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Polymers are widely used in dentistry for various applications. Dentures and dental implants are the major prosthetic devices given to restore physiological and esthetic functions of oral tissues of edentulous or partially edentulous patients. Complete and partial dentures based on polymeric compositions are the most popular devices since the cost...
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... 1930s, a co-polymer of vinyl chloride (80%) and vinyl acetate (20%) was introduced as a denture base material. The structure of PVC is shown in figure 5. The processing method to fabricate the denture was similar to celluloid [18,24] . The residual stresses may be introduced during processing that result in gradual deformation of the denture base leading fracture during service [24] . In addition, PVC may also discolour at temperature used during fabrication. However, PVC is still used currently as a denture lining material and also for construction of athletic mouth guards. PVC was plasticized with either dibutyl or dioctyl phthalate for this purpose. PVC is available as pre-plasticized sheet, which can be used to construct protective mouth guards. Processing generally involves heating the Pre-plasticised sheet followed by moulding it to the desired contour with the use of a vacuum to seal the sheet of material over a cast of the patient's teeth [26] . Even though the material is still used for this purpose, the material's properties are far from ideal. They harden over time as the plasticiser leaches out during service [2,27] . In addition, they are difficult to polish. This results in poor denture hygiene and acts as an irritant to the oral mucosal tissues [22,[28][29][30] ...
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Citations
... (2) It is superior to other materials since it is simple to work with and repair, nontoxic, and lightweight, but it has a number of disadvantages, one of which is that it has subpar mechanical qualities. (3) A denture fracture results from two different types of forces, namely impact and flexural fatigue. The most distant intraoral denture fracture through function arises mostly due to resin stress. ...
... The flexural and tensile strengths of acrylic resin are affected by the reinforcement with natural sisal fiber powder, although the impact strength is not significantly changed. (3) The aim of this work is preparation of nanocomposites material of PMMA (Poly Methyl Methacrylate) reinforced with PVA nanotextile fibers used in the manufacture of denture base. ...
... The SEM results indicated to obtain a fine and smooth PVA nanofiber with small diameters ranging from (350 to 500 nm) when using the preparation parameters (voltage = 20 KV, distance = 15 cm, temperature = 25 °C, https://doi.org/10.56294/sctconf2024873 3 Mohamed EJ, et al rotation speed = 480 rpm, and flow rate = 1 ml/hr), these small diameters of PVA nanofibers create a large surface area. (4,5) ...
This study attempts to prepare PMMA nano-composite samples armed with polyvinyl alcohol electrospun nanofibers. One layer, two layers, and three layers of nanofiber reinforcement were all utilized. As well as, one drop (0.01 g) and three drops of the cardamom oil were used. Using a differential calorimeter, thermal experiments were carried out, including those for the Tg and the thermal dissociation point. Mechanical tests were conducted on the samples, including compression testing to determine the elongation characteristics, compressive strength, Young's modulus, yield strength, and toughness. All samples were also subjected to an impact strength test. Results showed that the Tg point increased due to the presence of nanofibers from 136 to 195 Celsius, and that 277 Celsius was the thermal breakdown point. According to the mechanical property data, the impact strength increased as the percentage of nanofibers rose and increased further when one drop of cardamom oil was mixed with a very tiny amount (0.01 g) of material. Additionally, it was noted that the samples did not break easily since nanofibers and a drop of cardamom oil were present. Additionally, it was demonstrated that the sample's strength increased to 195 kJ/m2, as well as 0.02 weight % of fibers, the maximum strength value.
... Repetitive masticatory load results in distribution of cracks, weakening of the base of the denture and its eventual fracture. 1,2 Various attempts have been made to improve the impact strength and flexural strength of denture base acrylic resin. Properties of polymer were modified by adding specific fillers distributed at a nano-metric level inside the polymer matrix. ...
... Research has highlighted on modifying the composition or reinforcing the PMMA with stronger materials. 1,2,5 Flexural strength of silanated group with 0.5% nanofillers showed the highest mean of 99.58MPa, and control group showed a mean of 91.17MPa. As the filler concentration increased, the strength of the reinforced material decreased. ...
Statement of problem. Various studies are present to increase the strength and surface hardness of heat polymerized acrylic resin by addition of material or surface treatments. The present study to evaluate an effect of silica nanoparticles on flexural strength and surface hardness of heat polymerized acrylic resin. Purpose. The purpose of this study was effect of silica nanoparticles, incorporated into Polymethyl Methacrylate, on flexural strength and surface hardness. The present study compared the effect of silanated and non silanated silica nanoparticles on the flexural strength and surface hardness of heat polymerized acrylic resin. Material and Methods. A total of 270 acrylic bars were fabricated, in two batches of 135 each, for testing flexural strength by universal testing machine and surface hardness determined using a digital micro Vickers hardness tester. The control group and subgroups had a sample size of 15 each with varied concentrations of nanoparticles by weight. The fabricated samples were tested for flexural strength and surface hardness. Results. Flexural strength was highest for PMMA (Polymethyl methacrylate) with 0.5% silanated silica nano particles as fillers. In both the groups, the flexural strength decreased with increase in filler concentration. Surface hardness was highest in the PMMA group with non-silanated nano particles as fillers at 5% concentration. In both groups the surface hardness improved with an increase in filler concentration. ANOVA and TUKEY’s HSD test were used. P<0.05 was considered statistically significant. Conclusion. Lower concentrations of surface-treated silica nanoparticles should be used as fillers to enhance the flexural strength of commercially available heat polymerized acrylic resin. Bangladesh Journal of Medical Science Vol.23 (Special Issue) 2024 p.S79-S86
... Many research have been conducted with the purpose of increasing the characteristics of PMMA by including fillers into the composition. To enhance its physical and mechanical properties, PMMA is often mixed with fillers and particles (3,4,5). The heat-cure denture base resin or PMMA materials now available on the market are distributed as a two-part powder and liquid solution. ...
يأتي الاستخدام العالمي لبولي ميثيل ميثاكريلات (PMMA) كمادة أساسية لأطقم الأسنان من سهولة المعالجة والإصلاح والتوافق الحيوي والمظهر الجمالي الممتاز. ومع ذلك ، فإن أوجه القصور في مواد البوليمر ، مثل الخواص الميكانيكية والفيزيائية غير كافية. كان الغرض من هذه الدراسة هو تقييم القوة المستعرضة وقابلية البلل PMMA بعد الاختلاط مع جزيئات الزركونيا و PMMA المبلمرة [ZP] كمواد مالئة بنسبة مختلفة. المواد والأساليب: تم اقتراح مجموعتين وفقا لإضافة ZP بنسب مئوية مختلفة إلى ؛ المجموعة A مع 2 ٪ من ZP والمجموعة B مع 4 ٪ من ZP. كانت المجموعة الضابطة بدون إضافة ZP. تم تحضير مسحوق ZP وخلطه مع مسحوق PMMA بالوزن بنسبتين مختلفتين 2٪ و 4٪ [1.2 ميكرومتر و 30٪ ZrO و 0.69 ميكرومتر و 70٪ p-PMMA]. لبلمرة العينات ، تم استخدام إجراء المعالجة الحرارية المعتاد باستخدام حمام مائي ، لكل من اختبارات قوة المرونة وقابلية البلل. تم تحليل البيانات من الدراسة باستخدام تحليل التباين أحادي الاتجاه (ANOVA مع اختبارات Tukey's HSD و Dunnett's T3 اللاحقة) مع قيمة P معنوية تبلغ (p <0.05) .. وكانت النتائج زيادة معنوية في قوة المرونة المستعرضة لوحظت مع إضافة مسحوق ZP إلى PMMA بنسبة 2٪. بينما حدث انخفاض كبير بنسبة 4٪. لوحظت زيادة كبيرة في قابلية البلل بنسبة 2٪ و 4٪. مزيج من زركونيا وجزيئات PMMA المبلمرة المستخدمة كحشو الأسنان في 2 ٪ و 4 ٪ بالوزن. تعزيز وتقليل القوة المستعرضة على التوالي ، في حين عززت قابلية البلل مع زيادة التركيز. الكلمات المفتاحية: بولي ميثيل ميثاكريلات (PMMA) ، زركونيا ، PMMA مبلمر ، قوة المرونة وقابلية للبلل.
... The most dominant denture base material is Polymethyl methacrylate. PMMA used as a denture base material because its good quality, easy to process, stability in the oral environment, easy to repair and good esthetics [2]. As the main matrix, polymethyl methacrylate (PMMA) also has weaknesses such as bad surface and low mechanical properties, and then the strength of impact and flexural [3]. ...
Poly (methyl methacrylate) or PMMA is an acrylic material has been used widely as a denture base material. The denture base materials should exhibit good mechanical properties and dimensional stability in moist environment. Hydroxyapatite (HAp) as a filler is added to improve the mechanical properties of the denture base. Process for the manufacture of denture base composites consists of a synthesis of polymethyl methacrylate (PMMA) with suspension polymerization process, treatment filler hydroxyapatite, mixing component powder and liquid, molding and curing process. hydroxyapatite concentrations used were 0%, 1.5%, 3%, 4.5%, 6%, 7.5% and 9%. Characterization of PMMA product resulted an average particle size of 48.7 microns, dominant percentage of taxicity in atactic 39.5% and syndiotactic 60.7%. In the FTIR spectra, no impurity compounds were detected in PMMA products. The highest tensile strength value was found in hydroxyapatite which contained 6%, which was 63.87 MPa according to the PMMA standard for denture base.
... This confirms that PMMA is an advantageous resin for developing acrylic dental resins, which is why, for some years on, they have been used in dentistry as base materials for dentures due to their acceptable mechanical properties, including their relative high resistance, acceptable hardness, and low weights [19,20]. However, according to these values, also these materials have numerous of drawbacks that professionals frequently report, the most common being poor mechanical strength, relatively high mechanical deformations, and shrinkage during curing, all due to its relative low Young's, bulk, and shear modulus (shm), Poisson's ratio (Pr), and brittle fracture stress (bfs) [21,22]. ...
Polymethylmethacrylate (PMMA) is a polymer that has been used for several years in dental applications. But its mechanical properties need to be improved that is the tensile, compression, shear, and bulk deformations must be reduced when a strain is applied over PMMA dentures. PMMA is reinforced with graphene getting PMMA-Graphene, PMMA-G, with improved mechanical properties. Three different configurations of PMMA-G are studied and analyzed. Mechanical properties calculation of new PMMA-G polymer is made from a molecular structure of view is done using a method based on which expresses the searched properties of the polymer in terms of connectivity indices and topological variables. Some of the mechanical properties of the PMMA-G are obtained: the bulk modulus, Poisson’s ratios at 298 K, shear modulus, and Young’s modulus. Although some of the obtained properties in this work are not yet reported in scientific literature, the ones that are already are in good agreement.
... Particle agglomerates enabled more mobility for MMA, leading to evaporation at temperatures close to the unhindered monomer. However, these temperature shifts are minor, which leads to the conclusion that there would not be a significant difference in monomer leaching [73]. Furthermore, although other weaker endotherms indicate that volatile additives are easier to release and leach in composites, in PMMA-STO/MnO 2 there was a weaker endothermic peak compared to PMMA around 76 • C, which indicates that hybrid nanoparticles could more efficiently trap some of the smaller molecules. ...
... Particle agglomerates enabled more mobility for MMA, leading to evaporation at temperatures close to the unhindered monomer. However, these temperature shifts are minor, which leads to the conclusion that there would not be a significant difference in monomer leaching [73]. Furthermore, although other weaker endotherms indicate that volatile additives are easier to release and leach in composites, in PMMA-STO/MnO2 there was a weaker endothermic peak compared to PMMA around 76 °C, which indicates that hybrid nanoparticles could more efficiently trap some of the smaller molecules. ...
While dental poly methyl methacrylate(PMMA) possesses distinctive qualities such as ease of fabrication, cost-effectiveness, and favorable physical and mechanical properties, these attributes alone are inadequate to impart the necessary impact strength and hardness. Consequently, pure PMMA is less suitable for dental applications. This research focused on the incorporation of Strontium titanate (SrTiO3-STO) and hybrid filler STO/Manganese oxide (MnO2) to improve impact resistance and hardness. The potential of STO in reinforcing PMMA is poorly investigated, while hybrid filler STO/MnO2 has not been presented yet. Differential scanning calorimetry is conducted in order to investigate the agglomeration influence on the PMMA glass transition temperature (Tg), as well as the leaching of residual monomer and volatile additives that could pose a threat to human health. It has been determined that agglomeration with 1 wt% loading had no influence on Tg, while the first scan revealed differences in evaporation of small molecules, in favor of composite PMMA-STO/MnO2, which showed the trapping potential of volatiles. Investigations of mechanical properties have revealed the significant influence of hybrid STO/MnO2 filler on microhardness and total absorbed impact energy, which were increased by 89.9% and 145.4%, respectively. Results presented in this study revealed the reinforcing potential of hybrid nanoparticles that could find application in other polymers as well.
... However, PMMA is not considered a perfect material due to its poor mechanical and physical qualities. The denture base is subjected to various effects during use, including masticatory forces, thermal changes, saliva, food, and water exposure, and mechanical impacts, all of which can lead to denture failure [2,3] . However, PMMA base material has weak mechanical qualities against fatigue, impact, and bending and they may be modified to enhance PMMA denture base material [4] . ...
Objectives: The objective of this research was to investigate how boron nitride powder addition in percentages of 1% weight and 1.5% weight, affected the thermal conductivity, transverse strength, and surface hardness of heat cured acrylic resin denture base material. Methods: Ninety specimens were made from heat-cured acrylic resin and then divided into three groups based on the tests: a control group, a reinforced poly methyl methacrylate group with 1% weight boron nitride particles, and a reinforced poly methyl methacrylate group with 1.5% weight boron nitride particles. They investigated into the thermal conductivity, transverse strength, and surface hardness tests. Results: This research showed that 1% and 1.5% weight boron nitride particles significantly increased thermal conductivity and surface hardness in comparison to the controlled group. There was a highly significant increase in transverse strength compared to the control group; at the concentration of 1% weight boron nitride particles. Conclusion: Boron nitride particles enhance the thermal conductivity, transverse strength, and surface hardness when added to heat cure acrylic resin denture base material.
... Completely or partial removable dental prosthesis having acrylic denture bases that provide the support for the prosthesis and carry the artificial teeth. [1,2] Polymethyl-methacrylate (PMMA) has become the most broadly used material for the manufacture of denture-base because its moderate cost, has good esthetic appearance, light in weight, easy of processing, and chemically stable. [1,3] However, its poor mechanical properties can lead to denture base fracture. ...
... [1,2] Polymethyl-methacrylate (PMMA) has become the most broadly used material for the manufacture of denture-base because its moderate cost, has good esthetic appearance, light in weight, easy of processing, and chemically stable. [1,3] However, its poor mechanical properties can lead to denture base fracture. [1,4,5] After many years of wearing removable dentures, the denture base is weakened by persistent stress caused by poor denture fit and occlusion, which can lead fracture of the denture base. ...
... [1,3] However, its poor mechanical properties can lead to denture base fracture. [1,4,5] After many years of wearing removable dentures, the denture base is weakened by persistent stress caused by poor denture fit and occlusion, which can lead fracture of the denture base. [6] The characteristics of denture-based PMMA have been improved by many attempts either through chemical composition modifications or additives (macro-, micro-, or nano-fillers). ...
Objectives
Reinforcement of polymethylmethacrylate (PMMA) denture base resins (DBRs) with inorganic fillers with superior properties and accepted aesthetics are favored and still a big dilemma. This study was undertaken to evaluate the color change, flexural strength, and modulus of elasticity of heat-polymerized DBR material modified with silver nanoparticles (AgNPs) and zirconium dioxide nanoparticles (ZNPs).
Methods
Sixty acrylic specimens (30/color test, 30/flexural properties) were fabricated and divided according to nanoparticles type and addition into 3 groups (n = 10). Group-I; unmodified specimens, Group-II; modified specimens with 0.5wt% AgNPs (PMMA/AgNPs), and Group-III; modified specimens with 7.5wt% ZNPs (PMMA/ZNPs). Disc-shape (20 × 3 mm) and bar-shape (65 × 10 × 2.5 mm) specimens were fabricated for color and flexural properties, respectively. The spectrophotometer was used for evaluation of the color change (∆E). The flexural strength and elastic modulus evaluation was carried out using a 3-point bending test (5 mm/min). Tukey’s post hoc and one-way ANOVA were used to analyze the data at a significant level P ≤ 0.05.
Results
PMMA/AgNPs group exhibited a significant increase in color change when compared with PMMA/ZNPs. PMMA/ZNPs showed significantly the highest flexural strength value when compared with unmodified and PMMA/AgNPs groups (P < 0.001), however, there was an absence of significant differences in terms of flexural strength values between PMMA/AgNPs and unmodified groups (P > 0.05). PMMA/AgNPs insignificantly increased its modulus of elasticity strength (P = 0.09410) while PMMA/ZNPs significantly increased its modulus of elasticity strength (P = 0.00396).
Conclusion
The AgNPs and ZNPs addition to PMMA increased the color change and AgNPs change the color of DBRs. The flexural attributes of DBRs have been increased by ZNPs.
... Complete dentures are usually made with polymers, precious metal alloys and base metal alloys [1,2]. Among these, polymer-based materials, especially Poly (methyl methacrylate) resins are widely used for the fabrication of complete and partial dentures [3,4]. The reasons for using PMMA resin as the most common materials are due to its favourable working characteristics, accurate fit, and stability in the oral environment, superior aesthetics, and ease of processing with inexpensive equipment. ...
... The reasons for using PMMA resin as the most common materials are due to its favourable working characteristics, accurate fit, and stability in the oral environment, superior aesthetics, and ease of processing with inexpensive equipment. However, it has a few shortcomings such as the frequent fracture of dentures due to mechanical fatigue and chemical degradation of the base material, low thermal conductivity [1][2][3][4] and ease of microbial adherence to the intaglio surface [5,6]. Numerous researchers have studied the effect of the incorporation of various fillers like metallic particles, fibres, nanoparticles, etc., on the mechanical properties of PMMA materials with varying success [4]. ...
... Dentures, the preferred prosthetic devices for edentulous conditions, boast high success rates. Typically crafted from polymers, precious metal alloys, and base metal alloys [1,2], complete dentures often utilize Poly (methyl methacrylate) (PMMA) resins [3,4]. PMMA stands out due to its favourable attributes-easy workability, precise fit, stability in the oral environment, superior aesthetics, and cost-effective processing. ...
Background:Poly (Methyl methacrylic acid) based materials are widely used for the fabrication of removable complete and partial denture prostheses. these materials are prone to fractures when subjected to impact forces. While recent studies have explored the antimicrobial potential of denture base materials incorporating silver nanoparticles, their impact on the mechanical properties crucial for the prosthesis's durability has not been adequately established.Aim:To evaluate the impact strength of the heat-cure denture base materials incorporated with various concentrations of silver nanoparticles. Materials and Methods:Silver nanoparticles were incorporated at various concentrations (0.5, 1.0, 2.0 and 5.0 wt%) into three different heat-cure denture base materials. A total of 150 rectangular-shaped specimens (50 x 6 x 4), which comprises 50 samples from each of the three heat-cure acrylic resins were made using the compression molding technique. Ten specimens (n=10) were allocated for each concentration such as control, 0.5wt%, 1.0wt%, 2.0wt% and 5.0wt% concentrations of silver nanoparticles. A “V” notch was made exactly at the centre of each specimen to prevent the ductile fracture. The impact strength was evaluated using the Izod impact tester. The data were subjected to One-way ANOVA and Post hoctests for statistical analyses.Results: A decrease in the impact strength was observed in the modified groups compared to the control groups. One-way ANOVA showed significant differences (p=0.000) among the different concentrations of all three denture base materials.Conclusion:Silver nanoparticles incorporation reduced the impact strength of the denture base materials.
... The use of fluoridated dental material is the most effective manner for the prevention of dental caries (16) . It was demonstrated that fluorides containing dental acrylic resins are highly effective for suitable denture hygiene promotion, especially for old age people who require nursing care or have low abilities for performing normal daily living activities and children wearing acrylic appliances (17) . Fluorides which contain dental acrylic resin materials can improve acrylic resin properties (16) . ...
The control of oral hygiene is of great importance, particularly in dental work, to prevent caries caused by bacteria. One method to inhibit bacterial growth is usually by using fluoridated dental materials. The objectives are to assess the effect of sodium fluoride powder (NaF) inclusion with different concentrations on the surface roughness and hardness of heat-cured acrylic resins. A total of forty disc-shaped samples with a diameter of (12±0.1) mm and a thickness of (2±0.1) mm have been fabricated from heat cure acrylic resin. They were grouped into four subgroups according to different concentrations of NaF with 10 specimens for each group. Sodium fluoride powder (NaF) was incorporated into the monomer in concentrations of 0% (control group), 1%, 3%, and 5%. Then mixing was done with polymer according to manufacturer instructions and the conventional flasking, and packing procedures were used. Finally, the specimens are subjected to hardness and surface roughness tests. The results of this study revealed that the lowest mean value surface roughness (Ra) was with the (5%) group of NaF (7828). While, for the surface hardness test, the group (5%) of Naf showed the highest mean value among their subgroups (82.30). According to the results of the current study, sodium fluoride powder (NaF) has a positive effect on both the surface roughness and hardness of acrylic resin.
