# Emergence of Nano-Dentistry as a Reality of Contemporary Dentistry
## 1 Introduction  
The formation of the concept of nanomedicine began in the middle of the XX century. In 1959, [PERSON] published his lecture entitled \"There's Plenty of Room at the Bottom\", in which he substantiated the basic principles of the use of nanotechnology in medicine. Undoubtedly, it was [PERSON] who can be considered a prophet of the development of nanomedicine, because he foresaw the inevitability of the transition of the medical technology from the macro level to the micro-level and further to the atomic level. Nevertheless, establishment of the nano era started far before that date [1, 2]. Materials with a size of less than 100 nm in at least one dimension are considered nanomaterials [3]. They may include grains, fibers, clusters, nanoholes, or their combination. The key property is increased surface area per unit mass compared to bulk matter, which significantly modifies the physical and chemical properties of the material [4]. Nanoparticles such as silver, copper, and zinc produce antibacterial properties in bulk form but metals like iron are not antibacterial in macro form but they possess antibacterialactivity in nano form. Antibacterial nanoparticles possess multiple mechanisms by releasing metal ions, penetrating into cell walls and producing membrane damage [5]. The nanoparticles possess a good delivery system for the release of micronutrients, protection, and encapsulation. The smaller the size of the nanoparticles the more advantages they show: such as improved bioavailability, high optical clarity, gravitational separation, and stability to aggregate [6]. Nanotechnology is used in various fields of science and technology: physics, biology, microbiology, chemistry, and many others. Medicine and dentistry are no exceptions. To cooperate with the \"technology of the future\" in this field has become possible and affordable today, including the advent of nanoparticle materials, which have a much larger surface area per unit mass, compared to significantly larger particles (due to its properties, only one gram of a nanomaterial can be more effective than a ton of ordinary substance) [7]. All options for the application of nanotechnology in medicine can be divided into three major groups:  
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2. therapeutic approaches based on the use of nanotechnology;
3. diagnostic nanomedical procedures;
4. the use of nanomaterials in the technology of manufacturing various medical devices. Nanomedical approaches are being increasingly implemented in specific medical specialties, providing solutions to the problems of treatment of cardiovascular and endocrine disorders, as well as diseases of the nervous, digestive, respiratory and musculoskeletal systems, and cancer. In recent years, separate areas of nanomedicine have been formed, named according to the fields of medical knowledge, such as nanoneurology, nanooncology, nanoendocrinology, etc. Dentistry is no exception to the rule. Medicine, including dentistry, has become one of the areas of active and promising use of nanomaterials and nanotechnologies. The latter are used in areas such as preventive dentistry, restoration of teeth with nanocomposite materials in a case of caries and tooth wear, abrasion and attrition, treatment of enamel hypersensitivity, local anesthesia, coating of dental implants, nano-restorative bone cements, nano-impression materials, etc. (Figure 1) [8]. Figure 1: Variety of nanodental materials on the market. Nanotechnology has revolutionized modern diagnostics [9]. Thus, the use of certain types of nanoparticles allows in vivo visualization of individual pathologically altered cells and even molecules that are markers of some common diseases. Nano-diagnostics significantly increases the sensitivity and specificity of methods for recognizing biochemical and molecular markers of disease [10]. With the use of nanotechnology, it is possible to simultaneously diagnose and treat many diseases.