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Stilbenes are polyphenolic allelochemicals synthesized by plants, especially grapes, peanuts, rhubarb, berries, etc., to defend themselves under stressful conditions. They are now exploited in medicine for their antioxidant, anti-proliferative and anti-inflammatory properties. Inflammation is the immune system's response to invading bacteria, toxic chemicals or even nutrient-deprived conditions. It is characterized by the release of cytokines which can wreak havoc on healthy tissues, worsening the disease condition. Stilbenes modulate NF-κB, MAPK and JAK/STAT pathways, and reduce the transcription of inflammatory factors which result in maintenance of homeostatic conditions. Resveratrol, the most studied stilbene, lowers the Michaelis constant of SIRT1, and occupies the substrate binding pocket. Gigantol interferes with the complement system. Besides these, oxyresveratrol, pterostilbene, polydatin, viniferins, etc., are front runners as drug candidates due to their diverse effects from different functional groups that affect bioavailability and molecular interactions. However, they each have different thresholds for toxicity to various cells of the human body, and thus a careful review of their properties must be conducted. In animal models of autoinflammatory diseases, the mode of application of stilbenes is important to their absorption and curative effects, as seen with topical and microemulsion gel methods. This review covers the diversity seen among stilbenes in the plant kingdom and their mechanism of action on the different inflammatory pathways. In detail, macrophages' contribution to inflamed conditions in the liver, the cardiac, connective and neural tissues, in the nephrons, intestine, lungs and in myriad other body cells is explored, along with detailed explanation on how stilbenes alleviate the symptoms specific to body site. A section on the bioavailability of stilbenes is included for understanding the limitations of the natural compounds as directly used drugs due to their rapid metabolism. Current delivery mechanisms include sulphonamides, or using specially designed synthetic drugs. It is hoped that further research may be fueled by this comprehensive work that makes a compelling argument for the exploitation of these compounds in medicine.

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AIM: This study was aimed to evaluate the fracture resistance of proclined endodontically treated teeth with different post and core systems. SETTINGS AND DESIGN: Experimental in vitro study. METHODOLOGY: Eighty extracted maxillary central incisors were selected and decoronated keeping 2 mm of crown ferrule and were endodontically treated. Postspace was prepared retaining 5 mm apical gp using peeso 3. Samples were divided into two groups. In Group 1, Wax pattern fabricated to accommodate different core angulations to be casted with Ni-Cr alloy. In Group 2, ever stick posts were angulated and cemented followed by porcelain fused to metal crown cementation for both the groups. Samples were thermocycled and subjected to the universal testing machine. STATISTICAL ANALYSIS USED: One-way ANOVA and Tukey's post hoc test were used to compare the mean fracture resistance between different angulations in cast post and ever stick posts. Student's paired t-test was used to compare the mean fracture resistance between cast post and everstick posts for each angulations. P value was set at P < 0.05. RESULTS: The fracture resistance was the highest at 20° and lowest at 30° core angulations in both the groups. CONCLUSIONS: Changing core angulation up to 20° can be carried out safely using any of the post systems tested in the study. Core angulations >20°, should be used with caution, especially in patients with abnormal parafunctional habits and occlusal trauma.

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AIM: To evaluate the microtensile bond strength of teeth restored with packable composite after removing caries with three chemomechanical caries removal agents (Carisolv, Papacarie and Carie-care) and also to analyze its effect on chemical composition of dentin using energy-dispersive X-ray (EDX) analysis. DESIGN: A total of 40 carious molars with 1 to 1.5 mm of remaining dentin were selected and divided into four groups of 20 each. Group I (control)-bur, group II-Carisolv, group III-Papacarie, group IV-Carie-care. A total of 15 samples from each group were restored with composite; 1 mm thick sections were made and were debonded under tensile load. Remaining five samples from each group were subjected to EDX for elemental analysis of dentin surface. RESULTS: No statistically significant difference in the bond strength values and Ca/P ratio was observed between control group and three chemomechanical agents tested in the study. CONCLUSION: None of the chemomechanical agents tested in the study adversely affected the bond strength of composite resin to caries-affected dentin. Therefore, newer papain-based chemomechanical agent Carie-care can be considered as an equally effective economical alternative to commonly used agents Carisolv and Papacarie.How to cite this article: Nair S, Nadig RR, Pai VS, Gowda Y. Effect of a Papain-based Chemomechanical Agent on Structure of Dentin and Bond Strength: An in vitro Study. Int J Clin Pediatr Dent 2018;11(3):161-166.

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INTRODUCTION: Chlorine dioxide (ClO2) has been recently investigated as a possible root canal irrigant due to its broad spectrum of antimicrobial action, tissue dissolution and smear layer removal properties. Literature is scarce on the effect of chlorine dioxide irrigation on the resin sealer dentin bond strength. AIM: To compare 5% chlorine dioxide (ClO2) with or without Ethylene Diamine Tetra Acetic acid (EDTA) with 3% Sodium hypochlorite (NaOCl) and EDTA combination as endodontic irrigants on the adhesion of AH Plus sealer to radicular dentin using micro- Push out Bond Strength (µPBS) test. MATERIALS AND METHODS: Forty freshly extracted central incisors were decoronated and randomly divided into four groups based on the different irrigation regimes followed during irrigation: Group I - 3% NaOCl + 17% EDTA, Group II - 5% ClO2 + 17% EDTA, Group III - 5% ClO2 and Group IV - Saline, and canal enlarged till Protaper F3. All the samples were obturated with F3 gutta-percha cones using AH Plus sealer and sectioned perpendicular to long axis to obtain 1mm thick slices from the middle and coronal portions for µPBS measurement in universal testing machine followed by assessment of failure pattern under stereomicroscope. Data was analysed using One-way analysis of variance (ANOVA), Bonferroni and t-test. RESULTS: Bond strength values were in the following order: Group I>Group II>Group III>Group IV, with no statistically significant difference amongst experimental groups on intergroup comparison, except with saline. The µPBS values were more in coronal third than middle third in all specimens, with no statistical significant difference. Mode of failure showed mixed patterns in all experimental groups except saline. CONCLUSION: In the present study, the bond strength values of ClO2 were comparable with conventional NaOCl and EDTA combination and hence, ClO2 can be considered as an effective alternative endodontic irrigant.

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AIM: To evaluate the fracture resistance of simulated immature teeth with an apical plug of biodentine followed by composite resin vs total obturation with biodentine tested immediately and after 3 months of aging and also to find out the chemical composition of dentin in contact with these materials. MATERIALS AND METHODS: Extracted human maxillary central incisors with simulated immature apex with radicular dentin thickness (RDT) of 1 to 1.5 mm selected and divided into three groups of 20 each. Group I (control)-4 mm biodentine apically and thermoplasticized gutta-percha. Group II-4 mm biodentine apically and composite resin. Group III-complete obturation with biodentine. About 10 samples from each group were tested immediately and remaining 10 stored in phosphate buffered solution (PBS) and tested after 3 months for fracture resistance and chemical analysis of dentin. RESULTS: No significant difference in fracture resistance between the groups was observed when tested immediately. After 3 months of aging, only biodentine group showed a significant reduction in fracture resistance with increased Ca/P ratio of root dentine. CONCLUSION: Biodentine group has shown drastic reduction in fracture resistance after 3 months of aging, and hence, cannot be recommended as a reinforcement material in immature teeth with thin dentin walls.How to cite this article: Zhabuawala MS, Nadig RR, Pai VS, Gowda Y, Aswathanarayana RM. Reinforcing Effects of Calcium Silicate-based Cement and Dual Cure Composite Resin in Simulated Immature Teeth with an Open Apex: An in vitro Study. Int J Clin Pediatr Dent 2017;10(4):351-357.

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AIM: To evaluate the fracture resistance in simulated immature teeth that had been backfilled using composite resin and Biodentine after using Biodentine as an apical plug material immediately and after 3 months of aging. MATERIALS AND METHODS: Sixty extracted human maxillary central incisors were simulated in an immature open apex. The roots of all the specimens were then standardized to a length of 10 mm and canals were instrumented to obtain the radicular dentin thickness around 1.5 mm. All the specimens were then randomly divided into three groups of twenty teeth each. Group I (control) - 4 mm apical plug of Biodentine backfilled with thermoplasticized gutta-percha. Group II - 4 mm apical plug of Biodentine and then backfilled with ParaCore. Group III - completely filled with Biodentine. Ten samples from each group were randomly divided into two subgroups. In subgroup A: Specimens were stored for 1 week. In subgroup B: Specimens were stored in phosphate-buffered saline solution for 3 months and were subjected to universal testing machine. Statistical analysis was done using one-way analysis. RESULTS: No significant difference in fracture resistance between the groups was observed when tested immediately. After 3 months of aging, only Biodentine group showed a significant reduction in fracture resistance without significant reduction with other two groups. CONCLUSION: Biodentine group has shown a drastic reduction in fracture resistance after 3 months of aging, and hence cannot be recommended as a reinforcement material in immature teeth with thin dentin walls.

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