scholarly journals The Evaluation of Water Sorption/Solubility on Various Acrylic Resins

2008 ◽  
Vol 02 (03) ◽  
pp. 191-197 ◽  
Author(s):  
Suleyman Hakan Tuna ◽  
Filiz Keyf ◽  
Hasan Onder Gumus ◽  
Cengiz Uzun
Keyword(s):  
Water Sorption ◽  
Water Solubility ◽  
Pearson Correlation ◽  
Acrylic Resin ◽  
Mean Values ◽  
Dimensional Changes ◽  
Acrylic Resins ◽  
Heat Cure ◽  
Significant Difference ◽  
One Way Anova

ABSTRACTObjectives: The absorption of water by acrylic resins is a phenomenon of considerable importance since it is accompanied by dimensional changes, a further undesirable effect of absorbed water in acrylic resins to reduce the tensile strength of the material. Solubility is also an important property because it represents the mass of soluble materials from the polymers.Methods: Ten acrylic resin-based materials were evaluated: two heat cure acrylic resins (De Trey QC-20, Meliodent Heat Cure) and eight self cure acrylic resins (Meliodent Cold, Akrileks, Akribel, Akribel Transparent, Vertex Trayplast, Formatray, Dentalon Plus, Palavit G). To evaluate water sorption and water solubility, thirty square-shaped specimens (20×20×1.5 mm) were fabricated from the wax specimens. One way ANOVA test, Tukey test and Pearson correlation coefficient performed for data.Results: Water sorption mean values varied from 11.33±0.33 to 30.46±0.55 μg/mm3. Water solubility mean values varied from -0.05±0.23 to 3.69±0.12 �g/mm3. There was statistically significant difference between mean values of the materials (P<.05). There was no linear correlation between sorption and solubility values.Conclusions: The results of the water sorption and water solubility values of both self-cured and heat-cured acrylic resins were in accordance with the ISO specification. No correlation found between water sorption and water solubility values. (Eur J Dent 2008;2:191-197)

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 Influence of storage period and effect of different brands of acrylic resin on the dimensional accuracy of the maxillary denture base

2008 ◽  
Vol 19 (3) ◽  
pp. 204-208 ◽  
Author(s):  
Ana Carolina Miéssi ◽  
Marcelo Coelho Goiato ◽  
Daniela Micheline dos Santos ◽  
Stefan Fiúza de Carvalho Dekon ◽  
Ricardo Coelho Okida
Keyword(s):  
Storage Period ◽  
Dimensional Accuracy ◽  
Acrylic Resin ◽  
Microwave Energy ◽  
Denture Base ◽  
Significance Level ◽  
Dimensional Changes ◽  
Acrylic Resins ◽  
Significant Difference ◽  
Hot Bath

The aim of this study was to evaluate the dimensional changes of denture bases made from different resins after different storage periods. For this purpose, 25 sets of plaster models/resin bases were prepared using 4 acrylic resins submitted to two types of polymerization: 1- QC-20 submitted to polymerization by microwave energy; 2- QC-20 submitted to polymerization by water hot bath; 3- Vipi Cril submitted to polymerization by water hot bath; 4- Vipi Wave submitted to polymerization by microwave energy; and 5- Onda Cryl submitted to polymerization by microwave energy. After polymerization, the specimens were sectioned for accuracy readings using a comparison microscope. Readings were taken at 3 points: the crests of the right (A) and left (B) ridges, and the median region of the palate, in 4 different periods. The data obtained were submitted to two-way ANOVA and Tukey's test at 5% significance level. The greatest distortions were found in the posterior palatal region of the base (M), with statistically significant difference (p<0.05) for the studied resins. All acrylic resins presented dimensional changes and the storage period influenced these alterations.

scholarly journals Shear bond strength of novel calcium aluminate-based cement (EndoBinder) to root dentine

2014 ◽  
Vol 08 (04) ◽  
pp. 498-503 ◽  
Author(s):  
Lucas da Fonseca Roberti Garcia ◽  
Hebert Luis Rossetto ◽  
Fernanda de Carvalho Panzeri Pires-de-Souza
Keyword(s):  
Bond Strength ◽  
Calcium Aluminate ◽  
Shear Bond Strength ◽  
Testing Machine ◽  
Mineral Trioxide Aggregate ◽  
Acrylic Resin ◽  
Promising Alternative ◽  
Mean Values ◽  
Significant Difference ◽  
Molar Teeth

ABSTRACT Objective: To evaluate the shear bond strength of a novel calcium aluminate-based cement, EndoBinder (EB), to dentine in comparison with Grey and White Mineral Trioxide Aggregate (MTA). Materials and Methods: Root canal hemi-sections obtained from 30 extracted molar teeth were embedded in self-polymerized acrylic resin and were grounded wet in order to obtain a flat dentine surface. Next, the roots were randomly assigned into three groups (n = 10), according to the cement used, as follows: EB: EndoBinder; WMTA: White MTA and GMTA: Grey MTA. The shear bond strength test was performed using a Universal Testing Machine (0.5 mm/min) and the data were submitted to statistical analysis (1-way ANOVA and Tukey tests, P < 0.05). Results: EB presented the highest shear bond strength values; however, there was no statistically significant difference in comparison with GMTA (P > 0.05). WMTA presented the lowest mean values, which were significant in comparison with EB (P < 0.05). Conclusions: The novel calcium aluminate-based cement presented higher shear bond strength than WMTA, and should be considered as a promising alternative in endodontic therapy.

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.

Measurement of Calcaneal Angles and Its Clinical Significance in Han Chinese Adults in Northwest China

2021 ◽  
Author(s):  
Xianghui Dong ◽  
ZhanKui Jin ◽  
ZhengMing Sun ◽  
Jing Chen ◽  
YanHai Chang ◽  
...  
Keyword(s):  
Pearson Correlation ◽  
Age Groups ◽  
Han Chinese ◽  
Radiology Department ◽  
Reference Ranges ◽  
Chinese Adults ◽  
Mean Values ◽  
Plain Radiographs ◽  
Significant Difference ◽  
Ankle Joints

Abstract Objective We aimed to investigate differences in and trends of normal calcaneal angles among Han Chinese adults from different age groups to establish normal reference ranges of calcaneal angles in these age groups, thereby providing a theoretical basis and morphological reference for the treatment of calcaneal fractures. Methods We collected lateral plain radiographs (X-ray) of the normal ankle joints of 6,260 Han Chinese adults who visited the Radiology Department of Shaanxi Provincial People’s Hospital between November 2008 and December 2020 to measure the calcaneal angles, including the Böhler angle (BA), Gissane angle (GA), calcaneal pitch angle (CPA), posterior facet inclination angle (PFIA), and calcaneal-tibial angle (CTA). On this basis, we analyzed the calcaneal angles in different age groups to summarize the characteristics of normal calcaneal angles in Han Chinese adults. Results According to the lateral plain radiographs of the normal ankle joints of 6,260 (male: 3,380; female: 2,880) adults (mean age: 46.3 ± 18.2 ), the mean values of the BA, GA, CPA, PFIA, and CTA were 33.17° ± 6.08°, 114.99° ± 8.17°, 25.67° ± 4.72°, 64.35° ± 8.51°, and 91.59° ± 11.57°, respectively. Results of the Pearson correlation analysis suggested negative correlations between age and both BA and PFIA (P < 0.01, respectively) but a lack of correlation between age and the GA, CPA or CTA (P > 0.05, respectively). One-way analysis of variance (ANOVA) and the least significant difference (LSD) test showed that at above the age of 18, there were statistically significant differences both in the BA between different age groups and in the PFIA between different age groups above 41 years old. Conclusion In Han Chinese adults, there are significant differences in BA and PFIA between different age groups, with these calcaneal angles exhibiting a trend of decrease with age.

The Effect of Bleach Liquid and Household Cleaner on Surface Hardness and Roughness of Acrylic Base of Orthodontic Appliances

2021 ◽  
Author(s):  
Saeed Noorollahian ◽  
Farinaz Shirban ◽  
Vahid Mojiri
Keyword(s):  
Surface Roughness ◽  
Hydrochloric Acid ◽  
Sodium Hypochlorite ◽  
Surface Hardness ◽  
Acrylic Resin ◽  
Liquid Sodium ◽  
P Value ◽  
Orthodontic Appliances ◽  
Acrylic Resins ◽  
Significant Difference

Introduction: The daily use of orthodontic removable plates can interfere with the self-cleansing function of the mouth. Although various techniques have been proposed for cleaning removable orthodontic appliances, there is no consensus on the use of a safe method that preserves the physical properties of the appliance. This study aimed to investigate the effect of using hydrochloric acid (10%, for removal of mineral deposits) and sodium hypochlorite (5.25%, to remove organic matter and discolorations) on surface hardness and roughness of self-cure orthodontic acrylic resins. Materials & Methods: This cross-sectional laboratory study was conducted in the fall of 2017 at Isfahan University of Medical science and Isfahan University of Technology. In this study two orthodontic acrylic resins (Orthocryl® and Acropars®) were used. Eighty samples (12×10×3 mm) from each one were fabricated and divided into four groups (n = 20). Group 1: 15 minutes immersion in household cleaner liquid (Hydrochloric acid, 10%) followed by15 minutes immersion in household bleach liquid (Sodium Hypochlorite, 5.25%). In group 2, immersions were repeated just like group two times and in group 3, were done three times. Group 4 was as control and had no immersion. The surface hardness and roughness of samples were measured. Data were analyzed with Two Way ANOVA and the significance level was set at 0.05. Results: The number of immersion procedures did not significantly affect the surface hardness (p value = 0.958) and surface roughness (p value = 0.657) in the different study groups. There was no significant difference in the surface hardness between the two acrylic resin brands (p value = 0.077); however, Acropars acrylic resin samples exhibited significantly higher surface roughness compared to the Orthocryl acrylic resin samples(p value < 0.001). Conclusion: 15 minutes of immersion in 10% HCl, followed by 15 minutes of immersion in 5.25% NaOCl and repetition of the procedure three times did not significantly affect the surface hardness and roughness of self-cured acrylic resins.

scholarly journals Water sorption of heat-polymerized acrylic resins processed in mono and bimaxillary flasks

2006 ◽  
Vol 17 (2) ◽  
pp. 122-125 ◽  
Author(s):  
Carolina B. Meloto ◽  
Laís R. Silva-Concílio ◽  
Cristiane Machado ◽  
Margarete C. Ribeiro ◽  
Fábio A. Joia ◽  
...  
Keyword(s):  
Water Sorption ◽  
Acrylic Resin ◽  
Microwave Energy ◽  
Water Bath ◽  
Acrylic Resins ◽  
Energy Processing ◽  
Group 3 ◽  
Group 2 ◽  
Student’S T ◽  
Group 1

This study evaluated water sorption in heat-polymerized acrylic resins processed in monomaxillary flasks by water bath and in bimaxillary flasks by microwave energy and water bath. Fifty heat-polymerized acrylic resin specimens were fabricated according to the 12th specification of the American Dental Association and assigned to 3 groups: group 1 was processed by water bath in monomaxillary metallic flask; group 2 was processed by microwave energy in bimaxillary PVC flask; and group 3 was processed by water bath in bimaxillary metallic flask. Specimens were submitted to water sorption test, means were calculated and analyzed statistically by Student's t-test. Means (in g/cm³) were: group 1 - 0.024085, group 2 - 0.025312 and group 3 - 0.022098. Microwave energy processing and the amount of stone and resin used in the bimaxillary PVC flask did not influence water sorption; specimens processed in bimaxillary metallic flask by water bath presented lower water sorption means, suggesting an inadequate polymerization of the acrylic resin mass.

scholarly journals Influence of Different Concentration and Ratio of a Photoinitiator System on the Properties of Experimental Resin Composites

2017 ◽  
Vol 28 (6) ◽  
pp. 726-730 ◽  
Author(s):  
Caio Vinícius Signorelli Grohmann ◽  
Eveline Freitas Soares ◽  
Eduardo José Carvalho Souza-Junior ◽  
William Cunha Brandt ◽  
Regina Maria Puppin-Rontani ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Elastic Modulus ◽  
Flexural Strength ◽  
Tertiary Amine ◽  
Water Sorption ◽  
Water Solubility ◽  
Distilled Water ◽  
Resin Composites ◽  
Amine Concentration ◽  
One Way Anova

Abstract The aim in this study was to evaluate the influence of different ratio of camphorquinone/tertiary amine concentration on the flexural strength (FS), elastic modulus (EM), degree of conversion (DC), yellowing (YL), water sorption (WS) and water solubility (WSL) of experimental composites. Thus, acrylate blends were prepared with different camphorquinone (CQ) and amine (DABE) concentrations and ratios by weight: (CQ/DABE%): 0.4/0.4% (C1), 0.4/0.8% (C2), 0.6/0.6% (C3), 0.6/1.2% (C4), 0.8/0.8% (C5), 0.8/1.6% (C6), 1.0/1.0% (C7), 1.0/2.0% (C8), 1.5/1.5% (C9), 1.5/3.0% (C10). For the FS and EM, rectangular specimens (7x2x1 mm, n=10) were photo-activated by single-peak LED for 20 s and tested at Instron (0.5 mm/min). Then, the same specimens were evaluated by FTIR for DC measurement. For YL, disks (5x2 mm, n=10) were prepared, light-cured for 20 s and evaluated in spectrophotometer using the b aspect of the CIEL*a*b* system. For WS and WSL, the volume of the samples was calculated (mm³). For WS and WSL, composites disks (5x0.5 mm, n=5) were prepared. After desiccation, the specimens were stored in distilled water for 7 days and again desiccated, in order to measure the WS and WSL. Data were submitted to one-way ANOVA and Tukey’s test (5%). The groups C8, C9 and C10 showed higher DC, EM and YL means, compared to other composites. Therefore, the FS and WS values were similar among all groups. Also, C1, C2 and C3 presented higher WSL in 7 days, compared to other composites. In general, higher concentrations of camphorquinone promoted higher physical-mechanical properties; however, inducing higher yellowing effect for the experimental composites

scholarly journals Effects of prophylactic ketamine and pethidine to control postanesthetic shivering: A comparative study

2018 ◽  
Vol 5 (12) ◽  
pp. 2898-2903 ◽  
Author(s):  
Masoum Khoshfetrat ◽  
Ali Rosom Jalali ◽  
Gholamreza Komeili ◽  
Aliakbar Keykha
Keyword(s):  
Normal Saline ◽  
Pearson Correlation ◽  
Saline Group ◽  
Normal Saline Group ◽  
Chi Square ◽  
Double Blind ◽  
Postanesthetic Shivering ◽  
Significant Difference ◽  
The Mean ◽  
One Way Anova

Background: Shivering is an undesirable complication following general anesthesia and spinal anesthesia, whose early control can reduce postoperative metabolic and respiratory complications. Therefore, this study aims to compare the effects of prophylactic injection of ketamine and pethidine on postoperative shivering. Methods: This double-blind clinical trial was performed on 105 patients with short-term orthopedic and ENT surgery. The patients were randomly divided into three groups; 20 minutes before the end of the surgery, 0.4 mg/kg of pethidine was injected to the first group, 0.5 mg/kg of ketamine was injected to the second group, and normal saline was injected to the third group. After the surgery, the tympanic membrane temperature was measured at 0, 10, 20, and 30 minutes. The shivering was also measured by a four-point grading from zero (no shivering) to four (severe shivering). Data were analyzed by one-way ANOVA, Kruskal Wallis, Chi-square and Pearson correlation. Results: The mean age of patients was 35.8+/-11.45 years in the ketamine group, 34.8+/-11.64 years in the normal saline group, and 33.11+/-10.5 years in the pethidine group. The one-way ANOVA showed no significant difference in the mean age between the three groups (P=0.645). The incidence and intensity of shivering were significantly higher in the normal saline group than in the ketamine and pethidine groups (p=0.001). However, there was no significant difference in the incidence and the intensity of shivering between the ketamine and the pethidine groups (p=0.936). Conclusion: The results showed that the 0.5 mg/kg of ketamine could control the post-anesthetic shivering.  

scholarly journals Bond Strength of Repaired Acrylic Denture Teeth Using Visible Light Cure Composite Resin

2017 ◽  
Vol 11 (1) ◽  
pp. 57-64 ◽  
Author(s):  
Saja Ali Muhsin
Keyword(s):  
Bond Strength ◽  
Visible Light ◽  
Composite Resin ◽  
Acrylic Resin ◽  
P Value ◽  
Chemical Agents ◽  
Denture Teeth ◽  
Significant Difference ◽  
One Way Anova ◽  
Shear Tester

Background: Although bonding to denture teeth after surface treatment with chemical agents is desirable, there is little information on the use of Visible Light Cure composite resin (VLC) as bonding denture materials. Objectives: To determine the effect of various surface treatments on shear bond strength between Visible Light Cure composite resin and the acrylic denture teeth interface. Methods: Forty cylindrical sticks of acrylic resin with denture teeth mounted atop were prepared. Various treatments were implemented upon the acrylic resin teeth surfaces. The samples were divided into four groups (n = 10). Light-cured composite resin (LC) was applied over all treated and untreated surfaces of tested groups. The shear bond was tested using a universal tensile testing apparatus with the knife-edge of a 0.8mm shear tester. Data were statistically analyzed using one-way ANOVA performed at a confidence level of 95% and significant P-value of (P ≤ 0.05). Results: Analysis of variance (ANOVA) showed statistically significant difference (P < 0.05) between treated and untreated teeth surfaces. The treated surfaces exhibited various levels of bond strength depending on the type of treatment. Conclusion: Application of VLC bonding agent with prior treatment of methylmethacrylate (MMA) on the acrylic resin denture teeth resulted in maximum bond strength with composite resin.

Sign in / Sign up

Export Citation Format

Share Document