) was used to evaluate the porosity at five different magnifications (200×, 1000×, 4000×, 6000× and 10000×) in secondary backscattered electron mode. All analyses were performed at 20kV. The obtained images were subjected to qualitative evaluation regarding the porosity. Solubility was determined following the international standards organization (ISO) 6876 method. Twelve specimens in specially fabricated stainless steel ring molds were weighed, initially and after 24 hour and 28 days of immersion in distilled water. Each weight was measured three times to record the average weight. Solubility was measured by calculating the difference of the initial and final weight. Solubility of the NFC in comparison with MTA showed no statistical difference (p Value > 0.05) after one day and 28 days. NFC acted like MTA and showed an acceptable solubility value at exposure time intervals. In both groups, solubility increased as time went on (p Value<0.05). The porosity of NFC was comparable to MTA, and NFC presented a less porous and a slightly smoother surface compared to MTA. NFC has similar solubility and porosity to Proroot MTA. Therefore, it can be a good, more available and less expensive substitute for MTA.

Setting Time and Solubility of Thymol Incorporated Zinc Oxide-Guaiacol Root Canal Sealer: An in Vitro Study

Aims: This study aimed to establish whether changes in setting time and solubility of the locally prepared zinc oxide-guaiacol endodontic sealer when incorporated with thymol crystals as an antibacterial agent. Materials and Methods: zinc oxide-guaiacol endodontic sealer with thymol crystals incorporated at three different concentrations (2%, 5%, and10%) were tested, For setting time test similar specimens were prepared using ring molds with an internal diameter of (10 mm) and a height of (2 mm), nearly (120±10) seconds once mixing, the sample was located on a metal block in an incubator. A Gilmore needle with a mass of (100±0.5 g) which had (2±0.1 mm measurement) was used; the period of “no indent” was noted from the start of mixing. For the solubility test, similar specimens were prepared using ring molds with an internal diameter of (20 ± 0.1 mm) and a height of (1.5 ± 0.1 mm) and digitally weighted to register the mass of each specimen before and after immersion in distilled water. Solubility was determined after 24 hours and statistically analyzed using descriptive statistics, a One-Way ANOVA test, and post-hoc Duncanʼs Multiple Range Test was used. Results: The means of setting time of three experimental sealers were decreased as thymol crystal concentrations increased and the means of solubility for three experimental sealers were increased as the concentrations of thymol crystal increased. Conclusions: This study concluded that the prepared sealers with three concentrations were still adapted within the requirements of ANSIADA specifications NO.572008 for root canal sealer materials.

Abstract P1024: 3d Cardiac Tissue Rings With Exogenous Extracellular Matrix As A Model For Cardiac Fibrosis

Introduction: Cardiac fibrosis, or excess deposition of extracellular matrix (ECM) within heart muscle, acts as a protective mechanism following cardiac injury, but causes long-term heart stiffening and impaired contraction. In vitro models aid in understanding cardiac disease mechanisms, but current fibrosis models lack (i) native-like ECM and (ii) interactions between multiple cardiac cell types. Objective: Our 3D model containing induced pluripotent stem cell-derived cardiomyocytes (iPSC-CM) and cardiac fibroblasts (CF) with exogenous ECM will reproducibly assess contractile changes under fibrotic conditions. Methods: Human GCaMP-encoded iPSC-CM (day 19) and CF (3:1) were combined in a custom agarose ring mold with collagen I (Col) (0.02 or 0.5 mg/mL), laminin (Lam) (0.01 mg/mL), both Col+Lam (0.03 mg/mL), Matrigel (0.03 mg/mL), or no ECM, n=5 for each condition. Concentrations were based on in vivo ratios of Col and Lam in literature. After 24 hours, cells self-assembled into 3D rings (Fig. 1a). Results: All conditions formed robust rings; average thickness = 460 μm (Fig.1b, c). Spontaneous beating resumed 48 hours after seeding. After 3 days in culture, Ca 2+ flux videos were captured; rings without ECM displayed shorter contraction durations, as did Col+Lam rings (Fig. 1d, e). This suggests that exogenous ECM in ratios found in healthy hearts may aid in contraction. Conclusion: This ring platform provides a reproducible cardiac fibrosis model with native-like ECM conditions and interactions between multiple cardiac cell types. Further assessments of ring stiffness and additional ECM conditions will enable this model to be used in therapeutic development.

A Comparison of Solubility Among Zinc Oxide Eucalyptus and Zinc Oxide Eugenol: An In Vitro Study

Introduction: We aimed to compare solubility between zinc oxide eugenol and zinc oxide eucalyptus. Methods: One hundred and twenty standardized plastic ring molds were constructed and filled with zinc oxide eugenol and zinc oxide eucalyptus. The specimens were allowed to dry for 24 hours and then weighed to the nearest 0.0001 g. Then divided randomly into three groups and immersed in distilled water for 1, 7, and 21 days. Then samples were removed from the solution and allowed to dry for 24 hours. Then they were weighed again, the percentage of weight loss was then determined as solubility. Data analyzed by two-way repeated measures ANOVA and the Tukey’s post-hoc test using MedCalc 20.104. Results: Zinc oxide eucalyptus solubility is more than zinc oxide eugenol. All tests of between-subjects effects and within-subjects effects showed statistically significant differences (P < 0.001). Conclusion: The 1st day results showed solubility of not more than 3% following storage in distilled water which meet the requirements of ISO 6876, where both zinc oxide-eugenol (ZOE) (0.05%) and zinc oxide eucalyptus (0.15%) satisfied these criteria.

Efficiency of activated charcoal powder in stain removal and effect on surface roughness compared to whitening toothpaste in resin composite: In vitro study

ObjectivesTo evaluate the efficacy of activated charcoal powder on extrinsic stain removal and its effect on surface roughness in stained resin composite in comparison with whitening toothpaste. Materials and methodsSixty-six disk-shaped composite specimens were fabricated using a custom-made ring mold. The specimens were stained using a coffee solution and stored in distilled water at 37 °C. The specimens were divided randomly into two groups, Group 1: Thirty-Three disks were subjected to brushing using whitening toothpaste (Control), and Group 2: Thirty-Three disks were subjected to brushing using charcoal powder. Specimens were evaluated for surface color and surface roughness at baseline after staining protocol and after the brushing process. ResultsChanges in color and surface roughness were highly significant (p < 0.0001) after brushing with activated charcoal powder and whitening toothpaste. However, no significant differences were found in color (p = 0.90) and surface roughness (p = 0.33) between the two bleaching techniques. ConclusionThe changes in the color and surface roughness of resin composite was significant after brushing with activated charcoal powder and whitening toothpaste. However, there were no significant differences between the two techniques.

Comparative Evaluation of MTA and Biodentine as a Restorative Material In Deciduous Teeth

Introduction: Several medicaments have been used in pulpotomy procedures of primary teeth. The present study was conducted to compare MTA with biodentine as a restorative material in deciduous teeth. Materials &amp; Methods: Specimens were prepared with MTA (group-I) and Biodentine (Group-II) with mold with 10 in each group using stainless steel ring molds. Polyethylene tubes of 1 mm long were filled with MTA and biodentine and placed in flasks containing 10 ml distilled water at 37°C. After 2 h, the flasks were removed from hot air oven, and the water was assessed for pH. Results were tabulated and subjected to statistical analysis. Results: Each group had 20 teeth sample. In group I, MTA was used and in group II, biodentine material was used. The mean solubility value of MTA at 1st day was 1.55, at 4th day was 1.64, at 12thday was 2.15, at 30th day was 2.57 and at 45th day was 2.60. Similarly in group II at 1st day was 1.89, at 4th day was 2.11, at 12thday was 2.80, at 30th day was 3.61 and at 45th day was 5.34. pH at 2 hours was 9.28 in group I and 8.98 in group II, at 12 hours was 9.26 in group I and 9.39 in group II, at 24 hours was 9.20 in group I and 9.64 in group II, at 7 days was 8.76 in group I and 8.27 in group II, at 28 days was 7.62 in group I and 7.78 in group II. The difference was significant (P&lt; 0.05). Conclusion: Authors found that both materials can be used in deciduous teeth. However, biodentine revealed higher solubility and pH as compared to MTA in deciduous teeth.

Effect of mechanical alteration of enamel surface on shear bond strength of different bonding techniques

Aim:This study was conducted to evaluate the effect of mechanical alteration of enamel surface on shear bond strength in different bonding techniques.Materials and Methods:Seventy samples were fabricated and randomly divided into three groups: Group A (n = 30) – prepared enamel surfaces, Group B (n = 30) – unprepared enamel surfaces, and Group C (n = 10) – prepared enamel surfaces + etch and rinse which served as a control group. Group A and Group B were further divided into three subgroups (n = 10), sub-Group A1, B1 (nanohybrid composite + self-etch), sub-Group A2, B2 (self-adhering composite), and A3, B3 (self-adhering composite + self-etch). Teflon ring molds were used to make composite resin cylinders with the specific bonding protocol of each group. Shear bond strength testing was conducted, and data were analyzed.Results:Mean shear bond strength values were as follows: C> A1> A3>A2>B1> B3> B2.Conclusions:Prepared enamel surfaces resulted in higher shear bond strength values as compared to unprepared enamel surfaces. Prior application of self-etch agent resulted in higher shear bond strength values of self-adhering composite in prepared and unprepared enamel surfaces.

Comparative analysis of bond strength and microleakage of newer generation bonding agents to enamel and dentin: An in vitro study.

Aims:This study aims to evaluate the bond strength (BS) and microleakage (ML) of the newer bonding agents to enamel and dentin.Objective:(1) To analyze the BS between self-etch and total-etch adhesives. (2) To analyze the depth of ML between self-etch and total-etch adhesives.Materials and Methods:Sixty mandibular premolars were fabricated and randomly divided into three groups: Group I (n = 20)-bonded with self-etch adhesive + nanohybrid, Group II (n = 20) with total-etch adhesive + micro hybrid and Group III (n = 20) with total-etch adhesive + nanocomposite. Teflon ring molds were used to make composite resin cylinders bonded to the buccal surface. Class II box cavity was prepared on the samples' proximal surface and condensed with composite resin with each group's specific bonding protocol. Shear BS and ML testing were conducted, and data analyzed.Statistical Analysis:Kruskal–Wallis analysis was done to statistically differentiate the BS and ML between the three experimental groups; the P < 0.05, it showed a statistically significant difference. Intergroup comparison was made using the Mann–Whitney U test.Conclusions:Within this study's limitation, resin bonded with self-etch G-Premio Bond used in selective etch technique showed the highest BS and resistance to ML.

Spectrophotometer analysis of bulk-fill composites on various beverages: An in-vitro study

Spectrophotometer analysis of bulk-fill composites on various beverages: An in-vitro study - IJCE- Print ISSN No: - 2581-9534 Online ISSN No:- 2581-8988 Article DOI No:- 10.18231/2456-8953.2019.0004, IP Indian Journal of Conservative and Endodontics-IP Indian J Conserv Endod

Amalgam Strength Resistance to Various Contaminants.

The purpose of this study was to quantify the relative strength tolerance of 1-day and 30-day amalgam following saturation contamination with water, saliva, blood, and handpiece lubricant oil during condensation. Valiant PhD XT amalgam was tested with 300 shear-strength (N=15) and 120 compressive-strength (N=6) specimens, divided into 1-day and 30-day groups, each with control, water, saliva, blood, and lubricant oil contamination samples. Shear specimens were condensed in 4 × 4-mm anchor wells inundated with contaminant fluids before adding a ring mold with 3.5-mm-diameter central hole adapted immediately to the top for continued condensation under contaminant-submerged conditions. Compressive specimen samples were condensed while completely inundated by each contaminant using the American Dental Association Specification No. 1 amalgam mold apparatus. All specimens were tested with the Instron E3000 and E10000 at 0.5 mm/min, with data statistically evaluated using the Kruskal-Wallis procedure with IBM SPSS v25 and Wilcoxon signed ranks test. Shear test values (mean±SD) following intracapsular and extracapsular contamination after 30 days under 100% humidity at 37°C were as follows: control, 30.97±5.41 MPa; water, 30.63 ±4.41 MPa; saliva, 27.54 ±4.56 MPa; blood, 24.92 ±3.48 MPa; lubricant oil, 26.06 ±4.06 MPa. Compressive strengths (±SD) of similarly contaminated samples were as follows: control, 447.7 ±76.3 MPa; water, 343.6 ±70.1 MPa; saliva, 307.7 ±24.0 MPa; blood, 281.6 ±35.2 MPa; lubricant oil, 227.8 ±16.9 MPa. Saliva, blood, and handpiece oil diminish compressive strength significantly, but water shows no statistically significant effect ( p>0.05). Amalgam 30-day shear strength is significantly altered by contamination with water, blood, or handpiece lubricant oil ( p<0.05). Remaining amalgam strength after extensive contamination may still be clinically functional relative to a previous ADA recommendation and when compared with resin-based direct restorative materials.

Reliability Analysis of Ring Mold Granulator based on Minimum Maintenance Model

Reliability Analysis of Ring Mold Granulator based on Minimum Maintenance Model

Evaluation of mold-enclosed shear bond strength between zirconia core and porcelain veneer

This study aimed to evaluate the mold-enclosed shear bond strength (ME-SBS) of zirconia to veneering porcelain with different surface treatments. Colored or uncolored zirconia coupons were either highly polished or airborne-particle abraded. The specimens were divided into groups with/without application of liner. Veneering porcelain was fired into an alumina ring mold on the zirconia coupons. The assembled specimens were subjected to the ME-SBS test. The mean ME-SBS for groups ranged from 7-10 MPa with no significant difference (p>0.05). A three-way ANOVA showed that coloring and surface roughening of the zirconia specimen had no significant influence on the ME-SBS value, but liner application exhibited a significant effect with a minor decrease in the MESBS (p=0.049). Surface treatments (coloring, airborne-particle abrasion, and liner application) were found to not cause a significant increase to the zirconia-porcelain bond strength. The application of zirconia liner had a slight negative influence on the ME-SBS results.

Effect of Water Sorption and Solubility on Color Stability of Bulk-Fill Resin Composite

The objective of this study is to compare the bulk-fill resin composite to a conventional one, as regards; water sorption, solubility, and their effect on color stability. This study was conducted using two types of composites: Bulk-fill composite (Filtek Bulk-Fill) and nanohybrid composite for control (Filtek Z250 XT). Specimens were prepared using a ring mold, 10 from each material. Specimens were desiccated, then weighed in a digital balance until a stable mass was acquired. For water sorption test, specimens were immersed in distilled water and placed in a lightproof incubator at 37 ± 1°C and the mass was measured weekly for 8 weeks. For solubility test, specimens were desiccated again in the desiccator until a stable mass was achieved. A spectropho-tometer was used to record the baseline color measurements prior to water immersion and weekly for 8 weeks. Bulk-fill composite showed higher water sorption value and lower water solubility values compared with that of the conventional one. No statistically significant difference was found for water sorption (p = 0.104) or water solubility (p = 0.098) between groups. The mean ΔE was lower in bulk-fill than conventional composite, and results showed a statistically significant difference (p = 0.009). Bulk-fill resin composite yielded better color stability and similar water sorption and solubility values. Bulk-fill resin composite can be used in esthetically concerned patients.