scholarly journals Residual monomer content determination in some acrylic denture base materials and possibilities of its reduction

2009 ◽  
Vol 66 (3) ◽  
pp. 223-227 ◽  
Author(s):  
Milena Kostic ◽  
Nebojsa Krunic ◽  
Ljubisa Nikolic ◽  
Vesna Nikolic ◽  
Stevo Najman ◽  
...  
Keyword(s):  
Methyl Methacrylate ◽  
Steam Bath ◽  
Polymerization Process ◽  
Tolerance Range ◽  
Residual Monomer ◽  
Denture Base ◽  
Base Materials ◽  
Acrylic Resins ◽  
Monomer Content ◽  
Reduction Methods

Background/Aim. Polymethyl methacrylate is used for producing a denture basis. It is a material made by the polymerization process of methyl methacrylate. Despite of the polymerization type, there is a certain amount of free methyl methacrylate (residual monomer) incorporated in the denture, which can cause irritation of the oral mucosa. The aim of this study was to determine the amount of residual monomer in four different denture base acrylic resins by liquid chromatography and the possibility of its reduction. Methods. After the polymerization, a postpolymerization treatment was performed in three different ways: in boiling water for thirty minutes, with 500 W microwaves for three minutes and in steam bath at 22? C for one to thirty days. Results. The obtained results showed that the amount of residual monomer is significantly higher in cold polymerizing acrylates (9.1-11%). The amount of residual monomer after hot polymerization was in the tolerance range (0.59- 0.86%). Conclusion. The obtained results denote a low content of residual monomer in the samples which have undergone postpolymerization treatment. A lower percent of residual monomer is established in samples undergone a hot polymerization.

scholarly journals Poly(methyl methacrylate) denture base materials modified with ditetrahydrofurfuryl itaconate: Significant applicative properties

2015 ◽  
Vol 80 (9) ◽  
pp. 1177-1192 ◽  
Author(s):  
Pavle Spasojevic ◽  
Vesna Panic ◽  
Sanja Seslija ◽  
Vladimir Nikolic ◽  
Ivanka Popovic ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Methyl Methacrylate ◽  
Itaconic Acid ◽  
Sem Analysis ◽  
Denture Base ◽  
Elongation At Break ◽  
Poly Methyl Methacrylate ◽  
Base Materials ◽  
Monomer Content ◽  
Acid Esters

The aim of this work was to examine the possibility of modification of commercial denture base materials with itaconic acid esters, in order to obtain material with less toxicity and higher biocompatibility. Despite their relatively higher price compared to methacrylates, itaconic acid and itaconates are materials of choice for environmentally friendly applications, because they are not produced from petrochemical sources, but from plants. Commercial system based on poly(methyl methacrylate) was modified using ditetrahydrofurfuryl itaconate (DTHFI), wherein the ratio of DTHFI was varied from 2.5 to 10% by weight. Copolymerization was confirmed using FTIR spectroscopy, while SEM analysis showed the absence of micro defects and pores in the structure. The effect of the itaconate content on the absorption of fluids, the residual monomer content, thermal, dynamic-mechanical and mechanical properties (hardness, toughness, stress and elongation at break) was investigated. It was found that the addition of DTHFI significantly reduced the amount of residual methyl methacrylate, what made these materials less toxic. It was shown that the increase in DTHFI content gave materials with decreased glass transition temperature, as well as with decreased storage modulus, ultimate tensile strength and impact fracture resistance, however mechanical properties were in the rang prescribed by ADA standards, and can be used in practice. The deterioration of mechanical properties was therefore worth losing in order to gain lesser toxicity of the leached monomer.

Residual monomer content and its release into water from denture base materials

1995 ◽  
Vol 11 (5-6) ◽  
pp. 338-342 ◽  
Author(s):  
Pekka K. Vallittu ◽  
Varpu Miettinen ◽  
Pekka Alakuijala
Keyword(s):  
Residual Monomer ◽  
Denture Base ◽  
Base Materials ◽  
Monomer Content

scholarly journals Testing of residual monomer content reduction possibility on acrilic resins quality

2011 ◽  
Vol 65 (2) ◽  
pp. 171-177 ◽  
Author(s):  
Milena Kostic ◽  
Nebojsa Krunic ◽  
Ljubisa Nikolic ◽  
Vesna Nikolic ◽  
Stevo Najman ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Methyl Methacrylate ◽  
Surface Structure ◽  
Water Storage ◽  
Residual Monomer ◽  
Structure Characteristics ◽  
Acrylic Resins ◽  
Monomer Content ◽  
Dental Acrylic

Poly (methyl methacrylate) (PMMA) is material widely used in dentistry. Despite the various methods used to initiate the polymerization of acrylic resins, the conversion of monomer to polymer is not complete thus leaving some unreacted methyl methacrylate (MMA), known as residual monomer (RM), in denture structure. RM in dental acrylic resins has deleterious effects on their mechanical properties and their biocompatibility. The objective of the work was to test the residual monomer reduction possibility by applying the appropriate postpolymerization treatment as well as to determine the effects of this reduction on pressure yields stress and surface structure characteristics of the acrylic resins. Postpolymerization treatments and water storage induced reduction of RM amount in cold-polymerized acrylic resins improved their mechanical properties and the homogenized surface structure. After the polymerization of heat-polymerized acrylic resins the post-polymerization treatments for improving the quality of this material type are not necessary.

scholarly journals A GAS CHROMATOGRAPHY STUDY ON THE EFFECT OF TWO DIFFERENT CURING CYCLES ON THE RESIDUAL MONOMER CONTENT OF TWO DIFFERENT HEAT CURE DENTURE BASE RESINS.

2020 ◽  
pp. 4-6
Author(s):  
Joy PT ◽  
Bennett Atlin Correya ◽  
V. K Zahida ◽  
Gilsa K. Vasunni ◽  
Julie George Alapatt
Keyword(s):  
Mechanical Properties ◽  
Gas Chromatography ◽  
Allergic Reactions ◽  
Residual Monomer ◽  
Chromatography Method ◽  
Denture Base ◽  
Heat Cure ◽  
Monomer Content ◽  
Methacrylate Monomer ◽  
Methyl Methacrylate Monomer

The conversion of monomer to polymer is not complete in denture base resins and residual monomer left can cause mucosal irritation, inflammation, and allergic reactions in tissues adjacent to dentures. The mechanical properties of denture base resins have been found to be lacking with increased residual monomer content. Therefore, it is desirable to reduce the residual monomer content in the processed denture. In the present study Gas chromatography method was used to determine the levels of residual methyl methacrylate monomer of two different brands of heat cure denture base resins processed by two different polymerization cycles. The study concluded that while processing the denture sufficient length of boiling phase should be given and for each brand, manufacturer’s instructions should be strictly followed while selecting polymerization cycle.

Variation of residual monomer content of poly(methyl methacrylate) dental resins with time, and the influence of water immersion

1989 ◽  
Vol 4 (2) ◽  
pp. 173-182 ◽  
Author(s):  
Robin M. Basker ◽  
Jill Collier ◽  
Ian Smith ◽  
Keith D. Bartle ◽  
Bernard Frere ◽  
...  
Keyword(s):  
Methyl Methacrylate ◽  
Water Immersion ◽  
Residual Monomer ◽  
Poly Methyl Methacrylate ◽  
Dental Resins ◽  
Influence Of Water ◽  
Monomer Content

scholarly journals Comparison of Hardness and Surface Roughness of Two Denture bases Polymerized by Different Methods

2012 ◽  
Vol 3 (2) ◽  
pp. 171-175 ◽  
Author(s):  
Farideh Bahrani ◽  
Mahroo Vojdani ◽  
Anahita Safari ◽  
Ghasem Karampoor
Keyword(s):  
Mechanical Property ◽  
Surface Roughness ◽  
Injection Molding ◽  
Vickers Hardness ◽  
T Test ◽  
Hardness Testing ◽  
Denture Base ◽  
Hardness Tester ◽  
Base Materials ◽  
Acrylic Resins

ABSTRACT Purpose The aim of this study was to evaluate mechanical property hardness and surface roughness (Ra) of different polymerization acrylic resins used for denture bases. Materials and methods A total of 30 specimens were prepared and divided in two groups. A total of 15 samples were processed by the compression molding technique using Meliodent (heatcured). Another 15 samples were processed with cold-cured resin Futura Gen via the injection molding technique. Hardness testing was conducted using a Vickers hardness tester. The Ra test was performed by a profilometer. Data were analyzed using the independent sample t-test and differences were statistically significant at the 0.05 level. Results The Vickers hardness numbers (VHN) were 20.8 ± 2.39 for Meliodent and 21.18 ± 1.42 for FuturaGen, which was not significantly different (p > 0.05). The Ra of Meliodent was 0.92 ± 0.23 µm and for FuturaGen it was 0.84 ± 0.37 µm. There were no significant changes in roughness. Conclusion The hardness and Ra of Meliodent and FuturaGen were not significantly different. Therefore, we recommend the use of FuturaGen for manufacturing denture base materials. How to cite this article Bahrani F, Safari A, Vojdani M, Karampoor G. Comparison of Hardness and Surface Roughness of Two Denture bases Polymerized by Different Methods. World J Dent 2012;3(2):171-175.

scholarly journals MANUFACTURING OF FULL REMOVABLE LAMINAR DENTURES USING DIFFERENT GROUPS OF MATERIALS FOR DENTURE BASES AND THEIR COMPARATIVE CHARACTERISTICS

2020 ◽  
Vol 20 (3) ◽  
pp. 55-59
Author(s):  
V.S. Kuz ◽  
E.B. Tumakova ◽  
G.M. Kuz ◽  
A.I. Teslenko ◽  
L.B. Eris
Keyword(s):  
Base Material ◽  
Clinical Findings ◽  
Denture Base ◽  
Acrylic Plastic ◽  
Base Materials ◽  
Acrylic Resins ◽  
Functional Quality ◽  
Removable Denture ◽  
Edentulous Patients

Restoration of complete maxillary or mandibular adentia, despite the advances of dentistry nowadays, has always been and is still remaining one of the most challenging among the clinical issues of orthopedic dentistry. The effectiveness of a high-quality complete removable denture is largely predetermined by the properties of the denture base material. However, long experience in manufacturing the dentures has revealed a number of their disadvantages. The development of new denture base materials and their studies have been being carried out for many years. The aim of this work was to investigate the effectiveness of thermoplastic base material "Vertex ThermoSense" (Netherlands) and fluorine-containing acrylic plastic "Ftoraks" (Ukraine) used in manufacturing the dentures for edentulous patients who previously worn full removable dentures made of acrylic plastic over the past 3- 5 years. We examined and treated 43 patients with complete anodontia who went to the orthodontic clinic to order a new denture. We used fluorine-containing acrylic co-polymers "Ftorax" (Ukraine) and polyamide (nylon) "Vertex ThermoSense" (Netherlands), recommended by manufacturers for making removable dentures. We assessed the level subjective satisfaction with new dentures in different follow-up time intervals, checked the restoration of the chewing function in the patients using electromyographic techniques. Clinical findings obtained supported the superiority of Vertex ThermoSense thermoplastic material over fluorine-containing acrylic resins in terms of high functional quality and strength that facilitate the durability of these complete dentures. In addition, the denture base made of "Vertex ThermoSense" does not contain residual monomer, thereby preventing the occurrence of allergic reactions. The results of our work allow us to strongly recommend the material "Vertex ThermoSense" to implement into prosthodontic practice for manufacturing complete removable dentures.

Cytotoxicity of long-term denture base materials

2018 ◽  
Vol 41 (10) ◽  
pp. 677-683 ◽  
Author(s):  
Merve Çakırbay Tanış ◽  
Canan Akay ◽  
Handan Sevim
Keyword(s):  
Cell Viability ◽  
Cytotoxic Effect ◽  
Water Storage ◽  
Acrylic Resin ◽  
Denture Base ◽  
Base Materials ◽  
Acrylic Resins ◽  
Group I ◽  
Significant Difference ◽  
Similar Cell

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.

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