scholarly journals Characteristics of Dental Resin-Based Composites in Leukemia Saliva: An In Vitro Analysis

Biomedicines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1618
Author(s):  
Alexandru Mester ◽  
Marioara Moldovan ◽  
Stanca Cuc ◽  
Ciprian Tomuleasa ◽  
Sergiu Pasca ◽  
...  
Keyword(s):  
Acute Leukemia ◽  
Water Sorption ◽  
Water Solubility ◽  
Artificial Saliva ◽  
P Value ◽  
Residual Monomer ◽  
Experimental Conditions ◽  
Effective Response ◽  
Chronic Leukemia

Background: The aim was to analyze, in vitro, four resin based composite systems (RBCs) immersed in saliva of leukemia patients before starting chemotherapy regiments. Material and methods: Saliva was collected from 20 patients (4 healthy patients, 16 leukemia patients). Resin disks were made for each RBC and were immersed in the acute leukemia (acute lymphocytic (ALL), acute myeloid (AML)), chronic leukemia (chronic lymphocytic (CLL), chronic myeloid (CML)), Artificial saliva and Control environment, and maintained for seven days. At the end of the experiment, the characteristics and the effective response of saliva from the studied salivas’ on RBCs was assessed using water sorption, water solubility, residual monomer and scanning electron microscopy (SEM). Data analysis was performed and a p-value under 0.05 was considered statistically significant. Results: The behaviour of RBCs in different immersion environments varies according to the characteristics of the RBCs. RBCs with a higher filler ratio have a lower water sorption. The solubility is also deteriorated by the types of organic matrix and filler; the results of solubility being inversely proportional on the scale of negative values compared to sorption values. Chromatograms of residual monomers showed the highest amount of unreacted monomers in ALL and AML, and the Control and artificial saliva environments had the smallest residual monomer peaks. Because of the low number of differences between the experimental conditions, we further considered that there were no important statistical differences between experimental conditions and analysed them as a single group. Conclusion: The influence of saliva on RBCs depends on the type of leukemia; acute leukemia influenced the most RBCs by changing their properties compared to chronic leukemia.

scholarly journals A Comparison of Force Decay between Coil Spring, Elastomeric Chain and Tie-backs in Various Alcohol Concentrations found in Mouth Rinse: An In-vitro Study

2021 ◽  
pp. 155-162
Author(s):  
Asma Fatima ◽  
Prasad Konda ◽  
Asiya Fatima ◽  
Hidayathulla Shaikh ◽  
Butool Zohra ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Tooth Movement ◽  
Artificial Saliva ◽  
Alcohol Exposure ◽  
Control Group ◽  
P Value ◽  
Coil Spring ◽  
Mouth Rinses ◽  
Force Decay

Background: The ability to close space efficiently in Orthodontics is of major clinical importance. Elastomeric power chain, coil spring, and tiebacks are commonly used in Orthodontics to achieve tooth movement during the closure of spaces. Many mouth rinses which are used by the patients to achieve good oral hygiene affect the properties of the material used during treatment resulting in force decay if they contain alcohol. Aim: To know the effect of mouth rinses containing different alcohol Concentrations on the force decay of retraction materials. Materials and Methods: A study was carried out to test the effect of alcohol exposure found in mouth rinses on orthodontic NiTi closing coils, elastomeric chains, and tie-back. A total of 135 specimens were divided into one control group and two test groups submerged in artificial saliva at 37⁰ C. Two test groups each of them exposed to different alcohol-containing mouthwashes (Listerine and Povidone-iodine) for 60 seconds twice a day and the control group were exposed only to deionized (DI) water for 28 days. Force measurements were taken at six-time points (initial, 7 days, 14 days, 21 days, and 28 days) using a digital force gauge. Results: The comparison between the tensile strength was made by digital force gauge and the p-value (≤ 0.05) for tensile strength was derived by ANOVA test, multiple comparisons, and Tukey’s correction. Significant force decay was seen in test groups when compared to the control group. Conclusion: Force degradation of retraction products used during orthodontic treatment was effected by mouth rinses containing alcohol.

scholarly journals Evaluation of the Friction of Self-Ligating and Conventional Bracket Systems

2011 ◽  
Vol 05 (03) ◽  
pp. 310-317 ◽  
Author(s):  
Simona Tecco ◽  
Donato Di Iorio ◽  
Riccardo Nucera ◽  
Beatrice Di Bisceglie ◽  
Giancarlo Cordasco ◽  
...  
Keyword(s):  
In Vitro Study ◽  
P Value ◽  
Low Friction ◽  
Experimental Conditions ◽  
Beta Titanium ◽  
Conventional Brackets ◽  
Orthodontic Archwires ◽  
Post Hoc ◽  
Conventional Bracket

ABSTRACTObjectives: This in vitro study evaluated the friction (F) generated by aligned stainless steel (SS) conventional brackets, self-ligating Damon MX© brackets (SDS Ormco, Glendora, California, USA), Time3© brackets (American Orthodontics, Sheboygan, Wisconsin, USA), Vision LP© brackets (American Orthodontics), and low-friction Slide© ligatures (Leone, Firenze, Italy) coupled with various SS, nickel-titanium (NiTi), and beta-titanium (TMA) archwires. Methods: All brackets had a 0.022-inch slot, and the orthodontic archwires were 0.014-inch, 0.016-inch, 0.014×0.025-inch, 0.018×0.025-inch, and 0.019×0.025-inch NiTi; 0.017×0.025-inch TMA; and 0.019×0.025-inch SS. Each bracket-archwire combination was tested 10 times. In the test, 10 brackets of the same group were mounted in alignment on a metal bar. The archwires moved through all the 10 brackets at a crosshead speed of 0.5 mm/min (each run lasted approximately 5 min). The differences among 5 groups of brackets were analyzed through the Kruskal-Wallis test, and a Mann-Whitney test was calculated as post hoc analysis. The P value was set at 0.05. Results: Coupled with 0.014-inch NiTi and 0.016-inch NiTi, Victory Series© brackets generated the greatest F, while Damon MX© and Vision LP© brackets generated the lowest (P<.05); no significant differences were observed between Time3© brackets and Slide© ligatures. Coupled with all the rectangular archwires, Victory Series© brackets, Slide© ligatures, and Vision LP© self-ligating brackets generated significantly lower F than did Time3© and Damon MX© self-ligating brackets (P<.05). Conclusions: These findings suggest that self-ligating brackets are a family of brackets that, in vitro, can generate different levels of F when coupled with thin or thick, rectangular, or round archwires. Clinical conclusions based on our results are not possible due to the limitations of the experimental conditions. (Eur J Dent 2011;5:310-317)

scholarly journals The Effect of Chlorhexidine and Listerine® Mouthwashes on the Tensile Strength of Selected Absorbable Sutures: An In Vitro Study

2018 ◽  
Vol 2018 ◽  
pp. 1-8 ◽  
Author(s):  
Mohammed Alsarhan ◽  
Hourya Alnofaie ◽  
Rawan Ateeq ◽  
Ahmed Almahdy
Keyword(s):  
Tensile Strength ◽  
Artificial Saliva ◽  
Critical Role ◽  
Testing Machine ◽  
In Vitro Study ◽  
Vitro Study ◽  
Suture Materials ◽  
Experimental Conditions ◽  
Absorbable Sutures

Background. Suturing plays a critical role in the healing of surgical wounds. The tensile strength of suture materials indicates the ability of the material to withstand stress during knotting and protect the wound during an extended period of healing. Objective. An in vitro study was conducted to determine the effect of two commercially available mouthwashes on the tensile strength and breakage mode of two absorbable intraoral sutures. Materials and Methods. Two common absorbable sutures, Vicryl® and Monocryl®, both with 4-0 and 5-0 gauges were used. A total of 400 specimens were sutured around rubber rods and immersed in three thermostatically controlled experimental conditions: artificial saliva, 0.2% chlorhexidine gluconate (Parodontax® extra), and essential oils-based rinse (Listerine® Zero™), and these were compared to a nonimmersed dry condition. All specimens were stored in an incubator at 37°C. Tensile strengths were assessed after days 1, 3, 7, 10, and 14 of immersion using a universal Instron® testing machine. The maximum load for suture breakage and the location of the point of breakage were assessed. Results. Unlike Monocryl® 4-0, the tensile strength of both gauges of Vicryl® sutures significantly increased in chlorhexidine and Listerine®. There was a significant decrease in the strength for all suture types after day 10, regardless of the immersion solution. Listerine® significantly reduced the tensile strength of Monocryl® 5-0. Conclusion. Oral surgeons and periodontists should be cautious when prescribing commercial mouthwashes for patients relative to their selection of suture materials. However, further studies are needed to understand the molecular changes in sutures when exposed to chemical solutions found in mouthwashes.

scholarly journals COMPARATIVE EVALUATION OF WATER SORPTION AND SOLUBILITY OF DIFFERENT RESTORATIVE CEMENTS: AN IN-VITRO STUDY

2020 ◽  
pp. 1-4
Author(s):  
Gayatri Deshmukh ◽  
Anant A. Heda ◽  
Narendra U. Manwar ◽  
Shravan Rathi ◽  
Neelam Rahul ◽  
...  
Keyword(s):  
Water Sorption ◽  
Water Solubility ◽  
In Vitro Study ◽  
High Strength ◽  
Dry Mass ◽  
Distilled Water ◽  
Test Results ◽  
Gold Label ◽  
The Difference

Aim: The purpose of this study is to compare and evaluate the water sorption and solubility of ve different types of restorative cements, in order to show variations that may reduce their effectiveness. Materials and methods: Five discs each of ve different materials viz. Ketac Molar (3M ESPE), Universal Restorative 2 (GC Gold Label), Ionol plus (VOCO), High Strength Posterior Restorative 9 (GC Gold Label) and Cention-N (Ivoclar) were prepared. The discs were weighed individually on precision weight scale, dehydrated and weighed again after storing for 1 day at 37oC in 50 ml distilled water. Again, the discs were stored for a week in 50 ml of distilled water at 37oC. All the discs were weighed individually after 7 days, dehydrated and new weights were again recorded. Water solubility of material and its water sorption were obtained from the difference between the intial and the nal dry mass of each disc, after 1 day and 7 days of immersion in distilled water. Data was analyzed for signicant difference by one-way ANOVAand Tukey's test. Results: The water sorption values were minimal with Cention-N after 1 day followed by Ketac Molar, Ionol Plus, Universal Restorative 2 and High Strength Restorative 9; and after 7 days, water sorption values were minimal for High Strength Restorative 9 followed by Ketac Molar, Ionol Plus, Cention- N and Universal Restorative 2. The solubility values were minimal with Cention-N after 1 day and 7 days followed by Ionol plus, Ketac molar, High strength restorative 9 and Universal restorative 2. Conclusion: Among the tested restorative cements, water sorption was minimal with Cention –N after 1 day whereas it was minimal for High Strength Restorative 9 after 7 days. Solubility was minimal for Cention-N after 1 day and 7 days.

scholarly journals Degree of conversion and water sorption of self-adhesive and conventional flowable composites

2021 ◽  
Vol 19 ◽  
pp. e208556
Author(s):  
Ladan Ranjbar Omrani ◽  
Mahdi Abbasi ◽  
Fariba Motevasselian ◽  
Mohmad Amin Yektaei ◽  
Farhood Najafi
Keyword(s):  
Water Sorption ◽  
Artificial Saliva ◽  
Composite Resins ◽  
Degree Of Conversion ◽  
Flowable Composite ◽  
Significant Difference ◽  
Post Hoc ◽  
Flowable Composites ◽  
Vertise Flow

Aim: Self-adhesive flowable composite resins have been recently introduced to the market. Degree of conversion (DC) and water sorption (WS) are two important parameters affecting the properties of restorative materials. This study aimed to assess the DC and WS of a self-adhesive flowable composite resin in comparison with two conventional flowable composite resins. Methods: Vertise Flow (VF) self-adhesive and Tetric-N Flow (TF) and Grandio Flow (GF) conventional flowable composites were evaluated in this in vitro, experimental study. The DC (n=3) was determined by attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR). The WS (n=7) was measured after 7 days of immersion in artificial saliva according to ISO 4049 specifications. Data were analyzed by one-way ANOVA and a post-hoc test (p<0.05). Results: VF showed the highest DC percentage (84.3%) followed by GF (72.79%) and TF (68.7%). The latter two had no significant difference (p=0.8). WS was the highest in VF (55.2 μg/mm3), and the two conventional flowable composites had a significant difference in WS (19.5 μg/mm3 in TF and 11 μg/mm3 in GF; p<0.001). Conclusions: Flowable composite resins had significant differences in DC and WS, and VF demonstrated the highest DC and WS.

scholarly journals EFFECT OF ENERGY DRINK ON MICROHARDNESS OF DENTAL ENAMEL (IN VITRO)

2020 ◽  
Vol 6 (1) ◽  
pp. 32-41
Author(s):  
Prima Ulva ◽  
Idral Purnakarya ◽  
Arymbi Pudjiastuty
Keyword(s):  
Ph Value ◽  
Artificial Saliva ◽  
Dental Enamel ◽  
Energy Drink ◽  
Enamel Surface ◽  
Control Group ◽  
P Value ◽  
Control Group Design ◽  
Significant Difference

A prolonged acidic ambience of oral environment will lead to demineralization process. It caused erosion to enamel surface after long time of exposure.  Acidic beverages become the external factor of dental erosion. Energy drink is one of  popular beverages which has acid ingredients and pH value below the critical pH (5.5). The objective is to determine the effect of energy drink on microhardness of dental enamel (in vitro). Methods that were used in this study was experimental pre test - post test with control group design. A total of 36 premolar were used as samples which were divided into energy drink group and control group of artificial saliva. The treatment group were immersed for 8 cycle for 7 days. Dental enamel microhardness were measured by Vickers Hardness Tester before and after treatment. The result of this study was microhardness mean of enamel surface decreased from 306 VHN to 262 VHN after immersion for energy drink group and no significant difference in artificial saliva group. Independent T-test analysis showed p value <0,005, thus concluding there was significant difference between two groups. The conclusion of this study there was significant effect of energy drink immersion to dental enamel microhardness.

Observations of Frozen-Hydrated Microtubules

1990 ◽  
Vol 48 (1) ◽  
pp. 504-505
Author(s):  
D. Chrétien ◽  
D. Job ◽  
R.H. Wade
Keyword(s):  
Fourier Transforms ◽  
Structural Complexity ◽  
Image Contrast ◽  
Phase Behaviour ◽  
Experimental Conditions ◽  
Thin Sections ◽  
Surface Lattice ◽  
Cilia And Flagella ◽  
Outstanding Question

Microtubules are filamentary structures found in the cytoplasm of eukaryotic cells, where, together with actin and intermediate filaments, they form the components of the cytoskeleton. They have many functions and show various levels of structural complexity as witnessed by the singlet, doublet and triplet structures involved in the architecture of centrioles, basal bodies, cilia and flagella. The accepted microtubule model consists of a 25 nm diameter hollow tube with a wall made up of 13 paraxial protofilaments (pf). Each pf is a string of aligned tubulin dimers. Some results have suggested that the pfs follow a superhelix. To understand how microtubules function in the cell an accurate model of the surface lattice is one of the requirements. For example the 9x2 architecture of the axoneme will depend on the organisation of its component microtubules. We should also note that microtubules with different numbers of pfs have been observed in thin sections of cellular and of in-vitro material. An outstanding question is how does the surface lattice adjust to these different pf numbers?We have been using cryo-electron microscopy of frozen-hydrated samples to study in-vitro assembled microtubules. The experimental conditions are described in detail in this reference. The results obtained in conjunction with thin sections of similar specimens and with axoneme outer doublet fragments have already allowed us to characterise the image contrast of 13, 14 and 15 pf microtubules on the basis of the measured image widths, of the the image contrast symmetry and of the amplitude and phase behaviour along the equator in the computed Fourier transforms. The contrast variations along individual microtubule images can be interpreted in terms of the geometry of the microtubule surface lattice. We can extend these results and make some reasonable predictions about the probable surface lattices in the case of other pf numbers, see Table 1. Figure 1 shows observed images with which these predictions can be compared.

Superoxide, Xanthine Oxidase and Platelet Reactions: Further Studies on Mechanisms by which Oxidants Influence Platelets

1981 ◽  
Vol 45 (03) ◽  
pp. 290-293 ◽  
Author(s):  
Peter H Levine ◽  
Danielle G Sladdin ◽  
Norman I Krinsky
Keyword(s):  
Superoxide Dismutase ◽  
Cytochrome C ◽  
Xanthine Oxidase ◽  
Direct Effect ◽  
Platelet Function ◽  
Experimental Conditions ◽  
Release Reaction

SummaryIn the course of studying the effects on platelets of the oxidant species superoxide (O- 2), Of was generated by the interaction of xanthine oxidase plus xanthine. Surprisingly, gel-filtered platelets, when exposed to xanthine oxidase in the absence of xanthine substrate, were found to generate superoxide (O- 2), as determined by the reduction of added cytochrome c and by the inhibition of this reduction in the presence of superoxide dismutase.In addition to generating Of, the xanthine oxidase-treated platelets display both aggregation and evidence of the release reaction. This xanthine oxidase induced aggreagtion is not inhibited by the addition of either superoxide dismutase or cytochrome c, suggesting that it is due to either a further metabolite of O- 2, or that O- 2 itself exerts no important direct effect on platelet function under these experimental conditions. The ability of Of to modulate platelet reactions in vivo or in vitro remains in doubt, and xanthine oxidase is an unsuitable source of O- 2 in platelet studies because of its own effects on platelets.

Desmopressin (DDAVP) Enhances Platelet Adhesion to the Extracellular Matrix of Cultured Human Endothelial Cells through Increased Expression of Tissue Factor

1997 ◽  
Vol 77 (05) ◽  
pp. 0975-0980 ◽  
Author(s):  
Angel Gálvez ◽  
Goretti Gómez-Ortiz ◽  
Maribel Díaz-Ricart ◽  
Ginés Escolar ◽  
Rogelio González-Sarmiento ◽  
...  
Keyword(s):  
Extracellular Matrix ◽  
Endothelial Cells ◽  
Tissue Factor ◽  
Platelet Adhesion ◽  
Umbilical Vein ◽  
Procoagulant Activity ◽  
Experimental Conditions ◽  
Chromogenic Assay

SummaryThe effect of desmopressin (DDAVP) on thrombogenicity, expression of tissue factor and procoagulant activity (PCA) of extracellular matrix (ECM) generated by human umbilical vein endothelial cells cultures (HUVEC), was studied under different experimental conditions. HUVEC were incubated with DDAVP (1, 5 and 30 ng/ml) and then detached from their ECM. The reactivity towards platelets of this ECM was tested in a perfusion system. Coverslips covered with DD A VP-treated ECMs were inserted in a parallel-plate chamber and exposed to normal blood anticoagulated with low molecular weight heparin (Fragmin®, 20 U/ml). Perfusions were run for 5 min at a shear rate of 800 s1. Deposition of platelets on ECMs was significantly increased with respect to control ECMs when DDAVP was used at 5 and 30 ng/ml (p <0.05 and p <0.01 respectively). The increase in platelet deposition was prevented by incubation of ECMs with an antibody against human tissue factor prior to perfusion. Immunofluorescence studies positively detected tissue factor antigen on DDAVP derived ECMs. A chromogenic assay performed under standardized conditions revealed a statistically significant increase in the procoagulant activity of the ECMs produced by ECs incubated with 30 ng/ml DDAVP (p <0.01 vs. control samples). Northern blot analysis revealed increased levels of tissue factor mRNA in extracts from ECs exposed to DDAVP. Our data indicate that DDAVP in vitro enhances platelet adhesion to the ECMs through increased expression of tissue factor. A similar increase in the expression of tissue factor might contribute to the in vivo hemostatic effect of DDAVP.

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