Gloria Elena Guzmán-Celaya

Objective: Our objective was to determine the salivary levels of cobalt, nickel, chromium, and titanium ions at the end of fixed orthodontic treatment and during the post-removal period (1 and 3 months after removal of the fixed appliance). Methods: This pilot longitudinal study included fifteen individuals (10 females and 5 males). Five milliliters of saliva was collected at three time points: T1 (before withdrawal of orthodontic appliances), T2 (one month post-withdrawal), and T3 (three months post-withdrawal). The concentrations of nickel (Ni), titanium (Ti), chromium (Cr), and cobalt (Co) in the samples were analyzed using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). All samples were analyzed in triplicate. The data were analyzed by repeated-measures ANOVA, and differences were considered significant if the p-value was ≤0.05. Results: The concentrations of Co, Cr, and Ti at the three time points were low and decreased after the removal of the orthodontic appliance, while Ni showed an increase at T3. Co and Ni showed significant differences between T3 and T1 (p = 0.016 and p = 0.029, respectively). There was also significantly increased Ni ion release at T3 compared to T2 (p = 0.010). The Cr and Ti levels at all three time points were significantly different (Cr: p = 0.001; Ti: p = 0.001 and p = 0.005). Conclusions: The levels of cobalt, chromium, and titanium in saliva decreased after removal of the orthodontic appliance, whereas nickel increased at T3. However, the levels were below the mean dietary intake levels; therefore, these concentrations can be considered non-toxic. This study has limitations that should be considered when interpreting the results.

Background: Periodontal disease is a chronic inflammatory condition characterized by progressive destruction of the supporting tissues of the teeth. MicroRNAs (miRNAs) have emerged as key post-transcriptional regulators of immune and inflammatory responses; however, their coordinated expression patterns in periodontal disease remain incompletely understood. Objective: This study aimed to evaluate the expression of miR-141-3p, miR-146a-5p, and miR-148b-3p in periodontal disease and to explore their potential co-regulation in relation to periodontal inflammation. Methods: Gingival samples were collected from individuals with periodontal disease and periodontally healthy controls. miRNA expression levels were quantified by real-time quantitative PCR using TaqMan assays and normalized to miR-191-5p. Relative expression was calculated using the ΔΔCt method. Statistical analyses included group comparisons and correlation analyses to assess relationships among miRNA expression levels. Results: miR-146a-5p expression was significantly reduced in periodontal disease compared with healthy controls (p < 0.05), while miR-141-3p showed a consistent downward trend without reaching statistical significance. No significant differences were observed for miR-148b-3p expression between groups. Notably, strong positive correlations were identified among the three miRNAs, indicating coordinated expression patterns independent of disease stage or grade. Conclusions: The findings demonstrate altered expression of miR-146a-5p and coordinated regulation of miR-141-3p, miR-146a-5p, and miR-148b-3p in periodontal disease. These results support the concept that miRNAs act within regulatory networks rather than as isolated markers and contribute to a more nuanced understanding of miRNA-mediated regulation in periodontal inflammation.

Background/Objectives: The integration of silver nanoparticles (AgNPs) into plastic materials has emerged as a promising strategy to provide biomedical and dental devices with an active antimicrobial barrier. In this review, we aimed to synthesize the scientific evidence published between 2013 and 2024 regarding the therapeutic efficacy, biocompatibility, and safety of AgNP-functionalized plastics by following the 2020 PRISMA guidelines. Methods: Searches were conducted in PubMed, Scopus, Web of Science, SciELO, and ScienceDirect. A total of 634 records were identified, of which 21 studies met the inclusion criteria after full-text evaluation. Results: Plastics containing AgNPs show a significant reduction in microbial load (Escherichia coli, Stafilococcus aureus, and Candida albicans) and exhibit controlled release of Ag⁺ ions, with generally low cytotoxicity levels. The most frequent applications included catheters, dental prostheses, dressings, and orthodontic resins. However, methodological heterogeneity and the scarcity of clinical trials limit the extrapolation of findings. Conclusions: AgNPs confer relevant therapeutic advantages to polymers, but long-term clinical studies are needed to confirm their safety and effectiveness.