Self-assembled molecular network with waterwheel-like architecture: experimental and theoretical evaluation toward electron transport capabilities for optoelectronic devices.

In recent times, self-assembled electron transport materials for optoelectronic devices, both solar cells and organic light-emitting diodes (OLEDs), have been gaining much interest as they help in fabricating high-efficiency devices. However, designing organic small molecular materials with star-shaped self-assembled networks is a challenge. To achieve this sort of target, we chose triazine and benzene-1,3,5-tricarbonyl cores for developing such architecture, and we developed four molecular systems, vizTCpCN, TCmCN, TmCN, and TpCN. Successful isolation of single crystals followed by structural analysis of TmCN revealed interesting molecular arrangements in the solid state resulting in the formation of a waterwheel type architecture with an extended network bearing characteristic voids. Theoretical calculations was carried out to check their electron transportability. The natural transition orbital calculation helped in understanding the locally excited and charge transfer excited states. The low electron reorganization energies of these molecules indicated that these materials may have potential to be used in electron transport layers of optoelectronic devices, particularly in OLEDs. Moreover, the assembled networks have a relatively wide surface area and linked structures, which are advantageous for the conduction of carriers with poor electron recombination inside the ETL, and these may offer a straightforward channel for electron conduction to the emissive layer. Finally, the fabricated electron-only device indicated that the synthesized materials may be used as ETMs in the electron transport layer of optoelectronic devices.

Application of the Milan System for Reporting Salivary Gland Cytology: A Prospective Study.

Background & Objective: The Milan system of classification of the salivary gland lesions came up with an aim to establish a universal reporting protocol. The aim of this study was to classify the fine-needle aspiration cytology (FNAC) cases of salivary gland according to the Milan system. Methods: All the cases presenting with salivary gland lesion for FNAC were considered. The clinical data was recorded. Cytology findings were analyzed according to the Milan System. Histopathological correlation was made wherever available. Results: A total of 100 cases of salivary gland lesions were collected and categorized according to the Milan system. They were correlated with histopathology in 45 cases. The patients' age varied from 2-85 years. Parotid gland was the most commonly affected. Category 1 (non-diagnostic) comprised of three cases. Category 2 (non-neoplastic) had 40 cases. In category 4a (benign) there were 43 cases, and the most common lesion was pleomorphic adenoma. Category 5 (suspicious of malignancy) comprised of 3 cases. Category 6 (malignant) comprised of 11 cases and the most common lesion was mucoepidermoid carcinoma. In category 2, the cytological findings of 5 cases were concordant with histopathology while, 2 were discordant. In category 4a (benign), 20 cases were concordant, and 3 cases were discordant (2 cases were mucoepidermoid carcinoma, 1 was adenoid cystic carcinoma on histology). The risks of malignancy in NN, AUS, benign, SOM, and malignant were 33.3, 2.5, 0, 7, 66.6, and 100%, respectively. Conclusion: Milan system of reporting salivary gland cytopathology may have great potential of escalating clinical communication and may guide appropriate treatment.

Do implants made of polyetheretherketone and its composites have reduced stress shielding effects compared to other dental implant materials? A systematic review.

PURPOSE: The present systematic review was executed to evaluate the stress shielding effect of PEEK and its composite dental implants as compared to other implant (titanium and zirconia) materials in peri-implant bone. MATERIALS AND METHOD: The comprehensive online literature search was conducted on PubMed, Google Scholar, and Web of Science from January 2011 to January 2023. A total of 43 in vitro studies were identified related to the raised question. In all, 34 studies were excluded as they included in vitro studies focusing on stress distribution in prosthesis framework, abutments, crown, and on biological properties such as cell adhesion, etc. Only eight studies after full-text screening were included in the present systematic review. RESULTS: The data extracted from included studies showed that PEEK and its composite materials, have a less stress shielding effect due to their low modulus of elasticity resulting in higher stress concentration and strain in the peri-implant bone as compared to titanium and zirconia implant materials. CONCLUSION: The PEEK and its composites can be used as an alternative material in the esthetic region and in those who have an allergy to metal implants. However, due to the low elastic modulus of PEEK, a homogenous stress distribution is not observed along the entire length of the implant. Further studies are required to improve the composition of PEEK material so that a homogenous reduction of stress shielding effect along the whole length of a dental implant can be achieved.

Biomechanical efficiency of different implant-abutment connection: a systematic review of studies using photoelastic stress analysis.

PURPOSE: The present review aimed to comparatively evaluate the biomechanical efficiency of different implant-abutment connections studied by photoelastic stress analysis. MATERIALS AND METHODS: A comprehensive online literature search was conducted on Medline (Pubmed), Web of Science, and Google Scholar from 2000(Jan) to 2023(Jan). Keywords used initially to carry out the search included implant-abutment connection & photoelastic stress analysis, and stress distribution in different implant-abutment connections. 34 photoelastic stress analysis studies were screened and 30 studies were excluded after the screening of the title, abstract and full article. Finally, 4 studies were included for complete review. RESULT: The result of this systematic review showed that the internal connection was more efficient then the external connection as there was less marginal bone loss and favorable distribution of stress in internal connection. CONCLUSION: Crestal bone loss is more in external connection when compared to internal connection. In Internal connection, there is more intimate contact between the abutment's outer surface and implant which renders a more stable interface, which favoring uniform stress distribution and protects the retention screw.

Antibacterial Efficacy and Surface Characteristics of Boron Nitride Coated Dental Implant: An In-Vitro Study.

This in vitro study evaluated bacterial cell proliferation and biofilm adhesion on titanium discs with and without antibacterial surface treatment to reduce the chances of peri-implant infections. Hexagonal boron nitride with 99.5% purity was converted to hexagonal boron nitride nanosheets via the liquid phase exfoliation process. The spin coating method was used for uniform coating of h-BNNSs over titanium alloy (Ti6Al4V) discs. Two groups of titanium discs were formed: Group I (n = 10) BN-coated titanium discs and Group II (n = 10) uncoated titanium discs. Two bacterial strains, Streptococcus mutans (initial colonizers) and Fusobacterium nucleatum (secondary colonizers), were used. A zone of inhibition test, microbial colony forming units assay, and crystal violet staining assay were used to evaluate bacterial cell viability. Surface characteristics and antimicrobial efficacy were examined by scanning electron microscopy with energy dispersion X-ray spectroscopy. SPSS (Statistical Package for Social Sciences) version 21.0 was used to analyze the results. The data were analyzed for probability distribution using the Kolmogorov-Smirnov test, and a non-parametric test of significance was applied. An inter-group comparison was done using the Mann-Whitney U test. A statistically significant increase was observed in the bactericidal action of BN-coated discs compared to uncoated discs against S. mutans, but no statistically significant difference was found against F. nucleatum.

Do proton pump inhibitors affect the biomechanical efficiency of implant?- a systematic review.

Purpose: This systematic review was executed to determine the influence of proton pump inhibitors on biomechanical efficiency of dental implants. Materials and methods: The comprehensive online literature search was conducted on digital database of Pubmed, Cochrane database and EBSCO host, Web of Science and Scopus from 2010 to 2021(Dec).The studies included in our research comprised of randomized controlled trials and animal studies. Literature review, Letter to the editor, short communication and studies not related to the dental implants were excluded. A total of 6 studies were finalized and included in the systemic review. Result: The proton pump inhibitors have a negative influence on the bone metabolism and adversely affect the Osseointegration of the dental implants. Further they reduce the biomechanical efficiency of dental implant which ultimately results in their failure. Conclusion: Proton pump inhibitors are a risk factor for dental implant survival. This conclusion has been drawn from the limited research available. Hence well designed prospective randomized controlled trials should be carried out on a large population including the users and non-users, to more thoroughly elucidate the effect of proton pump inhibitor on osseointegration process of dental implants.

Is socket shielding an option in esthetic region?

The implant cannot preserve the surrounding bone from resorption when placed in the extraction socket. After teeth extraction, a change in the bony architecture of the anterior region makes oral rehabilitation difficult by an implant. This leads us to explore such a critical issue and the relevant data were collected from Pubmed, Google Scholar, and Cochrane database and reviewed. Socket shielding technique is intentional retention of the buccal segment of root fragment during the implant placement in the extraction socket. Socket shielding is an effective procedure in minimizing the buccal bone resorption along with minimizing the buccal contour changes it is minimally invasive as the bone graft is optional thus reducing the cost of the treatment procedure. The limited studies were available to support the routine clinical use of the socket shielding technique. Socket shielding seems to become the non-invasive technique for the preservation of hard and soft tissue by dental implant especially in the esthetic zone in the future. Therefore studies should be carried out on a large population to obtained more précised results related to the socket shielding technique.

Analysis of Denture Base Displacement between Conventional Acrylic Removable Partial Dentures and Click Fit Partials for Kennedy's Class I and II Situations: An In Vitro Study.

AIM/OBJECTIVE: The aim of this study was to evaluate the displacement of the denture base of conventional acrylic dentures and Click Fit partials in Kennedy's class I and II situations in the mandibular arch. MATERIALS AND METHODS: Four removable partial dentures-two conventional clasp dentures and two attachment dentures (Click Fit)-were designed. The two conventional clasp dentures were retained by C (conventional) clasps, and the two attachment dentures were retained by rigid precision attachments. The displacement of denture bases and the movements of denture bases were investigated, and the influences of denture design were studied. RESULT: The values obtained were statistically analyzed by using independent t-tests. For all statistical purposes, a p-value of ≤0.001 was considered significant. The results showed that mean vertical displacements (mm) of the conventional acrylic removable partial denture base for Kennedy's class I mandibular arch under 50, 75, and 100 N forces were 0.0317, 0.04377, and 0.06392, respectively, and those for Kennedy's class II mandibular arch under 50, 75, and 100 N forces were 0.04922, 0.09849, and 0.1522, respectively. Vertical displacements (mm) of the Click Fit removable partial denture base for Kennedy's class I mandibular arch under 50, 75, and 100 N forces were 0.02185, 0.03436, and 0.005365, respectively, and those for Kennedy's class II mandibular arch under 50N, 75N, and 100N forces were 0.0445, 0.07851, and 0.14457, respectively. The difference between the groups was statistically significant (p ≤0.001). CONCLUSION: The vertical displacement of the denture base retained by conventional C clasps was more than that of the denture base retained by rigid precision attachment. The displacement of the denture base tended to be less when the denture was designed with a rigid connection for the retainer and with cross-arch stabilization as in Kennedy's class I case. CLINICAL IMPLICATIONS: This research evaluated the vertical denture base displacement using different designs and retention types. Hence, it helped predict the prognosis of different removable partial denture base designs in various clinical conditions.

Comparative Evaluation of Tensile Bond Strength of Poly Ether Ether Ketone (PEEK) and Zirconia Copings Using Resin Cement with or without Adhesive: An In Vitro Study.

This in vitro research aimed to evaluate the Tensile Bond Strength of Poly Ether Ether Ketone and Zirconia copings using resin cement with or without Visio.link adhesive. From commercially available Zirconia and PEEK, blocks were machined milled using (CAD)/(CAM) to obtain 20 Zirconia and 20 PEEK copings. These specimens were sandblasted using 110 µm of alumina. The two main groups (20 Zirconia and 20 PEEK copings) were divided further into 4 subgroups, GROUP 1 (n = 10) PEEK substructure with self-adhesive resin cement without pretreatment, and GROUP 2 (n = 10) PEEK substructure with self-adhesive resin cement pre-treated with Visio.link adhesive. GROUP 3 (n = 10) Zirconia copings with self-adhesive resin cement without pretreatment. GROUP 4 (n = 10) Zirconia copings with self-adhesive resin cement pre-treated with Visio.link adhesive. Universal testing machine was used to evaluate the tensile bond strength of these copings. The results were analyzed using SPSS software Version 25.0 (SPSS Inc., Chicago, IL, USA). One-way ANOVA and independent t-test were used to compare the mean scores. Statistically significant increase was observed in Tensile Bond Strength of samples when Visio.link adhesive was used. Tensile Bond Strength of PEEK copings and Zirconia copings with Visio.link adhesive is considerably greater than PEEK copings and Zirconia copings without adhesive. The mean Tensile Bond Strength of Zirconia (with or without adhesive) is less as compared to Tensile Bond Strength of PEEK (with or without adhesive), but the difference is not statistically significant.

Comparison of Stress Distribution in Fixed Partial Prosthesis Restored with Different Combination of Support: A Finite Element Study.

AIM: This study was conducted to evaluate the distribution of stress in the bone around the natural tooth, endodontically treated tooth having post and core, and implant as an abutment in different combinations in fixed partial prosthesis using two-dimensional finite element analysis (FEA). MATERIALS AND METHODS: Six models were simulated using ANSYS Modeller19. All six models were divided into 12 zones and 4 lines, and stress values were calculated and compared. The study combinations were - tooth supported fixed partial prosthesis, fixed partial prosthesis having the combination of tooth and post- and core-treated tooth, fixed partial prosthesis with the combination of tooth and implant, fixed partial prosthesis having the combination of implant and post- and core-treated tooth, fixed partial prosthesis with the combination of post- and core-treated tooth on both sides, and fixed partial prosthesis having the combination of implant on both sides. RESULT: On comparing the stress values, the maximum stress value was observed in fixed partial prosthesis having the combination of implant on both sides (306.2434 MPa) followed by Model 4 (223.1255 MPa), Model 3 (154.3952 MPa), Model 5 (136.9041 MPa), Model 2 (116.2034 MPa), and least stress seen in Model 1 (99.6209 MPa), and minimum in tooth supported fixed partial prosthesis (99.6209 MPa). CONCLUSION: This study concluded that stress concentration in bone was maximum when the implant was used as an abutment in fixed partial prosthesis. The least stress was seen in bone around the natural tooth due to the dampening effect of the periodontal ligament. Further, the modulus of elasticity of a post acts as a vital parameter in the distribution of stress in post- and core-treated tooth. CLINICAL SIGNIFICANCE: The stress concentration in the bone around the abutments affects the longevity of the prosthesis, hence, the clinically appropriate combination of the abutments should be considered for a fixed partial prosthesis.

A Review on Green Synthesis, Characterization and Anticancer Application of Metallic Nanoparticles.

Cancer is one of the leading causes of death worldwide and also the main obstacle of accelerating anticipation. It is globally recognized as overwhelmingly challenging in terms of clinical management. Cancer is taken into account because a prime lethal disease affects different organs of the body. Even with the rapid improvements in the medical sciences, there are no proper medicines to treat specific kinds of cancer. One of the fundamental issues within the malignant growth treatment is the side effect because of conventional treatment systems. Nanotechnology might be an extremely encouraging field for the therapeutic and drug areas; thus, it assumes a crucial part in improving humankind's satisfaction. In the infield of nanotechnology, a plant-mediated fusion of metal nanoparticles has been developed as a substitute to defeat the limitations of traditional synthesis approaches similar to physical and synthetic strategies. These tunable properties of nanomaterials make them progressed apparatuses in the biomedical platform particularly for the improvement of new diagnostics and focused on therapeutics for malignancy.This review incorporates the characterization of nanoparticles with size and shape and features critical uses of biosynthesized green nanomaterials in cancer theranostics.

VEGF Promoter Region 18-bp Insertion-Deletion Polymorphism in Sickle Cell Disease Patients with Microalbuminuria: A Pilot Study.

PURPOSE: Vascular endothelial growth factor (VEGF) is a potent inducer of micro vascular permeability thus leading to nephropathy. Insertion/deletion (I/D) polymorphism of 18 bp at - 2549 position in VEGF gene causes increased transcription leading to increased production of VEGF. Thus, we aimed to associate I/D polymorphism of the 18 bp fragment at - 2549 position of the promoter region of VEGF gene with sickle cell nephropathy (SCN). METHODS: This observational analytical case control study included 30 subjects each of SCN, sickle cell disease (SCD) without nephropathy and the control group. The subjects were assessed for various hematological and biochemical parameters. Further, 18 bp I/D polymorphism of VEGF gene in all three study groups was assessed by polymerase chain reaction followed by electrophoresis and compared. RESULT: Though increased frequency of both DD genotype and D allele was found in SCN compared to SCD and control, only frequency of D allele was found to be significantly higher (p = 0.04). D allele posed marginal risk of microalbuminuria in SCD subjects compared to controls (OR = 2.11) as well as to SCD without MA subjects (OR = 1.84). CONCLUSION: D allele in I/D polymorphism in the promoter region of VEGF gene may be associated with marginal increase in risk of susceptibility to sickle cell nephropathy.