The biostability of the polymer is one of the critical parameter to use them for biomaterial application. Polyurethane being one of the most compliant polymer but there are concerns regarding its resistance to degradation, particularly from hydrolysis and oxidation. The aim of this study is to synthesise a novel bioactive composite by creating a covalent linkage between polyurethane and nano-apatites and to analyse the in-vitro hydrolytic degradation of a series of newly synthesised polyurethane (PU) and polyurethane/nano-hydroxyapatite (PU/n-HA) composites. Nanoapatite powder was produced through sol-gel technique. A novel polyurethane composite material was prepared by chemically bonding the n-HA to the diisocyanate component in the polyurethane backbone by utilising solvent polymerisation. The concentration of nano-apatite was 5, 10, 15 and 20% wt/wt in polyurethane. Hydrolytic degradation of the PU and PU/n-HA composites were carried out both in deionised water and in phosphate buffer solution (PBS) having (pH 7.4) at 37 C for a predetermined time interval of 90 days. The PU and PU/n-HA composites were physically and chemically characterised by using contact angle measurement, weight loss, Fourier Transform Infrared spectroscopy couples with Photoacoustic Sampling Cell (FTIR-PAS), Raman Spectroscopy, X-ray Diffraction (XRD) and Scanning electron microscopy (SEM). These characterisations showed that with the addition of n-HA the composite exhibits hydrophobic behaviour and degradation rate reduces due to covalent linkage between n-HA and PU. Hence it has been concluded that the degradation rate of the newly developed PU/n-HA composites can be controlled, which helps in tailor making the biomaterial for specific applications.
Objective: The purpose of this study was therefore, to assess the awareness and perception of dental students regarding these products, which are rapidly being marketed in Pakistan. Methods: The study was cross-sectional, close-ended questionnaire based and helped the investigators to compare the awareness and perception of dental students regarding nicotine pouches and e-cigarettes. Students in 1st, 2nd, 3rd and final year of nine dental colleges in Lahore city were targeted to fill the questionnaire via convenience sampling and Microsoft Excel was used to analyze the results obtained. Results: More than 70% of the participants were aware of nicotine pouches and e-cigarettes. However, very few participants had ever used them. Almost 1/3rd of the participants believed that both nicotine pouches and e-cigarettes are less harmful and less addictive than regular cigarettes and can help quit smoking. Conclusion: Generally, people were better aware of e-cigarettes and considered them less harmful and less addictive compared to NPs while NPs were considered as a better alternative to help quit smoking. Keywords: Nicotine pouches, E-cigarettes, new nicotine products, awareness, perception
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