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

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.

2008 ◽  
Vol 9 (4) ◽  
pp. 67-74 ◽  
Author(s):  
Behnaz Ebadian ◽  
Mohammad Razavi ◽  
Solmaz Soleimanpour ◽  
Ramin Mosharraf

Abstract Aim Controversy continues regarding the biocompatibility of denture base materials. One method to evaluate the biocompatibility of materials is in an animal study. Using dogs as subjects, the purpose of this study was to evaluate the vestibular tissue reaction to cobalt chromium (Co-Cr), heat cure acrylic resin, and acrylic resin mixed with aluminum oxide (Al2O3) compared with a control group using the histopathologic method. Methods and Materials Twelve disk shape samples (2 mm × 8 mm) in four groups of Co-Cr, acrylic resin, acrylic resin mixed with a 20% weight ratio of Al2O3, and a control group (Teflon) were fabricated. In one stage surgery two samples of each material (8 samples) was implanted in the buccal vestibule of each dog (n=6), subcutaneously. At 45 and 90-day intervals, half of the samples were excised along with peripheral tissue to assess the presence of inflammation by grading on a scale from 0 to 3 and the presence of a fibrotic capsule using histological observations. Data were analyzed using the Kruskal-Wallis, Mann-Whitney, and Tau b Kendal tests. Results Tissue reaction between Co-Cr and the control group was significant (P=0.02), but it was not significant between other groups. There was no significant difference between the 45 and 90-day postinsertion samples. The formation of fibrotic capsule groups was significant (P=0.01). It was significant between the Co-Cr and acrylic resin groups (P=0.01) and the acrylic resin and control groups (P=0.01). Conclusion The Co-Cr group was more toxic than the other groups. The inflammation increased during time. The inflammation in two acrylic groups was greater than the control and less than the Co-Cr group. The formation of fibrotic capsule, except in the acrylic resin with Al2O3 group, increased over time. Clinical Significance Co-Cr alloys are toxic and can produce damage to living tissue. Heat cure acrylic resin materials have less toxicity, and their use is safer than Co-Cr alloys. Citation Ebadian B, Razavi M, Soleimanpour S, Mosharraf R. Evaluation of Tissue Reaction to Some Denture-base Materials: An Animal Study. J Contemp Dent Pract 2008 May; (9)4:067-074.


2018 ◽  
Vol 9 (2) ◽  
Author(s):  
Aleksandra Maletin ◽  
Jovana Bastajić ◽  
Ivan Ristić ◽  
Branislava Petronijević Šarčev ◽  
Isidora Nešković ◽  
...  

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.


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.


2021 ◽  
Vol 25 (2) ◽  
pp. 108-113
Author(s):  
Ozlem Gurbuz Oflezer ◽  
Hakan Bahadır ◽  
Senem Ünver ◽  
Ceyhan Oflezer

Summary Background/Aim: Relining is defined as the procedure used to resurface the tissue side of a denture with new base material, thus producing an accurate adaptation is provided at the denture foundation area. During mastication, relined dentures have to withstand masticatory forces to prevent fracture. The aim of this study was to evaluate the flexural strength of acrylic resin denture base relined with different methods and materials. Material and Methods: Fourteen experimental groups and one control group were determined to consider different reline materials and processing methods. Acrylic resin specimens were prepared with the dimensions of 65× 10× 1.5 mm and reline materials (1.5 mm thickness) were placed on acrylic resins. Reline material was not used in control group specimens. Flexural strength values of relined and control specimens were measured with three-point bending test at a speed of 5 mm/min. Data were analyzed with using one way Anova and Student t tests. Results: The highest flexural strength values were shown in control group (86.51±1.08 MPa). There were significant differences among relined specimens (p< 0.05). For the relined specimens, the highest flexural strength values were found in the relined specimens with denture base material (77.90±1.93 MPa), and the lowest values were found in relined with autopolymerize acrylic material (59.81±1.50 MPa). Conclusions: Relining of the heat cure denture base material significantly decreases the flexural strength for all processing methods and materials.


Author(s):  
Rajeswari Pokuri ◽  
Durga Prasad Tadi ◽  
Sunil Tripuraneni ◽  
Hemchand Surapaneni ◽  
Sri Harsha Babu Vadapalli ◽  
...  

Introduction: In complete denture fabrication, the common denture base material used is heat activated Polymethyl Methacrylate (PMMA). Considering various advantages, still there are some disadvantages like poor flexural strength and poor wear resistance. The flexural strength of any material reflects its potential to resist catastrophic fracture under a flexural load. Another property that influences the surface characteristics of acrylic resins is the surface hardness, which indicates the ease of finishing a material and its resistance to in-service scratching during cleaning procedures and exposure to various oral fluids. Thus an ideal denture base material should exhibit greater flexural strength and high surface hardness for the longevity of the dentures. Aim: To evaluate the effects of adding different percentages of silanised aluminium oxide (Al2O3) nanoparticles on the flexural strength and surface hardness of a conventional heat-polymerised acrylic resin. Materials and Methods: The in-vitro experimental study was conducted between October 2020 to Janaury 2021 at Drs. Sudha and Nageswara Rao Siddhartha Institute of Dental Sciences, Vijayawada, Andhra Pradesh, India. A total of 120 samples were fabricated and were grouped into four groups coded A to D (n=30). Group A was the control group (without adding Al2O3). Specimens in the other three groups (B to D) were reinforced with silanised Al2O3 at loadings of 1%, 2.5% and 5% w/w. Flexural strength was assessed with a three-point bending test using a universal testing machine. Surface hardness test was conducted using a Vickers Hardness (VH) tester. Data was analysed using Analysis of Variance (ANOVA) and Tukey’s post-hoc test. Results: Among all the reinforced groups highest flexural strength value was seen in Group C- PMMA+2.5% w/w silanised aluminium oxide nanoparticles reinforced group (88.33 Mpa) and highest surface hardness value was seen in the Group D- PMMA+5% w/w silanised Aluminium oxide nanoparticles reinforced group (29.44 VH). Conclusion: Reinforcement of the conventional heat cured acrylic resin with 2.5% w/w silanised Al2O3 nanoparticles significantly increased its flexural strength and hardness.


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.


2008 ◽  
Vol 02 (03) ◽  
pp. 191-197 ◽  
Author(s):  
Suleyman Hakan Tuna ◽  
Filiz Keyf ◽  
Hasan Onder Gumus ◽  
Cengiz Uzun

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)


2021 ◽  
Vol 2114 (1) ◽  
pp. 012023
Author(s):  
Teba M. Hameed ◽  
Balqees M. Al-Dabbagh ◽  
Ragdaa K. Jasim

Abstract Materials and Methods: In total, 90 specimens were prepared to be used in the study. The specimens were divided into (3) main groups depended on the presence of sisal fibers powder, first group (30) specimens of heat cure PMMA without additives (control), second and third experimental groups of 60 specimens of heat cure PMMA with salinized sisal fibers powder with two different weight percentages (1 and 3%) wt. Three point bending test was used to measure the flexural strength of the specimens, while the impact strength was done by impact testing Charpy’s machine and tensile test was performed according to ASTM (D-638). Data analysis was performed using (ANOVA) test. The results of this study refer to a highly significant in the flexural strength and tensile strength of specimens reinforced with sisal fibers powder compared with control specimens. Non-significant difference was detected in impact strength among the reinforced groups and control gro. Reinforcement of acrylic resin with natural sisal fibers powder affects its flexural strength and tensile strength with non-significant in impact strength.


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