ENGINEERING HIGH PERFORMANCE EPOXY THERMOSETS USING NEXT-GENERATION IMPACT MODIFICATION

Optimization of fracture toughness of high Tg thermosets was done through systematic investigation of different formulations of reactive functional modifiers using soft particle impact modification. Important parameters like particle size, interparticle distance (IPD) were varied by altering cure kinetics and modifying the molecular architecture of the additives. The best performing systems showed an increase in fracture toughness of 70-80% with an optimum Rp of 1.3 μm and IPD of 0.4 μm at 15 vol% impact modifier. In addition, a new platform of using block copolymer blends was studied for its feasibility to achieve non-spherical morphology for effective impact modification. The micromechanics of this approach is discussed and techniques like optical and scanning electron microscopy were used to investigate the toughness mechanisms. Block copolymers with different molecular weights, backbone structures and architectures were blended in different ratios and the fracture toughness achieved using non-spherical morphologies was compared to the spherical modifiers. The effect of particle size and shape on the fracture was evaluated by defining a metric called shape factor. Fracture toughness was seen to correlate well with the morphology and three-fold improvement was observed over the conventional spherical modifiers. Fundamental studies on the effect of functional additives on network structure of thermosets were also done by measuring their physical and mechanical properties using techniques such as DSC, DMA and non-linear compression testing. Model non-stoichiometric networks were made with DGEBA and DDM with excess mole ratio of amine and epoxy groups. The trend in the properties of the networks at low strain regions in compression testing and before the Tg in DMA, exhibit effects similar to physical ageing due to the network being heterogenous and fragmented. At high strain regions and above the Tg, the effects of crosslink density and network connectivity are evident. The fracture toughness could be correlated well to the properties like Tg, yield stress, different moduli of the networks and the breadth of the α transition measured in the DMA, therefore demonstrating that these tools can be very effective in probing the network defects and correlating them to a non-linear engineering property like fracture toughness

Significance of Effect of Metformin on Cancer Stem Cells – “Need of an Hour” in oral cancer

Oral cancer is a life-threatening disease. Advanced therapeutic approaches are still insufficient to improve the prognosis. Effect of Metformin on cancer stem cells (CSCs) provides promising future. Research on diverse molecular mechanisms involved in different kinds of cancers showed a definite correlation. The role in oral squamous cell carcinoma(OSCC) is not yet defines. So, it will be fruitful in future if the research on metformin and CSCs would be done in oral cancer. It would be helpful in improving the results of current antitumor treatment in oral cancer

Efficacy of chewable brush compared to manual brush in school going children of age group 10–12 years

Aim: Chewable toothbrushes were compared to traditional manual toothbrushes in terms of their ability to remove plaque and their impact on salivary pH in a sample of school-aged children. Materials and Methods: The sample size for this research was 200 youngsters aged 10–12. Saliva was collected by spitting into a clean container, and the pH levels were measured using color-coded pH strips to determine where the person was starting from. The plaque score was measured using the OHI-S index after the application of the disclosing agent. The pH and plaque scores were also recalculated after brushing to see how they had changed after surgery. Results: Results indicated that both manual and chewable brushes significantly improved post-brushing pH ratings (P = 0.001), and that plaque scores decreased (P = 0.001). When compared to conventional manual toothbrushes, the chewable brush was much more successful in reducing plaque and elevating salivary pH (P = 0.001). Conclusion: As a result, parents may offer their kids a chewable toothbrush to help them maintain good oral hygiene after lunch and on lengthy car trips, when they would not have time to wash their teeth properly

Comparison between conventional radiograph and 3d volumetric radiograph for determining the morphology and morphometry of mental foramen

The mental foramen is used by oral surgeons during procedures such as extractions, implant placements, osteotomies, nerve blocks, and other surgeries that might potentially harm the neurovascular bundle in the area. The purpose of this research was to evaluate the accuracy of the digitalized volumetric tomography (DVT) in detecting the brain foramen and in assessing its size, shape, and clarity in comparison to the orthopantomogram (OPG) (DVT). Materials and Method: Twenty-five people total took part in the research, with men and women represented equally. Expert three-dimensional (3D) software in DVT and Annotation software in OPG were used to compare and contrast the location, contour, size, and clarity of the cerebral foramen. Results: “The mental foramen was located in the center of the jaw, between the roots of the upper and lower molars and the super inferior cortex of the mandible. The mental foramen was found to be in the same place by both OPG and DVT. Most mental foramen were found to be oval, with the highest definition seen in DVT. DVT provided a more distinct picture of the anatomy, and measurements of the mental foramen were determined to be 0.51 0.06 cm, compared to 0.49 0.05 cm in OPG

Comparative evaluation of extrusion of apical debris and irrigant using three different rotary systems with conventional irrigation methods - An< In vitro study

Aim: The present study aimed to compare and evaluate debris and irrigant extrusion from curved root canals using different rotary systems. Materials and Methods: 30 single-rooted mandibular canines were used in this study. The crown was decoronated, working length and initial apical diameter were established. A 1.5% agar gel model was used in this study. Samples were assigned randomly into 3 groups (n = 10 teeth per group). Protaper Next, OneShape, and Hanudent files were used according to the manufacturers' instructions for canal instrumentation. Apically extruded debris and irrigant was were computed by deducting the initial weight of the test apparatus without a tooth from its weight after the biomechanical preparation. Comparative analysis of the amount of apically extruded debris and irrigant for each of the instruments and the experimental models was performed. Results: The statistically significant difference was found between the three experimental groups. (P < .05). Among all the groups least extrusion was observed in the Protaper Next group when used in combination with conventional irrigation. Conclusion: All the instruments produced apically extruded debris and irrigant, but the maximum was seen with OneShape among the experimental groups

Virtual reality distraction: A novel behaviour management technique

Virtual reality distraction (VRD) is developing technologies for behavior management that can assist a child in adjusting to the dental setting and provide high-quality dental care. The purpose of this literature is to shed light on VRD and its application to the treatment of pediatric dental patients

Teledentistry: Evaluation of Instagram posts related to Bruxism

Background: Instagram statistic has attracted roughly one billion, monthly active users. In 2021, Instagram belonged to the most popular social networks worldwide. It has been considered an effective tool that contributes to the contemporary sharing of information for raising public awareness while providing educational information. The growing presence of Instagram and frequent user engagement has made it a potentially effective platform for patient communication, seeking educational information, product information for consumers, and advertisements in the form of images and videos. Objective: To assess and compare the contents of Instagram posts by healthcare professionals (HP) and non-professional healthcare workers (NPHW) on bruxism and to assess public engagement with this content. Methods: Twelve "hashtag" terms linked to bruxism were searched. HP and NPHW analyzed the content of relevant posts for the presence of domains. Discourse analysis assessed the post quality for themes. We conducted the descriptive and univariate statistical analysis, whereas Inter-rater reliability was tested using Cohen's kappa. Results: A total of 1184 posts were retrieved, with the majority uploaded by NPHW (622 posts). The posts by HPs were in Text and image(s) format (53%) with the range of 25-1100 Instagram post "Likes." "Mouthguard" (90) % was the most frequently included domain posted by HP, followed by "treatment plan/pain management, and complaints of clicking or locking of TMJ (84%). Greater number of domains (p= 0.03) were seen in the posts by NPHWs, compared to HP's having more bruxism-related content. The inter-rater reliability method (0.89) was used for the presence of domains. Conclusion: NPHW uses Instagram more frequently to post bruxism-related information than HP. HPs must ascertain that the content posted by NPHW is relevant and the concerns addressed in posts are to the purpose

Comparing patient outcomes for teeth treated with traditional root canal therapy versus pulpotomy: A randomized controlled trial

Background: Root canal therapy (RCT) and pulpotomy are two common treatment modalities for managing dental pulp infections, but their comparative effectiveness in terms of patient outcomes remains unclear. This root canal therapy (RCT) aimed to assess and compare patient outcomes between teeth treated with traditional RCT and pulpotomy. Materials and Methods: In this single-center RCT, a total of 120 patients presenting with symptomatic dental pulp infections were randomly assigned to either the RCT group or the pulpotomy group. The RCT group received conventional root canal treatment, which involved complete removal of infected pulp and obturation of the root canals. The pulpotomy group underwent a procedure where only the coronal pulp tissue was removed, followed by the placement of a medicament. Pain levels, infection resolution, and tooth survival were assessed at 6 months and 1 year posttreatment. Results: At the 6-month follow-up, patients in the RCT group reported significantly lower pain scores (2.5 ± 0.8) compared with the pulpotomy group (4.3 ± 1.2, P < 0.001). Infection resolution was also higher in the RCT group (92%) compared with the pulpotomy group (78%) at 6 months. Tooth survival rates at 1 year were significantly higher in the RCT group (95%) compared with the pulpotomy group (81%, P < 0.05). Conclusion: This RCT demonstrates that traditional RCT is superior to pulpotomy in terms of pain reduction, infection resolution, and tooth survival. Patients who underwent RCT experienced less pain, faster infection resolution, and better tooth survival rates compared with those who received pulpotomy. These findings support the use of RCT as the preferred treatment modality for dental pulp infections

Glucose and Serum Deprivation Led to Altered Proliferation, Differentiation Potential and AMPK Activation in Stem Cells from Human Deciduous Tooth

Stem cell therapy is an evolving treatment strategy in regenerative medicine. Recent studies report stem cells from human exfoliated deciduous teeth could complement the traditional mesenchymal stem cell sources. Stem cells from human exfoliated deciduous teeth exhibit mesenchymal characteristics with multilineage differentiation potential. Mesenchymal stem cells are widely investigated for cell therapy and disease modeling. Although many research are being conducted to address the challenges of mesenchymal stem cell therapy in clinics, most of the studies are still in infancy. Host cell microenvironment is one of the major factors affecting the homing of transplanted stem cell and understanding the factors affecting the fate of stem cells of prime important. In this study we aimed to understand the effects of serum deprivation in stem cells derived from human deciduous tooth. Our study aimed to understand the morphological, transcriptional, cell cycle and stemness based changes of stem cells in nutrient deprived medium. Our results suggest that stem cells in nutrient deprived media undergo low proliferation, high apoptosis and changed the differentiation potential of the stem cells. Serum deprived mesenchymal stem cells exhibited enhanced chondrogenic differentiation potential and reduced osteogenic differentiation potential. Moreover, the activation of key metabolic sensor AMP-activated kinase (AMPK) leads to activation of transcription factors such as FOXO3, which leads to an S phase quiescence. Serum deprivation also enhanced the expression of stemness related genes Sox2 and c-Myc

Water Uptake and Ion Mobility in Cross-Linked Bis(terpyridine)ruthenium-Based Anion Exchange Membranes

As an alternative to benzyltrimethylammonium (BTMA)-functionalized polymers for use as anion exchange membranes (AEMs), we report here on the properties of cross-linked polymers containing tethered bis­(terpyridine)­ruthenium­(II) complexes as AEMs with chloride, bicarbonate, and hydroxide mobile ions. The maximum conductivity for the Ru­(II)-complex-based membranes, measured at 30 °C in liquid water, depended on the water uptake and degree of cross-linking more than on the ion exchange capacity (IEC). For membranes with 2:1 cross-linker:monomer ratio, the highest conductivities were 7.9 mS cm^–1 for the 1.6 mequiv g^–1 IEC membrane in chloride form, with a hydration number of 51, and 6.5 mS cm^–1 for the 1.8 mequiv g^–1 IEC membrane in bicarbonate form, with a hydration number of 124. Additionally, we calculated the chloride and bicarbonate ion diffusion coefficients from conductivity measurements and the samples’ hydrated ion concentration, which enabled the membrane ion diffusion coefficients (<i>D</i>) to be related to the dilute solution ion diffusivity (<i>D</i>₀) through the ratio <i>D</i>/<i>D</i>₀. Although membranes with a 1:1 cross-linker:monomer ratio had the lowest barrier to transport, indicated by their high <i>D</i>/<i>D</i>₀ ratio, membranes with a 2:1 cross-linker:monomer ratio demonstrated the highest conductivity due to their balanced water uptake and ion concentration in the hydrated state. At hydration numbers greater than 20, the diffusion coefficient of the mobile chloride or bicarbonate ions was within an order of magnitude of the dilute solution limit. Finally, the properties of the Ru­(II)-complex-based AEMs were compared to BTMA-based AEMs by considering the size and charge distribution of the cationic center