scholarly journals Effect of Water-Based Disinfectants or Air-Drying on Dimensional Changes in a Thermoplastic Orthodontic Aligner

Materials ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 7850
Author(s):  
Davide Bresolato ◽  
Andrea Volpato ◽  
Lorenzo Favero ◽  
Riccardo Favero
Keyword(s):  
Artificial Saliva ◽  
Storage Conditions ◽  
Distilled Water ◽  
Air Drying ◽  
3D Images ◽  
Degree Of Deformation ◽  
Dimensional Changes ◽  
Significant Difference ◽  
Dry Conditions ◽  
Oral Conditions

The polymer structure of thermoplastic materials currently used to make aligners is altered by the oral conditions and this negatively affects their capacity to move teeth. This study aimed to compare different options for storing aligners when not in use by superimposing successive 3D images to identify which storage method least affects material shape and weight. Fifty PET-G aligners, produced using the CA Digital method, were divided into four groups (1A, 1B, 1C, and 2D) and were stored for 18 h a day in artificial saliva at 37 °C. Then, to mimic their storage conditions when not in use, aligners in group 1A were immersed for the remaining 8 hours a day in bicarbonate solution, those in group 1B in chlorhexidine solution, those in group 1C in distilled water, and those in group 2D were stored dry. The samples were scanned at the baseline (before the immersion cycles began) and again two weeks later. The digital scans were superimposed and the median deformation, its variability, and weight differences were recorded for each group. Statistical analysis showed aligner deformation (expansion) in all three groups stored in wet conditions, with a statistically significant difference between groups 1A and 1C. Aligners in group 2D shrank slightly, and to a significantly greater degree with respect to group 1C. Variability in the degree of deformation was similar among the three groups stored in wet conditions, but significantly greater in group 2D. Weight gains were recorded in all four groups, the smallest in group 2D and the largest in group 1A. Storing aligners in dry conditions promoted lower deformation in the material, involving a slight shrinkage, whereas wet storage conditions caused an expansion of the aligner, especially when distilled water is used.

Soil Retention and Bacterial Harborage on Simulated Pewter Dinnerware

1979 ◽  
Vol 42 (8) ◽  
pp. 645-650
Author(s):  
CLARENCE A. JOHNSON ◽  
DARLENE A. LEWIS
Keyword(s):  
Staphylococcus Aureus ◽  
The Other ◽  
Distilled Water ◽  
Cast Aluminum ◽  
Sand Cast ◽  
Air Drying ◽  
Surface Finishes ◽  
Significant Difference ◽  
Soil Retention ◽  
Triton X

Soil retention and harborage of Staphylococcus aureus ATCC 25923 were investigated comparing stainless steel, plastic dinnerware, sand-cast aluminum dinnerware with two different surface finishes and aluminum dinnerware after prolonged restaurant use. The test consisted of ten repetitions of soiling with inoculated food soil, air drying, then washing at either 160 F or 130 F and rinsing at 180 F before analysis. Samples were analyzed by swabbing one-half of the surface with swabs in 0.1 N HCl with subsequent atomic absorption spectroscopy to detect residual calcium left from food soil, and swabbing the other half with swabs in buffered distilled water and Triton-X 100 followed by pour-plating to recover S. aureus harbored on the surface. Statistical analysis of the data indicated that if detergent and dishmachine manufacturers' recommendations are carefully carried out, no significant difference in soil retention or bacterial harborage could be revealed between the various test materials or between wash solution temperatures.

scholarly journals A Comparative Evaluation of Static Frictional Resistance Using Various Methods of Ligation at Different Time Intervals: An In Vitro Study

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Amanpreet Singh Natt ◽  
Amandeep Kaur Sekhon ◽  
Sudhir Munjal ◽  
Rohit Duggal ◽  
Anup Holla ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Artificial Saliva ◽  
In Vitro Study ◽  
Frictional Resistance ◽  
Static Friction ◽  
Significant Difference ◽  
Dry Conditions ◽  
The Mean ◽  
Time Periods

Aim. To compare and evaluate the static frictional resistance offered by the four different types of ligation methods in both dry and wet conditions and at different durations when immersed in artificial saliva.Material and Methods. Alastik Easy to Tie modules, Super Slick Mini Stix elastomeric modules, Power “O” modules, and 0.009″Stainless Steel ligatures were used to compare the static friction using maxillary canine and premolar Preadjusted Edgewise brackets with 0.022″× 0.028″slot and 0.019″× 0.025″stainless steel wires.Results. The mean frictional resistance for Alastik modules was the lowest and that of Stainless Steel ligatures was found to be highest among the four groups compared and the difference among the four groups was statistically significant (P<0.005). The mean static frictional resistance in all groups under dry conditions was lower than that under wet conditions. No statistical significant differences were found when the groups were compared at different time periods of immersion in artificial saliva.Conclusion. This study concludes that the Alastik modules showed the lowest mean static frictional forces compared to any other ligation method, though no significant difference was found for different time periods of immersion in the artificial saliva.

scholarly journals Kelarutantumpatansementara Cavit dalamrendamansaliva buatan (Solubility of Cavit temporary filling immersed in artificial saliva)

2014 ◽  
Vol 13 (2) ◽  
pp. 69
Author(s):  
Juni Jekti Nugroho ◽  
Hasrul Husain
Keyword(s):  
Artificial Saliva ◽  
Distilled Water ◽  
Fourth Group ◽  
The Third ◽  
Significant Difference ◽  
Water Ph ◽  
One Way Anova ◽  
Temporary Filling

A continuous temporary filling inside the mouth would expose acid produced by microorganism during fermentation ofcarbohydrate that would lower the pH of saliva. The aim of this research is to determine the variation on solubilitylevels of Cavit temporary filling immersed in artificial saliva with pH 4, 6, and 8. Samples were placed in tubecontainers with 2 mm in height and 7 mm in diameter. Samples were immersed in four different groups of artificialsaliva based on the pH, in which the first group was immersed in artificial saliva pH 4, the second in pH 6, the third inpH 8, and the fourth group was immersed in distilled water (pH 7). The results showed that after 7 day of immersion,there was a significant difference on solubility levels between the four groups of treatment (p<0.05). The data weretabulated and analyzed using one-way ANOVA and least significant difference (LSD). Therefore, it can be concludedthat pH can affect the solubility levels of Cavit temporary filling.

scholarly journals Color variation of acrylic resins immersed in pigment beverages according to the consume habits: a pilot study

2014 ◽  
Vol 2 (3) ◽  
pp. 199
Author(s):  
Renato Fabrício de Andrade Waldemarin ◽  
Lucas Brum Cleff ◽  
Lauren Grandi Santos ◽  
Guilherme Brião Camacho ◽  
Luciana De Rezende Pinto
Keyword(s):  
Artificial Saliva ◽  
Black Tea ◽  
Color Variation ◽  
Distilled Water ◽  
Water Control ◽  
Color Changes ◽  
Acrylic Resins ◽  
Significant Difference ◽  
Before And After ◽  
Cie Lab

AIM: evaluate the color changes in acrylic resins immersed in two pigmented beverages in different time periods, proportional to the frequency and volume of consume by the population with and without the use of artificial saliva. MATERIAL AND METHODS: Thirty thermo-polymerizable resin disks were confectioned with 3.0 +- 0.1 mm thickness, initially immersed in distilled water for 24 hours and randomly divided into 2 groups (n=15): GC – with artificial saliva and GS – without artificial saliva. They were, then, subdivided into 3 subgroups (n=5): G1 – distilled water (control); G2 – red wine; G3 – black tea. These groups were daily immersed inside beverages for 15 days, with daily immersion frequency equal to the beverage ingestion and the period of each immersion equal to 1 minute/10 ml of beverage per capita. Between each immersion the disks were stored inside distilled water. The color of resins was measured according to the CIE-Lab scale before and after the immersion periods, and the color variation was calculated (ΔE). The values ΔL*, Δa* e Δb* were also evaluated. RESULTS: Analysis of variance was performed, and have shown significant difference (p<0.05) among G1 and the other solutions, without significant difference between G2 and G3 for ΔE, ΔL, Δa and the module Δb. There was no difference between GC and GS. CONCLUSION: It was concluded that the use of artificial saliva did not change pigmentation degree and that wine presents similar changes to the tea, considering the parameters used. 

Comparison of Volumetric Dimensional Changes of Calcium Aluminate, Resin Modified Glass Ionomers and Resin Luting Cements Among Different Storage Conditions

2021 ◽  
Vol 13 (2) ◽  
pp. 294-301
Author(s):  
Eassa Alobaidi ◽  
Nawaf Labban ◽  
Steven Haug ◽  
John A. Levon ◽  
David T. Brown ◽  
...  
Keyword(s):  
Calcium Aluminate ◽  
Storage Conditions ◽  
Calcium Aluminate Cement ◽  
Glass Ionomer ◽  
Ion Release ◽  
Dimensional Changes ◽  
Luting Agent ◽  
Significant Difference ◽  
Self Etch ◽  
Aluminate Cement

Objective: The aim was to evaluate the volumetric dimensional changes of calcium aluminate glass-ionomer luting agent to resin modified-Glass ionomer cement (RM-GIC), self-etch and conventional resin based cement (RBC) among different storage conditions. Methods: Twenty cylindrical specimens (7 mm × 2 mm) for four cements [Calcium aluminate (Ceramir-CM), RM-GIC (Fuji Plus-FP), RBC (Rely X Ultimate-RA) and RBC-self-etch (Rely X Unicem-RU)] were fabricated and polished. Five specimens from each material were randomly assigned to the four test conditions. These conditions were silicone oil at 22 °C and 37 °C and distilled water at 22 °C and 37 °C respectively. A resolution balance was used to measure the weight of each specimen at 1, 2, 3 and 4 weeks. Archimedes’ principle equations were used to measure volumetric dimensional changes. Ion release analysis for Ca+ and OH- of the storage medium solution of calcium aluminate cement was performed using atomic absorption spectroscopy and pH measurement respectively at 1, 2, 3 and 7 weeks. Data was analyzed using ANOVA and Tukey post hoc test. Results: A significant difference in volumetric changes (ρ < 0.05) was observed for different cements. Calcium aluminate (CM) showed maximum volumetric changes followed by FP. However, resin cements (RA and RU) showed significantly lower volumetric changes. Oil immersion exhibited shrinkage and water immersion showed volumetric expansion in all materials. Increase in duration of immersion, increased the dimensional changes (shrinkage or expansion) among all cement groups (ρ < 0.05). Both temperature and duration showed significant influence on Ca+ ion release. Conclusions: Calcium aluminate cement had the highest level of dimensional changes (17.28% and 20.52%) while both resin luting agents show least expansion without a significant difference between them. Ceramir luting agent expands significantly in water and continues to release Ca2+ ions with time and higher temperature. The clinical use of calcium aluminate cements based on the high dimensional changes observed in the study is debatable.

scholarly journals Effect of Nano-Filled Protective Coating and Different pH Enviroment on Wear Resistance of New Glass Hybrid Restorative Material

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 755
Author(s):  
Sandra Brkanović ◽  
Ana Ivanišević ◽  
Ivana Miletić ◽  
Dražen Mezdić ◽  
Silvana Jukić Krmek
Keyword(s):  
Wear Resistance ◽  
Artificial Saliva ◽  
Glass Ionomer Cement ◽  
High Viscosity ◽  
Storage Conditions ◽  
Low Ph ◽  
Distilled Water ◽  
Before And After ◽  
The Difference ◽  
Periodic Exposure

The purpose of the study was to determine the wear rate of Equia Forte HT Fil with Equia Forte Coat or without coating and compare it with Fuji IX GP high-viscosity glass ionomer cement (GIC) in conditions with acid load or at neutral pH. The samples were stored for 7 days: (1) in artificial saliva, (2) in artificial saliva and cyclically exposed to low pH, and (3) in distilled water and cyclically exposed to low pH. Wear was determined by measuring the difference in mass before and after brushing in an abrasion testing device. The wear of Fuji IX GP was significantly higher than that of Equia Forte HT Fil with or without coating (p = 0.000). The difference between Equia Forte HT Fil with and without Coat was not statistically significant (p < 0.803). The differences in wear resistance between samples stored in saliva and in distilled water were not significant (p = 0.588). Periodic exposure to the low pH solution significantly affected the wear resistance of all materials (p = 0.000). Equia Forte HT Fil was more resistant to wear than Fuji IX GP in all storage conditions. A resinous coat did not significantly increase wear resistance.

scholarly journals Nanotubular Oxide Layer Formed on Helix Surfaces of Dental Screw Implants

Coatings ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 115 ◽  
Author(s):  
Magdalena Jażdżewska ◽  
Michał Bartmański
Keyword(s):  
Oxide Layer ◽  
Cross Sections ◽  
Surface Coverage ◽  
Artificial Saliva ◽  
Corrosion Current ◽  
Optical Microscope ◽  
Significant Difference ◽  
Helix Surfaces ◽  
Future Work ◽  
Oxidation Parameters

Surface modification is used to extend the life of implants. To increase the corrosion resistance and improve the biocompatibility of metal implant materials, oxidation of the Ti-13Nb-13Zr titanium alloy was used. The samples used for the research had the shape of a helix with a metric thread, with their geometry imitating a dental implant. The oxide layer was produced by a standard electrochemical method in an environment of 1M H3PO4 + 0.3% HF for 20 min, at a constant voltage of 30 V. The oxidized samples were analyzed with a scanning electron microscope. Nanotubular oxide layers with internal diameters of 30–80 nm were found. An analysis of the surface topography was performed using an optical microscope, and the Sa parameter was determined for the top of the helix and for the bottom, where a significant difference in value was observed. The presence of the modification layer, visible at the bottom of the helix, was confirmed by analyzing the sample cross-sections using computed tomography. Corrosion tests performed in the artificial saliva solution demonstrated higher corrosion current and less noble corrosion potential due to incomplete surface coverage and pitting. Necessary improved oxidation parameters will be applied in future work.

scholarly journals Seed longevity of maize conserved under germplasm bank conditions for up to 60 years

2021 ◽  
Author(s):  
Filippo Guzzon ◽  
Maraeva Gianella ◽  
Jose Alejandro Velazquez Juarez ◽  
Cesar Sanchez Cano ◽  
Denise E Costich
Keyword(s):  
Seed Germination ◽  
Plant Genetic Resources ◽  
Seed Viability ◽  
Storage Conditions ◽  
Seed Longevity ◽  
Germplasm Bank ◽  
Significant Difference ◽  
Different Temperatures ◽  
Germination Experiments

Abstract Background and Aims The long-term conservation of seeds of plant genetic resources is of key importance for food security and preservation of agrobiodiversity. Nevertheless, there is scarce information available about seed longevity of many crops under germplasm bank conditions. Methods Through germination experiments as well as the analysis of historical monitoring data, we studied the decline in viability manifested by 1000 maize (Zea mays subsp. mays) seed accessions conserved for an average of 48 years at the CIMMYT germplasm bank, the largest maize seedbank in the world, under two cold storage conditions: an active (–3 °C; intended for seed distribution) and a base conservation chamber (–15 °C; for long-term conservation). Key Results Seed lots stored in the active chamber had a significantly lower and more variable seed germination, averaging 81.4 %, as compared with the seed lots conserved in the base chamber, averaging 92.1 %. The average seed viability detected in this study was higher in comparison with that found in other seed longevity studies on maize conserved under similar conditions. A significant difference was detected in seed germination and longevity estimates (e.g. p85 and p50) among accessions. Correlating seed longevity with seed traits and passport data, grain type showed the strongest correlation, with flint varieties being longer lived than floury and dent types. Conclusions The more rapid loss of seed viability detected in the active chamber suggests that the seed conservation approach, based on the storage of the same seed accessions in two chambers with different temperatures, might be counterproductive for overall long-term conservation and that base conditions should be applied in both. The significant differences detected in seed longevity among accessions underscores that different viability monitoring and regeneration intervals should be applied to groups of accessions showing different longevity profiles.

scholarly journals An Assessment of Treated Greywater Reuse in Irrigation on Growth and Protein Content of Prosopis and Albizia

Horticulturae ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 38
Author(s):  
Naji K. Al-Mefleh ◽  
Yahia A. Othman ◽  
Maher J. Tadros ◽  
Amani Al-Assaf ◽  
Samer Talozi
Keyword(s):  
Protein Content ◽  
Crude Protein ◽  
Dry Weight ◽  
World Health ◽  
Quality Analysis ◽  
Distilled Water ◽  
Albizia Lebbeck ◽  
Forage Production ◽  
Water Control ◽  
Significant Difference

This study investigated the influence of treated greywater on growth and protein content of multipurpose (forage and ornamental) transplants, Prosopis juliflora L., Prosopis tamarugo L., and Albizia lebbeck L. Transplants of tested species were irrigated with treated greywater, diluted greywater (grey + distilled water, 1:1/by volume), and distilled water (control) for seven months. Water quality analysis showed that the concentrations of nutrients and heavy metals found in the greywater were within the acceptable range compared with Jordan Institution for Standard and Metrology (JISM) and the World Health Organization (WHO) thresholds for safe use of greywater. Escherichia coli found in the greywater were lower compared to JISM and WHO guidelines for the safe use of greywater. Irrigation with treated greywater increased shoot fresh weight by 24–39% and dry weight by 34–40% compared to diluted greywater and control. No significant difference in crude protein was noticed between water treatments. Prosopis species (P. juliflora Albizia lebbeck L. and P. tamarugo Albizia lebbeck L.) had higher shoot fresh (35%) and dry weight the same species had lower crude protein (44%) when compared to Albizia lebbeck Albizia lebbeck L. The reuse of treated greywater for landscaping or forage production alleviates the demand for water resources and reduces the pressure on wastewater treatment plants. However, considering the controversial findings of previous studies on greywater quality (especially, long-term reuse), the reuse of treated greywater needs to be considered with caution and periodic quality analyses and economic assessments are required.

scholarly journals Evaluation of color stability of different temporary restorative materials

2015 ◽  
Vol 44 (5) ◽  
pp. 262-267 ◽  
Author(s):  
José Vitor Quinelli Mazaro ◽  
Luiz Miguel Minani ◽  
Adriana Cristina Zavanelli ◽  
Caroline Cantieri de Mello ◽  
Cleidiel Aparecido Araújo Lemos
Keyword(s):  
Storage Time ◽  
Color Change ◽  
Artificial Saliva ◽  
Color Stability ◽  
Time Interval ◽  
Acrylic Resins ◽  
Significant Difference ◽  
Restorative Materials ◽  
Before And After ◽  
Level Of Significance

AbstractIntroductionTemporary restorative materials are widely used, however, little is know about their color stability.Objectiveto evaluate the color stability of the following temporary restorative materials: acrylic and bis-acrylic resins after immersion in pigmenting solutions for different periods of storage.Material and methodFour materials were tested (Dêncor/Clássico, Protemp 4/3M ESPE; Structur 2 SC/Voco; Luxatemp AM Plus/DMG) and 30 test specimens (15 mm in diameter and 2 mm thick) per material were fabricated. They were divided according to the storage medium (artificial saliva, saliva + cola type soda, and saliva + coffee) and storage time intervals (2, 5, 7 and 15 days). Color measurements were made before and after immersions, with use of a spectrophotometer, by means of the CIE L*a*b* system. The data were analyzed by the analysis of variance and the Tukey Test, at a level of significance of 5%.ResultAcrylic resin presented greater color stability in comparison with bis-acrylic resins (p<0.001). When bis-acrylic resins were compared no significant difference was observed between the resins Structur and Luxatemp (p=0.767). As regards solutions tested, coffee showed the highest color change values (p<0.001), and the longer the storage time interval, the greater was the color change in all the temporary restorative materials analyzed (p<0.001).ConclusionAcrylic resin presented greater color stability in comparison with bis-acrylic resins (p<0.001). Coffee caused the greatest color change, and immersion time was determinant in color stability of the temporary materials analyzed.

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