Nanodentistry: A Paradigm Shift-from Fiction to Reality

Influence of inorganic nanoparticles on dental materials' mechanical properties. A narrative review

Inorganic nanoparticles have been widely incorporated in conventional dental materials to help in improving their properties. The literature has shown that incorporating nanoparticles in dental materials in different specialties could have a positive effect on reinforcing the mechanical properties of those materials; however, there was no consensus on the effectiveness of using nanoparticles in enhancing the mechanical properties of dental materials, due to the variety of the properties of nanoparticles itself and their effect on the mechanical properties. This article attempted to analytically review all the studies that assessed the effect of different types of inorganic nanoparticles on the most commonly used dental materials in dental specialties such as polymethyl methacrylate, glass ionomer cement, resin composite, resin adhesive, orthodontic adhesive, and endodontic sealer. The results had shown that those inorganic nanoparticles demonstrated positive potential in improving those mechanical properties in most of the dental materials studied. That potential was attributed to the ultra-small sizes and unique physical and chemical qualities that those inorganic nanoparticles possess, together with the significant surface area to volume ratio. It was concluded from this comprehensive analysis that while a definitive recommendation cannot be provided due to the variety of nanoparticle types, shapes, and incorporated dental material, the consensus suggests using nanoparticles in low concentrations less than 1% by weight along with a silane coupling agent to minimize agglomeration issues and benefit from their properties.

Nanoparticles: Taking a Unique Position in Medicine

The human nature of curiosity, wonder, and ingenuity date back to the age of humankind. In parallel with our history of civilization, interest in scientific approaches to unravel mechanisms underlying natural phenomena has been developing. Recent years have witnessed unprecedented growth in research in the area of pharmaceuticals and medicine. The optimism that nanotechnology (NT) applied to medicine and drugs is taking serious steps to bring about significant advances in diagnosing, treating, and preventing disease-a shift from fantasy to reality. The growing interest in the future medical applications of NT leads to the emergence of a new field for nanomaterials (NMs) and biomedicine. In recent years, NMs have emerged as essential game players in modern medicine, with clinical applications ranging from contrast agents in imaging to carriers for drug and gene delivery into tumors. Indeed, there are instances where nanoparticles (NPs) enable analyses and therapies that cannot be performed otherwise. However, NPs also bring unique environmental and societal challenges, particularly concerning toxicity. Thus, clinical applications of NPs should be revisited, and a deep understanding of the effects of NPs from the pathophysiologic basis of a disease may bring more sophisticated diagnostic opportunities and yield more effective therapies and preventive features. Correspondingly, this review highlights the significant contributions of NPs to modern medicine and drug delivery systems. This study also attempted to glimpse the future impact of NT in medicine and pharmaceuticals.

Application of Nanomaterials in Restorative Dentistry

Dental composite resins are widely popular restoratives, as, when using these tools to restore the tooth, only the infected and affected carious structures are removed. This allows the patient to retain a greater quantity of their natural tooth structure than they would have using conventional principles of cavity preparation. Nanomaterials are a new concept concerning the manipulation of materials on an atomic or molecular level. However, on a nanoscale, the chemical, biological, and physical properties of an atom vary compared to the properties of its naturally occurring compound form. The main idea of shifting focus to the inclusion of nanomaterials is to aid in the detection, treatment, and prevention of the recurrence of a pathology (secondary caries). The primary aim of using nanomaterials in composites is to augment their strength, wear resistance, and microhardness. This usage also reduces polymerization shrinkage. Nanomaterials are capable of enhancing mechanical properties, life, and bond strength between dentin and restoration. This review aims to highlight different research studies and experiments that have been conducted on the use of nanomaterials in restorative dentistry in order to understand the versatility of these materials and their viability in practice.

Nanomedicine: Photo-activated nanostructured titanium dioxide, as a promising anticancer agent

The multivariate condition of cancer disease has been approached in various ways, by the scientific community. Recent studies focus on individualized treatments, minimizing the undesirable consequences of the conventional methods, but the development of an alternative effective therapeutic scheme remains to be held. Nanomedicine could provide a solution, filling this gap, exploiting the unique properties of innovative nanostructured materials. Nanostructured titanium dioxide (TiO₂) has a variety of applications of daily routine and of advanced technology. Due to its biocompatibility, it has also a great number of biomedical applications. It is now clear that photo-excited TiO₂ nanoparticles, induce generation of pairs of electrons and holes which react with water and oxygen to yield reactive oxygen species (ROS) that have been proven to damage cancer cells, triggering controlled cellular processes. The aim of this review is to provide insights into the field of nanomedicine and particularly into the wide context of TiO₂-NP-mediated anticancer effect, shedding light on the achievements of nanotechnology and proposing this nanostructured material as a promising anticancer photosensitizer.

Patient Perceptions of New Robotic Technologies in Clinical Restorative Dentistry

Patient perception research has failed to focus on burgeoning technology within the dental field. Specifically, researchers have yet to focus on developing robotic technologies which are being utilized by dentists to help perform certain procedures with added precision and route mapping. The current study attempts to fill the gap created by a lack of intersection between dental technology research, consumer perceptions research, and automation research. The current research takes a two-study approach, with study 1 investigating if gender or price of the procedure affects willingness to undergo a robotic dental procedure. Study 2 further investigates this phenomenon, identifying ten separate types of dental procedures (ranging from minimally invasive to extremely invasive) to further understand consumer perceptions. Results indicate that females are less willing to undergo a robotic dental procedure, and that participants in general are more willing to undergo a procedure if it is half price than if it full price. Willingness is influenced by gender and the type of procedure being performed - participants were less willing to undergo invasive procedures such as gum surgery than noninvasive procedures such as teeth whitening. These results, and their theoretical and practical significance are discussed.

Nanomaterials in dentistry: a cornerstone or a black box?

Aim: The studies on tooth structure provided basis for nanotechnology-based dental treatment approaches known as nanodentistry which aims at detection and treatment of oral pathologies, such as dental caries and periodontal diseases, insufficiently being treated by conventional materials or drugs. This review aims at defining the role of nanodentistry in the medical area, its potential and hazards. Materials & methods: To validate these issues, current literature on nanomaterials for dental applications was critically reviewed. Results: Nanomaterials for teeth restoration, bone regeneration and oral implantology exhibit better mechanical properties and provide more efficient esthetic outcome. However, still little is known about influence of long-term function of such biomaterials in the living organism. Conclusion: As application of nanomaterials in industry and medical-related sciences is still expanding, more information is needed on how such nano-dental materials may interfere with oral cavity, GI tract and general health.

Nanotechnology in oral cancer: A comprehensive review

Oral health could be maintained by application of this technology in prevention, diagnosis and treatment. Oral cancer is a debilitating disease, and numerous research activities are being pursued worldwide to combat this deleterious process. Nanotechnology is very diverse field that has revolutionized the industry and is setting new trends in the management of oral cancer. Hence, we performed a PubMed search on nanotechnology in oral cancer and found 211 articles related to this search. We have reviewed the reported literature to the best of our abilities and summarized the various aspects of nanotechnology, its role in diagnosis - nanodiagnostics and treatment of oral cancer - nanotherapeutics in this article.

A comparative toxicity study between small and large size zinc oxide nanoparticles in tilapia (Oreochromis niloticus): Organ pathologies, osmoregulatory responses and immunological parameters

Tilapia (Oreochromis niloticus) was exposed to different sizes of zinc oxide nanoparticles (ZnO-NPs) to evaluate their organ pathologies (kidney, liver, gill, and intestine), osmoregulatory responses and immunological parameters. Sub-chronic exposure was conducted in fresh water with 1 and 10 mg/L concentrations of the small (10-30 nm) and large-size ZnO (100 nm) particles for 7 and 14 days. In this study, it is found that small and large forms of ZnO-NPs cause various pathologic findings in the target organs at all concentrations. These findings are increased of melanomacrophage aggregates, tubular deformations, necrosis and cytoplasmic vacuolations in the kidney, oedema, mononuclear cell infiltrations, fatty changes, pyknotic nuclei and hepatocellular vacuolations in the liver, hyperplasia, aneurysms, and epithelial liftings in the gills, and hyperplasia, swelled of goblet cells, villus deformations in the intestine. Results showed that respiratory burst and potential killing activity at the small-size ZnO concentration significantly increased compared to the control group (p < 0.05) but significant reductions of these parameters at the large-size ZnO concentrations compared to control (p < 0.05) were measured. These findings demonstrate the potential of each particle size to cause significant damage to the immune system. Moreover, because ZnO NPs inhibit the Na(+), K(+)-ATPase activity at all concentrations and increase serum Ca(2+) and Cl(-) levels especially in gill, these particles are osmoregulatory and toxicant for tilapia fish. As a summary, both sizes of the particles have led to organ damage, osmoregulatory changes and immune disorder in tilapia fish.

Fluoride releasing and enamel demineralization around orthodontic brackets by fluoride-releasing composite containing nanoparticles

INTRODUCTION

Fluoride-containing materials have been suggested to control enamel demineralization around orthodontic brackets during the treatment with fixed appliances. The improvement of their properties has been made through innovations, such as the application of nanotechnology by incorporation of nanofillers.

OBJECTIVE

This in vitro study evaluated the capacity of fluoride releasing and enamel demineralization inhibition of fluoride-releasing nanofilled cement around orthodontic brackets using an artificial caries biofilm model.

MATERIALS AND METHODS

Forty bovine enamel discs were selected by evaluating surface microhardness and randomized into four groups (n = 10): non-fluoride-releasing microfilled composite, fluoride-releasing microfilled composite, resin-modified glass ionomer cement (RMGI), and fluoride-releasing nanofilled composite (FN). After brackets bonding in each disc, the specimens were subjected to a cariogenic challenge through a Streptococcus mutans biofilm model. After the experimental period, the biofilm formed around the brackets was collected for fluoride analysis and the mineral loss around the brackets was determined by integrated demineralization via cross-sectional microhardness measurement at 20 and 70 μm from the bracket margin. Additionally, samples of each group were subjected to energy-dispersive X-ray spectroscopy (EDX) analysis examined under a scanning electron microscopy (SEM). ANOVA followed by Tukey test were applied for fluoride concentration and mineral loss data, respectively.

RESULTS

At both distances, only RMGI statistically differed from the other groups presenting the lowest demineralization, although there was a trend to a lower demineralization of enamel around brackets in FN group. Similar condition was found to fluoride concentration and EDX/SEM analysis.

CONCLUSIONS

Under the cariogenic exposure condition of this study, the fluoride-releasing nanofilled material had similar performance to fluoride-releasing microfilled materials.

CLINICAL RELEVANCE

The presence of nanofillers in the fluoride-releasing materials studied did not promote further benefits against caries lesion development around brackets and presented inferior demineralization inhibition than the resin-modified glass ionomer material.