Emerging Applications of Nanotechnology in Dentistry

Flexural strength and surface hardness of nanocomposite denture base resins

Purpose

Higher bending forces during chewing and occlusal loading can lead to the deformation of denture bases. Roughness and microbial adhesion can be the result of improper care of the denture. Many attempts have been made to improve the properties of denture bases through the addition of different materials. The present study aimed to evaluate the surface hardness and flexural strength (FS) of newly formulated nanocomposite denture base resin made by adding zinc oxide (ZnO) and titanium dioxide (TiO2) nanoparticles in heat polymerized polymethyl methacrylate resin in concentrations of 1 % and 2 %.

Methods

Rectangular metal master dies of dimension 65mm × 10mm × 3.3 mm for flexural strength and 30mm × 10mm × 3 mm for surface hardness were made. These dies were duplicated in 120 acrylic resin samples. These samples were divided into five groups in which group I is control group samples in conventional resin and group II,III, IV &V contained 1 % and 2 % concentrations of ZnO & TiO2 nanoparticles in heat cure acrylic resin. The processing and finishing of the models were done. Flexural strength was measured using a universal testing machine and surface hardness using a Rockwell hardness testing machine.

Results

The minimum SH reported was 101.7 HRM while FS was 81.1 MPa and maximum was 118.7 HRM and 131.8 MPa respectively. The results showed that group IV containing 1 % TiO2 nanoparticles showed the highest surface hardness values whereas the flexural strength was highest in group II containing 1 % ZnO nanoparticles. The analysis of variance showed a p value of <0.001 which was statistically highly significant.

Conclusion

Nanocomposite denture base resins modified with ZnO & TiO2 nanoparticles have more flexural strength and surface hardness than conventional denture base resin.

Clinical implication

The hardness of a denture base material can be increased by adding these nanoparticles for long term use in oral cavity and in cases prone to denture fracture.

Application of nanotechnology in the treatment of hepatocellular carcinoma

Hepatocellular carcinoma is the predominant histologic variant of hepatic malignancy and has become a major challenge to global health. The increasing incidence and mortality of hepatocellular carcinoma has created an urgent need for effective prevention, diagnosis, and treatment strategies. This is despite the impressive results of multiple treatments in the clinic. However, the unique tumor immunosuppressive microenvironment of hepatocellular carcinoma increases the difficulty of treatment and immune tolerance. In recent years, the application of nanoparticles in the treatment of hepatocellular carcinoma has brought new hope for tumor patients. Nano agents target tumor-associated fibroblasts, regulatory T cells, myeloid suppressor cells, tumor-associated macrophages, tumor-associated neutrophils, and immature dendritic cells, reversed the immunosuppressive microenvironment of hepatocellular carcinoma. In addition, he purpose of this review is to summarize the advantages of nanotechnology in guiding surgical excision, local ablation, TACE, standard chemotherapy, and immunotherapy, application of nano-vaccines has also continuously enriched the treatment of liver cancer. This study aims to investigate the potential applications of nanotechnology in the management of hepatocellular carcinoma, with the ultimate goal of enhancing therapeutic outcomes and improving the prognosis for patients affected by this malignancy.

Integrating enzyme-nanoparticles bring new prospects for the diagnosis and treatment of immune dysregulation in periodontitis

Enzymes play a significant role in mediating inflammatory and immune responses in periodontitis. Effective diagnosis, timely treatment, and continuous management of periodontal enzymes are essential to prevent undesirable consequences; however, this remains a significant challenge. Nanoparticles (NPs) have attracted significant attention in biomedicine because of their advantageous nanosized effects. NPs are conjugated with specific enzyme substrates at responsive sites that are triggered by periodontitis enzyme biomarkers, leading to functional or characteristic changes. In contrast, NPs with enzyme-mimetic activities exhibit catalytic activity, effectively destroying pathogenic biofilms and modulating the immune response in periodontitis. The unique properties of enzyme-targeting NPs have enabled the development of biosensors and fluorescent probes capable of identifying enzyme biomarkers associated with periodontitis. Enzyme-responsive and enzyme-mimetic NPs both exert therapeutic applications in the treatment of periodontitis. In this review, we provide a comprehensive overview of the enzymes associated with periodontitis, the mechanisms of enzyme-responsive and enzyme-mimetic NPs, recent advancements in the use of NPs for detecting these enzymes, and the therapeutic applications of NPs in targeting or mimicking enzyme functions. We also discuss the challenges and prospects of using NPs in the diagnosis and treatment of periodontitis.

Postoperative sensitivity of composites using novel Bacillus subtilis nanofortified adhesives: a triple-blind study

NANOTECHNOLOGY: is the art and science of dealing with nanoscale particles. This has transformed contemporary dental practices through myriad contributions to biomaterial science. Titanium dioxide nanoparticles procured from Bacillus subtilis, an eco-friendly and biogenic source, can significantly magnify the physiochemical attributes of dental materials. However, postoperative sensitivity is a major drawback of composite restorations. The incorporation of these nanoparticles into dental adhesives can greatly benefit clinical dentistry by resolving this issue. This trial aimed to evaluate the effectiveness of a novel titanium dioxide nanofortified adhesive on the postoperative sensitivity of composite restorations.

METHODS

This triple-blind, parallel-group randomized controlled trial was conducted at the Department of Operative Dentistry and Endodontics, School of Dentistry, Islamabad, from May 15, 2023, to November 25, 2023. Participants (n = 60) with Class I and II primary carious lesions with a minimum cavity depth of 3-5 mm were randomly assigned to two groups (n = 30). After obtaining informed consent, the restorative procedure was accomplished using a minimally invasive approach and etch-and-rinse adhesive strategy. In group A, a nanofortified adhesive was used for composite restoration, whereas in group B, an adhesive without nanoparticles was used. Postoperative sensitivity was evaluated using the Visual Analog Scale (VAS) score at follow-up periods: of one day, one week, two weeks and one month. A Chi-square test was used to compare postoperative sensitivity between the two groups. The level of significance was set at p < 0.05.

RESULTS

A noteworthy association was observed between sensitivity and the group variable at all four evaluation periods: after one day (p = 0.002), 1 week (p = 0.002), 2 weeks (p = 0.007) and one month. In conclusion, participants who underwent restorative intervention using titanium dioxide nanoreinforced adhesives reported a notable reduction in sensitivity at all time intervals. Hence, the occurrence and severity of postoperative sensitivity are significantly reduced using Bacillus subtilis-procured nanofortified adhesives as compared to conventional adhesives without nanoparticles.

TRIAL REGISTRATION

This trial was retrospectively registered at ClinicalTrials.gov (ID: NCT06242184) on 03/02/2024. All procedures involving human participants were performed in conformance with this protocol.

Nanotechnology and Its Application in Dentistry: A Systematic Review of Recent Advances and Innovations

Background: This study looks at the clinical applications of nanotechnology in dentistry, with an emphasis on implantology, preventive care, orthodontics, restorative dentistry, and endodontics. Methods: Following PRISMA criteria and registered in PROSPERO (ID: CRD 564245), a PubMed, Scopus, and Web of Science search was conducted for studies from January 2014 to April 2024. The criteria were English-language research on nanotechnology in dental coatings, with a focus on clinical trials and observational studies. The electronic database search yielded 8881 publications. Following the screening process, 17 records were selected for qualitative analysis. Results: Nanotechnology has revolutionized dentistry. In orthodontics, nanoparticles improve antibacterial characteristics, durability, and biocompatibility, lowering bacterial colonization and plaque. In preventative care, Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP) combined with stannous fluoride (SnF2) and nano-sized sodium trimetaphosphate (TMPnano) substantially remineralizes enamel. Nanostructured surfaces in dental implants, particularly those containing calcium, improve osseointegration and stability. Nanoparticles in restorative dentistry improve composite and adhesive strength, aesthetics, and longevity. Conclusions: Nanotechnology improves dental materials and equipment, resulting in better treatment outcomes and increased patient comfort. Its integration provides more effective treatments, which improves dental care and patient outcomes. More research is needed to overcome present problems and expand nanotechnology's medicinal applications.

Nanochemistry of gold: from surface engineering to dental healthcare applications

Advancements in nanochemistry have led to the development of engineered gold nanostructures (GNSs) with remarkable potential for a variety of dental healthcare applications. These innovative nanomaterials offer unique properties and functionalities that can significantly improve dental diagnostics, treatment, and overall oral healthcare applications. This review provides an overview of the latest advancements in the design, synthesis, and application of GNSs for dental healthcare applications. Engineered GNSs have emerged as versatile tools, demonstrating immense potential across different aspects of dentistry, including enhanced imaging and diagnosis, prevention, bioactive coatings, and targeted treatment of oral diseases. Key highlights encompass the precise control over GNSs' size, crystal structure, shape, and surface functionalization, enabling their integration into sensing, imaging diagnostics, drug delivery systems, and regenerative therapies. GNSs, with their exceptional biocompatibility and antimicrobial properties, have demonstrated efficacy in combating dental caries, periodontitis, peri-implantitis, and oral mucosal diseases. Additionally, they show great promise in the development of advanced sensing techniques for early diagnosis, such as nanobiosensor technology, while their role in targeted drug delivery, photothermal therapy, and immunomodulatory approaches has opened new avenues for oral cancer therapy. Challenges including long-term toxicity, biosafety, immune recognition, and personalized treatment are under rigorous investigation. As research at the intersection of nanotechnology and dentistry continues to thrive, this review highlights the transformative potential of engineered GNSs in revolutionizing dental healthcare, offering accurate, personalized, and minimally invasive solutions to address the oral health challenges of the modern era.

Analysis of Physical and Mechanical Properties of Universal Composites under Different Types of Polishing before and after Acid Challenge

This study aimed to evaluate in vitro the degree of surface smoothness provided by two different polishing techniques and the effect of acid challenge on the alteration of surface roughness (Ra), microhardness (Knoop), and color (ΔE00) of three nanoparticulate composites, simulating 1 year of exposure to hydrochloric acid (HCl). Eighty specimens for each composite were divided into four groups (n = 240), being control without polishing, control with wear, WPC (wear + polishing with Cosmedent Kit), and WPB (wear + BisCover LV liquid polish). Repeated measures ANOVA was applied for Ra and Knoop Microhardness. For the color (ΔE) three-way ANOVA was applied. In cases of statistically significant the Tukey posttest was applied (α = 0.05). Both types of polishing tested resulted in a surface smoothness below the critical value established by the studies (Ra ≥ 0.2 μm), even after immersion. The microhardness of all composite resins decreased after the challenges. The specimens immersed in HCl showed a lower microhardness (42.2 Kgf/mm2) when compared to the specimens immersed in artificial saliva (44.7 Kgf/mm2). Regarding the color change, the composites presented values compatible with clinical acceptability, with a statistically significant difference only between the control group and the other types of polishing for the Z350 XT resin (ΔE00 = 3.78). It was concluded that both mechanical and chemical polishing produced a satisfactory surface smoothness, even after immersions in artificial saliva and HCl. The microhardness of the composites was affected by the challenges and the composites tested were within clinical acceptability with regard to color change.