59 research outputs found
An experimental fibre-reinforced dental resin composite
No full textPhD ThesisFibre-reinforced dental resin composites (FRCs) have shown increased fracture
resistance and tensile strength compared with particulate filled composites (PFC).
However, clinically successful restorative materials require adequate bond strength and
wear resistance along with high strength.
An experimental FRC (ST) was developed and tested as a dentine replacement. It has
randomly distributed E-glass fibres above their critical length of 0.5-1.6 mm. This work
aimed to evaluate the possibility of using ST as a single restorative material by
assessing its three-body wear resistance and surface contact fatigue. The
polymerisation shrinkage, water sorption, and bond strength of ST were also assessed.
Two commercially available materials; an FRC (Build It FR) and PFC (Z250) were used
as comparators. ST showed significantly lower wear resistance and higher contact
fatigue. No significant difference was found regarding polymerisation shrinkage but ST
had significantly higher water sorption, lower shear bond strength (SBS) to human
dentine.
SBS of the interfacial layers within and between the dental resin composites was
evaluated after 24 hours and 1 year of water storage in the absence of an oxygen
inhibition layer. Build It/Z250 showed a significantly higher SBS at both time intervals.
The presence of an oxygen inhibited layer increased the interfacial strength in all groups
except ST/Z250.
ST formulations were varied in resin/diluent (Bis-GMA/TEGDMA) ratios, filler loading
and fibre lengths for development. Wear testing found changing the Bis-GMA/TEGDMA
ratio from 60/40 to 70/30 decreased the wear resistance regardless of filler loading and
fibre length.
In summary, wear resistance of ST and its variants was insufficient to recommend its
use as a single restorative material without a surface veneer of PFC. As a dentine
replacement, ST was only comparable with Z250 and Build It in polymerisation
shrinkage and SBS between composites in the absence of an oxygen inhibition layer
Surface roughness and gloss retention of bioactive resin composite after simulated toothbrush abrasion
No full textBackground. Newly introduced bioactive resin composites are being used more often. Few studies have evaluated the influence of toothbrush abrasion on their surface characteristics. Methods. This study aims to assess the surface roughness (Ra) and gloss values (GU) of 3 bioactive composites and a conventional nanohybrid composite before and after simulated toothbrush abrasion. Five samples each of Filtek Z250 XT, Beautifil Flow Plus, Activa Presto and Predicta Bioactive Bulk were subjected to 10,000 cycles of simulated toothbrush abrasion. Ra and GU values were evaluated at baseline and after each 2,500 cycles. Results. Significant difference was found in both Ra and GU (P 0.05). After 7,500 cycles, the mean Ra value of Activa Presto at 0.64 (0.14) was significantly higher than that of Z250 XT at 0.49 (0.03) (P < 0.001). At 10,000 cycles, Activa Presto had significantly higher Ra at 0.70 (0.10) when compared to Z250 XT at 0.52 (0.08), Beautifil Flow Plus at 0.56 (0.07) and Predicta Bioactive Bulk at 0.59 (0.10) (P < 0.001). Conclusion. All materials showed an increase in Ra and decrease in GU after simulated toothbrushing
Comparative analysis of finishing and polishing procedures on gloss and color stability in bioactive dental resin composites
No full textObjective . The aim of this study was to assess the effect of different polishing systems on the color stability of bioactive dental resin composites compared to a conventional composite. Materials and Methods . Two different bioactive dental resin composites (Beautifil Flow Plus F00 and Activa Presto) along with a nanohybrid composite (Filtek Z250 XT) were tested. A total of 20 samples per material were prepared and divided into four groups as per polishing protocol: Sof-Lex Diamond, Jiffy and TorVm polishing systems as well as a control group without polishing. A spectrophotometer was used to measure the color parameters before and after immersion in a coffee solution for 12 days. The color change (ΔE _00 ) was calculated after immersion for each sample. Gloss was also measured at baseline and post immersion using a gloss meter. Results . There was a significant change in both ΔE _00 and gloss in all materials (p < 0.05). Z250 XT exhibited better color stability and gloss retention, particularly with the Jiffy system. Beautifil Flow Plus F00 demonstrated acceptable color stability and high gloss with the TorVm discs. Activa Presto showed significant color changes across all polishing systems. Conclusions . This work highlights the importance of understanding the effect of polishing systems on dental resin composites for optimal aesthetic outcomes. Despite the obvious benefits of bioactivity in both Beautifil Flow Plus F00 and Activa Presto, their performance regarding both color stability and gloss retention was lower than the inert Z250 XT. These findings emphasize the need for careful material and technique selection in clinical practice to ensure the longevity and esthetic quality of dental restorations
Investigating the impact of whitening toothpastes on bioactive resin-based restorative materials: a comparative analysis
No full textAbstract Objective To assess the color stability and surface roughness of bioactive resin-based composite following exposure to coffee staining and brushing with whitening toothpastes. Methods Disk-shaped specimens of Filtek Z250 (FZ), Beautifil Flow Plus (BFP), Activa Presto (AP), and Fuji II LC (FII) were stained with coffee and then brushed with one of three toothpastes, conventional (C-TP), non-peroxide whitening (W-TP) or hydrogen peroxide-containing whitening toothpaste (HPW-TP) for 10 000 cycles. Changes in color (ΔE00) and surface roughness were measured. Results Two-way ANOVA revealed a significant interaction between restorative material and toothpaste type in roughness (p = 0.049) and ΔE00 (p = 0.007). FII consistently had the highest surface roughness change across all toothpastes, and AP showed significantly higher value than BFP and FZ with C-TP and W-TP (p 0.05). Additionally, the effect of toothpaste type on individual parameters, as well as the interaction between material and toothpaste type, was nonsignificant (p > 0.05). Conclusion All materials tested showed increased roughness and unacceptable staining with none returning to baseline color or achieving acceptable color change post toothbrushing, irrespective of toothpaste type. Clinical significance Understanding the effects of staining and whitening toothpastes on bioactive resin-based composites is important for optimizing material selection and maintenance protocols to ensure long-lasting esthetic outcomes in patients prone to staining
Utilizing Light Cure Units: A Concise Narrative Review
No full textThe use of photo-curable resin composite restorations is an essential treatment modality in modern dental practice. The success and longevity of these restorations depend on achieving predictable and effective polymerization. Understanding the dynamics of the polymerization and the effect of light cure units (LCUs) on this process is paramount. The goal of this concise narrative review is to provide a simplified presentation of basic principles of composite chemistry, polymerization reactions, and photo-curing with relevant terminologies. Clinical guidelines for choosing and maintaining LCUs, as well as safety precautions and factors under the control of the clinician are listed. Finally, clinical recommendations of LCUs’ usage and monitoring are included to aid practitioners in achieving predictable polymerization during the placement of direct resin composite restorations
HIJAB COMMODIFICATION IN REJOICE HIJAB SHAMPOO TELEVISION ADS BASED ON JOHN FISKE’S SEMIOTIC ANALYSIS
No full textThis study aims to determine how the semiotic meaning of veiled women in the shampoo advertisement of Rejoice Hijab #Hijabisa by Fatin Shidqia Lubis. Author using John Fiske's semiotics analysis to identify and describe meaning on its ads. John Fiske's semiotics theory consist of three main area, namely: the sign itself, the code or system that operates the mark, and the midwifery where the code and the sign work. John Fiske's semiotics analysis also have three levels, namely: the level of reality, the level of representation, and the level of ideology. But the author only use one group, that is the level of reality which includes several codes, such as display codes, dress codes, gesture codes, and expression codes. This research using descriptive-qualitative approach, while the research method used is John Fiske's semiotic analysis. The results of this study that Rejoice Hijab shampoo ad version of Fatin Shidqia Lubis is a commercial ad, the ad depicts the self-image of the veiled woman displayed in a trendy, fashionable, stylish and contemporary style by changing the veiled culture according to religion. Although shown with a very active and energetic role, but this message carries a religious symbol starting from the display code, where the gestures displayed do not comply with Islamic religious norms. The use of Fatin Shidqia Lubis as a veiled woman is a brand ambassador to convince audiences that the #Hijabisa tagline can indeed be proven by this singer even though she wears the hijab. Three benefits of 1 product are offered through a song by Fatin with a demonstration of 3 hair treatments. The use of women wearing hijab shows to attract the attention of consumers, where current hijab trends have developed so that producers are interested in creating the latest shampoo products by incorporating symbols from Islam
The concept of Ar Rijal Qawwamun ‘Ala An-Nisa' in combating domestic violence during Covid-19 pandemic in Malaysia / Farah Safura Muhammud and Fatin Nur Majdina Nordin
No full textThe country’s Covid 19 pandemic has prompted the government to implement MCO beginning in March 2020. According to Royal Malaysia Police (PDRM) statistics, a total of 5260 cases of domestic violence were reported from January to December 2020.While Talian Kasih Ministry of Women, Family and Community Development (KPWKM) statistics show a total of 2540 cases were received during the same period. Meanwhile, 902 cases of domestic violence were reported in the first four months of 2021, from January to April. These statistics show that the issue of domestic violence necessitates the intervention and cooperation of multiple parties.The objective of this writing is to understand the empowerment of men in the Quran through the concept of ar rijal qawwamun ‘ala an-nisa’. Secondly to propose a strategy for combating domestic violence in Malaysia and thirdly to introduce the initiative of NGO such as HELWA ABIM in combating domestic violence during pandemic. According to studies, financial problems and uncertainty about the future are among the factors that contribute to the occurrence of domestic violence. This issue should be thoroughly researched, beginning with the development and empowerment of men through the concept of ar rijal qawwamun ‘ala an-nisa. This conceptual paper focuses on several document analysis methods and discusses ar rijal qawwamun ‘ala an-nisa’ concept and domestic violence. As a result, the author proposes a strategy for empowering men in the household in order to reduce domestic violence in Malaysia such as enhancement to the marriage course module, male economic system empowerment and salary cuts for fixed income with direct payments into dependent bank accounts
An experimental study on stabilization of Pekan clay using polyethylene and polypropylene
No full textMany countries are expressing concern over the growing issues of polyethylene terephthalate (PET) bottles and polypropylene (PP) products made by the household sector. The rapid increase in the generation of plastic waste all around the world is due to the economic development and population growth. PP is the world's second-most widely produced synthetic plastic, after polyethylene. Statistics show that nearly 50% of the municipal solid waste in Malaysia comes from the institutional, industrial, residential, and construction waste. This paper presents the results of an investigation on the utilisation of fibres as products of PET bottles and PP products in order to improve the engineering properties of clay soil in Pekan. The soil samples were taken from Kampung Tanjung Medang, Pekan, Pahang. The basic properties of the clay soil were determined as follows; optimum moisture content: 32.5%, maximum dry density: 13.43 kN/m3, specific gravity: 2.51, liquid limit: 74.67%, plastic limit: 45.98%, and plasticity index: 28.69%. This investigation concentrates on the shear strength of the reinforced clay soils with PET and PP in random orientation. The reinforced soil samples were subjected to unconfined compression test (UCT) to differentiate their shear strength with that of the unreinforced soil. The tests found that the waste fibres (PET and PP) improved the strength properties of the Pekan clayey soils. The unconfined compressive strength (UCS) value increased with the increasing percentage of PET fibre and reached the optimum content at 10% reinforcement, where it showed the highest improvement of 365 kN/m2 from 325 kN/m2 and depleted when the optimum content reached 20% reinforcement. For PP fibre, the reinforced soil showed the highest UCS at 20% reinforcement with the improvement of 367 kN/m2. The study concluded that the PET and PP fibres can be utilised successfully as reinforcement materials for the stabilisation of clayey soils. The use of these waste compounds as alternative materials for clay soil stabilisation is reasonable and cost effective since they are constantly available
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