scholarly journals TESTING OF THE FRACTURE RESISTANCE OF THE HEAT-CURING DENTURE BASE ACRYLIC RESIN

2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Aleksandra Maletin ◽  
Jovana Bastajić ◽  
Ivan Ristić ◽  
Branislava Petronijević Šarčev ◽  
Isidora Nešković ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Fracture Resistance ◽  
Acrylic Resin ◽  
Denture Base ◽  
Universal Testing ◽  
Heat Curing ◽  
Significant Difference ◽  
Student’S T ◽  
Student’S T Test

For many years, poly-methyl methacrylate has been used as a material of choice for making the denture base, thanks to its good and desirable performances, such as: simplicity in work, possibility of reparation, aesthetics and affordable price. Considering to its insufficient hardness and fracture resistance, there is a tendency to improve the mechanical properties of the material, by changing its basic composition. The aim of the research was to determine the fracture resistance of the heat-curing denture base acrylic resin materials. Materials and methods: For the research ,20 samples of the 2 heat-curing acrylics had been prepared, standard ones and reinforced acrylic resin material. After the storage in the saline for 15 days, measurements of the fracture resistance were performed by using the universal testing device. The data were statistically processed using the Student’s t-test for independent samples. Results: By measuring the flexural strength and deflection at breakage, it has been proven that there was, statistically, a significant difference of the flexural strength between reinforced (179.91-248.72MPa) and standard heat-curing acrylics (183.25- 200.74MPa). The deflection at breakage showed approximately the same values for both materials (1,0-1,4mm; 1.0-1.5mm). Conclusion: By enhancing the polymer, the mechanical properties of the denture base acrylic resin materials will be improved, primarily, higher fracture resistance, that means that these technologies need to be improved.

scholarly journals Effects of Denture Base Thicknesses and Reinforcement on Fracture Strength in Mandibular Implant Overdenture with Bar Attachment: Under Various Acrylic Resin Types

2019 ◽  
Vol 13 (01) ◽  
pp. 064-068
Author(s):  
Selen Tokgoz ◽  
Arda Ozdiler ◽  
Burc Gencel ◽  
Ergun Bozdag ◽  
Gulbahar Isık-Ozkol
Keyword(s):  
Fracture Strength ◽  
Fracture Resistance ◽  
Glass Fibers ◽  
Testing Machine ◽  
Acrylic Resin ◽  
Base Thickness ◽  
Denture Base ◽  
Significant Difference ◽  
Implant Overdenture ◽  
Student’S T

Abstract Objective This study aimed to assess the effect of reinforcement, denture base thickness, and acrylic resin types on dynamic and static fracture strength in mandibular implant overdentures with bar attachment. Materials and Methods One hundred and eight experimental mandibular implant overdentures with bar attachments were fabricated in three main groups, namely unreinforced (control: C), reinforced with unidirectional glass fibers (FR), and Co–Cr cast metal (MR). Each group included denture bases of 2-, 3-, and 4-mm thicknesses and produced with conventional (CA) and high-impact acrylic (HIA) resins. Specimens were thermocycled (5,000 times, 5–55°C) then subjected to a 400,000 cyclic load regime. Unbroken specimens were then loaded until fracture by a universal testing machine. Differences in mean fracture resistance among the groups were compared using the one-way analysis of variance (with post hoc Tukey's honestly significant difference test) and Student's t-tests (α = 0.05). Results Fracture strength increased significantly when the denture base thickness was increased (p = 0.001). The 2-mm denture base thickness was not enough for reinforcement. The fracture strength of the FR groups was significantly higher than other groups for 3- and 4-mm thicknesses (p = 0.001). The fracture strength of the HIA resin was significantly higher than CA resin in FR groups (p = 0.029 and p = 0.001). MR groups showed the weakest fracture strength. Conclusions The 2-mm denture base thickness had sufficient fracture strength without reinforcement and a positive relationship between acrylic resin thickness and fracture resistance was found.

scholarly journals Comparison of Mechanical Properties of PMMA Disks for Digitally Designed Dentures

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1745
Author(s):  
Tamaki Hada ◽  
Manabu Kanazawa ◽  
Maiko Iwaki ◽  
Awutsadaporn Katheng ◽  
Shunsuke Minakuchi
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Water Sorption ◽  
Water Solubility ◽  
Flexural Modulus ◽  
Manufacturing Method ◽  
Heat Curing ◽  
Significant Difference ◽  
Cad Cam ◽  
Curing Method

In this study, the physical properties of a custom block manufactured using a self-polymerizing resin (Custom-block), the commercially available CAD/CAM PMMA disk (PMMA-disk), and a heat-polymerizing resin (Conventional PMMA) were evaluated via three different tests. The Custom-block was polymerized by pouring the self-polymerizing resin into a special tray, and Conventional PMMA was polymerized with a heat-curing method, according to the manufacturer’s recommended procedure. The specimens of each group were subjected to three-point bending, water sorption and solubility, and staining tests. The results showed that the materials met the requirements of the ISO standards in all tests, except for the staining tests. The highest flexural strength was exhibited by the PMMA-disk, followed by the Custom-block and the Conventional PMMA, and a significant difference was observed in the flexural strengths of all the materials (p < 0.001). The Custom-block showed a significantly higher flexural modulus and water solubility. The water sorption and discoloration of the Custom-block were significantly higher than those of the PMMA-disk, but not significantly different from those of the Conventional PMMA. In conclusion, the mechanical properties of the three materials differed depending on the manufacturing method, which considerably affected their flexural strength, flexural modulus, water sorption and solubility, and discoloration.

scholarly journals Polytetrafluorethylene added to acrylic resins: mechanical properties

2010 ◽  
Vol 21 (1) ◽  
pp. 55-59 ◽  
Author(s):  
Fabiana Gouveia Straioto ◽  
Antonio Pedro Ricomini Filho ◽  
Alfredo Júlio Fernandes Neto ◽  
Altair Antoninha Del Bel Cury
Keyword(s):  
Mechanical Properties ◽  
Impact Strength ◽  
Flexural Strength ◽  
Flexural Modulus ◽  
Peak Load ◽  
Surface Hardness ◽  
Acrylic Resin ◽  
Denture Base ◽  
Standard Data ◽  
Acrylic Resins

The addition of different polymers, such as polytetrafluorethylene (PTFE), to denture base resins could be an option to modify acrylic resin mechanical properties. This study evaluated the surface hardness, impact and flexural strength, flexural modulus and peak load of 2 acrylic resins, one subjected to a long and another subjected to a short polymerization cycle, which were prepared with or without the addition of 2% PTFE. Four groups were formed according to the polymerization cycle and addition or not of PTFE. Forty specimens were prepared for each test (10 per group) with the following dimensions: hardness (30 mm diameter x 5 mm thick), impact strength (50 x 6 x 4 mm) and flexural strength (64 x 10 x 3.3 mm) test. The results of the flexural strength test allowed calculating flexural modulus and peak of load values. All tests were performed in accordance with the ISO 1567:1999 standard. Data were analyzed statistically by ANOVA and Tukey's test with the level of significance set at 5%. No statistically significant differences (p>0.05) were found for surface hardness. Flexural strength, impact strength and peak load were significantly higher (p<0.05) for resins without added PTFE. The flexural modulus of the acrylic resin with incorporated 2% PTFE polymerized by long cycle was significantly higher (p<0.05) than that of the other resins. Within the limits of this study, it may be concluded that the addition of PTFE did not improve the mechanical properties of the evaluated acrylic resins.

scholarly journals Effect of finishing and polishing methods on surface roughness of autopolymerized acrylic resins

2017 ◽  
Vol 65 (4) ◽  
pp. 303-307
Author(s):  
Gabriel Lúcio Calazans DUARTE ◽  
Angélica Kercya Pereira de MENDONÇA ◽  
Ana Roberta Assunção de FREITAS ◽  
Antônio Ricardo Calazans DUARTE ◽  
Julita de Campos Pipolo HOLANDA
Keyword(s):  
Surface Roughness ◽  
Acrylic Resin ◽  
T Test ◽  
Test Results ◽  
Acrylic Resins ◽  
Significant Difference ◽  
Student’S T ◽  
Student’S T Test

ABSTRACT Objective : To evaluate the surface roughness of two makes of autopolymerized acrylic resin (Classic Dencor® and Duralay®) with two different methods of finishing and polishing (conventional and using the Dhpro® finishing & polishing kit). Methods : A total of 20 specimens (10 of each make) was obtained using Zetalabor®--Zhermak condensation silicone molds. After polymerization, 20 blocks of resin were divided in two and subjected to two types of finishing and polishing, one at each end. The types of finishing and polishing were as follows: conventional (lathe) and using the Dhpro® finishing & polishing kit. Once finished and polished, the specimens were subjected to surface roughness testing using a roughness meter and were analyzed via the Student’s t-test. Results : There is a statistically significant difference between the forms of polishing, unrelated to the brand of acrylic resin. Conventional polishing achieved a level of 0.12 µm for both resins and the DhPro® polishing presented roughness a little above 0.2 µm. Conclusion : Conventional polishing is superior to the DhPro® kit, as it achieves lower levels of roughness. There is no significant difference between the acrylic resins in terms of surface roughness after the finishing and polishing processes.

scholarly journals Variations in Flexural Strength of Heat-polymerized Acrylic Resin after the Usage of Denture Cleansers

2016 ◽  
Vol 17 (4) ◽  
pp. 322-326 ◽  
Author(s):  
M Kalavathi ◽  
Mallikarjuna Ragher ◽  
G Vinayakumar ◽  
Sanketsopan Patil ◽  
Aishwarya Chatterjee ◽  
...  
Keyword(s):  
Flexural Strength ◽  
Testing Machine ◽  
Peak Load ◽  
Acrylic Resin ◽  
Control Group ◽  
Denture Base ◽  
Acrylic Resins ◽  
Significant Difference ◽  
Base Resin ◽  
Denture Cleansers

ABSTRACT Objective The objective of this study was to evaluate and compare changes in the flexural strength of heat-cured denture base resins when treated using denture cleansers. Study design A total of 40 specimens with dimension 65 mm length, 10 mm width, and 3 mm thickness were prepared as per ISO 1567 specification. A total of 10 specimens were immersed in distilled water to be used as control. Of the remaining 30 samples, 10 were treated with Clinsodent, 10 with VI-Clean, and 10 with Clanden denture cleansers. Specimens in each group were subjected to three-point flexural load in universal testing machine at a cross-head speed of 5 mm/min. The peak load (N) was recorded and flexural strength was calculated. The findings were analyzed using Kruskal–Wallis analysis of variance and Mann–Whitney test. Results Heat-cured denture base resin selected for this study showed significant difference in flexural strength after immersion in denture cleansers Clinsodent, VI-Clean, and Clanden solutions, when compared with the control group. Conclusion Findings of this study showed that denture cleansers altered the flexural strength of heat polymerized acrylic resins that endured soaking cycles which simulated 180 days of use. Hence, denture cleansers should be used with caution, once a day after brushing the dentures. It is advisable for patients to follow the manufacturer's instructions. How to cite this article Ragher M, Vinayakumar G, Patil S, Chatterjee A, Mallikarjuna DM, Dandekeri S, Swetha V, Pradeep MR. Variations in Flexural Strength of Heat-polymerized Acrylic Resin after the Usage of Denture Cleansers. J Contemp Dent Pract 2016;17(4):322-326.

scholarly journals The effect of nanoparticles TiO2 on the flexural strength of acrylic resin denture plate

2018 ◽  
Vol 30 (1) ◽  
pp. 35 ◽  
Author(s):  
Edwin Tandra ◽  
Endang Wahyuningtyas ◽  
Erwan Sugiatno
Keyword(s):  
Flexural Strength ◽  
Testing Machine ◽  
Base Material ◽  
Acrylic Resin ◽  
Control Group ◽  
Denture Base ◽  
Denture Plate ◽  
Significant Difference ◽  
Strength Difference ◽  
The One

Introduction: Acrylic resin is still the most commonly used denture base material due to its ideal properties. However, acrylic resin denture fractures are still considered a major unsolved problem thus the addition of nanoparticles as filler was performed to increase its mechanical properties. The purpose of this study was to discovered the effect of nanoparticles TiO2 on the flexural strength of acrylic resin denture plate. Method: This study used 27 heat-cured acrylic resin specimens sized 65 x 10 x 2.5 mm. The samples were divided into three concentration groups (n = 9), the control group; 1% of nanoparticles TiO2; and 3% of nanoparticles TiO2. The flexural strength was tested using the Universal Testing Machine. All data were analysed using the one-way ANOVA test with 95% confidence level then continued with the Least Significant Difference (LSD) test. Results: There were significant flexural strength differences in different concentration of nanoparticles TiO2. The highest flexural strength value was found in the 1% of nanoparticles TiO2 group (106.99 ± 6.09 MPa), whilst the lowest flexural strength value was found in the 3% of nanoparticles TiO2 group (91.64 ± 5.38 MPa). Significant flexural strength difference was found between the control group and the 1% of nanoparticles TiO2 group, and also between the 1% of nanoparticles TiO2 group with the 3% of nanoparticles TiO2 group (p < 0.05). Conclusion: From this study can be concluded that concentration of 1% of nanoparticles TiO2 was able to increase the flexural strength of acrylic resin denture plate.

scholarly journals Effect of Addition Of Zirconium Oxide Nanoparticles on Flexural Strength and Porosity of Heat Cure Acrylic Resin

2018 ◽  
Vol 2 (2) ◽  
pp. 96-119
Author(s):  
Ranj Omer ◽  
Fahd Ikram
Keyword(s):  
Flexural Strength ◽  
Zirconium Oxide ◽  
Pearson Correlation ◽  
Acrylic Resin ◽  
Oxide Nanoparticles ◽  
Denture Base ◽  
Heat Cure ◽  
Significant Difference ◽  
Removable Prosthesis ◽  
Zirconium Oxide Nanoparticles

Heat cure denture base is the most commonly used material for fabrication of removable prosthesis to the present day. However difficulties persist in fabrication of satisfactory prosthesis due to poor mechanical properties which have resulted in frequent repairs in dental practice. The present study is aimed to investigate the effect of Zirconium oxide nanoparticles (ZrO2NPs) on flexural strength and porosity of denture base and its correlation. X-ray diffraction (XRD) was used to check the purity of NPs. NPs was dispersed at 1%, 3% and 5% by weight to the monomer of methyl methacrylate with aid of probe sonicator. In addition, Scanning Electron Microscope (SEM) was used to observe agglomeration of particles within the acrylic. The results revealed significant flexural strength difference (p<0.05) between each concentration of ZrO2NPs. The analysis showed 17% and 11% reduction for 1% and 3% ZrO2NPs respectively while 5% caused a drastic reduction by 32% in reference to control. In regards to porosity, the results present no statistically significant difference among the concentrations in contrast to control. Pearson correlation showed strong and a negative relation (-0.83) between flexural strength and porosity. However, the results was not statistically significant (p=0.369). Within the limitations of this study, it can be concluded that the addition of ZrO2 caused reduction in flexural strength for all concentrations added. While it caused non-significant effect on porosity of acrylic. suitable additive to enhance the properties of PMMA.

scholarly journals 3D-Printed vs. Heat-Polymerizing and Autopolymerizing Denture Base Acrylic Resins

Materials ◽  
2021 ◽  
Vol 14 (19) ◽  
pp. 5781
Author(s):  
Leila Perea-Lowery ◽  
Mona Gibreel ◽  
Pekka K. Vallittu ◽  
Lippo V. Lassila
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Elastic Modulus ◽  
Flexural Strength ◽  
Water Solubility ◽  
Base Material ◽  
Acrylic Resin ◽  
Denture Base ◽  
3D Printed ◽  
Work Of Fracture

The aim of this work was to investigate the effect of two post-curing methods on the mechanical properties of a 3D-printed denture base material. Additionally, to compare the mechanical properties of that 3D-printed material with those of conventional autopolymerizing and a heat-cured denture base material. A resin for 3D-printing denture base (Imprimo®), a heat-polymerizing acrylic resin (Paladon® 65), and an autopolymerizing acrylic resin (Palapress®) were investigated. Flexural strength, elastic modulus, fracture toughness, work of fracture, water sorption, and water solubility were evaluated. The 3D-printed test specimens were post-cured using two different units (Imprimo Cure® and Form Cure®). The tests were carried out after both dry and 30 days water storage. Data were collected and statistically analyzed. Resin type had a significant effect on the flexural strength, elastic modulus, fracture toughness, and work of fracture (p < 0.001). The flexural strength and elastic modulus for the heat-cured polymer were significantly the highest among all investigated groups regardless of the storage condition (p < 0.001). The fracture toughness and work of fracture of the 3D-printed material were significantly the lowest (p < 0.001). The heat-cured polymer had the lowest significant water solubility (p < 0.001). The post-curing method had an impact on the flexural strength of the investigated 3D-printed denture base material. The flexural strength, elastic modulus, fracture toughness, work of fracture of the 3D-printed material were inferior to those of the heat-cured one. Increased post-curing temperature may enhance the flexural properties of resin monomers used for 3D-printing dental appliances.

scholarly journals ASSOCIATION BETWEEN SERUM URIC ACID AND METABOLIC SYNDROME

2018 ◽  
Vol 11 (10) ◽  
pp. 400 ◽  
Author(s):  
Thaslima Nandhini Js ◽  
Savitha Basker G ◽  
Vishnupriya V
Keyword(s):  
Metabolic Syndrome ◽  
Uric Acid ◽  
Venous Blood ◽  
Fasting Blood Glucose ◽  
Control Group ◽  
Serum Triglycerides ◽  
Significant Difference ◽  
Disease Condition ◽  
Student’S T ◽  
Student’S T Test

Objective: Metabolic syndrome is a cluster of disease condition characterized by truncal obesity, hypertriglyceridemia, elevated blood pressure, and insulin resistance. An excessive circulating uric acid (UA) level even within normal range is always comorbid with metabolic syndrome and its components. The aim of the current study was to investigate the association between metabolic syndrome and serum UA level.Methods: A total of 60 subjects were divided into two groups of healthy (30 individuals) and metabolic syndrome patients (30 individuals) from dental outpatient department of Saveetha Dental College and Hospitals. 5 ml of fasting venous blood was collected in the plain collection tubes and centrifuged, and then serum was separated. Then, the serum was used to analyze the fasting blood glucose, serum triglycerides (TGLs), and serum UA by GOD-POD, enzymatic colorimetric, and uricase method, respectively. A statistical analysis was performed using Student’s t-test. p<0.05 was considered to be statistically significant.Result: Mean body mass index (BMI), fasting blood sugar (FBS), TGL, and UA level of control group were 23.36±1.81, 84.45±13.1, 110.9±22.6, and 3.48±1.21 respectively. Mean BMI, FBS, TGL, and UA level of study group were 35.24±3.04, 122.85±23.3, 212.1±39.6 and 9.08±2.63 respectively. There is a significant difference between these two groups with p<0.0001.Conclusion: This study showed that those individuals with metabolic syndrome have higher UA level that indicates hyperuricemia which is a significant predictor of metabolic syndrome.

scholarly journals Effect of the ketoprofen on the preemptive analgesia in female cats undergoing to ovariohysterectomy

Revista CERES ◽  
2017 ◽  
Vol 64 (1) ◽  
pp. 18-24
Author(s):  
Dayvid Vianêis Farias de Lucena ◽  
Fernanda Vieira Henrique ◽  
Amara Gyane Alves de Lima ◽  
Almir Pereira de Souza ◽  
Pedro Isidro da Nóbrega Neto
Keyword(s):  
Statistical Analysis ◽  
Preemptive Analgesia ◽  
Pain Scores ◽  
Significant Difference ◽  
Reduction Of Pain ◽  
Baseline Values ◽  
Student’S T ◽  
Level Of Significance ◽  
Postoperative Administration ◽  
Student’S T Test

ABSTRACT The objective of this study was to investigate the effect of the ketoprofen on the preemptive analgesia in female cats submitted to ovariohysterectomy. Sixteen healthy cats were distributed into two groups, with eight animals each, by means of a draw, in a preemptive group (PREG), in which the animal received ketoprofen (1 mg/kg) subcutaneously two hours before the surgery; and postsurgery group (POSG), in which ketoprofen (1 mg/kg) was administered subcutaneously immediately after surgery. In both groups, ketoprofen was given 24, 48 and 72 hours after the first adminstration. Heart and respiratory frequencies and glycemia were measured in all animals during the days first ten postsurgery. Analgesia was measured by assigning scores at zero, two, four, six, 12, 24, 48, 72, 96, 120, 144, 168, 192, 216 and 240 hours after the surgical procedure. Statistical analysis was performed using two-way analysis of variance followed by Tukey's test to compare the moments and Student's t-test for comparison between groups. Pain scores were evaluated using test of U-Mann-Withney or Kruskall-Wallis, all at the 5% level of significance. Pain scores were significantly lower in PREG in M0, M6, M72, M96 and M120. No significant difference was found in the levels of glycemia in comparison to baseline values. Ketoprofen promotes postsurgery analgesia in female cats submitted to ovariohysterectomy and preemptive and postsurgery administration provides an earlier reduction of pain scores when compared to postoperative administration, only.

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