There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality.

Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

I and i

Mineral trioxide aggregate (MTA) is a dental material used extensively for vital pulp therapies (VPT), protecting scaffolds during regenerative endodontic procedures, apical barriers in teeth with necrotic pulps and open apices, perforation repairs as well as root canal filling and root-end filling during surgical endodontics. A number of bioactive endodontic cements (BECs) have recently been introduced to the market. Most of these materials have calcium and silicate in their compositions; however, bioactivity is a common property of these cements. These materials include the following: BioAggregate, Biodentine, BioRoot RCS, calcium-enriched mixture cement, Endo-CPM, Endocem, EndoSequence, EndoBinder, EndoSeal MTA, iRoot, MicroMega MTA, MTA Bio, MTA Fillapex, MTA Plus, Neo MTA Plus, Ortho MTA, Quick-Set, Retro MTA, Tech Biosealer, and TheraCal LC. It has been claimed that these materials have properties similar to those of MTA but without the drawbacks. In Part I of this review, the available information on the chemical composition of the materials listed above was reviewed and their applications for VPT was discussed. In this article, the clinical applications of MTA and other BECs will be reviewed for apexification, regenerative endodontics, perforation repair, root canal filling, root-end filling, restorative procedures, periodontal defects and treatment of vertical and horizontal root fractures. In addition, the literature regarding the possible drawbacks of these materials following their clinical applications is reviewed. These drawbacks include their discolouration potential, systemic effects and retreatability following use as a root filling material. Based on selected keywords, all publications were searched regarding the use of MTA as well as BECs for the relevant clinical applications. Numerous publications were found regarding the use of BECs for various endodontic applications. The majority of these investigations compared BECs with MTA. Despite promising results for some materials, the number of publications using BECs for various clinical applications was limited. Furthermore, most studies had several methodological shortcomings and low levels of evidence.

https://onlinelibrary.wiley.com/doi/epdf/10.1111/iej.12843

Mineral trioxide aggregate and other bioactive endodontic cements: an updated overview - part II: other clinical applications and complications.

Regenerative Endodontic Treatment (Revascularization) for Necrotic Immature Permanent Molars: A Review and Report of Two Cases with a New Biomaterial

Vermicomposting is a process in which earthworms are used to convert organic materials into humus-like material known as vermicompost. A number of researchers throughout the world have found that the nutrient profile in vermicompost is generally higher than traditional compost. In fact, vermicompost can enhance soil fertility physically, chemically and biologically. Physically, vermicompost-treated soil has better aeration, porosity, bulk density and water retention. Chemical properties such as pH, electrical conductivity and organic matter content are also improved for better crop yield. Nevertheless, enhanced plant growth could not be satisfactorily explained by improvements in the nutrient content of the soil, which means that other plant growth-influencing materials are available in vermicomposts. Although vermicomposts have been shown to improve plant growth significantly, the application of vermicomposts at high concentrations could impede growth due to the high concentrations of soluble salts available in vermicomposts. Therefore, vermicomposts should be applied at moderate concentrations in order to obtain maximum plant yield. This review paper discusses in detail the effects of vermicompost on soil fertility physically, chemically and biologically. Future prospects and economy on the use of organic fertilizers in the agricultural sector are also examined.

The use of vermicompost in organic farming: overview, effects on soil and economics

Viruses are the smallest known microbes, yet they cause the most significant losses in human health. Most of the time, the best-known cure for viruses is the innate immunological defense system of the host; otherwise, the initial prevention of viral infection is the only alternative. Therefore, diagnosis is the primary strategy toward the overarching goal of virus control and elimination. The introduction of a new class of nanoscale materials with multiple unique properties and functions has sparked a series of breakthrough applications. Gold nanoparticles (AuNPs) are widely reported to guide an impressive resurgence in biomedical and diagnostic applications. Here, we review the applications of AuNPs in virus testing and detection. The developed AuNP-based detection techniques are reported for various groups of clinically relevant viruses with a special focus on the applied types of bio-AuNP hybrid structures, virus detection targets, and assay modalities and formats. We pay particular attention to highlighting the functional role and activity of each core Au nanostructure and the resultant detection improvements in terms of sensitivity, detection range, and time. In addition, we provide a general summary of the contributions of AuNPs to the mainstream methods of virus detection, technical measures, and recommendations required in guidance toward commercial in-field applications.

Applications of gold nanoparticles in virus detection.

Biomaterials play a crucial role in the field of tissue engineering. They are utilized for fabricating frameworks known as scaffolds, matrices or constructs which are interconnected porous structures that establish a cellular microenvironment required for optimal tissue regeneration. Several natural and synthetic biomaterials have been utilized for fabrication of tissue engineering scaffolds. Amongst different biomaterials, polymers are the most extensively experimented and employed materials. They can be tailored to provide good interconnected porosity, large surface area, adequate mechanical strengths, varying surface characterization and different geometries required for tissue regeneration. A single type of material may however not meet all the requirements. Selection of two or more biomaterials, optimization of their physical, chemical and mechanical properties and advanced fabrication techniques are required to obtain scaffold designs intended for their final application. Current focus is aimed at designing biomaterials such that they will replicate the local extra cellular environment of the native organ and enable cell-cell and cell-scaffold interactions at micro level required for functional tissue regeneration. This article provides an insight into the different biomaterials available and the emerging use of nano engineering principles for the construction of bioactive scaffolds in tooth regeneration.

Biomaterials in Tooth Tissue Engineering: A Review

Botulinum neurotoxins, causative agents of botulism in humans, are produced by Clostridium botulinum, an anaerobic spore-former Gram-positive bacillus. Botulinum neurotoxin poses a major bioweapon threat because of its extreme potency and lethality; its ease of production, transport, and misuse; and the need for prolonged intensive care among affected persons. This paper aims at discussing botulinum neurotoxin, its structure, mechanism of action, pharmacology, its serotypes and the reasons for wide use of type A, the various indications and contraindications of the use of botulinum neurotoxin and finally the precautions taken when botulinum neurotoxin is used as a treatment approach. We have searched relevant articles on this subject in various medical databases including Google Scholar, PubMed Central, ScienceDirect, Wiley Online Library, Scopus, and Copernicus. The search resulted in more than 2669 articles, out of which a total of 187 were reviewed. However, the review has been further constricted into only 54 articles as has been presented in this manuscript keeping in mind the page limitation and the limitation to the number of references. A single gram of crystalline toxin, evenly dispersed and inhaled, can kill more than one million people. The basis of the phenomenal potency of botulinum toxin (BT) is enzymatic; the toxin is a zinc proteinase that cleaves neuronal vesicle-associated proteins responsible for acetylcholine release into the neuromuscular junction. A fascinating aspect of BT research in recent years has been the development of the most potent toxin into a molecule of significant therapeutic utility. It is the first biological toxin which is licensed for the treatment of human diseases. The present review focuses on both warfare potential as well as medical uses of botulinum neurotoxin.

Botulinum toxin the poison that heals: A brief review.

Aim: The purpose of this study was to compare the efficacy of platelet-rich plasma (PRP), platelet-rich fibrin (PRF), and hydroxyapatite (HA) for reduction of pain and swelling, absence of dry socket, soft tissue healing, and bone regeneration after mandibular third molar extraction in human patients. Materials and Methods: Forty patients requiring extraction of mandibular third molars were randomly grouped as control, PRP, PRF, and HA-treated. The patients were assessed for postoperative pain, swelling, dry socket, and soft tissue healing on the 3rd, 7th, and 14th day of postoperative periods depending on the standard methods. Radiological assessment of the extraction site was done at 1, 2, and 6 months interval to compare the change in bone density in the sockets in control and treated patients. Results: Pain and swelling were less on PRP and PRF site when compared to HA and control site. PRP and PRF site showed better soft tissue healing when compared to HA and control site. Radiographic assessment showed comparatively lesser bone density values in PRP, PRF, and control site at 1, 2, and 6 months than HA site. Conclusion: Our study showed that PRP and PRF are better graft materials than HA regarding pain, swelling, dry socket, and soft tissue healing. Bone regeneration is induced promptly by HA as compared to other graft materials. However, a more elaborate study with a larger number of clinical cases is very much essential to be more conclusive regarding the efficacy of the graft materials.

A randomized comparative prospective study of platelet-rich plasma, platelet-rich fibrin, and hydroxyapatite as a graft material for mandibular third molar extraction socket healing

Background: Local anesthetic injection is one of the most anxiety- provoking procedure for both children and adult patients in dentistry. A computerized system for slow delivery of local anesthetic has been developed as a possible solution to reduce the pain related to the local anesthetic injection. Study design: The present study was conducted to evaluate and compare pain perception rates in pediatric patients with computerized system and traditional methods, both objectively and subjectively. Study design: It was a randomized controlled study in one hundred children aged 8-12 years in healthy physical and mental state, assessed as being cooperative, requiring extraction of maxillary primary molars. Children were divided into two groups by random sampling - Group A received buccal and palatal infiltration injection using Wand, while Group B received buccal and palatal infiltration using traditional syringe. Visual Analog scale (VAS) was used for subjective evaluation of pain perception by patient. Sound...

Pain Perception: Computerized versus Traditional Local Anesthesia in Pediatric Patients.

From the moment an egg is fertilized and a single cell zygote formed, it begins to divide and redivide, simultaneously differentiating into specialized cells that give rise to different body parts. A certain population of these cells which exhibit similar but limited potential to differentiate continue to exist in various tissues of the body throughout the lifetime of an organism. The science of tissue engineering exploits this valuable ability of stem cells/progenitor cells to regenerate or repair new tissues. In conservative dentistry, regenerative endodontic procedures aim to regenerate the pulp dentin complex utilizing dental stem cells, growth factors and scaffold matrix. Ability to isolate and harvest stem cells, improvements in the design of scaffold materials, advances in cell culture technology and commercial availability of growth factors has facilitated regeneration of pulp and dentin. Clinical techniques whereby these tissues can be regenerated include the surgical implantation of laboratory grown synthetic pulp and dentin tissues; implanting a mix of scaffold and growth factors and promoting endogenous recruitment of stem cells; or enhancing revascularization into root canals by encouraging stem cells to grow into natural fibrin clots. In this article, the components and techniques for pulp dentin regeneration will be discussed. Several preclinical studies have reported positive results but clinical cases reported in the literature are still very few. Additional research involving multiple disciplines that will translate these preclinical research outcomes into successful clinical applications need to be conducted. Every year a huge population of dental patients suffer from diseases like dental caries, which left untreated can progress to cause extensive loss of enamel and dentin with concomitant pulpal involvement. Currently, the treatment options available for a carious tooth are restoration of the defect with a filling material when the lesion size is small to moderate. In deep lesions extending close to a vital pulp, capping the pulp with a material which promotes pulpal healing and reparative dentin formation is the treatment of choice. In cases where the pulp is involved beyond repair, the dentist is left with no other option but to perform a root canal treatment which includes removing whole of the dental pulp and replacing it with an artificial filling material. Efforts have continuously focused to overcome limitations associated with existing restorative materials and evolve a material that mimics natural tooth structure as closely as possible. Clinical outcomes are also not always predictable especially in teeth with incompletely formed roots, resorption defects, fractures and extensive caries. Moreover, endodontic treatment leaves a tooth brittle and more prone to caries because the tooth is devoid of its blood supply, innervation and ability to produce secondary dentin. Developing a treatment therapy that will eliminate the use of any artificial material and enable replacement of lost tissues with natural pulp and dentin is an attractive option. Applying tissue engineering concepts can help turn this dream into reality. A combination of stem cells, scaffold and growth factors maintained in a controlled and regulated environment has shown immense potential to repair and generate tissues of the endodontium. doi : 10.5214/ans.0972.7531.2010.170109 Co mpeting interests: None. Source of Funding: None Received Date: 16 Dec 2009 Revised Date: 13 Jan 2010 Accepted Date: 28 Jan 2010

Sarang Sharma

Papers

Biomaterials in Tooth Tissue Engineering: A Review

Botulinum toxin the poison that heals: A brief review.

A randomized comparative prospective study of platelet-rich plasma, platelet-rich fibrin, and hydroxyapatite as a graft material for mandibular third molar extraction socket healing

Pain Perception: Computerized versus Traditional Local Anesthesia in Pediatric Patients.

Regeneration of tooth pulp and dentin : trends and advances