Nanotechnology describes the science and technology related to the control and manipulation of matter and devices on a scale less than 100nm and involves fields such as applied physics, materials science, chemistry, biology, biomedical engineering, surface science, electrical engineering, and robotics. At the nanoscale level, the properties of matter are dictated and there are fewer boundaries between scientific disciplines. There are two main approaches that have been used in nanotechnology. These are known as the “bottom-up” and “top-down” approaches. The former involves building up from atoms into molecules to assemble nanostructures, materials, and devices. The second approach involves making structures and devices from larger entities without specific control at the atomic level. Progress in both approaches has been accelerated in recent years with the development and application of highly sensitive instruments. For example, atomic force microscopy, scanning tunneling microscopy, electron beam lithography, molecular beam epitaxy, etc. have become available to push forward developments in this exciting new field. These instruments allow observation and manipulation of novel nanostructures. By investigating and understanding the functionality of materials at the micro/nanoscale level, the scientific community is working toward finding new techniques to achieve maximum functional output from these materials with minimum energy and resource input. Research is being carried out worldwide to understand the advantages and limitations of nanotechnology and its applications in a wide range of disciplines from material science, biomedical research, to space research. In medicine, nanotechnology is being used in nanoparticle-based drug delivery, nanoscale diagnostic tools, tissue engineering, and biosensors. For dentistry, extensive research has recently explored the applications of nanotechnology in dental biomaterials, dental implantology, dental instruments, nanoparticles/scaffolds for bone regeneration around dental implants and the maxillofacial region, and nanodiagnostic tools to diagnose oral pathology. This chapter outlines some applications of nanotechnology in dentistry which are described in detail in subsequent chapters of this book.

Saliva as a diagnostic fluid is gaining wider acceptance for diagnosing diseases. The growing interest in saliva as a biological fluid is due to its noninvasiveness, easy-to-do, cost-effective, and multiple sample collection possibilities, as well as minimal risk to healthcare professionals of contracting infectious organisms such as human immunodeficiency virus and hepatitis B. However, the clinical translation of saliva is hampered by our lack of understanding of the biomolecular transportation from blood into saliva, the diurnal variations of biomolecules present in saliva and relatively low levels of analytes (100–1000-fold less than in blood). We provide information on the current status of salivary research, salivary diagnostics empowered by nanotechnology, and future prospects in this emerging field of saliva diagnostics.

One-dimensional carbon nanomaterials, such as carbon nanotubes (CNTs) and carbon nanofibers (CNFs), have been thought to be able to provide a favorable extracellular environment for cell adhesion due to their similar dimensions to natural collagen fibers. Studies have shown that CNTs and CNFs can selectively promote adhesion of bone-related cells (e.g., osteoblasts and mesenchymal stem cells), while reducing cell adhesion of fibroblasts and chondrocytes. However, carbon nanomaterials are inherently bioinert, only having osteoconductivity but no osteoinductivity. An effective way to improve their biological properties is to combine CNTs/CNFs with bioactive compounds like calcium phosphate (CaP) and bioactive glass (BG) compounds. Techniques including biomineralization and sol–gel/electrospinning are very useful in fabricating CNTs/CNFs with improved biological properties. Surface-functionalized CNTs and newly developed CaP (or BG) nanoparticle (NP)-decorated CNFs provide new opportunities in controlling cell growth and differentiation. Especially for CaP (or BG) NP-decorated CNFs, which are prepared by sintering electrospun polyacrylonitrile (PAN) nanofibers with sol–gel precursors containing calcium nitrate tetrahydrate, triethyl phosphate and/or tetraethyl orthosilicate precursors, show good biocompatibility, tunable degradation ability and controllable osteocompatibility, and are more favorable than pure CNFs to be applied as scaffolds for bone tissue engineering. This chapter also discusses the applications of CNT coatings on titanium implant surfaces and their potential applications in implant dentistry.

Nanotechnology in dentistry has evolved over the last few decades. Its applications in orthodontics have been introduced in orthodontic bonding to improve fixed orthodontic appliance bonding, exploration of gene therapy to enhance mandibular growth stimulation, investigation of a nanofabricated ultrasound device to assuage external apical root resorption associated with orthodontic treatment, and exploration of nanomechanical sensors for real-time orthodontic forces and moments measurement. This chapter presents the contemporary evidence of using nanotechnology in these applications and their potential future use. Also, limitations of their use in orthodontics are presented.

Bone implants constitute an ideal option for people in good general bone health who have suffered bone fractures or other disease. Although titanium (Ti)-based orthopedic implants are used routinely in clinics, they still need further improvement for faster and more rigid osseointegration. Highly ordered titania nanotubes (NTs) have several outstanding merits, such as good cytocompatibility from titania, simple fabrication process, well-controlled diameters from tens to hundreds of nanometers, and drug-loading capacity to achieve augmented bioactivity as well as other abilities, making them highly attractive for applications. Some inorganic ions, such as strontium, zinc, and magnesium, are involved in various cellular functions and play important roles in the osseointegration process. Other inorganic ions, such as silver, are good antibacterial agents. In this chapter, the method of introducing inorganic ions into NTs and the osteoinductive activity and antibacterial activity of the inorganic-ion-doped NTs in vitro and in vivo are systematically reviewed. Inorganic-ion-doped NTs on Ti implants not only provide a nanotopographical surface to foster bone formation effectively, but also serve as a good drug-loading and -delivering platform for various targeted agents to attain extra functions to prevent implant-associated infection and to enhance osteogenic activity.

Since their discovery in 1991, carbon nanotubes (CNTs) have attracted attention for use in the healthcare industry. One of their important uses is as biomaterials for tissue regeneration. The use of CNT-based material for biomedical applications in dentistry and regenerative medicine is the focus of this chapter. The various methods of incorporating CNTs for use as biomaterials are reviewed. These include melt compounding, solution blending, in situ polymerization, electrospinning, and layer-by-layer assembly. The relative merits and drawbacks of each processing technique are discussed. Electrical properties of CNT composites are briefly addressed with a view to potential applications as electroactive biomaterials. The recent literature with respect to the biocompatibility of CNT and CNT-based materials is reviewed and discussed. Finally, potential applications of CNT-based materials in the healthcare system are discussed.

Nanotechnology has become an extremely active field of research in the last decade, because of its potential application in different medical areas such as pharmacy, tissue engineering, dentistry, etc. Nanotechnology has emerged as a promising area of interest in dentistry due to the variety of new treatment options it offers. The unique properties of nanosized materials, which are the subject of quantum mechanics, determine this great interest. The main purpose of using nanotechnologies in dental materials is in achieving better mechanical properties, higher abrasion resistance, less shrinkage, and improved optical and aesthetic properties. Till now nanotechnology has been used in the production of a wide range of dental materials, such as light polymerizable composites and their bonding systems, impression materials, ceramics, dental implant coatings, and bioceramics. The aim of this chapter is to give an overview of the nanomaterials used in dentistry.

Within the field of restorative dentistry, the incredible advances in dental materials research have led the profession into the “post-amalgam era” with state-of-the-art patient care. These new materials and techniques have emerged to blur the interface between biological and artificial structures. It has been clearly established that this new biomimetic approach to restorative dentistry is possible through the use of glass ionomer cements (GICs). The development of nanomaterials has moved nanotechnology from its theoretical foundations into mainstream practice. The chemistry and structure of the GICs and the nature and morphology of the particles are reviewed in relation to their influence on setting behavior and adhesive potential. To further that aim, this chapter investigated the various composition and their individual properties including mechanical, physical, thermal, biocompatibility, technique sensitivity, and mode and rate of failure of restorations from a search of peer-reviewed literature. As a result of ongoing research in this area and with the development of nanotechnology, the future prospects of glass ionomer and resin-modified GICs are encouraging. The clinical indication of GIC in a mechanically loaded situation is usually hindered, therefore reducing the glass particles to a nanoscale enhances the mechanical properties and ever-increasing research effort leads it to be a promising future clinical material.

Nanotechnology has played an increasing pivotal role in tissue engineering of bone regenerative approaches. There has been a great deal of research focused on the fabrication of materials with properties that support the cellular processes involved in bone regeneration and repair and provide a scaffold for optimal three-dimensional tissue formation. This chapter highlights some of the recent advances in the development of nanoceramics that fulfill many of the desired qualities for a bone scaffold and have great clinical potential in bone regenerative procedures in dentistry. The materials discussed include: nanophase hydroxyapatite, nanohydroxyapatite composites, hydrogels and nanohydroxyapatite, chitosan, nano-bioactive glass composites, and nanocalcium sulfate.

The use of herbal medicine for the control of oral/dental diseases and daily care has been practiced since ancient times. Now the new breakthrough is the development of herbal medicine-incorporated nanoparticle formulations in dentistry, as the plant-mediated biogenic metal nanoparticles can overcome the drawbacks of herbal drugs. Green synthesis of metal nanoparticles like silver, copper, and gold nanoparticles facilitated by various medicinal plant extracts has been found to be successful in the treatment of many oral/dental diseases, in fact it is more effective than conventional materials. These are also used in daily dental care products, like toothpaste and mouthwash. Yet, the knowledge regarding the safety of nanomaterials is insufficient, which compels more research. Nanoparticles incorporated with a combination of various plant extracts would address many issues, including drug resistance.