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 Hardness of denture base and hard chair-side reline acrylic resins

2005 ◽  
Vol 13 (3) ◽  
pp. 291-295 ◽  
Author(s):  
Andrea Azevedo ◽  
Ana Lucia Machado ◽  
Carlos Eduardo Vergani ◽  
Eunice Teresinha Giampaolo ◽  
Ana Cláudia Pavarina
Keyword(s):  
Surface Hardness ◽  
Acrylic Resin ◽  
Polymerization Reaction ◽  
Time Intervals ◽  
Denture Base ◽  
Continuous Increase ◽  
Hardness Tester ◽  
Dry Storage ◽  
Base Materials ◽  
Acrylic Resins

INTRODUCTION: The hardness of denture base materials may undergo changes due to continued polymerization reaction and water uptake. However, the extent to which these processes affect the hardness of materials is still unclear. OBJECTIVE: In this study, the degree of conversion of two hard chair-side reline resins (Duraliner II-D and Kooliner-K) and one heat-cured acrylic resin (Lucitone 550-L) was evaluated indirectly by measuring the surface hardness. The effect of immersion in water on this property was also analyzed. MATERIALS AND METHODS: After processing following the manufacturers' instructions, specimens (5mm diameter and 2mm thickness) were dry stored at room temperature and the Vickers hardness (VHN) was measured with a hardness tester after 0, 2, 7, 30 and 90 days. Specimens were then immersed in water at 37ºC and hardness was evaluated after the same time intervals. Five specimens were prepared for each material. Data were analyzed by Kruskal-Wallis test (P=.01). RESULTS: When dry stored, material L showed an increase in hardness (P<.01) from 0-day (VHN=23.2) to 30-day (VHN=27.1), after which no significant change was observed. A continuous increase in hardness was observed for material D from 0-day (VHN=4.6) to 90-day dry storage (VHN=7.3). For material K, an increase in hardness was observed up to 7-day (VHN=9.2), and then leveled off (P>.01). After 2-day water storage, all materials showed a significant reduction in hardness (P<.01). CONCLUSION: In general, the hardness of the materials evaluated increased during dry storage and decreased after immersion in water.

scholarly journals PERBANDINGAN KUALITAS MATERIAL BEARING MERK SKF, FMB, NKK, DAN JAL TERHADAP TERHADAP SIFAT FISIS DAN MEKANIS

2017 ◽  
Vol 18 (2) ◽  
Author(s):  
Masyrukan Masyrukan ◽  
Ngafwan Ngafwan ◽  
Taufik Surya Nugroho
Keyword(s):  
Surface Roughness ◽  
Vickers Hardness ◽  
Ball Bearing ◽  
Hardness Testing ◽  
Test Analysis ◽  
Hardness Tester ◽  
Microstructure Observation ◽  
Materials Used ◽  
Working Parameters

ABSTRAK Penelitian ini bertujuan untuk mengetahui kualitas bahan yang digunakan pada empat merk bearing (SKF, FMB, NKK, dan JAL) berdasarkan data-data pengujian sifat- sifat mekanik serta struktur intern (struktur mikro) pada benda uji tersebut dan dapat membandingkan ketahanan dan kekuatan keempat merk bearing tersebut berdasarkan analisis pengujian terhadap kegunaannya. Pengujian yang dilakukan meliputi pengujian kekerasan menggunakan alat Micro Vickers Hardness Tester, pengamatan struktur mikro menggunakan alat Olympus Metallurgical Microscope dan Olympus Phtomicrographics Systems, serta pengujian kekasaran permukaan menggunakan alat Surfcorder. Pengujian kekerasan maupun struktur mikro dilakukan pada bagian cincin luar bantalan (outer bearing) dan ball bearing. Sedangkan pengujian kekasaran permukaan hanya pada bagian outer bearing. Setelah dilakukan semua pengujian dapat disimpulkan bahwa berdasarkan kekuatan, kekerasan (ketahanan aus) serta kekasaran permukaan pada bagian outer bearing dan ball bearing maka merk yang memenuhi kualitas optimum adalah merk FMB karena sudah mencukupi dengan parameter kerja bantalan sehingga membuat umur pakai lebih panjang pada aspek penggunaan yang sama. Kata kunci: bearing, kekerasan, struktur mikro, kekasaran permukaan ABSTRACT This study aims to determine the quality of materials used in four bearing brands (SKF, FMB, NKK, and JAL) based on data testing of mechanical properties as well as internal structure (micro structure) on the specimens and can compare the endurance and the strength of the four brands bearings based on the test analysis of its usefulness. The tests include hardness testing using the Micro Vickers Hardness Tester tool, microstructure observation using Olympus Metallurgical Microscope and Olympus Phtomicrographics Systems, and surface roughness testing using Surfcorder tool. Hardness testing and microstructure are performed on outer bearing and ball bearing parts. While the surface roughness testing only on the outer bearing. After all tests, it can be concluded that based on strength, hardness (wear resistance) and surface roughness on outer bearing and ball bearings, the brand that meets the optimum quality is the FMB brand because it is sufficient with the bearing working parameters that make longer life on the same aspect of use. Keywords: bearing, strengthness, microstructure, surface roughness

Surface Roughness of Denture Base Acrylic Resins After Processing and After Polishing

2006 ◽  
Vol 15 (3) ◽  
pp. 180-186 ◽  
Author(s):  
Julie C. Berger ◽  
Carl F. Driscoll ◽  
Elaine Romberg ◽  
Qing Luo ◽  
Geoffrey Thompson
Keyword(s):  
Surface Roughness ◽  
Denture Base ◽  
Acrylic Resins

scholarly journals Surface Characteristics of Milled and 3D Printed Denture Base Materials Following Polishing and Coating: An In-Vitro Study

Materials ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3305
Author(s):  
Pablo Kraemer Fernandez ◽  
Alexey Unkovskiy ◽  
Viola Benkendorff ◽  
Andrea Klink ◽  
Sebastian Spintzyk
Keyword(s):  
Surface Roughness ◽  
3D Printing ◽  
In Vitro Study ◽  
Surface Characteristics ◽  
Denture Base ◽  
Liquid Resin ◽  
Base Materials ◽  
Superior Surface ◽  
3D Printed

(1) Background: To date, no information on the polishability of milled and 3D-printed complete denture bases has been provided, which is relevant in terms of plaque accumulation. (2) Methods: three groups (n = 30) were manufactured using the cold-polymerization polymethilmethacrilate, milling (SM) and 3D printing (AM). 10 specimens of each group were left untreated (reference). 10 more specimens were pre-polished (intermediate polishing) and 10 final specimens were highgloss polished. An additional 20 specimens were 3D printed and coated with the liquid resin (coated), 10 of which were additionally polished (coated + polished). For each group Ra and Rz values, gloss value and REM images were obtained. (3). The “highgloss-polished” specimens showed statistically lower Ra and Rz values in the SM, followed by AM and conventional groups. In the AM group statistically lower surfaces roughness was revealed for highgloss-polished, “coated + polished”, and “coated” specimens, respectively. (4) Conclusions: The milled specimens demonstrated superiors surface characteristics than 3D printed and conventionally produced after polishing. The polished specimens demonstrated superior surface characteristics over coated specimens. However, the surface roughness by both polished and coated specimens was within the clinically relevant threshold of 0.2 µm.

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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