Effect of Interchanging Liquid Components of Two Auto-Polymerizing Orthodontic Acrylic Resins in their Flexural Properties

2014 ◽  
Vol 1025-1026 ◽  
pp. 797-802 ◽  
Author(s):  
Tassanaporn Saen-Isara ◽  
Surachai Dechkunakorn ◽  
Niwat Anuwongnukroh ◽  
Toemsak Srikhirin ◽  
Siriporn Tanodekaew

Objective: To evaluate the effects of interchanging the liquid components of two commercially available orthodontic auto-polymerizing acrylic resin in their flexural properties, clarity and setting time

Author(s):  
Amin Khaleghi ◽  
Malihe Taghizadeh ◽  
Mohsen Hormozi

Introduction: The purpose of this study was to investigate and compare the dimensional changes in the acrylic patterns that were stored in the different times and conditions of storage. Materials& Methods: In this experimental study The sample number was 28 in 4 groups. The mixed paste of acrylic samples were placed inside a metal mold and after setting time with the slightest of deformations it was removed. Using this method 28 samples were prepared for each material. The diameters of samples were then measured immediately using a digital caliper with a precision of 0.01 mm. The samples were then divided into four quadruple groups and stored at 22° C room temperature, 22° Cat water, Dry 4° C environment and 4° C water. The dimensions of the four groups were measured at intervals of 1, 8, 24, and 48 hours after polymerization and being removed from the metal molds. The ANOVA test was used for data analysis (p value = 0.05). Results: The findings of the current study showed that the dimensional changes of Duralay and GC acrylic resins at both 4 and 22° C in dry and water environments are decreasing over time (p value < 0.001). This study indicated that the contraction rate of two types of acrylic resins, Duralay and GC, at two temperatures of 4 and 22° C, and dry and humid conditions and at various times were not different. Conclusion: Dimensional changes in of the two types of acrylic resin, Duralay and GC, During the lapse, the procedure is going to be decreased but have not seen any statistical difference between these type of acrylic resin in environment storage.


Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1234
Author(s):  
António Sérgio Silva ◽  
Aurora Carvalho ◽  
Pedro Barreiros ◽  
Juliana de Sá ◽  
Carlos Aroso ◽  
...  

Thermal and self-curing acrylic resins are frequently and versatilely used in dental medicine since they are biocompatible, have no flavor or odor, have satisfactory thermal qualities and polishing capacity, and are easy and fast. Thus, given their widespread use, their fracture resistance behavior is especially important. In this research work, we comparatively analyzed the fracture resistance capacity of thermo and self-curing acrylic resins in vitro. Materials and Methods: Five prosthesis bases were created for each of the following acrylic resins: Lucitone®, ProBase®, and Megacryl®, which were submitted to different forces through the use of the CS® Dental Testing Machine, usually mobilized in the context of fatigue tests. To this end, a point was defined in the center of the anterior edge of the aforementioned acrylic resin bases, for which the peak tended until a fracture occurred. Thermosetting resins were, on average, more resistant to fracture than self-curable resins, although the difference was not statistically significant. The thermosetting resins of the Lucitone® and Probase® brands demonstrated behavior that was more resistant to fracture than the self-curing homologues, although the difference was not statistically significant. Thermosetting resins tended to be, on average, more resistant to fracture and exhibited the maximum values for impact strength, compressive strength, tensile strength, hardness, and dimensional accuracy than self-curing resins, regardless of brand.


Author(s):  
Saeed Noorollahian ◽  
Farinaz Shirban ◽  
Vahid Mojiri

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.


2006 ◽  
Vol 17 (2) ◽  
pp. 122-125 ◽  
Author(s):  
Carolina B. Meloto ◽  
Laís R. Silva-Concílio ◽  
Cristiane Machado ◽  
Margarete C. Ribeiro ◽  
Fábio A. Joia ◽  
...  

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.


2013 ◽  
Vol 18 (6) ◽  
pp. 26-30 ◽  
Author(s):  
Glaucio Serra ◽  
Liliane Siqueira de Morais ◽  
Carlos Nelson Elias

INTRODUCTION: The finishing and polishing phases are essential to improve smoothness and shining on the surface of acrylic resins used to make removable orthodontic appliances. A good surface finishing reduces roughness, which facilitates hygiene, prevents staining and provides greater comfort to the patients. OBJECTIVE: The aim of this paper was to analyze the changes on surface morphology of acrylic resins during finishing and polishing phases. METHODS: Thirty discs (10 mm in diameter and 5 mm in length) were made with acrylic resin and randomly divided into ten groups. The control group did not receive any treatment while the other groups received gradual finishing and polishing. The last group received the entire finishing and polishing procedures. Surface morphology was qualitatively analyzed through scanning electron microscopy and quantitatively analyzed through a laser profilometer test. RESULTS: The acrylic resin surfaces without treatment showed bubbles which were not observed in the subsequent phases. Wearing out with multilaminated burs, finishing with wood sandpaper and finishing with water sandpaper resulted in surfaces with decreasing irregularities. The surfaces that were polished with pumice and with low abrasive liquids showed high superficial smoothness. CONCLUSION: Highly smooth acrylic resin surfaces can be obtained after mechanical finishing and polishing performed with multilaminated burs, wood sandpaper, water sandpaper, pumice and low abrasive liquids.


2015 ◽  
Vol 63 (3) ◽  
pp. 315-318 ◽  
Author(s):  
Carmen Beatriz Borges FORTES ◽  
Vicente Castelo Branco LEITUNE ◽  
Fabrício Mezzomo COLLARES ◽  
Nélio Bairros DORNELLES JUNIOR ◽  
Stéfani Becker RODRIGUES ◽  
...  

Objective: The objective of this study was to evaluate the effectiveness of disinfection methods in microwave and immersion in peracetic acid in heat-cured, self-cured and microwave-cured acrylic resin, contaminated with Candida albicans. Methods: Five specimens were prepared for each type of acrylic resin. All were infected with Candida Albicans, incubated at 37°C for 24 hours. The group which underwent microwave energy was irradiated with a power of 840W for 1 minute and the other group underwent disinfection by soaking of 0.2% peracetic acid for 5 minutes. Results: All samples proved to be contaminated after the incubation period. After the different processes of disinfection, both immersion in 0.2% peracetic acid as microwave irradiation were effective in disinfection of the 3 types of acrylic resins contaminated by Candida Albicans. Conclusion: Concluded that soaking in 0,2% peracetic acid for 5 minutes with microwave irradiation power 840W for 1 minute are effective methods for disinfecting heat-cured acrylic resin, self-cured acrylic resin and microwave-cured acrylic resin, contaminated with Candida Albicans.


2006 ◽  
Vol 17 (2) ◽  
pp. 117-121 ◽  
Author(s):  
Ana Lúcia Campani Chassot ◽  
Maria Inês Pereira Poisl ◽  
Susana Maria Werner Samuel

The purpose of this study was to assess the antimicrobial efficacy of a peracetic acid-based disinfectant for decontamination of heat-polymerized, chemically activated and microwave-polymerized acrylic resins. Resin plates were contaminated in vivo upon intraoral use by 10 volunteers for 7 nights and slabs were contaminated in vitro by contact with Bacillus subtilis and Bacillus stearothermophilus. The contaminated acrylic resin specimens were immersed in a 0.2% peracetic acid-based disinfectant (Sterilife®; Lifemed) for 5 min or 10 min and placed in a BHI culture medium. After incubation at 37°C for 48 h, bacterial growth was assessed by analyzing turbidity of the medium. For all types of acrylic resin, no turbidity of the medium was observed for any of the resin specimens immersed in the peracetic acid-based disinfectant for either 5 or 10 min. On the other hand, the media with specimens that were not immersed in the disinfectant (control) showed turbidity in 100% of the cases, indicating the presence of microorganisms in both tested conditions. In conclusion, immersion for at least 5 min in a 0.2% peracetic acid-based disinfectant promoted high-level disinfection of heat-polymerized, chemically activated and microwave-polymerized acrylic resins contaminated with either human saliva or Bacillus subtilis or Bacillus stearothermophilus.


2017 ◽  
Vol 65 (1) ◽  
pp. 8-12
Author(s):  
Carmen Beatriz Borges FORTES ◽  
Fabrício Mezzomo COLLARES ◽  
Vicente Castelo Branco LEITUNE ◽  
Juliana Gehlen WALCHER ◽  
Stéfani Becker RODRIGUES ◽  
...  

ABSTRACT Objective: The aim of this study is to analyze if both color and nylon fibers have an influence on microwave-cured acrylic resin properties. Methods: Rectangular and disk-shaped specimens were prepared using acrylic resins; medium pink with and without nylon fibers and colorless without nylon fibers. To obtain the rectangular specimens, a stainless steel die was used with the following dimensions: 64 X 10 x 3 mm (± 0.5mm). To obtain disk-shaped specimens, a die 50mm (±0.5mm) in diameter and 0.5mm (±0.05mm) thick was employed. They were randomized to form groups: control (colorless acrylic) and experimental (medium pink, with and without nylon fibers), with each group consisting of ten (10) specimens rectangular in shape and five (5) disk-shaped. They were analyzed in six (6) assays (izod impact strength, n=10; Knoop hardness, n=10; glass transition temperature, n=3; water sorption and solubility, n=5; degree of monomer/polymer conversion, n=1; flexural strength and flexural modulus, n=10). All variables were subjected to the analysis of variance test followed by Tukey's multiple comparison test, at a 5% level of significance. Results: The analysis of the monomer/polymer degree of conversion did not reveal any difference between the three groups of resins (medium pink, with and without nylon fibers and colorless resin); it was approximately 88%. The results did not show significant differences between the groups for each variable (p>0.05). Conclusion: The results showed that color and presence of nylon fibers in acrylic resins did not affect the properties analyzed in this study.


2011 ◽  
Vol 74 (12) ◽  
pp. 2107-2112 ◽  
Author(s):  
G. GOZZELINO ◽  
D. E. ROMERO TOBAR ◽  
N. CHAITIEMWONG ◽  
W. HAZELEGER ◽  
R. BEUMER

Antibacterial polymers suitable for coating applications without leaching of the biocidal component have been obtained by UV copolymerization of acrylic resins with acrylic monomers containing quaternary ammonium moieties. Suitable reactive biocides, based on quaternary ammonium monomers (QAMs), endowed with undecylacryloyl group and alkyl chains with 2 (QAM-C2), 8 (QAM-C8), and 16 (QAM-C16) carbon atoms have been synthesized. Aqueous solutions of QAMs showed biocidal activity against Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes strains both in suspension and adhered to stainless steel surfaces. QAM-C16 and QAM-C8 evidenced higher activity toward bacteria in suspension and on stainless steel, respectively. The QAMs have shown sufficient reactivity to be copolymerized, by UV irradiation, with a commercial urethane acrylic resin for coating. Bioactivity tests, performed on free films of crosslinked coatings containing 1% of copolymerized QAM, have shown an increasing inactivation effect in the order of magnitude L. monocytogenes &lt; E. coli &lt; S. aureus with a maximum activity of the QAM-C8.


Plants ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1292
Author(s):  
Song-Yi Yang ◽  
Min-Kyung Kang

We conducted surface characterization to assess the biocompatibility and investigate the antimicrobial activity against oral pathogens in autopolymerizing acrylic resins, coated with light-curable coating resin, containing various concentrations of Reynoutria elliptica extract (0, 200, 400, and 600 µg/mL). The R. elliptica extract powder was prepared using a freeze-drying technique. Further, a goniometer and microhardness tester were used to determine the water contact angle, and Vickers hardness, respectively; color measurements were performed on the uncoated and coated acrylic resin disks. The polyphenol content of the extracts from the coated acrylic resin disk was analyzed using UV-VIS spectroscopy. The antimicrobial activity of the coated acrylic resin disk against Streptococcus mutans and Candida albicans was observed for 24 and 48 h by measuring the optical density using spectrophotometry. In addition, biocompatibility was confirmed by testing the cell viability according to ISO 10993-5. The water contact angle, Vickers hardness, and color change values of the coated acrylic resin disks were not significantly different from the control. Polyphenol was detected in all experimental groups, with no significant differences between the experimental groups. The experimental groups exhibited significant antimicrobial activity against S. mutans and C. albicans compared to the control group, after 48 h of incubation. The cell viability between the control and experimental groups was not significantly different. The proposed coating resin containing R. elliptica extract is applicable on dental acrylic resins, due to their antimicrobial properties and excellent biocompatibility, with no deterioration of surface characteristics.


Sign in / Sign up

Export Citation Format

Share Document