A Study of the Interface between Resilient Denture Liners and Polymethylmethacrylate

1980 ◽  
Vol 9 (2) ◽  
pp. 75-80 ◽  
Author(s):  
Wala M Amin ◽  
A M Fletcher ◽  
G M Ritchie

Four of the commonly used resilient denture lining materials were investigated, they were of different chemical composition, physical forms and processing cycles. Scanning electron microscope examinations of the interface between the liners and the regular acrylic resin base material were carried out in an attempt to assess the bonding of these materials to the denture base, and to evaluate the reliability of their use. The effect of water on the liner/denture base interface was also investigated, and the validity of roughening the tissue surface of the denture base prior to processing the liner was assessed. The findings point to the advisability of using the acrylic type of soft liners whenever resilient liners are indicated. Roughening the fitting surface of the denture base to which the resilient lining materials is to be applied has a weakening effect on the bond between the lining and the denture base. Long term exposure of the liners to water has a destructive effect. The infused water into the material leads to swelling and stresses build up at the denture base interface and these tend to promote distortion and reduction in bonding.

2018 ◽  
Vol 21 (1) ◽  
pp. 87-91
Author(s):  
Wesam E Badr ◽  
Hassan M Sakr ◽  
Muhammad A Masoud ◽  
Mohamed A Quassem

2018 ◽  
Vol 15 (4) ◽  
pp. 449-454
Author(s):  
Baghdad Science Journal

This work aims to investigate the tensile and compression strengths of heat- cured acrylic resin denture base material by adding styrene-butadiene (S- B) to polymethyl methacrylate (PMMA). The most well- known issue in prosthodontic practice is fracture of a denture base. All samples were a blend of (90%, 80%) PMMA and (10%, 20%) S- B powder melted in Oxolane (Tetra hydro furan). These samples were chopped down into specimens of dimensions 100x10x2.5mm to carry out the requirements of tensile tests. The compression strength test specimens were shaped into a cylinder with dimensions of 12.7mm in diameter and 20mm in length. The experimental results show a significant increase in both tensile and compression strengths when compared to control (standard) results for the preparation material.


Polymers ◽  
2022 ◽  
Vol 14 (2) ◽  
pp. 230
Author(s):  
Salwa Omar Bajunaid ◽  
Bashayer H. Baras ◽  
Michael D. Weir ◽  
Hockin H. K. Xu

Denture stomatitis is a multifactorial pathological condition of the oral mucosa that affects up to 72% of denture wearers. It is commonly seen on the palatal mucosa and characterized by erythema on the oral mucosa that are in contact with the denture surface. The aim of this study was to incorporate 2-methacryloyloxyethyl phosphorylcholine (MPC) and dimethylaminohexadecyl methacrylate (DMAHDM) into a high impact polymethylmethacrylate heat-cured denture base acrylic resin as a potential treatment for denture stomatitis. We used a comparative study design to examine the effect of incorporating MPC as a protein repellent agent and DMAHDM as an antifungal agent to prevent the adherence of Candida albicans to the denture base material. The dual incorporation of MPC and DMAHDM reduced C. albicans biofilm colony-forming unit by two orders of magnitude when compared to the control group devoid of the bioactive agents. Although the addition of MPC and DMAHDM alone or in combination significantly reduced the flexural strength of the material, they showed reduced roughness values when compared to control groups. This new denture acrylic resin provides the benefit of enhancing C. albicans biofilm elimination through dual mechanisms of action, which could potentially reduce the prevalence of denture stomatitis.


2020 ◽  
Vol 32 (1) ◽  
pp. 66
Author(s):  
Siti Wahyuni ◽  
Chairunnisa Ricca

Pendahuluan: Nilon termoplastik merupakan basis gigi tiruan yang banyak diminati oleh para dokter gigi karena memiliki beberapa keuntungan dibandingkan bahan basis gigi tiruan resin akrilik. Diantara jenis nilon termoplastik yang sering dijadikan basis gigi tiruan adalah poliamida 6 dan poliamida mikrokristalin. Poliamida Mikrokristalin merupakan poliamida generasi baru yang dibuat untuk menanggulangi kelemahan pada poliamida sebelumnya. Tujuan penelitian ini adalah menganalisis pengaruh minuman teh pada pengguna gigi tiruan nilon termoplastik terhadap penyerapan air dan stabilitas warna. Metode: Jenis penelitian ini adalah experimental laboratoris. Jumlah sampel terdiri dari 40 dengan  ukuran diameter 15 mm ± 1 mm dan ketebalan 0.5 mm ± 0,1 mm (ISO 4049) dan terbagi menjadi 4 kelompok (kelompok A poliamida 6 dan kelompok B poliamida mikrokristalin untuk penyerapan air serta kelompok C poliamida 6 dan kelompok D poliamida mikrokristalin untuk uji stabilitas warna). Semua sampel direndam dalam larutan teh selama 7 hari. Data dianalisis dengan uji T Independen. Gambaran mikroskopis sampel diuji dengan SEM Hasil: Berdasarkan uji T Independen hasil menunjukkan perbedaan yang signifikan diantara kelompok A dan B, C dan D.  Uji T independen menunjukkan perbedaan yang signifikan diantara kelompok A dan B, C dan D (p=0,0001, p<0,05) Simpulan: Terdapat pengaruh minuman teh pada pengguna gigi tiruan nilon termoplastik. Poliamida Mikrokristalin memiliki penyerapan air yang lebih sedikit dan stabilitas warna yang lebih baik dibandingkan Poliamida 6.Kata kunci: Nilon termoplastik, poliamida 6, poliamida mikrokristalin, penyerapan air, stabilitas warna, SEM. ABSTRACTIntroduction: Thermoplastic nylon is a denture base mostly demanded by dentists due to its several advantages over acrylic resin denture base material. Among the types of thermoplastic nylon that are often used as denture bases are polyamide 6 and microcrystalline polyamide. Microcrystalline polyamide is the new generation of polyamides created to overcome the weaknesses of previous polyamides. The purpose of this study was to analyse the effect of tea on thermoplastic nylon denture wearers on water absorption and colour stability. Methods: This research was experimental laboratory research on 40 samples with a diameter of 15 mm ± 1 mm, and a thickness of 0.5 mm ± 0.1 mm (ISO 4049), divided into four groups (Group A was the polyamide 6; Group B was the microcrystalline polyamide on the water absorption; Group C was polyamide 6; and Group D was microcrystalline polyamide on the colour stability). All samples were immersed in the tea solutions for 7 days. Data were analysed with independent t-test. The microscopic structure was analysed using the scanning electron microscope (SEM). Results: The results showed significant differences between group A, B, C, and D. The independent t-test also showed significant differences between group A, B, C, and D (p = 0.000; p < 0.05). Conclusion: There is an effect of tea on the thermoplastic nylon denture wearers. Microcrystalline polyamides have less water absorption and better colour stability than Polyamide 6.Keywords:  Polyamide 6, thermoplastic nylon, microcrystalline polyamide, water absorption, colour stability, SEM.


2014 ◽  
Vol 782 ◽  
pp. 603-606 ◽  
Author(s):  
Ondrej Milkovič ◽  
Karel Saksl ◽  
Mária Hagarová ◽  
Štefan Michalik ◽  
Jana Gamcová

This paper is focused to structure characterization of two differently electrodeposited Ni-Co alloys on the copper surface. The chemical composition of the layers was determined by the EDX analysis in the scanning electron microscope. Phase analysis was realized by diffraction in the transmission mode using synchrotron radiation. Diffraction patterns also show the preferred orientation in the coating with saccharine addition.


1991 ◽  
Vol 65 (6) ◽  
pp. 859 ◽  
Author(s):  
John R. Ivanhoe ◽  
Eric D. Adrian ◽  
William A. Krantz

2020 ◽  
Vol 856 ◽  
pp. 36-42
Author(s):  
Chuleeporn Paa-Rai

This work investigates the effect of rejuvenation heat treatment, with double-step solution treatment at the temperature from 1150 °C to 1200 °C, on the recovered microstructure of IN-738 cast superalloy. The superalloy has been long-term exposed as a turbine blade in a gas turbine prior to this study. After double solution treatment and aging at 845 °C for 12 h and 24 h, the recovered microstructures were examined by using a scanning electron microscope. Coarse γ΄ particles, that have presented in damaged microstructures, could not be observed in the samples after the rejuvenation heat treatment. In addition, the image analysis illustrates that the reprecipitated γ΄ particles in the samples with double-step solution treatments increase significantly in sizes during aging than that in the samples with the single-step solution treatment. Furthermore, the measurement of the samples hardness presents that the as-receive sample hardness is improved after rejuvenation heat treatment studied in this work.


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