Approach-Based Analysis on Wireless Power Transmission for Bio-Implantable Devices

The wireless power transmission (WPT) is a systematic technology improve many constraints affecting implantable devices. Many methods have been introduced over the years for WPT. In this article, based on different approaches, we discuss and analyze philosophically the recent existing methodologies and techniques for efficient WPT in implantable devices. For each recent powering method or approach, the working principle and their outcomes are mapped. The performance, efficiency, operating frequency and stability of the systems have been highlighted and listed

Evaluation of microshear bond strength and nanoleakage of etch-and-rinse and self-etch adhesives to dentin pretreated with silver diamine fluoride/potassium iodide: An in vitro study

Aims: The aim of this in vitro study was to comparatively evaluate the microshear bond strength (MSBS) of etch-and-rinse and self-etch (ER and SE) bonding systems to dentin pretreated with silver diamine fluoride/potassium iodide (SDF/KI) and nanoleakage at the resin-dentin interface using transmission electron microscope (TEM). Subjects and Methods: Seventy-two dentin slabs of 3 mm thickness were prepared from extracted human permanent third molars and divided into four groups (n = 18) based on the dentin surface treatment as follows: (1) ER adhesive bonding without dentin pretreatment; (2) SDF/KI pretreatment of dentin followed by ER adhesive bonding; (3) SE adhesive bonding without dentin pretreatment; and (4) SDF/KI pretreatment of dentin followed by SE adhesive bonding. Resin composite was built on the dentin slabs to a height of 4 mm incrementally, and dentin-composite beams of approximately 1 mm 2 cross-sectional area were prepared. The beams were subjected to MSBS analysis, and the fractured surface was observed under scanning electron microscope to determine the mode of failure. The resin-dentin interface was examined under TEM for evaluation of nanoleakage. Statistical Analysis Used: One-way ANOVA followed by Tukey′s post hoc multiple comparison tests. Results: Pretreatment of dentin with SDF/KI increased the MSBS of ER and SE adhesives, though not statistically significant, except between Groups 2 and 3. In all the groups, the predominant mode of failure was adhesive followed by cohesive in resin, mixed and cohesive in dentin. TEM examination of resin-dentin interface showed that pretreatment with 38% SDF/KI reduced nanoleakage regardless of the type of bonding system used. Conclusions: Pretreatment of dentin with SDF/KI minimized nanoleakage at the resin-dentin interface without adversely affecting the bond strength of resin composite to dentin

Antibacterial efficacy of curcumin, allicin, gingerol and cinnamon against Enterococcus faecalis: An in vitro study

Introduction: Bioactive compounds from plants have potential antimicrobial activity. The aim of this in vitro study was to evaluate the antimicrobial efficacy of curcumin, allicin, gingerol and cinnamon compared to 4% sodium hypochlorite (NaOCl) against Enterococcus faecalis and its biofilm. Methods: The dry herbal compounds were diluted with dimethyl sulfoxide (DMSO). Antimicrobial activity was evaluated using agar diffusion test, minimum inhibitory concentration (MIC) assay, minimum bactericidal concentration (MBC) test, time kill study, and biofilm susceptibility assay. The zone of inhibition (ZOI) was determined using agar diffusion test on Muller Hinton (MH) agar plates. MIC was evaluated using the tube dilution method. Root canals of extracted human anterior teeth were instrumented, split into two halves, autoclaved, and incubated with brain heart infusion broth containing E. faecalis for 21 days to form a biofilm. The susceptibility of the biofilm to the test solutions was evaluated by counting bacterial colonies on MH agar. Results: NaOCl exhibited potent antimicrobial activity under all tested parameters. Allicin showed a significantly greater ZOI, while curcumin showed the least MIC among the tested herbal extracts (P0.05). Gingerol and cinnamon were significantly superior to the other groups killing E. faecalis within 4-4.2 min (P0.05). Conclusion: NaOCl emerged as the most efficacious antibacterial agent and all herbal extracts showed significant antibacterial activity against E. faecalis

Oyster shell-derived nano-hydroxyapatite and proanthocyanidin pretreatment on dentinal tubule occlusion and permeability before and after acid challenge—an in vitro study

Abstract This in vitro study evaluated the dentinal tubule occlusion (TO), depth of penetration (DoP), and dentin permeability (DP) of oyster shell-derived nanohydroxyapatite (os-nHAp) with and without 15% proanthocyanidin (PA) pretreatment. os-nHAp was synthesized via the precipitation method and it was characterized. The morphology and particle size of os-nHAp were analyzed using a high-resolution transmission electron microscope (HRTEM). Cytotoxicity of os-nHAp, PA/os-nHAp, and casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) was assessed by (3-(4,5-dimethythiazol-2-yl) 2,5-diphenyl tetrazolium bromide (MTT) assay using human osteosarcoma (MG-63) cell line. One hundred and ninety-seven dentin discs of 3 mm thickness were prepared from the crown portion of extracted human teeth. The dentinal surfaces of the discs were etched for 2 min with 6% citric acid to simulate dentin hypersensitivity. Five discs were randomly selected and the patency of dentinal tubules was confirmed using a scanning electron microscope (SEM). The remaining 192 discs were divided into four groups (n = 48) depending on the type of remineralization as follows: group 1: os-nHAp, group 2: PA/os-nHAp, group 3: CPP-ACP, and group 4: no treatment. The remineralization protocol was followed for 21 days. Out of the 48 dentin discs in each group, 32 discs were used to evaluate dentinal tubule occlusion (TO) and depth of penetration (DoP) using SEM. The remaining 16 discs were subjected to an assessment of dentin permeability (DP) using a hydraulic conductance model. TO, DoP and DP were evaluated after remineralization and acid challenge. Characterization studies confirmed the presence of pure phase apatite. HRTEM confirmed the nanometric particle size of os-nHAp. MTT assay results showed that all the tested materials exhibited >80% cell viability when tested up to a concentration of 100 µg/mL. The results demonstrated a significantly higher mean percentage of TO, DoP, and lesser mean DP after remineralization in groups 1, 2, and 3 (p < 0.05). After the acid challenge, group 3 showed a significant reduction in TO and DoP, and increased DP (p < 0.05). However, no such changes were observed in groups 1 and 2. Within the limitations of this study, it can be concluded that os-nHAp and PA/os-nHAp could serve as potential and durable therapeutic agents in the treatment of dentin hypersensitivity. Graphical Abstrac