Multi-drug resistance is a growing problem in the treatment of infectious diseases and the widespread use of broad-spectrum antibiotics has produced antibiotic resistance for many human bacterial pathogens. Advances in nanotechnology have opened new horizons in nanomedicine, allowing the synthesis of nanoparticles that can be assembled into complex architectures. Novel studies and technologies are devoted to understanding the mechanisms of disease for the design of new drugs, but unfortunately infectious diseases continue to be a major health burden worldwide. Since ancient times, silver was known for its anti-bacterial effects and for centuries it has been used for prevention and control of disparate infections. Currently nanotechnology and nanomaterials are fully integrated in common applications and objects that we use every day. In addition, the silver nanoparticles are attracting much interest because of their potent antibacterial activity. Many studies have also shown an important activity of silver nanoparticles against bacterial biofilms. This review aims to summarize the emerging efforts to address current challenges and solutions in the treatment of infectious diseases, particularly the use of nanosilver antimicrobials.

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Silver nanoparticles as potential antibacterial agents.

Multidrug resistance of the pathogenic microorganisms to the antimicrobial drugs has become a major impediment toward successful diagnosis and management of infectious diseases. Recent advancements in nanotechnology-based medicines have opened new horizons for combating multidrug resistance in microorganisms. In particular, the use of silver nanoparticles (AgNPs) as a potent antibacterial agent has received much attention. The most critical physico-chemical parameters that affect the antimicrobial potential of AgNPs include size, shape, surface charge, concentration and colloidal state. AgNPs exhibits their antimicrobial potential through multifaceted mechanisms. AgNPs adhesion to microbial cells, penetration inside the cells, ROS and free radical generation, and modulation of microbial signal transduction pathways have been recognized as the most prominent modes of antimicrobial action. On the other side, AgNPs exposure to human cells induces cytotoxicity, genotoxicity and inflammatory response in human cells in a cell-type dependent manner. This has raised concerns regarding use of AgNPs in therapeutics and drug delivery. We have summarized the emerging endeavors that address current challenges in relation to safe use of AgNPs in therapeutics and drug delivery platforms. Based on research done so far, we believe that AgNPs can be engineered so as to increase their efficacy, stability, specificity, biosafety and biocompatibility. In this regard, three perspectives research directions have been suggested that include 1) synthesizing AgNPs with controlled physico-chemical properties, 2) examining microbial development of resistance towards AgNPs, and 3) ascertaining the susceptibility of cytoxicity, genotoxicity, and inflammatory response to human cells upon AgNPs exposure.

/pdf/mechanistic-basis-of-antimicrobial-actions-of-silver-1vmm44o6it.pdf

Mechanistic Basis of Antimicrobial Actions of Silver Nanoparticles.

http://www.biofilling.com/article/7_2Mineral.pdf

Mineral Trioxide Aggregate: A Comprehensive Literature Review—Part III: Clinical Applications, Drawbacks, and Mechanism of Action

Mineral trioxide aggregate: a comprehensive literature review--Part I: chemical, physical, and antibacterial properties.

http://www.endoexperience.com/filecabinet/Endo%20Related%20Restorative%20Dentistry/Post%20and%20Cores/scwartz%20post%20review%20article.pdf

Post placement and restoration of endodontically treated teeth: a literature review.

The restoration of endodontically treated teeth has been the focus of considerable controversy and empiricism. Time-tested methods have been highly successful in some respects, but failures are still apparent. The inherent causes of failure are rarely evaluated and the limitations of specific restorative systems are seldom identified. Regardless of the system, there should be a thorough understanding of the anatomy and biology of the dentin and root supporting the restoration on the part of the practitioner, because both endodontic and restorative procedures alter the hard tissues.

The dentin-root complex: anatomic and biologic considerations in restoring endodontically treated teeth.

Evaluation of the antibacterial efficacy of silver nanoparticles against Enterococcus faecalis biofilm.

Cone-Beam Computed Tomography Study of Root and Canal Morphology of Maxillary First and Second Molars in an Indian Population

The expanded use of nickel-titanium (NiTi) rotary instruments in root canal procedures has led to the development of a wide variety of shapes, designs and applications. Root canal anatomy has not changed, however, and the same challenges exist in both initial treatment and the revision of unacceptable treatment. These challenges include application with high levels of achievement and low to no levels of adverse effects, such as instrument fracture, root canal wall ledging, dentine wall perforation and so forth. To that end, many manufacturers have been seeking ways to alter the presently available and wide range of root canal instrument designs, with a focus on altering the surface of the alloy or altering the alloy microstructure with post-machining or post-twisting heat treatment. This focused review will address the impact that these modifications have had on instrument flexibility, resistance to cyclic fatigue and cutting efficiency.

Alteration in the inherent metallic and surface properties of nickel-titanium root canal instruments to enhance performance, durability and safety: a focused review.

Zuolo ML, Ferreira MOF, Gutmann JL. Prognosis in periradicular surgery: a clinical prospective study. International Endodontic Journal, 33, 91–98, 2000.

Aim  The purpose of this prospective study was to evaluate the prognosis of periradicular surgery using well-defined case selection and a rigorous surgical protocol.

Methodology Teeth to be treated surgically demonstrated a periradicular lesion of strictly endodontic origin with or without clinical signs and symptoms of inflammation. A total of 114 teeth were treated. Following the reflection of a full mucoperiosteal tissue flap, residual soft tissues were curetted, root ends were resected with a fine high-speed diamond bur, root-end cavities were prepared ultrasonically with diamond tips, and IRM root-end fillings were placed. Cases were

followed clinically and radiographically for a period ranging from 1 to 4 years.

Results  The results of this study showed 91.2% success out of a total of 102 teeth available for follow-up, based on accepted parameters of evaluation. Cases were considered successful if there were no clinical signs or symptoms present and there was radiographic evidence of complete or incomplete healing (scar tissue). Factors related to case selection, parameters of healing and surgical technique are discussed in relation to the success rate identified in this prospective study.

Conclusions  Adherence to a strict endodontic surgical protocol and the use of contemporary techniques and materials will result in a predictably successful outcome in a wide range of teeth.

James L. Gutmann

Papers

The dentin-root complex: anatomic and biologic considerations in restoring endodontically treated teeth.

Evaluation of the antibacterial efficacy of silver nanoparticles against Enterococcus faecalis biofilm.

Cone-Beam Computed Tomography Study of Root and Canal Morphology of Maxillary First and Second Molars in an Indian Population

Alteration in the inherent metallic and surface properties of nickel-titanium root canal instruments to enhance performance, durability and safety: a focused review.

Prognosis in periradicular surgery: a clinical prospective study.