Fully digital workflow of occlusal reconstruction treatment in a patient with congenital dentition defects.

OBJECTIVE: Occlusal reconstruction is a critical intervention for patients with dental hard tissue defects, temporomandibular joint (TMJ) disorders, and jaw position abnormalities. Clinical efficiency and outcomes of these procedures have improved with advances in digital technologies. This case report aims to illustrate a comprehensive digital workflow for occlusal reconstruction in a patient with congenital dentition defects, emphasizing the application of digital technologies to enhance treatment outcomes. CLINICAL CONSIDERATIONS: A 28-year-old woman with previously installed porcelain-fused-to-metal bridge restorations presented with a fractured prosthesis and TMJ symptoms. A multidisciplinary approach was adopted involving the use of digital facebow, intraoral scanners, digital smile design, and CAD/CAM technologies. The process included the extraction of defective restorations, temporary restorations to refine jaw position, and final permanent restorations. The digital workflow facilitated precise diagnostics and treatment, culminating in the successful installation of permanent restorations. Regular follow-ups at one- and three-months post-treatment confirmed stable occlusal function and high patient satisfaction. CONCLUSIONS: This case report showcases the potential of multiple digital technologies to streamline complex dental treatments and achieve high-quality results. CLINICAL SIGNIFICANCE: The integration of digital technologies in occlusal reconstruction treatments offers significant benefits in terms of precision, patient comfort, and esthetic outcomes.

Boosting the Performance of Nanofiltration Membranes in Removing Organic Micropollutants: Trade-Off Effect, Strategy Evaluation, and Prospective Development.

In view of the high risks brought about by organic micropollutants (OMPs), nanofiltration (NF) processes have been playing a vital role in advanced water and wastewater treatment, owing to the high membrane performance in rejection of OMPs, permeation of water, and passage of mineral salts. Though numerous studies have been devoted to evaluating and technically enhancing membrane performance in removing various OMPs, the trade-off effect between water permeance and water/OMP selectivity for state-of-the-art membranes remains far from being understood. Knowledge of this effect is significant for comparing and guiding membrane development works toward cost-efficient OMP removal. In this work, we comprehensively assessed the performance of 88 NF membranes, commercialized or newly developed, based on their water permeance and OMP rejection data published in the literature. The effectiveness and underlying mechanisms of various modification methods in tailoring properties and in turn performance of the mainstream polyamide (PA) thin-film composite (TFC) membranes were quantitatively analyzed. The trade-off effect was demonstrated by the abundant data from both experimental measurements and machine learning-based prediction. On this basis, the advancement of novel membranes was benchmarked by the performance upper-bound revealed by commercial membranes and lab-made PA membranes. We also assessed the potentials of current NF membranes in selectively separating OMPs from inorganic salts and identified the future research perspectives to achieve further enhancement in OMP removal and salt/OMP selectivity of NF membranes.

PEGylated Cationic Vectors Containing a Protease-Sensitive Peptide as a miRNA Delivery System for Treating Breast Cancer.

Several targeted drug delivery systems have recently been developed to increase the bioavailability of a drug at its site of action, allowing simultaneous reduction of the total necessary drug dose as well as side effects. Here, we designed a cationic gene vector containing matrix metalloproteinase-2 (MMP2)-cleavable substrate peptides that specifically target tumor sites where MMP2 levels are high. The targeted delivery system is fabricated by linking enzyme-cleavable polyethylene glycol (PEG) derivatives to cationic ß-cyclodextrin-polyethylenimine conjugates, which reduce the toxicity of polyethylenimine and condense the therapeutic cargo. In the present study, tumor suppressor microRNA miR-34a, which suppresses onset and progression of many types of cancers, was investigated for its therapeutic potential for treating breast cancer. The PEG coating markedly reduces nonspecific interaction between cationic particles and serum proteins, permitting accumulation at the target site; subsequent peptide cleavage by MMP2 facilitates miR-34a delivery into tumor cells. The nanopreparation shows excellent stability, and its internalization, tumor targeting, and antitumor efficacy in vitro and in vivo are better than those of a nanopreparation containing MMP2-uncleavable peptide.

Synthesis of a novel monomer "DDTU-IDI" for the development of low-shrinkage dental resin composites.

OBJECTIVE: The current dental resin composites often suffer from polymerization shrinkage, which can lead to microleakage and potentially result in recurring tooth decay. This study presents the synthesis of a novel monomer, (3,9-diethyl-1,5,7,11-tetraoxaspiro[5,5]undecane-3,9-diyl)bis(methylene) bis((2-(3-(prop-1-en-2-yl)phenyl)propan-2-yl)carbamate) (DDTU-IDI), and evaluates its effect in the formulation of low-shrinkage dental resin composites. METHODS: DDTU-IDI was synthesized through a two-step reaction route, with the initial synthesis of the required raw material monomer 3,9-diethyl-3,9-dihydroxymethyl-1,5,7,11-tetraoxaspiro-[5,5] undecane (DDTU). The structures were confirmed using Fourier-transform infrared (FT-IR) spectroscopy and hydrogen nuclear magnetic resonance (1HNMR) spectroscopy. Subsequently, DDTU-IDI was incorporated into Bis-GMA-based composites at varying weight percentages (5, 10, 15, and 20 wt%). The polymerization reaction, degree of conversion, polymerization shrinkage, mechanical properties, physicochemical properties and biocompatibility of the low-shrinkage composites were thoroughly evaluated. Furthermore, the mechanical properties were assessed after a thermal cycling test with 10,000 cycles to determine the stability. RESULTS: The addition of DDTU-IDI at 10, 15, and 20 wt% significantly reduced the polymerization volumetric shrinkage of the experimental resin composites, without compromising the degree of conversion, mechanical and physicochemical properties. Remarkably, at a monomer content of 20 wt%, the polymerization shrinkage was reduced to 1.83 ± 0.53%. Composites containing 10, 15, and 20 wt% DDTU-IDI exhibited lower water sorption and higher contact angle. Following thermal cycling, the composites exhibited no significant decrease in mechanical properties, except for the flexural properties. SIGNIFICANCE: DDTU-IDI has favorable potential as a component which could produce volume expansion and increase rigidity in the development of low-shrinkage dental resin composites. The development of low-shrinkage composites containing DDTU-IDI appears to be a promising strategy for reducing polymerization shrinkage, thereby potentially enhancing the longevity of dental restorations.

Application and limitations of configuration factor (C-factor) in stress analysis of dental restorations.

OBJECTIVE: The configuration factor (C-factor) is an index used to evaluate the relationship between cavity configuration and the development of polymerization shrinkage stress in dental restorations. Although C-factor has been widely researched, its correlation with stress analysis in dental restorations remains controversial. This review aims to discuss the application and limitations of C-factor and define the restricted conditions under which the C-factor "rule of thumb" is applicable. METHODS: A thorough literature review was conducted on the application and limitations of C-factor in stress analysis of dental restorations. This was principally based on MEDLINE/PubMed and Web of Science databases and a review of the relevant studies and publications in scientific papers in international peer-reviewed journals for the specific topic of C-factor and polymerization shrinkage. RESULTS: The C-factor alone cannot provide an accurate prediction of the shrinkage stress of restorations and the mechanical behavior of material-tooth interfaces. C-factor is only applicable under one condition not typically seen in clinical practice: low, near-rigid compliance. SIGNIFICANCE: Conditions for the application of C-factor have been explicitly defined. A more accurate and precise understanding and utilization of the C-factor is of benefit as it contributes to better understanding of polymerization shrinkage behavior of restorations.

Multifunctional dental resin composite with antibacterial and remineralization properties containing nMgO-BAG.

The inherent characteristics of resin composite can lead to micro-leakage after polymerization shrinkage. The bacteria invasion through edge micro-leakage and attachment onto the material surface can cause secondary caries, reducing the service life of resin composites. In this study, magnesium oxide nanoparticles (nMgO) as an inorganic antimicrobial agent and bioactive glass (BAG) as a remineralization agent were simultaneously incorporated into the resin composite. With the addition of both nMgO and BAG, the resin composite showed an excellent antimicrobial effect compared to the resin composite with nMgO or BAG only. The remineralization capacity of demineralized dentin increased with the increasing content of BAG. Vickers hardness, compressive strength, and flexural strength of the resin composite with nMgO-BAG were not significantly affected compared to the ones with the same total filler amount but with BAG only. The depth of cure and water sorption values of the resin composite showed an increasing trend with the increasing total amount of nMgO and BAG fillers. This developed multifunctional resin composite is expected to reduce bacterial invasion and promote remineralization of early caries damage.

Antibacterial and physical properties of resin cements containing MgO nanoparticles.

Cariogenic bacteria and dental plaque biofilm at prosthesis margins are considered a primary risk factor for failed restorations. Resin cement containing antibacterial agents can be beneficial in controlling bacteria and biofilm. This work aimed to evaluate the impact of incorporating magnesium oxide nanoparticles (MgONPs) as an antibacterial filler into dual-cure resin cement on bacteriostatic activity and physical properties, including mechanical, bonding, and physicochemical properties, as well as performance when subjected to a 5000-times thermocycling regimen. Experimental resin cements containing MgONPs of different mass fractions (0, 2.5%, 5%, 7.5% and 10%) were developed. Results suggested that the inclusion of MgONPs markedly improved the materials' bacteriostatic effect against Streptococcus mutans without compromising the physical properties when its addition reached 7.5 wt%. The mechanical properties of the specimens did not significantly decline after undergoing aging treatment, except for the flexural properties. In addition, the cements displayed good bonding performance and the material itself was not prone to cohesive fracture in the failure mode analysis. Furthermore, MgONPs possibly have played a role in decelerating material aging during thermocycling and enhancing bonding fastness in the early stage of cementation, which requires further investigation. Overall, developing MgONPs-doped resin cements can be a promising strategy to improve the material's performance in inhibiting cariogenic bacteria at restoration margins, in order to achieve a reduction in biofilm-associated secondary caries and a prolonged restoration lifespan.

Potentiating bacterial cancer therapy using hydroxychloroquine liposomes.

Salmonella VNP20009 inhibits tumor growth in preclinical models but its efficacy in humans is limited, potentially because cells mount an autophagy response that destroys the therapeutic bacteria. To neutralize this protective response, we combined VNP20009 with long-circulating liposomes containing the autophagy arrest agent hydroxychloroquine. This combination was associated with significantly larger numbers of intracellular Salmonella, accumulated autophagic vacuoles and much greater cell death in vitro. The combination was also associated with greater tumor-targeting ability, slower tumor growth and longer survival than free hydroxychloroquine in a murine model of melanoma. Our results suggest that combining tumor-targeting Salmonella with autophagy arrest may be effective for treating highly aggressive melanoma.