ABSTRACT
Fullerene C60 is a ubiquitous material for application in organic electronics and nanotechnology, due to its desirable optoelectronic properties including good molecular orbital alignment with electron-rich donor materials, as well as high and isotropic charge carrier mobility. However, C60 possesses two limitations that hinder its integration into large-scale devices: (1) poor solubility in common organic solvents leading to expensive device processing, and (2) poor optical absorbance in the visible portion of the spectrum. Covalent functionalization has long been the standard for introducing structural tunability into molecular design, but non-covalent interactions have emerged as an alternative strategy to tailor C60-based materials, offering a versatile and tuneable alternative to novel functional materials and applications. In this work, we report a straightforward non-covalent functionalization of C60 with a branched polyethylene (BPE), which occurs spontaneously in dilute chloroform solution under ambient conditions. A detailed characterization strategy, based on UV-vis spectroscopy and size-exclusion chromatography was performed to verify and investigate the structure of the C60+BPE complex. Among others, our work reveals that the supramolecular complex has an order of magnitude higher molecular weight than its C60 and BPE constituents and points towards oxidation as the driving force behind complexation. The C60+BPE complex also possesses significantly broadened optical absorbance compared to unfunctionalized C60, extending further into the visible portion of the spectrum. This non-covalent approach presents an inexpensive route to address the shortcomings of C60 for electronic applications, situating the C60+BPE complex as a promising candidate for further investigation in organic electronic devices.
ABSTRACT
BACKGROUND: Despite substantial breakthroughs in instrumentation systems and pharmaceutical interventions, pain following endodontic therapy remains a serious concern. The effect of the type of endodontic instrumentation system in post-operative pain after endodontic therapy has been a matter of debate. AIM: To evaluate different endodontic instrumentation systems, namely Reciproc (GmbH, Munich), OneShape® (MicroMega, France), Protaper Gold (Dentsply Sirona, USA), and Hyflex® EDM (Coltène/Whaledent Inc., USA) file systems, regarding post-operative pain after endodontic therapy Methods and materials: The endodontic department treated healthy patients aged 20 to 50 years who were experiencing symptoms of irreparable pulpitis in one or more maxillary molars or mandibular molars. Five hundred was the determined size of the sample. The study participants were divided into five categories, each comprising 100 participants. These categories were: Category 1: Reciproc instrumentation system. Category 2: OneShape® instrumentation system. Category 3: ProtaperGold instrumentation system. Category 4: HyFlex® EDM instrumentation system. Category 5: Control (stainless steel K-files). Following endodontic therapy, these scores were recorded at 6 hours, 12 hours, 24 hours, 48 hours, and 72 hours using the VAS scale. RESULTS: The visual analog scale (VAS) score (mean±SD) in the control group was 0.73± 0.40 (<0.001). The VAS score in the Reciproc group was 0.43± 0.05 (<0.001). The VAS score in the OneShape® group was 0.36±0.09 (<0.001). The VAS score in the Protaper Gold group was 0.41 ±0.08 (<0.001). The VAS score in the HyFlex® EDM group was 0.55 ±0.02 (<0.001). The VAS score in all instrumentation techniques at 72 hours follow-up was lesser in comparison to a control group with meaningful statistical significance (<0.001). However, the post-operative pain among the Reciproc, OneShape®, Protaper Gold, and HyFlex® EDM instrumentation systems was not different clinically when compared among themselves. However, VAS values were greater in OneShape® and HyFlex® EDM compared to Reciproc and Protaper Gold, showing increased post-operative pain in OneShape and HyFlex® EDM compared to Reciproc and Protaper Gold. It was also observed that there was a decline in the VAS score in all instrumentation systems as the follow-up period increased from 6 hours to 72 hours, with maximum post-operative pain at 6 hours of follow-up and minimum post-operative pain at 72 hours of follow-up. However, the decline was lesser in OneShape® and HyFlex® EDM in comparison to Reciproc and Protaper Gold, with increased post-operative pain in OneShape® and HyFlex® EDM in comparison to Reciproc and Protaper Gold. CONCLUSION: Post-operative pain at all follow-ups of endodontic procedures was less in Reciproc, OneShape®, Protaper Gold, and HyFlex® EDM than in the control group. VAS scores were higher in the OneShape® and HyFlex® EDM groups compared to the Reciproc and Protaper Gold groups, indicating increased post-operative pain with OneShape® and HyFlex® EDM instruments in comparison to Reciproc and Protaper Gold.
ABSTRACT
BACKGROUND AND AIM: A sessile multicellular organism that is immersed in a self-produced matrix of extracellular polymeric substances and has its cells firmly attached to a surface is referred to as a microbial biofilm. When it comes to pulp and periradicular pathosis, biofilms are crucial. To reduce the number of microorganisms in the root canal and assist in treating periapical pathosis, endodontic therapy must include decontamination of the system of tooth root canals through biomechanical preparation and irrigation of the root canal. This study compares sodium hypochlorite (NaOCl), povidone-iodine, chlorhexidine, curcumin, and triphala as endodontic irrigating solutions regarding their capacity to eliminate biofilm from root canals. MATERIALS AND METHODS: A total of 60 patients were included if they had pulpitis. Two specific samples (samples A and B) were chosen for analysis from a collection of samples so that their bacterial composition is most similar to that of acute pulpitis. The suspensions of bacterial cells from this polymicrobial culture have been collected from frozen stock and then regrown by inoculation on Columbia agar base (Basingstoke, UK) with the addition of vitamin K1, hemin, and 5% (v/v) calf blood. The pureness of the suspensions was assessed using colony morphology and Gram staining. Analytical profile index (API) 20A tests or automated test for bacteria (ATB) ID 32A tests were initially used to identify the isolates. These polymicrobial cultures' in vitro biofilms were developed using membrane filters made of cellulose nitrate. The tested irrigating solutions were as follows: 5.25% sodium hypochlorite, 10% triphala, 0.2% chlorhexidine gluconate, 10% povidone-iodine, and 5% curcumin (CUR). On the other hand, phosphate-buffered saline was taken as a control agent. RESULTS: As the standard of excellence in endodontic irrigation, NaOCl has eliminated all germs in sample A following 15 minutes of culture and in both of the specimens after 40 minutes. Iodine also eliminated all germs after 40 minutes of administration, indicating that it would be worth exploring using iodine as a potential endodontic irrigant. Iodine achieved total bacterial elimination after 40 minutes in both samples; however, it was less effective after 15 minutes. Our findings indicate that iodine solution is the most suitable alternative after the supremely effective NaOCl, although it requires longer contact times to generate the necessary and recognized broad-spectrum antibacterial properties, including in the case of biofilms. Furthermore, curcumin also showed significant results after NaOCl and iodine. CONCLUSION: The antibacterial potency of each studied irrigant was significant, supporting their usage in endodontics. It was observed that NaOCl has the maximum antibacterial activity.