scholarly journals Effect of intrinsic pigmentation on the flexural strength of a microwave-cured acrylic resin

2002 ◽  
Vol 13 (3) ◽  
pp. 205-207 ◽  
Author(s):  
Frederico Augusto Peixoto Silva ◽  
Tatiana Bernardon Peixoto Silva ◽  
Altair Antoninha Del Bel Cury

This study investigated the effect of intrinsic pigmentation on the transverse strength of a microwave-cured acrylic resin. Forty transverse strength specimens were fabricated according to ADA specification #12 and divided into 5 groups. No fibers were added to group I (GI, control group); acrylic stain (AS) was added to GII and GIII in concentrations of 0.5 and 1.5% w/w, respectively; acrylic fibers (AF) were added to groups GIV and GV in concentrations of 0.5 and 1.5% w/w, respectively. All specimens were irradiated in a microwave oven with a cycle of 3 min at 360 W, followed by 4 min resting, then 3 min at 810 W. Flasks were bench-cooled for 30 min at room temperature, followed by immersion in cold tap water for 30 min. After storage in distilled water at 37ºC for 48 h, all specimens were tested for flexural strength in a testing machine (EMIC-DL 500) at a crosshead speed of 0.5 cm/min. Mean and standard deviation (MPa) for the flexural strength test were: GI=86.0 ± 7.9; GII=86.0 ± 9.8; GIII=86.6 ± 7.7; GIV=84.9 ± 5.3; GV=84.9 ± 5.2. No statistical differences were detected among the groups (ANOVA, p>0.05). The addition of the acrylic fibers or the acrylic stain did not affect the transverse strength of the microwave-cured acrylic resin.

2013 ◽  
Vol 14 (1) ◽  
pp. 80-83 ◽  
Author(s):  
Naveen S Yadav ◽  
Teerthesh Jain ◽  
Amrita Pandita ◽  
SMA Feroz ◽  
UK Kartika ◽  
...  

ABSTRACT Aim The purpose of this study was to evaluate and compare the flexural strength of commercially available acrylic (trevalone) and modified polymethylmethacrylate (PMMA). Materials and methods Four groups were tested; Group 1— control group regular MMA, group 2—2% methacrylic acid, 88% MMA, group 3—16% methacrylic acid, 84% MMA group 4— 20% methacrylic acid, 80% MMA 15 resin specimens of each group were polymerized. After processing, the specimens were subjected for flexural strength testing using three point bending test in a Universal Testing Machine. All data was statistically analyzed with one-way ANOVA, differences within the groups were analyzed by Scheffe's analysis. Results As the ratio of incorporated methacrylic acid to PMMA increased, the flexural strength decreased. Analysis of data revealed a significant decrease in flexural strength of specimens (p < 0.000) after incorporation of 12%, 16%, 20% methacrylic acid to heat polymerized acrylic resin, when compared with the control group. Lowest flexural strength was observed with specimens containing 20% methacrylic acid and highest flexural strength was observed with specimens containing conventional monomer without methacrylic acid. Conclusion It was observed that as the concentration of methacrylic acid in heat polymerized acrylic resin increases, the flexural strength decreases. Lowest flexural strength was observed with specimens containing 20% methacrylic acid and highest flexural strength was observed with specimens containing conventional monomer without methacrylic acid. Clinical significance The major advantages of addition of methacrylic acid to polymethylmethacrylate could be for the elderly people with restricted manual dexterity or cognitive disturbances, especially for patients who do not follow an adequate denture cleansing protocol and diabetic patients who are more susceptible for denture stomatitis. How to cite this article Jain T, Yadav NS, Pandita A, Feroz SMA, Kartika UK, Singh PP. A Comparative Evaluation of Flexural Strength of Commercially Available Acrylic and Modified Polymethylmethacrylate: An in vitro Study. J Contemp Dent Pract 2013;14(1):80-83.


2019 ◽  
Vol 10 (2) ◽  
pp. 1464-1469
Author(s):  
Adnan R. Al Assal ◽  
Abdalbaset A Fatalla ◽  
Mohammed Moudhaffar ◽  
Ghasak H Jani

The general upgrading of polymer denture base material and research continuously looking for ideal restorative dental material with better properties, adequate esthetic properties, less expensive and easier to handle material to develop photo polymerization dental materials. This study was conducted to evaluate the effect of addition polyamide on mechanical microparticle properties light cure denture base material. One hindered sixty specimens from light-cured acrylic resin (Aurora). The divided mainly into four groups according to test used (Transverse strength test, impact strength test, hardness test and tensile strength test) with 40 specimens for each group. The results show an increase in Transverse strength, impact strength, hardness and tensile strength in all experimental group when compared to control group the highest mean values for all tests included in the study appeared in group B 1% polyamide. The addition of polyamide microparticle improves transverse, tensile, impact strength and hardness properties of denture base material.


2015 ◽  
Vol 1 (1) ◽  
pp. 102
Author(s):  
Pramudya Aditama ◽  
Siti Sunarintyas ◽  
Widjijono Widjijono

Resin akrilik merupakan bahan yang sering digunakan dalam pembuatan basis gigi tiruan. Kelemahan resin akrilik adalah mudah patah. Salah satu cara untuk mengatasi masalah tersebut adalah dengan menambahkan polyethylene (PE) atau glass fiber. Tujuan dari penelitian ini untuk mengetahui pengaruh jenis dan volumetrik fiber terhadap kekuatan transversal reparasi plat resin akrilik. Penelitian ini menggunakan dua puluh lima plat resin akrilik kuring panas berukuran 65 x 10 x 2,5 mm. Subjek dipreparasi untuk membuat jarak 3 mm dan sudut bevel 45o. Subjek dibagi menjadi 5 kelompok, masingmasing kelompok terdiri dari 5 subjek. Kelompok 1 (kontrol) tanpa penambahan fiber, kelompok II dengan penambahan 3,7% v/v PE fiber, kelompok III dengan penambahan 7,4% v/v PE fiber, kelompok IV dengan penambahan 3,7% v/v E-glass fiber, dan kelompok V dengan penambahan 7,4% v/v E-glass fiber. Seluruh plat direndam dalam air destilasi selama satu hari pada suhu 37oC. Pengujian kekuatan transversal plat resin akrilik dengan menggunakan Universal Testing Machine dan data yang didapat dianalisis menggunakan ANAVA dua jalur dengan tingkat kepercayaan 95%. Rerata kekuatan transversal (MPa) reparasi plat resin akrilik yang diperkuat fiber: 3,7% v/v PE fiber (67,77±3,34); 7,4% v/v PE fiber (80,37±8,42); 3,7% v/v E-glass fiber (96,72±5,43); 7,4% v/v E-glass fiber (109,44±4,98); sedangkan reparasi plat resin yang tidak diperkuat fiber menghasilkan kekuatan transversal 56,27±4,7 MPa. Hasil analisis menggunakanANAVA dua jalur menunjukkan variabel jenis dan volumetrik fiber memberikan pengaruh signifikan (p<0,05), sedangkan interaksi antara jenis dan volumetrik fiber tidak berpengaruh signifikan (p>0,05). Uji post hoc Tukey menunjukkan perbedaan signifikan (p<0,05) untuk seluruh kelompok perlakuan. Penambahan E-glass fiber dalam reparasi plat resinakrilik mampu meningkatkan kekuatan transversal lebih tinggi dibandingkan dengan menggunakan PE fiber. Peningkatan volumetrik fiber dapat meningkatkan kekuatan transversal reparasi plat resin akrilik. Effect Of Type And Volumetric Fiber On Transverse Strength Of Acrylic Resin Plate Repair. Acrylic resin is the most common denture base material. A disadvantage of acrylic resin is that it is easily fractured. One way to resolve this problem is by adding polyethylene (PE) or glass fibers. The purpose of this research is to find out about the effect of type and volumetric fiber on transverse strength of acrylic resin plate repaired. The experiment involved twenty five plates of heat cured acrylic with the dimensions of 65 x 10 x 2.5 mm. The speciments were prepared to create a 3 mm gap and 45° bevel. The subjects were divided into 5 groups; each group consisted of 5. Group I (control) was without fiber reinforcement, group II reinforced with 3.7% v/v PE fiber, group III reinforced with 7.4% v/v PE fiber, group IV reinforced with 3.7% v/v E-glass fiber, and group V reinforced with 7.4% v/v E-glass fiber. All plates were soaked in distilled water for one day at 37° C temperature. The plates were tested for transverse strength with Universal Testing Machine and all data obtained were analyzed with two way ANOVA at 95% confidence level. The mean of transverse strength (MPa) of the acrylic resin plate repair reinforced with fiber: 3.7% v/v PE fiber was (67.77±3.34); 7.4% v/v PE fiber (80.37±8.42); 3.7% v/v E-glass fiber (96.72±5.43); 7.4% v/v E-glass fiber (109.44±4.98); while the transverse strength of the acrylic resin plate with no fiber reinforced was 56.27±4.7 MPa. Two way ANOVA analysis shows that type and volumetric fiber had significant effect (p<0.05), while the interaction between type and volumetric fiber had no significant effect (p>0.05). Tukey post hoc test shows significant difference (p<0.05) for all groups. The addition of E-glass fibers in the acrylic resin plate repaired increased the transverse strength higher than that with PE fibers. The increase in volumetric fibers might improve the transverse strength of the acrylic resin plate repaired.


2017 ◽  
Vol 1 ◽  
Author(s):  
Annisa Mayang Rusdi ◽  
Lasminda Syafiar ◽  
Astrid Yudhit

<p class="AbstractContent"><strong>Objective:</strong> The purpose of this study was to evaluate transverse strength of heat cured acrylic resin after immersed in 0,2% chlorhexidine gluconate mouthwash for 15, 30, 45, and 60 minutes.</p><p class="AbstractContent"><strong>Methods:</strong> This was an experimental laboratory study with posttest only group design. The samples were heat cured acrylic resin plate with size 65mm x 10mm x 2,5mm. Polymerization of the heat cured acrylic was done by water bath (74 °C for 2hrs followed by 100 °C for 1hr). Totally 30 samples were prepared and divided into 5 groups (n=6) which are group I as control, and others were immersed in 0, 2% chlorhexidine gluconate, group II (15 minutes), group III (30 minutes), group IV (45 minutes) and group V (60 minutes) respectively. The transverse strength was test using Torsee’s Universal Testing machine, Japan with crosshead 1/10 mm/seconds. The data was statistically analyzed using one way ANOVA (p≤0,005).</p><p class="AbstractContent"><strong>Results:</strong> Means and Standard deviation of Transverse strength were 92.382±11.786 N/mm2, 92.186±13.349 N/mm2,92.578±12.492 N/mm2, 92.382±13.939 N/mm2, and 91.989±12.285 N/mm2 for group I, II, III, IV, and V respectively. Statistic analyzed showed no significant difference among groups with p value= 1,000 (p &lt; 0, 05).</p><p class="AbstractContent"><strong>Conclusion:</strong> The immersion in 0, 2% chlorhexidine gluconate mouthwash at different period does not changed transverse strength of heat cured acrylic resin.</p>


2019 ◽  
Vol 1 (1) ◽  
pp. 35
Author(s):  
Pramudya Aditama ◽  
Erwan Sugiatno ◽  
Sabdayana Sabdayana

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.


2015 ◽  
Vol 3 (2) ◽  
pp. 68-73
Author(s):  
Riezka Hanafiah Putri ◽  
Zulkarnain Agus ◽  
Eni Rahmi

Heat-polymerized  acrylic  resins  is  the  most  used  denture  base  material  in  prosthodontics.  One  of  mechanical properties of acrylic resins is transverse strength. It represents the masticatory pressure that is applied to denture base. Black tea is the second largest consumed beverage in the world. The aim of this study was to investigate the effect of black tea beverage on transverse strength of heat-polymerized acrylic resins. A total of 24 heat-polymerized acrylic resin plates (65×10×2,5 mm) were immersed in black tea beverage for 1, 4, and 20 days as treatment group and in aquadest for 1, 4, and 20 days as control group. The transverse strength of  acrylic samples were measured by three–point bending test by universal testing machine. Data were statistically analyzed using Independent t test. The transverse strength values of acrylic resin immersed in black tea beverage had no significant differences to the transverse strength values of acrylic resin immersed in aquadest with similar immersion time (p>0,05). There was no effect of black tea beverage on transverse strength of heat-polymerized acrylic resins. Immersion time decrease the transverse strength of heat-polymerized acrylic resins due to water sorption. Keywords: Heat-polymerized acrylic resins, black tea, transverse strength


2016 ◽  
Vol 17 (4) ◽  
pp. 322-326 ◽  
Author(s):  
M Kalavathi ◽  
Mallikarjuna Ragher ◽  
G Vinayakumar ◽  
Sanketsopan Patil ◽  
Aishwarya Chatterjee ◽  
...  

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.


2018 ◽  
Vol 30 (2) ◽  
pp. 5-9
Author(s):  
Zahraa S. Abed karkosh ◽  
Basima M.A. Hussien

Background: acrylic resin denture base consider a common denture base material for its acceptable cost, aesthetic and easy processing but still has disadvantages including easy of fracture and low impact strength. Material and method: The experimental group was prepared by addition of 15% phosphoric acid 2-hydroxyethyl methacrylate ester (PA2HEME) with polymethyl methacrylate monomer; the experimental groups was compared with the control one. The specimens were prepared according to ADA specification No. 12 with dimension 65 mm x 10 mm x2.5 mm (length x width x thickness respectively). The prepared specimens were tested by three-point flexural strength utilizing Instron Universal Testing Machine (WDW, Layree Technology Co.), Shore D hardness tester used to measure hardness test. Statistical analysis used student T- test, mean and standard deviation. Results: The result of PA2HEME group showed high significant reduction comparing to the control group for both transverse strength and hardness test. Conclusion: Mixing 15% of PA2HEME with 85% methyl methacrylate (MMA) can reduce the mechanical properties of new modified polymethyl methacrylate (PMMA) acrylic resin.


2012 ◽  
Vol 23 (1) ◽  
pp. 28-35 ◽  
Author(s):  
Cleusa Vieira ◽  
Yara T. Correa Silva-Sousa ◽  
Nelize Marcelino Pessarello ◽  
Fuad Abi Jaccob Rached-Junior ◽  
Aline Evangelista Souza-Gabriel

This study evaluated the effect of bleaching agents on bond strength at the dentin/resin interface and the flexural strength of dentin. Forty maxillary canines were selected for the study. In the shear strength test, 40 slabs of intracoronary dentin (5 x 5 mm) obtained from buccal surfaces of the crowns were included in acrylic resin. In the flexural strength test, 40 dentin bars (8 x 2 x 2 mm) were obtained from the roots. The 40 hemi-sections of the lingual surface were prepared for scanning electron microscopy (SEM). The specimens were divided into 4 groups according to the bleaching protocol (n=10): Unbleached (control), Sodium perborate + 20% hydrogen peroxide (SP + 20% HP), 37% carbamide peroxide (37% CP) and 38% hydrogen peroxide (38% HP). After 7 days, the bond strength specimens were restored and tested. Dentin bars were bleached and subjected to a three-point bending test. Data (MPa) were analyzed by ANOVA and Tukey's test (α=0.05). In the shear test, the control group was superior (p<0.05) to the bleached groups, which, in turn, were statistically similar (p>0.05). In the flexural strength test, the control group also had the highest values and differed significantly from the other groups (p<0.05). SEM revealed smear layer in all groups, with fissures in the bleached specimens. SP + 20% HP and 38% HP showed discontinuous interfaces with few tags. In conclusion, bond strength of restorative material to dentin and flexural strength of dentin were reduced after the use of high-concentration bleaching agents.


2018 ◽  
Vol 30 (1) ◽  
pp. 35 ◽  
Author(s):  
Edwin Tandra ◽  
Endang Wahyuningtyas ◽  
Erwan Sugiatno

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.


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