Antifungal biomaterial for reducing infections caused by Candida albicans in edentulous patients.

INTRODUCTION: Polymethylmethacrylate (PMMA) acrylic resins are used to make dentures for edentulous patients. OBJECTIVE: To find out the prevalence of Candida species in patients with and without removable prostheses from a dental clinic in León, Guanajuato, as well as to assess the antifungal effect and biological behavior of an experimental PMMA with silver nanoparticles for its possible application in prostheses. METHOD: To identify Candida species, smear samples were obtained from the palatal mucosa of 140 patients aged ≥ 60 years. The experimental PMMA with silver nnoparticles was placed in Candida albicans cultures, which were stained with the Live/Dead® kit for analysis under confocal microscopy; subsequently, it was implanted in Wistar rats in order to know its behavior in the surrounding tissues. RESULTS: Candida albicans was the most prevalent species in the evaluated patients, followed by Candida tropicalis and Candida krusei. The acrylic resin with silver nanoparticles significantly decreased the presence of Candida albicans. In the animal model, a discrete and controlled inflammatory reaction was found, which indicated biocompatibility of the acrylic resin that was used. CONCLUSIONS: It is possible for the nanostructured material with antifungal effect to be used in order to promote the reduction of oral Candida infections in edentulous patients.

INTRODUCCIÓN: Las resinas acrílicas de polimetilmetacrilato (PMMA) son utilizadas para elaborar dentaduras para pacientes edéntulos. OBJETIVO: Conocer la prevalencia de las especies de Candida en pacientes con y sin prótesis removibles de una clínica de odontología en León, Guanajuato; así como valorar el efecto antifúngico y el comportamiento biológico de un PMMA experimental con nanopartículas de plata para su posible aplicación en prótesis. MÉTODO: Para identificar las especies de Candida se obtuvieron muestras para frotis de la mucosa palatina de 140 pacientes con edad ≥ 60 años. El PMMA experimental con nanopartículas de plata fue colocado en cultivos de Candida albicans, los cuales fueron teñidos con el kit Live/Dead® para su análisis bajo microscopia confocal; posteriormente, se implantó en ratas Wistar para conocer su comportamiento en los tejidos circundantes. RESULTADOS: Candida albicans fue la especie más prevalente en los pacientes valorados, seguida de Candida tropicalis y Candida krusei. La resina acrílica con nanopartículas de plata disminuyó significativamente la presencia de Candida albicans. En el modelo animal se encontró reacción inflamatoria discreta y controlada, lo cual indicó la biocompatibilidad de la resina acrílica utilizada. CONCLUSIONES: Es posible utilizar el material nanoestructurado con efecto antifúngico para promover la reducción de infecciones orales por Candida en pacientes edéntulos.

Antifungal and Cytotoxic Evaluation of Photochemically Synthesized Heparin-Coated Gold and Silver Nanoparticles.

Heparin-based silver nanoparticles (AgHep-NPs) and gold nanoparticles (AuHep-NPs) were produced by a photochemical method using silver nitrate and chloroauric acid as metal precursors and UV light at 254 nm. UV-Vis spectroscopy graphs showed absorption for AgHep-NPs and AuHep-NPs at 420 nm and 530 nm, respectively. TEM revealed a pseudospherical morphology and a small size, corresponding to 10-25 nm for AgHep-NPs and 1.5-7.5 nm for AuHep-NPs. Their antifungal activity against Candida albicans, Issatchenkia orientalis (Candida krusei), and Candida parapsilosis was assessed by the microdilution method. We show that AgHep-NPs were effective in decreasing fungus density, whereas AuHep-NPs were not. Additionally, the viability of human gingival fibroblasts was preserved by both nanoparticle types at a level above 80%, indicating a slight cytotoxicity. These results are potentially useful for applications of the described NPs mainly in dentistry and, to a lesser extent, in other biomedical areas.

Mineral trioxide aggregate enriched with iron disulfide nanostructures: an evaluation of their physical and biological properties.

The purpose of this study was to characterize mineral trioxide aggregates (MTA) enriched with iron disulfide (FeS2 ) nanostructures at different concentrations, and to investigate their storage modulus, radiopacity, setting time, pH, cytotoxicity, and antimicrobial activity. Iron disulfide nanostructures [with particle size of 0.357 ± 0.156 µm (mean ± SD)] at weight ratios of 0.2, 0.4, 0.6, 0.8, and 1.0 wt% were added to white MTA (wMTA). The radiopacity, rheological properties, setting time, and pH, as well as the cytotoxicity (assessed using the MTT assay) and antibacterial activity (assessed using the broth microdilution test) were determined for MTA/FeS2 nanostructures. The nanostructures did not modify the radiopacity values of wMTA (~6 mm of aluminium); however, they reduced the setting time from 18.2 ± 3.20 min to 13.7 ± 1.8 min, and the storage modulus was indicative of a good stiffness. Whereas the wMTA/FeS2 nanostructures did not induce cytotoxicity when in contact with human pulp cells (HPCs) and human gingival fibroblasts (HGFs), they showed bacteriostatic activity against Staphylococcus aureus, Escherichia coli, and Enterococcus faecalis. Adding FeS2 nanostructures to MTA might be an option for improving the root canal sealing and antibacterial effects of wMTA in endodontic treatments.

Cytotoxicity of solutions recommended for the storage of avulsed teeth in cultures with periodontal ligament cells. / Citotoxicidad de soluciones recomendadas para el almacenamiento de dientes avulsionados en cultivo con células del ligamento periodontal.

Introduction: The medium for avulsed teeth storage until their reimplantation is key to the preservation of human periodontal ligament fibroblasts (HPLF). Objective: Our purpose was to compare the cytotoxic effect of milk and isotonic solution, used for the storage of avulsed teeth, on the preservation of HPLF. Method: A subculture of periodontal ligament fibroblasts was carried out with a density of 1:2 (3 ×105 cells/mL) and was incubated for 48 hours. The cells were divided in two groups, which were placed either in milk or isotonic solution for 24 hours at 5% CO2, 37 ºC and 95% humidity. The number of viable cells was determined with a colorimetric fast assay by the reduction of MTT and mitochondrial activity. Data were processed with the Shapiro-Wilk normality test, Student's t-test and paired Student's t-test (with significance set at 0.05). Results: The cells exposed to milk for 24 hours showed statistically significant cytotoxicity at concentrations of 0.09, 0.39, 0.78, 1.56, 3.125, 6.25 and 50%. HPLFs exposed to isotonic solution showed no significant reduction in the number of cells at concentrations of 25 and 50%. Conclusion: Isotonic solution appears to be better for HPLF 24-hour storage in comparison with whole milk.

Introducción: El medio de almacenamiento de los dientes avulsionados hasta su reimplante es vital para conservar los fibroblastos del ligamento periodontal humano (HPLF). Objetivo: Comparar el efecto citotóxico para conservar los HPLF de la leche y la solución isotónica para almacenamiento de dientes avulsionados. Método: Se realizó subcultivo de fibroblastos del ligamento periodontal con una densidad de 1:2 (3 × 105 células/mL), que fueron incubados por 48 horas. Se integraron dos grupos de células, que se colocaron en leche y solución isotónica durante 24 horas a 5 % de CO2, a 37°C y 95 % de humedad. El número de células viables fue determinado por colorimetría rápida por reducción de MTT y actividad mitocondrial. Los datos fueron sometidos a pruebas de normalidad de Shapiro-Wilk, t de Student y t de Student pareada (significación de 0.05). Resultados: Las células expuestas a la leche por 24 horas mostraron citotoxicidad estadísticamente significativa a concentraciones de 0.09, 0.39, 0.78, 1.56, 3.125, 6.25 y 50 %. Los HPLF expuestos a solución isotónica no mostraron reducción significativa del número de células a concentraciones de 25 y 50 %. Conclusión: La solución isotónica parece mejor para el almacenamiento de HPLF en 24 horas, comparada con la leche entera.

Anterior Hyperfunction Syndrome: Literature Review and Conceptual Model.

Combined Kelly syndrome, also known as anterior hyperfunction syndrome, is a complex pathological condition of the stomatognathic system, originally established by five characteristics but primarily triggered by edentulism, specifically, the absence of the upper and posterior mandibular teeth. This condition is characterized by a series of clinical features, such as bone loss, tuberosity growth, enamel wear, periodontal damage, muscle fatigue, pain, and temporomandibular joint issues. However, these features are not unique and rather reflect an oral hyperfunction state. There is a lack of consensus on the best way to assess and diagnose this condition, which is proposed to be understood as an "oral hyperfunction state" rather than a syndrome. This study aims to conduct a literature review to analyze the available information on anterior hyperfunction syndrome in dentistry, with the goal of proposing a conceptual model of the etiological risk factors that contribute to early diagnosis and the prevention of complications. This approach has important clinical implications, as it would allow for the early identification and management of risk factors, thus improving the quality of life of patients and preventing malpractice that could compromise their oral health.

Assessment of cytotoxicity, odontoblast-like differentiation, shear bond strength, and microhardness of four orthodontic adhesive composites.

PURPOSE: To determine and compare the cytotoxicity, odontoblast-like differentiation, shear bond strength (SBS) and Vickers microhardness of four commercial light-cured orthodontic adhesives. METHODS: The orthodontic resins selected were Transbond XT - GI, Transbond Plus Color Change - GII (both from 3M Unitek), Enlight - GIII and Blugloo - GIV (both from Ormco). Samples were prepared, and leached monomers were obtained. Cytotoxicity was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and deposited calcium was analyzed using Alizarin red staining (ARS). SBS and the adhesive remnant index (ARI) were determined using 120 human premolars. The Vickers microhardness test was performed on the resin discs. RESULTS: All adhesives showed moderate to severe cytotoxicity (21-37%) and promoted similar formation of calcium deposits. A SBS of 6-8 MPa was achieved only by Blugloo (7.1 ± 2.4 MPa), and Enlight showed the lowest Vickers hardness score (40 ± 2.5 HV). Transbond Plus Color Change (score 0 = 42.9%) and Blugloo (score 0 = 46.4%) showed better ARI scores than Transbond XT (score 0 = 7.1%) and Enlight (score 0 = 3.6%). CONCLUSION: On the basis of the properties evaluated, Blugloo seems to be the best option.

Adhesive Performance of Pit and Fissure Sealants on Deproteinized Enamel with Different Proteolytic Agents: In Vitro Study.

The objective of this work was to assess the efficacy of different proteolytic agents on the bond strength of pit and fissure sealants to bovine enamel. Eighty-four bovine enamel specimens were randomly assigned in groups according to the pit and fissure sealant applied (HelioSeal F or Dyad Flow). Then, the specimens were subdivided according to the proteolytic agent used (n = 7): Group 1, distilled water (control); Group 2, 10 wt.% Tergazyme®; Group 3, 10 wt.% ZYME®; Group 4, 10% papain gel; Group 5, 10% bromelain gel; and Group 6, 5.25 wt.% sodium hypochlorite. The cell viability of the proteolytic solutions was assessed through the MTT assay. The proteolytic agents were applied on the enamel surface prior to the acid-etching procedure; then, the pit and fissure sealants were placed. The micro-shear bond strength was evaluated after 24 h or 6 months of water storing at 37 °C. Representative SEM images were taken for each experimental group. The bond strength data were statistically analyzed by a three-way ANOVA test using a significance level of α = 0.05. Bromelain and papain proteolytic solutions did not exert any cytotoxic effect on the human dental pulp cells. After 24 h and 6 months of aging, for both pit and fissure sealants, sodium hypochlorite, papain, bromelain, and Tergazyme® achieved statistically significant higher bond strength values (p < 0.05). Irrespective of the deproteinizing agent used, Dyad Flow resulted in a better bond strength after 6 months of aging. The type 1 etching pattern was identified for sodium hypochlorite, papain, and bromelain. Tergazyme®, papain, and bromelain demonstrated efficacy in deproteinizing enamel surfaces prior to acid etching, leading to the improved bond strength of pit and fissure sealants. Clinically, this suggests that these proteolytic agents can be considered viable alternatives to traditional methods for enhancing sealant retention and longevity. Utilizing these agents in dental practice could potentially reduce sealant failures.

State-of-the-art: MXene structures in nano-oncology.

Cancer nanomedicine has been investigated widely and boomed in the last two decades, resulting in designing nanostructures with biofunctionalization, giving rise to an "All-in-One" multifunctional platform. The development of rational design technology with extended functionalities brought interdisciplinary researchers to work continuously, aiming to find a prevent or effectively treat the deadly disease of the century. Thus, it led to some Food and Drug Administration (FDA)-approving nano-based formulations for cancer treatment and opening a vast area of promising discoveries by exploiting different nanomaterials. Two-dimensional (2D) materials have recently gained tremendous interest among scientists because of their outstanding structural, optical, electronic, thermal, and mechanical characteristics. Among various 2D nanomaterials, MXenes are a widely studied nanosystem because of their close similarity to graphene analogs. So, it is synthesized using multiple approaches and exploits their inherited properties. But in most cases, surface functionalization techniques are carried out for targeting, site-specific drug clearance, renal clearance, and biocompatible with healthy cells. Thus, fabricating a multimodal agent for mono or combined therapies is also an image-guided diagnostic agent. This review will explain the recent and emerging advancements of MXenes-based composites as a multifunctional theragnostic agent and discuss the possibilities of transferring laboratory research to clinical translation.

Cytotoxicity, Differentiation, and Biocompatibility of Root-End Filling: A Comprehensive Study.

Assessing the biocompatibility of endodontic root-end filling materials through cell line responses is both essential and of utmost importance. This study aimed to the cytotoxicity of the type of cell death through apoptosis and autophagy, and odontoblast cell-like differentiation effects of MTA, zinc oxide-eugenol, and two experimental Portland cements modified with bismuth (Portland Bi) and barium (Portland Ba) on primary cell cultures. Material and methods: The cells corresponded to human periodontal ligament and gingival fibroblasts (HPLF, HGF), human pulp cells (HPC), and human squamous carcinoma cells from three different patients (HSC-2, -3, -4). The cements were inoculcated in different concentrations for cytotoxicity evaluation, DNA fragmentation in electrophoresis, apoptosis caspase activation, and autophagy antigen reaction, odontoblast-like cells were differentiated and tested for mineral deposition. The data were subject to a non-parametric test. Results: All cements caused a dose-dependent reduction in cell viability. Contact with zinc oxide-eugenol induced neither DNA fragmentation nor apoptotic caspase-3 activation and autophagy inhibitors (3-methyladenine, bafilomycin). Portland Bi accelerated significantly (p < 0.05) the differentiation of odontoblast-like cells. Within the limitation of this study, it was concluded that Portland cement with bismuth exhibits cytocompatibility and promotes odontoblast-like cell differentiation. This research contributes valuable insights into biocompatibility, suggesting its potential use in endodontic repair and biomimetic remineralization.

Effects of Nitrurized Titanium on Microhardness and Human Dental Pulp Stem Cell Adhesion and Differentiation.

To compare the Vickers microhardness, surface roughness, initial adhesion, and osteogenic differentiation on titanium (Ti) and nitrurized titanium (NTi) plates were treated by UV irradiation and chitosan. Each plate was subjected to Vickers hardness with a pressure of 2.9 N for 10 seconds and roughness evaluation by atomic force microscope (AFM) analysis. Three groups of each type of plates were tested: control (C), ultraviolet irradiation (UV), and chitosan (Q). The UV group was exposed to UV-irradiation for 20 min at 253.7 nm (52 µW/cm2). The Q group was coated with 1% chitosan, and the C group had no treatment. The osteoblasts (2 × 106 cells/mL) were inoculated in each group for 60 min and their viability was determined by the MTT bioassay. Osteogenic differentiation was performed over 4 weeks and determined by alizarin red staining. The mean was analyzed with the Shapiro-Wilks, Kruskall-Wallis, and Mann-Whitney U tests of normality (n = 9/gp). The NTi plates hardness (125.1 ± 4.01 HV) was higher (P = 0.026) than the Ti plates (121.3 ± 2.23 HV). The surface topography was: NTi (Ra = 0.098 µm) and Ti (Ra = 0.212 µm). The quantification of cell adhesion was: Ti + Q = 123 ± 4.9% (P < 0.05) < NTi + Q = 107 ± 3.3% < Ti = 100 ± 10.7% < NTi = 72 ± 6.8% < NTi + UV = 71 ± 4.4% < Ti + UV = 69 ± 3.5%, regardless the plates, the presence of chitosan induce a faster osteogenic differentiation. The Ti + Q plates tested the highest cell attachment and osteogenic adhesion suggesting their potential use of chitosan for cell-implant interaction.

Decellularized Scaffolds of Nopal (Opuntia Ficus-indica) for Bioengineering in Regenerative Dentistry.

Opuntia Ficus-indica, or nopal, is traditionally used for its medicinal properties in Mexico. This study aims to decellularize and characterize nopal (Opuntia Ficus-indica) scaffolds, assess their degradation and the proliferation of hDPSC, and determine potential pro-inflammatory effects by assessing the expression of cyclooxygenase 1 and 2 (COX-1 and 2). The scaffolds were decellularized using a 0.5% sodium dodecyl sulfate (SDS) solution and confirmed by color, optical microscopy, and SEM. The degradation rates and mechanical properties of the scaffolds were determined by weight and solution absorbances using trypsin and PBS and tensile strength testing. Human dental pulp stem cells (hDPSCs) primary cells were used for scaffold-cell interaction and proliferation assays, as well as an MTT assay to determine proliferation. Proinflammatory protein expression of COX-I and -II was discovered by Western blot assay, and the cultures were induced into a pro-inflammatory state with interleukin 1-ß. The nopal scaffolds exhibited a porous structure with an average pore size of 252 ± 77 µm. The decellularized scaffolds showed a 57% reduction in weight loss during hydrolytic degradation and a 70% reduction during enzymatic degradation. There was no difference in tensile strengths between native and decellularized scaffolds (12.5 ± 1 and 11.8 ± 0.5 MPa). Furthermore, hDPSCs showed a significant increase in cell viability of 95% and 106% at 168 h for native and decellularized scaffolds, respectively. The combination of the scaffold and hDPSCs did not cause an increase in the expression of COX-1 and COX-2 proteins. However, when the combination was exposed to IL-1ß, there was an increase in the expression of COX-2. This study demonstrates the potential application of nopal scaffolds in tissue engineering and regenerative medicine or dentistry, owing to their structural characteristics, degradation properties, mechanical properties, ability to induce cell proliferation, and lack of enhancement of pro-inflammatory cytokines.

Natural Bioactive Epigallocatechin-Gallate Promote Bond Strength and Differentiation of Odontoblast-like Cells.

The (-)-Epigallocatechin-gallate (EGCG) metabolite is a natural polyphenol derived from green tea and is associated with antioxidant, biocompatible, and anti-inflammatory effects. OBJECTIVE: To evaluate the effects of EGCG to promote the odontoblast-like cells differentiated from human dental pulp stem cells (hDPSCs); the antimicrobial effects on Escherichia coli, Streptococcus mutans, and Staphylococcus aureus; and improve the adhesion on enamel and dentin by shear bond strength (SBS) and the adhesive remnant index (ARI). MATERIAL AND METHODS: hDSPCs were isolated from pulp tissue and immunologically characterized. EEGC dose-response viability was calculated by MTT assay. Odontoblast-like cells were differentiated from hDPSCs and tested for mineral deposition activity by alizarin red, Von Kossa, and collagen/vimentin staining. Antimicrobial assays were performed in the microdilution test. Demineralization of enamel and dentin in teeth was performed, and the adhesion was conducted by incorporating EGCG in an adhesive system and testing with SBS-ARI. The data were analyzed with normalized Shapiro-Wilks test and ANOVA post hoc Tukey test. RESULTS: The hDPSCs were positive to CD105, CD90, and vimentin and negative to CD34. EGCG (3.12 µg/mL) accelerated the differentiation of odontoblast-like cells. Streptococcus mutans exhibited the highest susceptibility < Staphylococcus aureus < Escherichia coli. EGCG increased (p < 0.05) the dentin adhesion, and cohesive failure was the most frequent. CONCLUSION: (-)-Epigallocatechin-gallate is nontoxic, promotes differentiation into odontoblast-like cells, possesses an antibacterial effect, and increases dentin adhesion.

Evaluation of the biological responses of silver nanoparticles synthesized using Pelargonium x hortorum extract.

Silver nanoparticles (AgNPs) are one of the widely studied nanomaterials for diverse biomedical applications, in particular, as antimicrobial agents to kill bacteria, fungi, and viruses. In this report, AgNPs were synthesized using a geranium (Pelargonium x hortorum) leaves extract and tested for their antimicrobial and cytotoxic activity and reactive oxygen species (ROS) production. Using green biosynthesis, the leaves extract was employed as a reducing and stabilizing agent. Synthesis parameters like reaction time and precursor (silver nitrate AgNO3) volume final were modified, and the products were tested against Streptococcus mutans. For the first time, the metabolomic analysis of extract, we have identified more than 50 metabolites. The UV-Vis analysis showed a peak ranging from 410-430 nm, and TEM confirmed their nearly spherical morphology for all NPs. The antimicrobial activity of the NPs revealed a minimum inhibitory concentration (MIC) of 10 µg mL-1. Concerning cytotoxicity, a dose-time-dependent effect was observed with a 50% cellular cytotoxicity concentration (CC50) of 4.51 µg mL-1 at 24 h. Interestingly, the cell nuclei were visualized using fluorescence microscopy, and no significant changes were observed. These results suggest that synthesized spherical AgNPs are promising potential candidates for medical applications.

Efficacy of Antineoplastic Nanocarriers on 3D Oral Cancer Spheroids.

BACKGROUND/AIM: Cancer is a leading cause of death worldwide. Conventional treatments as surgery, chemotherapy, radiotherapy, and combined therapies are commonly used. However, these therapies have several limitations and side effects. To address these issues, innovative research is being conducted on nanocarriers (NCs) functionalized with antineoplastic agents. These NCs aim to overcome limitations and improve patients' lives. However, before they can be used clinically, these NCs are primarily assessed on a lab scale to determine their efficacy. MATERIALS AND METHODS: A primary cell culture was established from a lymphoblastic neoplasm in the maxilla. After characterization, the cells were cultured in 2D to evaluate the dose-effect of nanoparticles (NPs), such as Zinc oxide (ZnO) and Magnesium oxide (MgO), as well as those of free drugs of 5-fluorouracil (5-FU) and cisplatin (Cis). Based on the results, a 3D spheroid culture was used for further study. Finally, the spheroids were histologically processed for immuno-morphological observation. RESULTS: To evaluate spheroid cell viability, we conducted an MTT assay. Treatment of cell spheroids with ZnONPs, 5-FU, and NPs conjugated with antitumor agents such as 5-FU-ZnO and Cis-ZnO decreased cell viability by >25%, >60% and >10% and <20% at a concentration of 0.06, 0.015 and 0.015 & 0.03 mg/ml, respectively. CONCLUSION: Nanoparticles conjugated with antitumor agents showed promising antineoplastic effects on both 2D and 3D cell cultures. However, the efficacy of the nanoparticles varied between the different models. This highlights the importance of selecting appropriate in vitro culture models for the evaluation of biomedical agents.

Gelatin-Chitosan Hydrogel Biological, Antimicrobial and Mechanical Properties for Dental Applications.

Chitosan, a natural polysaccharide sourced from crustaceans and insects, is often used with hydrogels in wound care. Evaluating its cytotoxicity and antimicrobial properties is crucial for its potential use in dentistry. OBJECTIVE: To investigate the mechanical properties of gelatin hydrogels based on decaethylated chitosan and antimicrobial activity against Streptococcus mutans and their biological effects with stem cells from apical papilla (SCAPs). MATERIAL AND METHODS: Gelatin-chitosan hydrogels were synthesized at concentrations of 0%, 0.2% and 0.5%. Enzymatic and hydrolytic degradation, along with swelling capacity, was assessed. Fourier transform infrared spectroscopy (FTIR) analysis was employed to characterize the hydrogels. The interaction between hydrogels and SCAPs was examined through initial adhesion and cell proliferation at 24 and 48 h, using the Thiazolyl Blue Tetrazolium Bromide (MTT assay). The antimicrobial effect was evaluated using agar diffusion and a microdilution test against S. mutans. Uniaxial tensile strength (UTS) was also measured to assess the mechanical properties of the hydrogels. RESULTS: The hydrogels underwent hydrolytic and enzymatic degradation at 30, 220, 300 min and 15, 25, 30 min, respectively. Significantly, (p < 0.01) swelling capacity occurred at 20, 40, 30 min, respectively. Gelatin-chitosan hydrogels' functional groups were confirmed using vibrational pattern analysis. SCAPs proliferation corresponded to 24 h = 73 ± 2%, 82 ± 2%, 61 ± 6% and 48 h = 83 ± 11%, 86 ± 2%, 44 ± 2%, respectively. The bacterial survival of hydrogel interaction was found to be 96 ± 1%, 17 ± 1.5% (p < 0.01) and 1 ± 0.5% (p < 0.01), respectively. UTS showed enhanced (p < 0.05) mechanical properties with chitosan presence. CONCLUSION: Gelatin-chitosan hydrogels displayed favorable degradation, swelling capacity, mild dose-dependent cytotoxicity, significant proliferation with stem cells from apical papilla (SCAPs), substantial antimicrobial effects against S. mutans and enhanced mechanical properties. These findings highlight their potential applications as postoperative care dressings.

CRISPR/Cas gene-editing technology and its advances in dentistry.

A recent discovery of revolutionary Clustered regularly interspaced palindromic repeats (CRISPR) is a gene-editing tool that provides a type of adaptive immunity in prokaryotic organisms, which is currently used as a revolutionizing tool in biomedical research. It has a mechanism of correcting genome errors, turning on/off genes in cells and organisms. Most importantly playing a crucial function in bacterial defence by identifying and destroying Deoxyribonucleic acid (DNA) segments during bacteriophage invasions since the CRISPR-associated protein 9 (Cas9) enzyme recognizes and cleaves invasive DNA sequences complementary to CRISPR. Therefore, researchers employ this biological device to manipulate the genes to develop new therapies to combat systemic diseases. Currently, the most significant advance at the laboratory level is the generation of cell and animal models, functional genomic screens, live images of the cell genome, and defective DNA repairs to find the cure for genetic disorders. Even though this technology has enormous biomedical applications in various sectors, this review will summarize CRISPR/Cas emphasizing both the therapeutic and diagnostic mechanisms developed in the field of dentistry and the promising attempts to transfer this technology to clinical application. Finally, future developments are also described, which proposes to use CRISPR/Cas systems for prospective clinical dentistry applications.

[Cancer stem cells in oral squamous cell carcinoma. Literature review]. / Células troncales cancerígenas en carcinoma oral de células escamosas. Revisión de la literatura.

Objective: To perform a literature review on oral squamous cell carcinoma, the presence of cancer stem cells; their association with the course of the disease and therapeutic applications. Methods: : A search was performed in the PubMed database by entering the following algorithm: ((((neoplastic stem cells [MeSH Terms ]) OR (Cancer stem cells [Text Word ])) AND (Squamous Cell Carcinoma of Head and Neck [MeSH Terms])) AND (Oral squamous cell carcinoma [Text Word ]), to find articles in english published between 2012 and 2022. The PRISMA diagram was used to identify and select the articles. Results: A result of 49 articles was obtained; of which 27 were chosen according to the title and abstract in their association with the topic. In addition, 8 additional articles suggested by their relationship with the information previously searched were included. In total, 35 articles were evaluated. There has been found that tumoral cells in squamous oral carcinoma are heterogeneous since they include cancer stem cells wich possess characteristics of stem and neoplasic cells; which possess characteristics of stem cells as well as neoplastic cells; they have been associated with disease progression, recurrence, and metastasis and have been considered to be a key mechanism of therapy failure. Conclusions: The expression of stem cell markers in oral squamous cell carcinomas has been demonstrated and has contributed to their identification in oral squamous cell carcinomas and has been implicated in the behavior of cancer cells. New therapeutic measures aimed at eliminating cancer stem cells have been proposed and developed.

Enhancement of fluoride release in glass ionomer cements modified with titanium dioxide nanoparticles.

BACKGROUND: Several efforts have been made to improve the glass ionomer cements (GICs) properties with nanotechnology. Fluoride release in once of most beneficial properties of GICs. The purpose of this study was to evaluate the fluoride release, recharge, and cytotoxicity in GICs reinforced with titanium dioxide nanoparticles (TiO2N). OBJECTIVE: Evaluate the fluoride release, recharge, and cytotoxicity in GICs reinforced with TiO2N. METHODS: Four GICs, FUJI IX EXTRA (G1c), KETAC MOLAR (G2c), IONOFILL MOLAR (G3c), and FUJI IX (G4c) were combined with TiO2N (G1e, G2e, G3e, and G4e) and divided into blocks of 5-mm width and 1-mm thickness 10 each. A total of 80 samples were arranged as follows: GICs alone as negative control (n = 40) and GICs + TiO2N as experimental groups (n = 40). The fluoride release was determined for periods of 1, 2, 6, 10, 31, 90, 180, 240, and 300 days. On days 30 and 179, samples were recharged by submerging in 1 mL of 20,000 ppm sodium fluoride gel. Cytotoxic activity was carried out with gingival fibroblasts, using 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide cell viability assay. RESULTS: The experimental groups obtained the highest and more constant fluoride released when compared to control groups. After the first recharge, experimental groups (G1e, G3e, and G4e) showed statistically significant results (P = .001, 0.010, and 0.001 respectively) enhancing their recharge ability regarding control groups. The second recharge showed better results in G1e concerning the rest of the groups. No cytotoxic activity was observed in all experimental groups, although significant differences were observed in G3e and G4e regarding control group. CONCLUSION: The incorporation of TiO2N enhance the fluoride release in glass ionomers with a noncytotoxic effect on human gingival fibroblasts.

Gel dressing based on type I collagen modified with oligourethane and silica for skin wound healing.

Cutaneous wound healing is a complex process that leads the skin reparation with the formation of scar tissue that typically lacks skin appendages. This fact drives us to find new strategies to improve regenerative healing of the skin. This study outlines, the contribution of colloidal silica particles and oligourethane crosslinking on the collagen material properties and the effect on skin wound healing in rats. We characterized the gel properties that are key forin-situgelation, which is accomplished by the latent reactivity of oligourethane bearing blocked isocyanate groups to crosslink collagen while entrapping silica particles. The swelling/degradation behavior and the elastic modulus of the composite gel were consistent with the modification of collagen type I with oligourethane and silica. On the other hand, these gels were characterized as scaffold for murine macrophages and human stem cells. The application of a composite gel dressing on cutaneous wounds showed a histological appearance of the recovered skin as intact skin; featured by the epidermis, hair follicles, sebaceous glands, subcutaneous adipose layer, and dermis. The results suggest that the collagen-based composite dressings are promising modulators in skin wound healing to achieve a regenerative skin closure with satisfactory functional and aesthetic scars.

Perspectives for the use of silver nanoparticles in dental practice.

Nanotechnology has been used for medical applications in several forms, including dental practice with the development of silver nanoparticles (Ag NPs) as a useful tool. The aim of this review was to identify the properties and appliances of Ag NPs in dental practice. Silver compounds and NPs have already been used as dental restorative material, endodontic retrofill cements, dental implants and caries inhibitory solution. Despite the effectiveness that Ag NPs has shown in dental practice, Ag NPs remain a controversial area of research with respect to their toxicity in biological and ecological systems. Therefore any application of Ag NPs in dentistry requires more studies. In order to avoid the toxicity of these materials Ag NPs can be temporarily used in dentistry.