Metal-semiconductor heterojunction accelerates the plasmonically powered photoregeneration of biological cofactors.

Photocatalysis with plasmonic nanoparticles (NPs) is emerging as an attractive strategy to make and break chemical bonds. However, the fast relaxation dynamics of the photoexcited charge carriers in plasmonic NPs often result in poor yields. The separation and extraction of photoexcited hot-charge carriers should be faster than the thermalization process to overcome the limitation of poor yield. This demands the integration of rationally chosen materials to construct hybrid plasmonic photocatalysts. In this work, the enhanced photocatalytic activity of gold nanoparticle-titanium dioxide metal-semiconductor heterostructure (Au-TiO2 ) is used for the efficient regeneration of nicotinamide (NADH) cofactors. The modification of plasmonic AuNPs with n-type TiO2 semiconductor enhanced the charge separation process, because of the Schottky barrier formed at the Au-TiO2 heterojunction. This led to a 12-fold increment in the photocatalytic activity of plasmonic AuNP in regenerating NADH cofactor. Detailed mechanistic studies revealed that Au-TiO2 hybrid photocatalyst followed a less-explored light-independent pathway, in comparison to the conventional light-dependent path followed by sole AuNP photocatalyst. NADH regeneration yield reached ~70% in the light-independent pathway, under optimized conditions. Thus, our study emphasizes the rational choice of components in hybrid nanostructures in dictating the photocatalytic activity and the underlying reaction mechanism in plasmon-powered chemical transformations.

Nanoparticle Self-Assembly: From Design Principles to Complex Matter to Functional Materials.

The creation of matter with varying degrees of complexities and desired functions is one of the ultimate targets of self-assembly. The ability to regulate the complex interactions between the individual components is essential in achieving this target. In this direction, the initial success of controlling the pathways and final thermodynamic states of a self-assembly process is promising. Despite the progress made in the field, there has been a growing interest in pushing the limits of self-assembly processes. The main inception of this interest is that the intended self-assembled state, with varying complexities, may not be "at equilibrium (or at global minimum)", rendering free energy minimization unsuitable to form the desired product. Thus, we believe that a thorough understanding of the design principles as well as the ability to predict the outcome of a self-assembly process is essential to form a collection of the next generation of complex matter. The present review highlights the potent role of finely tuned interparticle interactions in nanomaterials to achieve the preferred self-assembled structures with the desired properties. We believe that bringing the design and prediction to nanoparticle self-assembly processes will have a similar effect as retrosynthesis had on the logic of chemical synthesis. Along with the guiding principles, the review gives a summary of the different types of products created from nanoparticle assemblies and the functional properties emerging from them. Finally, we highlight the reasonable expectations from the field and the challenges lying ahead in the creation of complex and evolvable matter.

Accuracy of magnetic resonance imaging in the assessment of depth of invasion in tongue carcinoma: A systematic review and meta-analysis.

Tongue carcinoma constitutes 10.4-46.9% of all oral squamous cell carcinomas (OSCCs) and is notoriously known for invading tissues deeper than the evident gross margins. The deeper the tumor invades, the higher are its chances of future morbidity and mortality due to extensive neck dissection and risk of recurrence. Magnetic resonance imaging (MRI) is a noninvasive diagnostic aid used for measuring a preoperative tumor's depth of invasion (DOI) as it can efficiently outline soft tissue tumors from adjacent normal tissue. To assess various MRI modalities used in measuring DOI in tongue carcinoma and their reliability compared with other DOI measuring modalities. The protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) database (CRD42022330866), and the following Preferred Reporting Items for a Systematic Review and Meta-Analysis (PRISMA) Diagnostic Test Accuracy guidelines were performed. PubMed electronic database was searched using a combination of keywords for relevant articles in the English language since 2016. Critical appraisal was carried out using the Quality Assessment of Diagnostic Accuracy Studies-Comparative (QUADAS-C) risk-of-bias (RoB) assessment tool. A weighted mean difference (WMD) was calculated between MRI and histopathological DOI along with pooled correlation and subgroup analysis, where possible. A total of 795 records were retrieved of which 17 were included in the final review with 13 included for meta-analysis. A high RoB was found for most studies for all parameters except flow and timing. WMD showed a statistically significant MRI overestimation of 1.90 mm compared with histopathology. Subgroup analysis showed the 1.5 Tesla machine to be superior to the 3.0 Tesla machine, while imaging sequence subgroup analysis could not be performed. MRI is a viable preoperative DOI measurement modality that can help in efficient treatment planning to decrease surgical morbidity and mortality.

Comprehensive Morpho-Functional and Dental Rehabilitation of a Complete Unilateral Cleft Lip and Palate Patient.

Congenital clefts cause compromised function and esthetics, inadvertently affecting a patient's social and mental health. These defects can be successfully managed by a multidisciplinary team that can provide holistic care from birth till adulthood and beyond. A 17-year-old girl with left side congenital cleft, who had undergone cleft surgeries at our center, reported with a chief complaint of a missing front tooth in the upper region. Clinical and radiographic investigations showed a need for tertiary grafting, which was done using an autologous iliac graft. After six months, a dental implant was placed and immediately loaded after implant stability quotient assessment. Treatment of cleft patients is arduous and technique sensitive and should be done following pre-defined protocols. Each case should be handled by a multidisciplinary team giving attention to each aspect of the treatment requirement. It is an added advantage if the treatment is holistically catered at a single center as it provides patient comfort and avoids patient dependence on past records.

Efficient lead preconcentration using two chemically functionalized carbon nanotubes in hyphenated flow injection-flame atomic absorption spectrometry system.

Lead contamination in drinking and natural water has reached alarming concentrations, thus necessitating the development of accurate and rapid determination systems for Pb(II) in aqueous systems. Two hyphenated flow injection-solid phase extraction- FAAS (FI-SPE-FAAS) systems using oxidized and m-phenylenediamine functionalized multiwalled carbon nanotubes for Pb(II) preconcentration from industrially contaminated real water samples have been proposed. The chemical and hydrodynamic parameters affecting Pb(II) sorption/desorption were optimized. The effect of common interfering ions in water was also studied. Different figures of merit such as preconcentration factor (> 70), detection limit (≤ 1.5 µg L-1), and relative standard deviation (≤ 1.3%) were achieved at the preconcentration time of 120 s for both the preconcentration systems. The method was applied to industrially contaminated real water samples and the spike recovery tests were carried out using standard Pb(II) solution traceable to NIST. The proposed method was validated using standard reference material 1640a supplied by NIST Gaithersburg, MD, USA.

Intraoral Bone Regeneration Using Stem Cells-What a Clinician Needs to Know: Based on a 15-Year MEDLINE Search.

The choice of an appropriate autogenous source of stem cells has not been adequately addressed especially for intraoral bone regeneration. The current review aims to assess the clinical success of various human stem cells in oral bone regeneration. Articles studying the potential of various stem cells utilized for reconstruction of intraoral bone defects in humans were included in this review. Relevant articles were electronically searched in MEDLINE-PubMed database using keywords with different combinations. Only the articles published in English between 2006 and 2020 were included in this review. It was concluded that intra and extraoral stem cells can be successfully used for bone regeneration of various jaw defects. Depending on the origin, quantity, and quality, each cell type has its own advantages and disadvantages. Also, it brings to the fore the need for more clinical studies to validate and adopt the use of stem cells in regular clinical practice.

Platelet-Rich Fibrin for Hard- and Soft-Tissue Healing in Mandibular Third Molar Extraction Socket.

BACKGROUND: Successful management of patients reporting with extreme sensitivity in second molar after surgical extraction of deeply impacted mandibular third molar poses a big challenge to oral surgeons and periodontists worldwide. A variety of grafts, barrier membranes, and guided tissue regeneration techniques have been used postsurgically for soft- and hard-tissue formation. In the current study, platelet-rich fibrin (PRF), a second-generation platelet aggregate, was assessed for its effectiveness in promoting hard- and soft-tissue healing. OBJECTIVE: The aim of the study was to evaluate the efficacy of PRF in hard- and soft-tissue healing after extraction of mandibular third molar. MATERIALS AND METHODS: Bilateral surgical disimpaction of mandibular third molar was done on 25 patients. In every patient, randomly allocated test side received PRF and the other side acted as control. Pain, edema, tenderness, sensitivity, Sulcus Bleeding Index (SBI), Plaque Index, clinical attachment level (CAL), probing depth, and bone height were measured at different intervals for a maximum period of 6 months. RESULTS: There was a statistically significant improvement in patients' signs and symptoms of pain, tenderness, edema, and sensitivity with the use of PRF. A statistically significant improvement was seen in SBI, Plaque Index, and probing depths, while CALs and bone height were not influenced by PRF use. CONCLUSION: PRF is a very viable and useful biomaterial for soft-tissue healing and relieving patient symptoms, however, it does not help in hard-tissue healing with respect to cortical bone.

Oral stem cells in intraoral bone formation.

BACKGROUND: Craniofacial bone loss is a common phenomenon ranging from small periodontal defects to large defects following trauma, surgery or congenital malformations. It is imperative to address these defects with utmost care and precision to avoid functional and aesthetic problems. The human oral cavity is a rich source of adult mesenchymal stem cells. Researchers have documented their isolation and studied them extensively for their invitro capacity of hard and soft tissue regeneration. One of the widely studied properties is their osteogenic potential. Bone formation using oral stem cells has shown successful results in numerous animal trials. Some studies have progressed to evaluate their future potential in humans. HIGHLIGHT: This review aimed at discussing the use of human oral stem cells, specifically for bone regeneration in human maxillofacial region. CONCLUSION: Oral stem cells have excellent potential for bone formation and can be successfully used to replace traditionally used bone marrow stem cells. Some sources like stem cells from human exfoliated deciduous teeth (SHED), dental follicle stem cells (DFSC), Stem Cells from Apical Papilla (SCAP), and others need assessment beyond animal models and require human studies for clinical use. More clinical trials of randomized nature are suggested to standardize the clinical procedure and strengthen the claim of oral stem cells as potential replacement of bone marrow counterparts.

Comprehensive Chart for Dental Age Estimation (DAEcc8) based on Demirjian 8-teeth method: Simplified for operator ease.

With an alarming increase in number of juveniles in conflict with the law, in India as well as worldwide, more emphasis lies on radiographic dental age estimation (DAE) methods for different ethnic populations having specific formulas based on large sample databases. Of these, Chaillet and Demirjian modification of original Demirjian method was devised to increase the applicability to 18-year-old individuals. However, this method is cumbersome with multiple tables and difficulty in comprehension, thus deterring its use on a wider scale. The current study was aimed at developing a comprehensive DAE chart "DAEcc8", inclusive of all tables and regression equations of above modification along with improvisation of pictorial representation of stages based on Demirjian and Nolla. The method of filling this chart is explained in this communication along with selection of corresponding scores for each stage for both males and females and final computation of estimated age is done by application of total score in the regression equation. Hence, this study proposes the use of DAEcc8 for age estimation due to ease in comprehension and execution. It suggests a future scope of its use in educational and on field application in forensic dentistry.

Demirjian approach of dental age estimation: Abridged for operator ease.

BACKGROUND: Present times have seen an alarming increase in incidence of crimes by juveniles and of mass destruction that Highlight the preponderance of individual age estimation. Of the numerous techniques employed for age assessment, dental age estimation (DAE) and its correlation with chronological age (CA) have been of great significance in the recent past. Demirjian system, considered as gold standard in DAE is a simple and convenient method for DAE, though,, although, referring to multiple tables make it cumbersome and less eco friendly due to excessive paper load. AIM: The present study was aimed to develop a comprehensive chart (DAEcc) inclusive of all Demirjian tables and developmental stages of teeth and also to as well as to test the operator ease of 50 undergraduate dental students in performing DAE using this chart. MATERIALS AND METHODS: The study was performed in two stages, wherein the first stage was aimed at formulation of the comprehensive chart (DAECC) which included pictorial representation of calcification stages, the Federation Dentaire Internationale notation of the teeth, and the corresponding scores for each stage with a concluding column at the end to enter the total score. The second stage assessed the applicability of the ease of DAE by DAECC, whereby fifty 2nd year BDS students were asked to trace the calcification stages of the seven permanent left mandibular teeth on a panorex, identify the correct stage, assign the corresponding score, and to calculate the total score for subsequent dental age assessment. RESULTS AND CONCLUSIONS: showed that average time taken by the students for tracing seven mandibular teeth was 5 min and for assessment of dental age was 7 min. The total time taken for DAE was approximately 12 min, thus making the procedure less time consuming. Hence, this study proposes the use of DAEcc for age estimation due to ease in comprehension and execution of Demirjian system.