Displaying publications 61 - 73 of 73 in total

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  1. Aiemeeza Rajali, Siti Fauzza Ahmad
    MyJurnal
    Introduction: The compatibility of denture cleanser is crucial in the prevention of failure of adhesion between silicone soft liner and acrylic denture base, thus ensuring the durability of the prosthesis. This scanning electron microscope (SEM) study was to determine the mode of failure and measured the gap formation between silicone soft liners and Polymethylmethacrylate (PMMA) denture base after immersion in denture cleansers. Methods: A total of 135 specimens of PMMA denture base lined with three different silicone soft liners (GC Reline Soft, Mollosil and Tokuyama Sofreliner Tough) were immersed into denture cleansers (Polident® and Stearadent) daily and stored in distilled water at 37±1°C. Specimens were examined and sectioned at 2.5mm and 5.0mm from the margin after 1 day, 30 days and 90 days before analyzed. Results: No significant difference detected in the mode of failure and gap formation after one-day immersion. Adhesive failure was the commonest failure at the margin after 30 days (71.11%) and after 90 days (95.56%). However, 33.33% of specimens showed mixed failure at 5.0mm sectioned after 90 days. A significant difference of gap formation was demonstrated from Mollosil in Steradent at the margin and at 2.5 mm sectioned after 30 days and after 90 days (p
    Matched MeSH terms: Polymethyl Methacrylate
  2. Bean LS, Heng LY, Yamin BM, Ahmad M
    Bioelectrochemistry, 2005 Feb;65(2):157-62.
    PMID: 15713567
    A single-step fabrication of a glucose biosensor with simultaneous immobilization of both ferrocene mediator and glucose oxidase in a photocurable methacrylic film consisting of poly(methyl methacrylate-co-2-hydroxylethyl methacrylate) was reported. The entrapped ferrocene showed reversible redox behaviour in the photocured film and no significant leaching of both entrapped ferrocene and enzyme glucose oxidase was observed because of the low water absorption properties of the co-polymer films. From electrochemical studies, ferrocene entrapped in the co-polymer film demonstrated slow diffusion properties. A linear glucose response range of 2-11 mM was obtained at low applied potential of +0.25 V. The glucose biosensor fabricated by this photocuring method yielded sensor reproducibility and repeatability with relative standard deviation of <10% and long-term stability of up to 14 days. The main advantage of the use of photocurable procedure is that biosensor membrane fabrication can be performed in a single step without any lengthy chemical immobilization of enzyme.
    Matched MeSH terms: Polymethyl Methacrylate
  3. Kannaiyan K, Rakshit P, Bhat MPS, Sadasiva SKK, Babu SC, Ummer H
    J Contemp Dent Pract, 2023 Nov 01;24(11):891-894.
    PMID: 38238278 DOI: 10.5005/jp-journals-10024-3563
    AIM: The current study aimed to determine the impact of three different disinfectants on the surface roughness and color stability of heat-cure acrylic denture material.

    MATERIALS AND METHODS: Using a stainless-steel mold, disc-shaped wax patterns with dimensions of 10 mm in diameter and 2 mm thick (in accordance with ADA Specification No. 12) were created and prepared for a total of 75 acrylic samples. Dimensions of all 75 acrylic samples were checked with a digital Vernier caliper. About 25 samples of denture base material were immersed in three different chemical disinfectants: Group I: immersed in chlorhexidine gluconate solution, group II: immersed in sodium hypochlorite solution, and group III: immersed in glutaraldehyde solution. All samples were scrubbed daily for 1 minute with the appropriate disinfectant and submerged for 10 minutes in the same disinfectant. Between disinfection cycles, samples were kept in distilled water at 37°C. Color stability was measured using a reflection spectrophotometer. Surface roughness values were measured by a profilometer at baseline following 15 days and 30 days.

    RESULTS: After 15 days, the color stability was better in chlorhexidine gluconate solution group (4.88 ± 0.24) than sodium hypochlorite solution (4.74 ± 0.18) and glutaraldehyde solution group (4.46 ± 0.16). The mean surface roughness was less in glutaraldehyde solution group (2.10 ± 0.19), followed by chlorhexidine gluconate solution group (2.48 ± 0.09) and sodium hypochlorite solution group (2.64 ± 0.03). After 30 days, the color stability was significantly better in chlorhexidine gluconate solution group (4.40 ± 0.02), followed by sodium hypochlorite solution (4.06 ± 0.16) and glutaraldehyde solution group (3.87 ± 0.17). The mean surface roughness was significantly lesser in glutaraldehyde solution group (2.41 ± 0.14), followed by chlorhexidine gluconate solution group (2.94 ± 0.08) and sodium hypochlorite solution group (3.02 ± 0.13).

    CONCLUSION: In conclusion, the color stability was significantly better in chlorhexidine gluconate solution group than sodium hypochlorite solution and glutaraldehyde solution group. But the surface roughness was significantly lesser in the glutaraldehyde solution group, followed by the chlorhexidine gluconate and sodium hypochlorite solution group.

    CLINICAL SIGNIFICANCE: The maintenance of the prosthesis requires the use of a denture disinfectant; therefore, it is crucial to select one that is effective but would not have a negative impact on the denture base resin's inherent characteristics over time. How to cite this article: Kannaiyan K, Rakshit P, Bhat MPS, et al. Effect of Different Disinfecting Agents on Surface Roughness and Color Stability of Heat-cure Acrylic Denture Material: An In Vitro Study. J Contemp Dent Pract 2023;24(11):891-894.

    Matched MeSH terms: Polymethyl Methacrylate
  4. Singho ND, Johan MR, Lah NA
    Nanoscale Res Lett, 2014;9(1):42.
    PMID: 24450850 DOI: 10.1186/1556-276X-9-42
    Ag/PMMA nanocomposites were successfully synthesized by in-situ technique. Transmission electron microscopy (TEM) images show that the particles are spherical in shape and their sizes are dependent on temperature. The smallest particle achieved high stability as indicated from Zeta sizer analysis. The red shift of surface plasmon resonance (SPR) indicated the increases of particle sizes. X-ray diffraction (XRD) patterns exhibit a two-phase (crystalline and amorphous) structure of Ag/PMMA nanocomposites. The complexation of Ag/PMMA nanocomposites was confirmed using Raman spectroscopy. Fourier transform infrared spectroscopy spectra confirmed that the bonding was dominantly influenced by the PMMA and DMF solution. Finally, thermogravimetric analysis (TGA) results indicate that the total weight loss increases as the temperature increases.
    Matched MeSH terms: Polymethyl Methacrylate
  5. Hariyanto AP, Endarko E, Mardat MD, Almira L, Ng KH
    Radiography (Lond), 2026 Oct;32(7):103543.
    PMID: 42648226 DOI: 10.1016/j.radi.2026.103543
    INTRODUCTION: Commercial polymethyl methacrylate (PMMA) computed tomography dose index (CTDI) phantoms are widely used for CT dose assessment, but their cost and limited availability may restrict routine quality assurance, especially in resource-limited settings. This study evaluated the feasibility of a low-cost 3D-printed polylactic acid (PLA) head CTDI phantom as a complementary to commercial PMMA phantoms for CT dosimetry.

    METHODS: A 160-mm-diameter PLA head CTDI phantom with five dosimetry holes was fabricated using fused deposition modeling. Its elemental composition, density, effective atomic number, electron density, Hounsfield units (HU), and CT dosimetry parameters were characterized. Measurements were performed on 128-slice Ingenuity Philips and GE Discovery scanners, at 80, 120, and 140 kV. CTDI was measured at two different times and then compared with PMMA.

    RESULTS: PLA showed properties close to PMMA, with differences of 5.08% in density, -0.015% in effective atomic number, and -4.46% in electron density. PLA HU values were lower than PMMA, ranging from 22.5 to 45.3 HU on Philips and 25.1-49.1 HU on GE. CTDIvol deviations between PLA and PMMA ranged from -9.00% to -2.82% in November 2025 and from -5.78% to -3.83% in June 2026. These deviations remained within <10%, which was generally considered acceptable for comparative phantom-based CT dosimetry.

    CONCLUSION: The PLA CTDI phantom showed good effective atomic number, electron density, and dosimetric agreement with the standard PMMA phantom across two CT systems and two measurement time points.

    IMPLICATIONS FOR PRACTICE: 3D-printed PLA CTDI phantom could offer a practical, low-cost complementary tool for comparative CTDI measurement, education, protocol optimization, and quality assurance.

    Matched MeSH terms: Polymethyl Methacrylate
  6. Elshereksi NW, Ghazali MJ, Muchtar A, Azhari CH
    J Dent, 2017 Jan;56:121-132.
    PMID: 27916635 DOI: 10.1016/j.jdent.2016.11.012
    OBJECTIVES: This study aimed to fabricate and characterise silanated and titanated nanobarium titanate (NBT) filled poly(methyl methacrylate) (PMMA) denture base composites and to evaluate the behaviour of a titanate coupling agent (TCA) as an alternative coupling agent to silane. The effect of filler surface modification on fracture toughness was also studied.

    METHODS: Silanated, titanated and pure NBT at 5% were incorporated in PMMA matrix. Neat PMMA matrix served as a control. NBT was sonicated in MMA prior to mixing with the PMMA. Curing was carried out using a water bath at 75°C for 1.5h and then at 100°C for 30min. NBT was characterised via Fourier transform-infrared spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and Brunauer-Emmett-Teller (BET) analysis before and after surface modification. The porosity and fracture toughness of the PMMA nanocomposites (n=6, for each formulation and test) were also evaluated.

    RESULTS: NBT was successfully functionalised by the coupling agents. The TCA exhibited the lowest percentage of porosity (0.09%), whereas silane revealed 0.53% porosity. Statistically significant differences in fracture toughness were observed among the fracture toughness values of the tested samples (p<0.05). While the fracture toughness of untreated samples was reduced by 8%, an enhancement of 25% was achieved after titanation. In addition, the fracture toughness of the titanated samples was higher than the silanated ones by 10%.

    CONCLUSION: Formation of a monolayer on the surface of TCA enhanced the NBT dispersion, however agglomeration of silanated NBT was observed due to insufficient coverage of NBT surface. Such behaviour led to reducing the porosity level and improving fracture toughness of titanated NBT/PMMA composites. Thus, TCA seemed to be more effective than silane.

    CLINICAL SIGNIFICANCE: Minimising the porosity level could have the potential to reduce fungus growth on denture base resin to be hygienically accepTable Such enhancements obtained with Ti-NBT could lead to promotion of the composites' longevity.

    Matched MeSH terms: Polymethyl Methacrylate/chemistry*
  7. Ling BC
    PMID: 11709981
    Standard prosthodontic procedures require five visits to construct a set of complete maxillary and mandibular dentures. Various attempts have been made to reduce these procedures to four or three appointments. However, most of these techniques require the use of visible light polymerized resin as the final denture base materials. Visible light-cured resin materials have inferior physical properties and biocompatibility problems as compared with heat cured polymethylmethacrylate. This paper describes a system of complete denture construction which requires three clinical appointments instead of the usual five visits. This system is made possible by using the VLC base/tray material as the preliminary impression material as well as the application of a new biometric wax occlusion rim. It retains the use of polymethylmethacrylate as the denture base material. This system also utilizes all the procedures used in the conventional five appointment system of complete denture construction.
    Matched MeSH terms: Polymethyl Methacrylate/chemistry
  8. Ling BC
    Quintessence Int, 2004 Apr;35(4):294-8.
    PMID: 15119715
    This article describes a technique of constructing a set of maxillary and mandibular complete dentures in three visits instead of the usual five clinical appointments. This system of complete-denture construction is made possible because of the combined use of visible light-cured material as an impression tray and record base material, as well as the use of new biometric wax occlusion rims. Unlike some earlier techniques that use light-cured resin composites as the denture base materials, this method retains the use of heat-cured polymethylmethacrylate as the denture base material.
    Matched MeSH terms: Polymethyl Methacrylate/chemistry
  9. Haseeb A, Ajit Singh V, Teh CSJ, Loke MF
    J Orthop Surg (Hong Kong), 2019 5 30;27(2):2309499019850324.
    PMID: 31138005 DOI: 10.1177/2309499019850324
    BACKGROUND: Ceftaroline is a cephalosporin that is effective against methicillin-resistant Staphylococcus aureus (MRSA) infections. The objective of this study was to determine the feasibility of using ceftaroline-loaded Polymethyl methacrylate (PMMA) as antibiotic cement against MRSA versus vancomycin-loaded PMMA in an in vitro setting.

    METHODS: PMMA pellets were prepared with three separate concentrations of each of the two antibiotics tested. They were tested to determine the effect of increasing concentration of antibiotics on the biomechanical properties of PMMA and antibiotic activity by measuring the zone of inhibition and broth elution assay.

    RESULTS: Ceftaroline PMMA at 3 wt%, three-point bending was 37.17 ± 0.51 N ( p < 0.001) and axial loading was 41.95 N ± 0.51 ( p < 0.001). At 5-wt% vancomycin-PMMA, three-point bending was 41.65 ± 0.79 N ( p = 0.02) and axial loading was 49.49 ± 2.21 N ( p = 0.01). Stiffness of ceftroline-loaded PMMA in low and medium concentration was significantly higher than the vancomycin. The zone of inhibition for ceftaroline was higher than vancomycin. Ceftaroline at 3 wt% eluted up to 6 weeks (0.3 ± 0.1 μg/ml) above the minimum inhibitory concentration (MIC) and vancomycin at 2.5 wt% eluted up to 3 weeks, same as MIC, that is, 0.5 ± 0.0 μg/ml.

    CONCLUSIONS: Ceftaroline, loaded at similar concentrations as vancomycin into PMMA, is a more potent alternative based on its more favourable bioactivity and elution properties, while having a lesser effect on the mechanical properties of the cement. The use of 3-wt% ceftaroline as antibiotic laden PMMA against MRSA is recommended. It should be noted that this was an in vitro study and to determine the clinical efficacy would need prospective, controlled and randomized studies.

    Matched MeSH terms: Polymethyl Methacrylate*
  10. Seow, L.L., Chong, S.Y., Lau, M.N., Tiong, S.G., Yew, C.C.
    Malaysian Dental Journal, 2008;29(1):34-39.
    MyJurnal
    Certain beverages e.g. coffee, tea, soft drinks, fruit juices, alcoholic beverages, may affect the physical properties of composite resins. Objectives: The objectives of this study were to: (1) evaluate the effect of different beverages and chilli sauce on the wear resistance of composite resins, (2) evaluate effect of the duration of immersion in the beverages and chilli sauce on the wear resistance of composite resins.

    Materials and methods: Disc specimens were fabricated using two different types of composite resins: (i) Filtek Z350 (3M ESPE, USA, nano-filled composite, 40 specimens) and (ii) Solare P (GC Dental Products Corp, Japan, microhybrid composite, 40 specimens). After polymerization, all the specimens were polished using Enhance Polishing System (Dentsply International Inc.,USA). The specimens were air-dried before weighing using Sartorius BP 221S weighing balance (Sartorius AG, Goettingen, Germany). Ten specimens from each type of composite were immersed in distilled water (control group), Coca cola®, orange juice (Peel Fresh®) and chilli sauce (Maggi®) respectively. The duration of immersion was 6 hours and 1 week. A reciprocal compression-sliding system was used to evaluate the wear resistance of the specimens. The specimens were moved back and forth with a loaded counter-body (235g) against sand paper (P1000, 3M ESPE, USA) in running water. The weight of the specimens were measured after 6 hours of immersion and 20,000 wear cycles and also at 1 week of immersion with further 20,000 wear cycles. The wear resistances were tabulated as percentage of weight loss from the specimens. Results were statistically analyzed using one way ANOVA and post-hoc Tukey’s test (p= 0.05).
    Results: The results showed that Solare P has significantly lower wear resistance compared to Filtek Z350. There was no significant difference in wear resistance for Filtek Z350 when immersed in chili sauce, Coca-cola® and orange juice in comparison with control group for 6 hours and 1 week. Similar findings were observed for Solare P.

    Conclusion: Within the limitations of this study, it was concluded that Solare P has poorer wear resistance than Filtek Z350. The soaking medium investigated and duration of immersion have no influence on the wear resistance of Solare P and Filtek Z350.
    Matched MeSH terms: Polymethyl Methacrylate
  11. Mohd Nazri Idris, Hazizan Md. Akil, Zainal Arifin Ahmad
    MyJurnal
    Sodium silicate was used to synthesize silica fine particles at room temperature using non-ionic surfactant of triethanolamine (TEA), dissolution salt and precipitating agent. The experiments were conducted by different composition of precursor material, nonionic surfactant and dissolution salt concentrations through the sol-gel process. Various particle sizes in the range 100-300nm were synthesized. The particle size of silica powders were analyzed via Field Emission Scanning Electron Microscope (FESEM), Energy Dispersive X-ray Analysis (EDAX), X-Ray Fluorescence (XRF), and Fourier Transformation Infrared (FTIR). The result has demonstrated that the particle size can be controlled by changing the ratio of non-ionic surfactant and dissolution salt or the sodium silicate concentration.
    Matched MeSH terms: Polymethyl Methacrylate
  12. Omar MM, Wan Ibrahim WA, Elbashir AA
    Food Chem, 2014 Sep 1;158:302-9.
    PMID: 24731346 DOI: 10.1016/j.foodchem.2014.02.045
    A sol-gel hybrid sorbent, methyltrimethoxysilane-tetraethoxysilane (MTMOS-TEOS) was successfully used as new dispersive solid phase extraction (dSPE) sorbent material in the determination of acrylamide in several Sudanese foods and analysis using GC-MS. Several important dSPE parameters were optimised. Under the optimised conditions, excellent linearity (r(2)>0.9998) was achieved using matrix matched standard calibration in the concentration range 50-1000 μg kg(-1). The limits of detection (LOD) and limit of quantification ranged from 9.1 to 12.8 μg/kg and 27.8-38.9 μg/kg, respectively. The precision (RSD%) of the method was ⩽6.6% and recoveries of acrylamide obtained were in the range of 88-103%, (n=3). The LOD obtained is comparable with the LODs of primary secondary amine dSPE. The proposed MTMOS-TEOS dSPE method is direct and safe for acrylamide analysis, showed reliable method validation performances and good cleanup effects. It was successfully applied to the analysis of acrylamide in real food samples.
    Matched MeSH terms: Polymethyl Methacrylate
  13. Ali IL, Yunus N, Abu-Hassan MI
    J Prosthodont, 2008 Oct;17(7):545-9.
    PMID: 18761582 DOI: 10.1111/j.1532-849X.2008.00357.x
    This study compared the surface hardness, flexural strength, and flexural modulus of a light- and heat-cured urethane dimethacrylate (UDMA) to two conventional polymethyl methacrylate (PMMA) denture base resins. The effect of less-than-optimal processing condition on the hardness of internal and external surfaces of UDMA specimens was also investigated.
    Matched MeSH terms: Polymethyl Methacrylate
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