Thermogravimetric Characterization of the Microstructure Composition of Polyamide Injection Molded Denture Base Material vs Conventional Compression Molded Heat-cured Denture Base Material

2016 ◽  
Vol 17 (2) ◽  
pp. 99-104 ◽  
Author(s):  
Ayman Al-Dharrab ◽  
Lana Shinawi
Keyword(s):  
Weight Loss ◽  
Base Material ◽  
Thermoplastic Resin ◽  
Denture Base ◽  
Excellent Thermal Stability ◽  
Rapid Injection ◽  
Group I ◽  
Injection Molded ◽  
Group Ii

ABSTRACT Background Thermoplastic resin polymers are widely used in medicine due to their biostability and hypoallergenic properties, making them a possible alternative to poly-methylmethacrylate (PMMA). The current research examined the microstructure of a rapid injection molding system thermoplastic resin for construction of flexible denture compared with that of heatcured PMMA. Materials and methods A total of 40 disk-shaped specimens (25 mm in diameter and 3 mm in thickness) were prepared and divided into two groups of 20 disks each (group I samples were of thermoplastic acrylic resin while group II was heat-cured PMMA resin). Results In group I, thermogravimetric analyzer showed that increasing the temperature up to 169°C resulted in about 1.3% of the material loss, and after that the material remains thermally stable up to 200°C. Group II showed 2.24% weight loss at 171°C, and further weight loss (12.025%) was observed on heating to 230°C. Fourier transform infrared (FTIR) spectrophotometer analysis in the range of 400–4000 cm-1 detected the presence of an amine group (N-H) in group I samples and the presence of methylene group attached to inorganic Si as reinforcement filler (Si-CH3). Conclusion Thermoplastic resin displayed excellent thermal stability and the absence of residual monomer within the polymerized material, suggesting its suitability for the fabrication dentures. How to cite this article Al-Dharrab A, Shinawi L. Thermogravimetric Characterization of the Microstructure Composition of Polyamide Injection Molded Denture Base Material vs Conventional Compression Molded Heat-cured Denture Base Material. J Contemp Dent Pract 2016;17(2):99-104.

scholarly journals AB1062 LIPODERMATOSCLEROSIS AS A TYPE OF LOBULAR PANNICULITIS: THE EFFECTIVENESS OF NON-PHARMACOLOGICAL TREATMENT METHODS

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 1821.1-1821
Author(s):  
M. Sukhareva ◽  
O. Egorova ◽  
B. Belov
Keyword(s):  
Subcutaneous Fat ◽  
Lymphatic Drainage ◽  
Normal Body Mass Index ◽  
Positive Trend ◽  
Group I ◽  
Positive Clinical Effect ◽  
Group Ii ◽  
The Cost ◽  
Lobular Panniculitis

Background:In medical practice lobular panniculitis-lipodermatosclerosis (LDS) is becoming more and more common. It is manifested by degenerative-dystrophic changes in subcutaneous fat (SCF) and occurs more often in middle-aged women affected by chronic venous insufficiency.Objectives:to evaluate the effectiveness of mesotherapy (MT) and shockwave ultrasound therapy (UST) for LDSMethods:among 539 patients referred to the V.A. Nasonova Research Institute of Rheumatology with the referral diagnoses of erythema nodosum or panniculitis 8.5% (46) of patients (44 women, 2 men) aged 18 to 82 with overweight (32) LDS with the disease duration of 11,8±6.4 months was verified. Patients were randomized into two groups of 23 patients each: group I received daily MT (10 sessions) therapy with drugs that have antioxidant, anti-inflammatory, lymphatic drainage and lipolytic effects, and 3 MHz UST of the node area twice a week (5 sessions). In group II MT was performed daily with 9% Natrii chloridum solution at a dose comparable to group I. The control methods included general clinical examination (characterization of induration on the lower legs with an assessment of the effect of pain pressing according to visual analogue scale (VAS pain), general blood and urine tests and ultrasound with elastography (USE) of the compaction. The main stages of control: initial (T0), after 14 days (T1), 1 month (T2) and 3 months (T3).Results:before treatment 38 patients with LDS demonstrated asymmetric (83%) inflammation of SCF of the lower legs (100%) on its medial surface (91%). LDS regressed faster with normal body mass index (p = 0,04). In all patients of group I, after a course of physiotherapy a positive trend was registered, that is a decrease in VAS pain intensity (T0 50±18 mm; T1 35±11 mm), decrease in diameter (T0 6±2.2 cm; T1 4.5±1, 7 mm) and color intensity of the node (p<0.002), SCF thickening which results in “lumping” with macrovascularization according to USE, and decrease in ESR and CRP. In 44% of cases the treatment effect increased to T2 (p <0.05). After 3 months of observation, 15 patients required a second course of physiotherapy. In group II a positive clinical effect was registered for T2 in 14 patients (60.8%) and for T3 in 19 patients (83%) (p<0.05). Over the entire observation period LDS recurrence was registered in 19 patients (41%), the median of recurrence was 3 [1; 6] months, mainly in patients of group I. Recurrence was associated with node fusion into conglomerates (OR 4.33, 95% CI 1.05-17.8; p = 0.037). MT and UST were tolerated well, no side effects were detected.Conclusion:the use of MT with 9% Natrii chloridum solution allowed us to achieve positive dynamics in patients with LDS, which significantly reduced the cost of treatment. Further studies are needed to evaluate the significance of these techniques.Disclosure of Interests:None declared

Heterogeneity of the εγδβ Thalassemias: Characterization of 3 Novel English Deletions.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3609-3609
Author(s):  
Helen Rooks ◽  
Jean Bergounioux ◽  
Laurence Game ◽  
James P. Close ◽  
Steve Best ◽  
...  
Keyword(s):  
Gene Cluster ◽  
Olfactory Receptor ◽  
De Novo ◽  
Globin Gene ◽  
Inherited Disorders ◽  
Chromosome 11P15 ◽  
Globin Gene Cluster ◽  
Group I ◽  
Group Ii

Abstract The thalassemias are inherited disorders classified genetically into α, β, γ, δβ, δ and εγδβ varieties according to the type of globin(s) that are underproduced. At the molecular level, the εγδβ thalassemias fall into two categories; Group I removes all, or a greater part, of the β globin gene cluster which is embedded in an array of olfactory receptor genes on chromosome 11p15. Group II removes extensive upstream regions leaving the β globin gene itself intact despite which, its expression is silenced due to inactivation of the upstream locus control region (β LCR). Recently, two novel deletions causing εγδβ thalassemia have been reported; a 153 kb deletion removing the entire β globin cluster in a Chilean family (Game, L., et al., Br J Haematol2003, 123:154–9) and an upstream deletion of 112 kb in a Dutch family (Dutch III) (Harteveld, C.L., et al., Br J Haematol2003,122: 855–8). We describe here the characterization of another three novel εγδβ thalassemia deletions, in three English families, named English II, III and IV, to differentiate them from the previously reported English (I) deletion (Curtin, P., et al., J Clin Invest1985, 76: 1554–8). Deletion English II removed 98 kb extending 90 kb upstream of the ε gene to 8 kb upstream of the Gγ gene, and included 4 upstream olfactory receptor (HOR) genes. Deletion English III removed 114 kb extending 60 kb upstream of the ε gene to 9 kb downstream of the β globin gene, thus including the entire β globin gene cluster as well as two upstream HOR genes. English IV is the largest deletion (439 kb) reported so far; starting 326 kb upstream of the ε gene to 70 kb downstream of the β gene and included 13 upstream, and 3 downstream, HOR genes plus the intervening β globin gene cluster. Breakpoints of all the 3 deletions occurred within regions of L1 or Alu repeat elements and contained short regions of direct homology between the flanking sequences, a feature that is likely to have contributed to the illegitimate recombinations. Deletions English II and III appear to be de novo while English IV is not. The proband for the English IV deletion had neonatal hemolytic anemia and required blood transfusions while 3 other family members who were heterozygous for the same deletion, had uneventful post-natal periods. The English III proband also required a blood transfusion soon after birth while the English II proband did not. Although in later life, heterozygotes for εγδβ thalassemia are transfusion-independent, and have a blood picture typical of β thalassemia trait but with normal Hb A2 levels, our data suggest that heterozygotes for εγδβ thalassemias have more severe microcytosis and hypochromia than β thalassemia carriers. To date, a total of 15 deletions causing εγδβ thalassemia have been described - five upstream deletions (Group II) associated with intact β globin genes and ten (Group I) that include the entire β globin gene cluster. These deletions are all unique and illustrate the heterogeneity of the εγδβ thalassemias.

scholarly journals CHEMICAL CHARACTERIZATION OF GLYCOPEPTIDES FROM HUMAN γM-GLOBULINS

1968 ◽  
Vol 128 (4) ◽  
pp. 699-713 ◽  
Author(s):  
Joseph M. Davie ◽  
C. Kirk Osterland
Keyword(s):  
Molecular Weight ◽  
Sialic Acid ◽  
Gel Filtration ◽  
Chemical Characterization ◽  
Carbohydrate Composition ◽  
Total Percentage ◽  
Group I ◽  
Group Ii ◽  
Group 1

A survey of human pathological macroglobulins revealed that γM can be divided into at least two groups on the basis of carbohydrate composition. Differences between the two groups exist in the total percentage of carbohydrate (10.69 ± 1.49% for group 1, 7.71 ± 0.65% for group II) which is attributable to variation in hexose content. Glycopeptides from macroglobulins of each group were purified from pronase digests and characterized chemically. Macroglobulins from each group contain three types of oligosaccharides. Glycopeptide I for each group consisted of mannose, galactose, and NAG with a ratio of 3:2:1 for group I and a ratio of 2:1:2 for group II. Glycopeptide II consisted of mannose, galactose, and NAG (9:1:2) for group I, and mannose, fucose, galactose, and NAG (2:1:3:2) for group II. Glycopeptide III in both groups consisted of mannose, fucose, galactose, NAG, and sialic acid with a ratio of 6:2.5:2.5:5.5:2 for group I and a ratio of 5:1:1:6:1 for group II. Molecular weight estimations by gel filtration indicates that there are 10 glycopeptides I and II and 20 units of glycopeptide III per molecule of γM.

scholarly journals The transversal strength comparison between polyethylene and glass fiber as an acrylic resin denture plate repair material

2019 ◽  
Vol 1 (1) ◽  
pp. 35
Author(s):  
Pramudya Aditama ◽  
Erwan Sugiatno ◽  
Sabdayana Sabdayana
Keyword(s):  
Glass Fiber ◽  
Glass Fibers ◽  
Testing Machine ◽  
Base Material ◽  
Acrylic Resin ◽  
Repair Material ◽  
Denture Base ◽  
Transverse Strength ◽  
Group I ◽  
Denture Plate

Acrylic resin is the most commonly used denture base material. However, it has a shortage of being easily broken. One way to resolve this problem is by adding polyethylene (PE) or glass fibers. The purpose of this research is to compare the transversal strength of PE and glass fibers from denture plate acrylic resin repair material. The experiment involved 32 plates of heat cure acrylic with the dimensions of 65 mm x 10 mm x 2.5 mm. The speciments were prepared to create a 3 mm gap and 45° bevel. Subjects were divided into 2 groups, each group containing 16 plates. Group I was reinforced with PE fiber and Group II was reinforced with glass fiber. All plates were soaked in distillation water for one day at 37 °C. Plates were tested for transverse strength with universal testing machine and all data were analyzed with independent t-tes at 95% confidence level. Macro photo analysis was used to observed the bond failure on fiber and resin. The mean of transverse strength (MPa) denture plate acrylic resin repair material reinforced with PE fiber was (67.38 ± 4.31) MPa, while glass fiber was (93.61 ± 6.14) MPa. Independent t-tes showed that type of fiber had a significant effect (p<0.05). Thus, it is possible to conclude that addition of glass fibers in denture plate acrylic resin repair material increased the transverse strength and made it stronger than those added with PE fibers.

scholarly journals Coronary Atherosclerotic Plaque Vulnerability Rather than Stenosis Predisposes to Non-ST Elevation Acute Coronary Syndromes

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Mohamed Laimoud ◽  
Farouk Faris ◽  
Helmy Elghawaby
Keyword(s):  
Stable Angina ◽  
Acute Coronary Syndromes ◽  
Syntax Score ◽  
Atherosclerotic Lesions ◽  
Group I ◽  
Coronary Syndromes ◽  
St Elevation ◽  
Coronary Lesions ◽  
Group Ii

Background. Non-ST elevation acute coronary syndromes (NSTE-ACS) may arise from moderately stenosed atherosclerotic lesions that suddenly undergo transformation to vulnerable plaques complicated by rupture and thrombosis. Objective. Assessment and tissue characterization of the coronary atherosclerotic lesions among NSTE-ACS patients compared to those with stable angina. Methodology. Evaluation of IVUS studies of 312 coronary lesions was done by 2 different experienced IVUS readers, 216 lesions in 66 patients with NSTE-ACS (group I) versus 96 lesions in 50 patients with stable angina (group II). Characterization of coronary plaques structure was done using colored-coded iMap technique. Results. The Syntax score was significantly higher in group I compared to group II (18.7 ± 7.8 vs. 8.07 ± 2.5, p=0.001). Body mass index (BMI) was significantly higher in group II while triglycerides levels were higher in group I (P=0.01 & P=0.04, respectively). History of previous MI and PCI was significantly higher in group I (P=0.016 & P=0.001, respectively). The coronary lesions of NSTE-ACS patients had less vessel area (9.86 ± 3.8 vs 11.36 ± 2.9, p=0.001), stenosis percentage (54.7 ± 14.9% vs 68.6 ± 8.7%, p=0.001), and plaque burden (54.4 ± 14.7 vs 67.8 ± 9.8, p=0.001) with negative remodeling index (0.95 ± 20 vs 1.02 ± 0.14, p=0.008) compared to the stable angina group. On the other hand, they had more lipid content (21.8 ± 7.03% vs 7.26 ± 3.47%, p=0.001), necrotic core (18.08 ± 10.19% vs 15.83 ± 4.9%, p=0.02), and calcifications (10.4 ± 5.2% vs 4.19 ± 3.29%, p=0.001) while less fibrosis (51.67 ± 7.07% vs 70.37 ± 11.7%, p=0.001) compared to the stable angina patients. Syntax score and core composition especially calcification and lipid content were significant predictors to NSTE-ACS. Conclusions. The vulnerability rather than the stenotic severity is the most important factor that predisposes to non-ST segment elevation acute coronary syndromes. The vulnerability is related to the lesion characteristics especially lipidic core and calcification while lesion fibrosis favours lesion stability.

scholarly journals Isolation and characterization of β- and γ-caseins from horse milk

1982 ◽  
Vol 203 (1) ◽  
pp. 131-139 ◽  
Author(s):  
S Visser ◽  
R Jenness ◽  
R J Mullin
Keyword(s):  
Room Temperature ◽  
Sodium Dodecyl ◽  
Sulphate Group ◽  
Group Iii ◽  
Isolation And Characterization ◽  
Group I ◽  
Beta Casein ◽  
Group Ii ◽  
Phosphate Groups

Three groups of casein components were isolated from horse milk. Group I is almost insoluble at acid and neutral pH, and is rather heterogeneous on alkaline gels with or without sodium dodecyl sulphate. Group II shows strong similarity to beta-casein from other species, as concluded from its amino acid composition and its N- and C-terminal sequences. This group consists of five electrophoretically distinguishable forms, all containing ester phosphate groups but no carbohydrate. Group III is composed of C-terminal fragments of the beta-like (group II) fraction and probably arises from the action of a plasmin-like enzyme present in horse milk. It does not contain phosphate or carbohydrate. Homology of this group with bovine gamma-caseins is demonstrated. Both beta- and gamma-like caseins are more soluble at 4 degrees C than at room temperature.

scholarly journals The comparison of color stability between thermoplastic nylon resin and heat-cured acrylic resin after tea-soaking using spectrophotometer

2009 ◽  
Vol 21 (3) ◽  
Author(s):  
Lisa Putri Lestari ◽  
Kosterman Usri ◽  
Renny Febrida
Keyword(s):  
Base Material ◽  
Color Stability ◽  
Acrylic Resin ◽  
Colour Stability ◽  
Thermoplastic Resin ◽  
Denture Base ◽  
Material Requirement ◽  
System Data ◽  
Materials Used ◽  
Tea Drinking

Color stability is one of the denture base material requirement. Nowadays, nylon thermoplastic resin and heat-cured acrylic resin which is used as denture base materials can be changed in colour. One of a colour-changed factor is the tea drinking habit. The objective of this research was to compare the colour stability between nylon thermoplastic resin and heat-cured acrylic resin after soaked in tea. Materials used for the research were nylon thermoplastic resin from Valplast and heat-cured acrylic resin QC-20, with a sample size of 64x(10±0.03)x(2.5±0.03)mm. The sample would be assessed of colour stability after the denture base soaked in tea for 7 days. The colour measurement of each sample was done by spectrophotometer equipment (CIE lab system). Data gathered later on statistically processed with ANOVA testing. The result showed that the comparison ratio of colour stability between nylon thermoplastic resin and heat-cured acrylic resin after soaked in tea was 1.9886:1.1152. The conclusion was that colour stability in the nylon thermoplastic resin was lower than heat-cured acrylic resin after soaked in tea. This result was due to a polymer chain of nylon thermoplastic which was lower than heat-cured acrylic resin and its porosity which was higher, so tea easily soaked into the materials.

scholarly journals Effect of microwave treatments on dimensional accuracy of maxillary acrylic resin denture base

2005 ◽  
Vol 16 (2) ◽  
pp. 119-123 ◽  
Author(s):  
Sabrina Pavan ◽  
João Neudenir Arioli Filho ◽  
Paulo Henrique dos Santos ◽  
Francisco de Assis Mollo Jr.
Keyword(s):  
Dimensional Accuracy ◽  
Acrylic Resin ◽  
Microwave Treatment ◽  
Control Group ◽  
Denture Base ◽  
Group Iii ◽  
Dental Prostheses ◽  
Group I ◽  
Group Ii ◽  
Cycle Group

Microwave energy has been used as an alternative method for disinfection and sterilization of dental prostheses. This study evaluated the influence of microwave treatment on dimensional accuracy along the posterior palatal border of maxillary acrylic resin denture bases processed by water-bath curing. Thirty maxillary acrylic bases (3-mm-thick) were made on cast models with Clássico acrylic resin using routine technique. After polymerization and cooling, the sets were deflasked and the bases were stored in water for 30 days. Thereafter, the specimens were assigned to 3 groups (n=10), as follows: group I (control) was not submitted to any disinfection cycle; group II was submitted to microwave disinfection for 3 min at 500 W; and in group III microwaving was done for 10 min at 604 W. The acrylic bases were fixed on their respective casts with instant adhesive (Super Bonder®) and the base/cast sets were sectioned transversally in the posterior palatal zone. The existence of gaps between the casts and acrylic bases was assessed using a profile projector at 5 points. No statistically significant differences were observed between the control group and group II. However, group III differed statistically from the others (p<0.05). Treatment in microwave oven at 604 W for 10 min produced the greatest discrepancies in the adaptation of maxillary acrylic resin denture bases to the stone casts.

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