scholarly journals Tensile and transverse strength of novel copolymers for denture base.

2019 ◽  
Vol S (1) ◽  
pp. 7-10
Author(s):  
Ahmed Asim Saeed Al-Ali ◽  
◽  
Ammar k. Al-Noori ◽  
Amer A. Taqa ◽  
◽  
...  

Objectives: Compare tensile and transverse strength of new copolymers for denture base. Materials and methods: The specimens were prepared from heat cured acrylic resin with three types of additives: Acryester B, Ethoxycarbonylethylene, and Propenoic acid at a percentage of 5% and 10%. The tensile and transverse strains were tested, recorded and compared. Results: The analysis of variance display statistically significant difference. The p-value was 0.001 for each of tensile and transverse strain tests. Conclusions: The tensile strength of the novel copolymers increased. The transverse strength of some of the novel copolymers increased.

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.


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>


2018 ◽  
Vol 41 (10) ◽  
pp. 677-683 ◽  
Author(s):  
Merve Çakırbay Tanış ◽  
Canan Akay ◽  
Handan Sevim

Introduction: The aim of this study was to evaluate the cytotoxic effect of various denture base materials following four different aging periods. Methods: In total, 48 disc-shaped specimens per each group were prepared: Group I: acrylic resin polymerized in cool water and heated up to 100°C over 45 min and boiled for 15 min; Group II: acrylic resin polymerized under pressure in 40°C–45°C water bath for 10 min; Group III: autopolymerized hard relining resin Cold Liner Rebase; Group IV: autopolymerized hard relining resin Truliner; Group V: soft relining resin DentuSil. Then the specimens were stored in water for 24 h or 15 days, or thermocycled 2500 times or 10,000 times. Cytotoxicity was evaluated with 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay using L929 cells after 72-h cell incubation. Cell viability percentages were counted and statistical analyses were performed. The results were also evaluated according to ISO standard 10993-5. Results: All materials showed similar cell viability percentages following 24-h water storage and 2500 and 10,000 thermal cycles. Following 15-day water storage, a statistically significant difference was observed between the materials. Comparisons of the aging periods for each material showed statistically significant differences. Groups III and IV showed moderately cytotoxic effect following 15-day water storage. The remaining groups showed slightly cytotoxic or non-cytotoxic effect. Discussion: Polymerizing acrylic resins under pressure can be an alternative to conventional polymerizing to ensure a faster denture repair while providing similar cell viability values. Heat-cured acrylic resins provide higher cell viability than hard chairside lining materials in a 15-day period.


2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Mohammed Gad ◽  
Aws S. ArRejaie ◽  
Mohamed Saber Abdel-Halim ◽  
Ahmed Rahoma

Objective.The aim of this study was to evaluate the effect of incorporation of glass fiber, zirconia, and nano-zirconia on the transverse strength of repaired denture base.Materials and Methods.Eighty specimens of heat polymerized acrylic resin were prepared and randomly divided into eight groups (n=10): one intact group (control) and seven repaired groups. One group was repaired with autopolymerized resin while the other six groups were repaired using autopolymerized resin reinforced with 2 wt% or 5 wt% glass fiber, zirconia, or nano-zirconia particles. A three-point bending test was used to measure the transverse strength. The results were analyzed using SPSS and repeated measure ANOVA and post hoc least significance (LSD) test (P≤0.05).Results.Among repaired groups it was found that autopolymerized resin reinforced with 2 or 5 wt% nano-zirconia showed the highest transverse strength (P≤0.05). Repairs with autopolymerized acrylic resin reinforced with 5 wt% zirconia showed the lowest transverse strength value. There was no significant difference between the groups repaired with repair resin without reinforcement, 2 wt% zirconia, and glass fiber reinforced resin.Conclusion.Reinforcing of repair material with nano-zirconia may significantly improve the transverse strength of some fractured denture base polymers.


Author(s):  
Eddy Dahar ◽  
Raudhatul Husna

Heat polymerized acrylic resin is the most common material used for making denture base because of it’s advantages. However, this material still hasn’t fulfill all the ideal requirements as a denture base. Some disadvantages that need to be fixed are low impact and transverse strength causing an easy base of fracture. Several attempts were made to improve the mechanical properties of heat polymerized acrylic resin materials by adding reinforcing materials. Zirconium oxide is one of chemical group that can be used as a reinforcing material and polypropylene fiber which is including in fiber reinforcing groups. This study aims to determine whether there is a difference in the effect of the addition of 5% ZrO2 nanoparticles and 2% chopped polypropylene fibers 6 mm in length on the impact and transverse strength of heat polymerized acrylic resin denture base material. The design of this study is a laboratory experimental and the number of samples in this study are 60 samples. The result of this study shows the mean value of the impact and transverse strength of heat polymerized acrylic resin with ZrO2 nanoparticles reinforced is greater than the control group and heat polymerized acrylic resin group with polypropylene fiber reinforced with significant difference, and the mean value of impact and transverse strength of heat polymerized acrylic resin with polypropylene fibers reinforced is greater than the control group with significant difference.


Author(s):  
Syafrinani Syafrinani ◽  
Yudi Setiawan

Denture base widely were made from heat polymerized acrylic resin. Either one of physical properties on this material must be concern is surface roughness, rough surface could interfere patient’s comfort, and microbial colonization. Therefore polishing procedure were needed, polishing material that mostly used on acrylic resin was pumice, there is another alternative material i.e eggshell and toothpaste because had abrasive ability. The aim of this research is to determine the difference surface roughness of heat polymerized acrylic denture base resin used pumice, eggshell and toothpaste as polishing materials. The design research in this study is laboratory experimental with rectangle sample with size 50 x 20 x 3 ±1 mm. There are 30 samples for 3 groups. The result of this research shows a significant difference between pumice group and eggshell group with p value = 0,0001 (p < 0,05), pumice and toothpaste with p value = 0,0001 (p < 0,05), egghsell and toothpaste with p value = 0,032 (p < 0,05). Polishing that used an alternative material from eggshell and toothpaste produce lower surface roughness score rather than pumice.


2016 ◽  
Vol 4 (3) ◽  
pp. 476-481 ◽  
Author(s):  
Amani Ramadan Moussa ◽  
Wessam Mohamed Dehis ◽  
Asmaa Nabil Elboraey ◽  
Hisham Samir ElGabry

AIM: This study aimed to verify the influence of oral environment and denture cleansers on the surface roughness and hardness of two different denture base materials. METHODS: A total of sixteen identical removable disc specimens (RDS) were processed. Eight RDS were made from heat-cured acrylic resin (AR) and the other eight were fabricated from thermoplastic injection moulded resin (TR). Surface roughness and hardness of DRS were measured using ultrasonic profilometry and Universal testing machine respectively. Then the four RDS (two AR and two of TR) were fixed to each maxillary denture, after three months RDS were retrieved. Surface roughness and hardness of RDS have measured again.RESULTS: The surface roughness measurements revealed no significant difference (p >0.05) for both disc groups at baseline. However, both groups showed a significant increase in the surface roughness after three months with higher mean value for (TR) group. On the other hand, the (AR) group showed higher hardness mean value than (TR) group at baseline with no significant decrease in the hardness values (p >0.05) following three months follow-up period. CONCLUSIONS: Denture cleansers have an effect on the denture’s surface roughness and hardness concurrently with an oral condition which will consequently influence the complete dentures’ lifetime and patients’ satisfaction.


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.


2021 ◽  
Vol 17 (1) ◽  
pp. 22-26
Author(s):  
Kadek Ayu Wirayuni ◽  
◽  
I Made Hendri Dwi Saputra ◽  

Introduction: The denture base is the part of the removable denture that is supported by good adaptation to the underlying oral tissue. Most of the denture bases are made of acrylic or polymethyl methacrylate resin, better known as PMMA. However, the acrylic resin also has disadvantages such as easily broken and absorbs liquids both water and chemicals. The chemical absorption like alcohol, ethanol, and some drinks that contain acidic materials will chemically be induced with acrylic resin and settle in the pores of the acrylic resin. The chemical damage or defect creates roughness on the surface of the acrylic resin which can cause cracking or crazing and a decrease in surface strength and hardness. Materials and Methods: The method used in this research was a laboratory experimental design with a post-test-only control group using 12 samples consisting of 2 different types of samples by measuring the surface roughness of the acrylic resin after immersing the sample with a predetermined time. Results and Discussions: One-way ANOVA test results showed a significant difference in surface roughness after the samples immersion with a value of p = 0.006 (p <0.05). Conclusions: Based on this research, can be concluded that there is an increase in the surface roughness of the heated polymerized acrylic resin for 3 hours and 4 hours of immersion. The longer the heated polymerized acrylic resin is soaked in arak hence the level of surface roughness increases.


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