Karthikeyan Subramani

Chapter 19 – Nanodiagnostics in microbiology and dentistry

n Abstractn n Nanotechnology is the engineering of functional systems at the molecular scale. The term “nanotechnology” is now commonly used to refer to the creation of new objects with nanoscale dimensions between 1 and 100nm. Functionalities can be added to nanomaterials by interfacing them with biological molecules or structures. The integration of nanomaterials with biology has led to the development of diagnostic devices, contrast agents, analytical tools, and drug-delivery vehicles. Many diseases that do not have a cure today may be cured by nanotechnology in the future. Nanoscience does have an impact on several areas of microbiology. It allows for the study and visualization at the molecular assembly level of a biological process. More studies are needed to determine the environmental and health risks associated with nanomaterials. The current crossdisciplinary inclinations of dental research groups to the nanotechnological field, altogether with the major investments aimed toward developing the methods to grow tooth structures artificially by soft chemical approaches and to understand the mechanism for remineralization of dental defects at various scales in vivo, certainly present a promising trend. Nevertheless, the pace of application of nanotechnology to dentistry has been less than revolutionary. Scientists believe that nanotechnology could give man a better quality of life, power to prevent diseases, speed up tissue reconstruction, and alter his genetic sequence in the future. “There is plenty of room at the bottom.”n n

Chapter 7 – Titanium nanotubes as carriers of osteogenic growth factors and antibacterial drugs for applications in dental implantology

This chapter discusses the potential applications of titanium nanotubes as carriers of osteogenic growth factors and antibacterial drugs for applications in dental implantology. Anodization is a cost-effective technique by which titanium dioxide (TiO2) nanotubes can be fabricated on pure titanium and titanium alloy surfaces. With recent advances in nano-fabrication techniques and multidisciplinary research work focusing on bridging biomaterials for medical applications, TiO2 nanotubes have been extensively studied for the purpose of orthopedic and dental implant fabrication. The need for titanium implant surface that can closely mimic nanoscale architecture of human bone to achieve better osseointegration has become a priority. For such a purpose, TiO2 nanotubes of different dimensions and architectural fashions at the nanoscale level are being evaluated. Such nanotubular surfaces can closely mimic the intricate nanoscale architecture of human bone and can also be used for osteoinductive growth factor or antibacterial/anti-inflammatory drug delivery. These newer generations of titanium surfaces may have significant advantages in overcoming the limitations of conventionally available titanium implants. This chapter briefly reviews the studies done in the past decade about nanotube fabrication on titanium and its alloys. It also addresses recent studies done on nanotubular surface for the effective delivery of osteoinductive growth factors and antibacterial/anti-inflammatory drugs to promote osseointegration and to prevent peri-implant infection (peri-implantitis).

Chapter 13 – Surface engineering of dental tools with diamond for enhanced life and performance

This chapter describes the surface engineering of tungsten carbide dental burs using vertical hot filament chemical vapour deposition (CVD) process. The nucleation and structure of the polycrystalline diamond films deposited onto the burs have been analysed using scanning electron microscope (SEM-EDX) and Raman spectroscopy. The film properties and performance of the coated burs are highly dependent on the growth parameters such as substrate preparation, bias voltage, substrate temperature, gas flow rates, the ratio of hydrogen and methane and the filament characteristics. The performance of the uncoated, conventional diamond dental and the CVD coated dental burs have been compared. The CVD coated burs have been shown to have superior performance in terms of wear and life than the uncoated and conventional burs.

Chapter 5 – Impact of nanotechnology on dental implants

The long-term clinical success of dental implants is related to their early osseointegration. This chapter reviews the different steps of the interactions between biological fluids, cells, tissues, and surfaces of implants. Immediately following implantation, implants are in contact with proteins and platelets from blood. The differentiation of mesenchymal stem cells will then condition the peri-implant tissue healing. Direct bone to implant contact is desired for a biomechanical anchoring of implants to bone rather than fibrous tissue encapsulation. Surfaces properties such as chemistry and roughness play a determinant role in these biological interactions. Physicochemical features in the nanometer range may ultimately control the adsorption of proteins as well as the adhesion and differentiation of cells. Nanotechnologies are increasingly used for surface modifications of dental implants. Another approach to enhance osseointegration is the application of thin calcium phosphate (CaP) coatings. Bioactive CaP nanocrystals deposited on titanium implants are resorbable and stimulate bone apposition and healing. Future nanometer–controlled surfaces may ultimately direct the nature of peri-implant tissues and improve their clinical success rate.

Chapter 12 – Self-assembly of proteins and peptides and their applications in bionanotechnology and dentistry

Self-assembly of biological molecules forms the basic principle in the formation of complex biological structures. Numerous proteins and peptides have been emerging as nanobiomaterials due to their ability to self-assemble into nanoscale structures like nanotubes, nanovesicles, helical ribbons, and three-dimensional fibrous scaffolds. This chapter discusses the basic principle underlying molecular self-assembly of proteins and peptides toward designing novel biomimetic nanomaterials and their potential applications in nanobiotechnology and dentistry.

Chapter 6 – Titanium surface modification techniques for dental implants—From microscale to nanoscale

Abstract This chapter reviews the techniques of titanium surface modification and their applications in orthopedic and dental implants. There are a few limitations in the long-term prognosis of orthopedic and dental implants. Poor osseointegration with bone, peri-implant infection leading to implant failure, and short-term longevity demanding revision surgery, are to mention a few. There has been tremendous advancement over the past few years in the field of micro and nanofabrication techniques and multidisciplinary research studies focusing on titanium surface modification for orthopedic and dental implants. Numerous studies have shown that micro and nanoscale modification of titanium implant surface using physicochemical, morphological, and biochemical approaches have resulted in higher bone to implant contact ratio and improved osseointegration. Surface modifications at the micro and nanoscale level have led to greater insight about the cell-implant interaction for better osseointegration and long-term prognosis of implants. This chapter discusses in brief about the in vitro and in vivo approaches on titanium surface modification techniques, from microscale to nanoscale.

Chapter 1 – Nanotechnology and its applications in dentistry—An introduction

Abstract Nanotechnology is a term that is used to describe the science and technology related to the control and manipulation of matter and devices on a scale less than 100xa0nm in dimension. It involves a multidisciplinary approach involving 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. Generally, two main approaches 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 (AFM), scanning tunnelling microscope (STM), electron beam lithography, molecular beam epitaxy, and so on 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. Extensive research is being done worldwide to understand the advantages and scientific limitations of nanotechnology and its applications in a wide range of disciplines from material science, biomedical research to space research. In the field of medicine, nanotechnology has been extensively applied in nanoparticle-based drug delivery, nanoscale diagnostic tools, tissue engineering, and biosensors. In the field of dentistry, there have been numerous research work done over the past few decades exploring the applications of nanotechnology in dental biomaterials, dental implantology, dental instruments, nanoparticles/scaffolds for bone regeneration around dental implants and maxillofacial region, and nanodiagnostic tools to diagnose oral pathology. In this chapter the applications of nanotechnology in dentistry have been outlined and are described in the subsequent chapters of this book.

Nanotechnology in operative dentistry: A perspective approach of history, mechanical behavior, and clinical application

Abstract In few years, the basic science research of nanotechnology has changed the dental practice. Nanofilled restorative materials are already a reality for direct or indirect (CAD/CAM) approaches. The aim of this chapter were review the pertinent literature, discuss mechanical properties of nanostructured dental restorative materials and present clinical application cases.

Chapter 18 – Carbon nanotubes: Applications in cancer therapy and drug delivery research

Abstract Carbon nanotubes (CNTs) are novel nanocarrier systems that have a wide range of applications in science, engineering, and, the environment. Owing to the possible functionalization of CNTs (i.e., surface-engineering of the nanotubes) with certain chemical groups their physical or biological properties can be manipulated for various applications. In addition to the ability of CNTs to act as carriers for a wide range of therapeutic molecules, their large surface area and possibility to manipulate their surfaces and physical dimensions have been exploited to use them in thermal conductivity in order to photothermally kill cancer cells. This review will discuss the therapeutic applications of CNTs with a major focus on cancer.

Chapter 14 – Nanomechanical characterization of mineralized tissues in the oral cavity

Abstract Accurate measurement of the mechanical properties of the oral mineralized tissues is important for assessing and understanding the clinical performance of these tissues. Nanoindentation has found vast range of applications in the mechanical characterization of synthetic materials at the nano- and microscale. However, direct application of this technique to biological tissues often leads to erroneous results because some of the characteristics of these biological materials, such as viscoelasticity and moisture content are significant but are not addressed in the conventional data analysis protocol developed for nanoindentation on hard materials. For accurate measurement of their mechanical properties, the choice of appropriate indentation parameters, hardware and analysis methods are critical. This chapter provides a brief insight into some of the practical issues which need attention when using nanoindentation to characterize the mineralized tissues found in the oral cavity.