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1.
Clin Oral Investig ; 27(8): 4653-4658, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37328611

RESUMEN

OBJECTIVE: The aim of this study is to evaluate the effect of using anti-stress balls in reducing patients' pain during injection of the inferior alveolar nerve block (IANB). MATERIALS AND METHODS: In this randomized clinical trial, 32 individuals were divided into two groups. The conventional method of anesthesia injection was performed using IANB conventional injection technique. During the injection, individuals in the anti-stress ball group were asked to use the anti-stress ball as a distraction technique. For the control group, no supersede methods were used for pain control. Finally, both groups were asked to record their pain utilizing the numerical rating scale (NRS). The participants' vital signs were monitored before and after injection. Kolmogorov-Smirnov test, independent T-test, and Fisher's exact chi-square test were performed for statistical analysis (α = 0.05). RESULTS: Sixteen females and 16 males in the age range of 40 to 20 years old participated in this study. The mean pain score in the anti-stress ball group was significantly lower (p < 0.001). In both sexes, the pain score in the anti-stress ball group was significantly lower (males p < 0.001 and females p = 0.001). In addition, in all age ranges, the pain score in the control group was higher except for the above 35 years old participants (p = 0.078). Moreover, there were no significant differences in individuals' vital signs (p > 0.05). CONCLUSION AND CLINICAL RELEVANCE: Utilizing an anti-stress ball reduces patients' pain significantly during IANB in both sexes and individuals who are below 35 years without changing vital signs. CLINICAL REGISTRATION NUMBER: IRCT20220815055704N1.


Asunto(s)
Anestesia Dental , Bloqueo Nervioso , Pulpitis , Masculino , Femenino , Humanos , Adulto , Anestésicos Locales/farmacología , Bloqueo Nervioso/métodos , Nervio Mandibular , Dolor , Anestesia Local/métodos , Anestesia Dental/métodos , Pulpitis/cirugía , Método Doble Ciego
2.
Int J Mol Sci ; 18(10)2017 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-29027958

RESUMEN

Bone regeneration in craniomaxillofacial surgery represents an issue that involves both surgical and aesthetic aspects. The most recent studies on bone tissue engineering involving adipose-derived stromal/stem cells (ASCs) have clearly demonstrated that such cells can play a crucial role in the treatment of craniomaxillofacial defects, given their strong commitment towards the osteogenic phenotype. A deeper knowledge of the molecular mechanisms underlying ASCs is crucial for a correct understanding of the potentialities of ASCs-based therapies in the most complex maxillofacial applications. In this topical review, we analyzed the molecular mechanisms of ASCs related to their support toward angiogenesis and osteogenesis, during bone regeneration. Moreover, we analyzed both case reports and clinical trials reporting the most promising clinical applications of ASCs in the treatment of craniomaxillofacial defects. Our study aimed to report the main molecular and clinical features shown by ASCs, used as a therapeutic support in bone engineering, as compared to the use of conventional autologous and allogeneic bone grafts.


Asunto(s)
Tejido Adiposo/citología , Regeneración Ósea , Trasplante de Células Madre Mesenquimatosas , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/metabolismo , Animales , Ensayos Clínicos como Asunto , Anomalías Craneofaciales/cirugía , Humanos , Osteogénesis , Proteoma , Ingeniería de Tejidos , Andamios del Tejido , Transcriptoma
3.
Clin Oral Investig ; 18(2): 571-8, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-23604784

RESUMEN

OBJECTIVES: The purpose of the study was to evaluate by micro-computerized tomography (microCT) areas and volumes of post, cement, and voids/bubbles in the post space of oval-shaped premolars restored either with oval or circular posts. MATERIALS AND METHODS: Twelve extracted premolars were divided into two groups according to the drill-fiber post system used: (1) GC Fiber Post Drill + circular post GC Fiber Post; (2) Ellipson tip(TM) + oval post Ellipson post(TM). Each tooth was scanned using microCT, and areas and volumes of canal, post space, post, cement, and voids at coronal, medium, and apical level were calculated by using a three-dimensional visualization software. Two-way analyses of variance and Tukey tests were used for statistical analysis (p < 0.05). RESULTS: The area of voids was significantly greater at apical level of oval posts, but no difference was found between the levels among the groups. Regardless of post shape, the volume of voids and of cement was significantly higher at the coronal level. With oval posts, the total volume of cement was twice as much as with circular posts, and the difference was statistically significant. CONCLUSIONS: Our results indicate that the volume of voids does not depend on post shape. Moreover, the microCT analysis demonstrated that the volume of cement was greater with oval posts compared to circular posts. CLINICAL RELEVANCE: The microCT analysis provided interesting information on voids distribution and on the ratio between post shape and cement thickness. These results might address the clinician in the reconstruction of teeth with fiber posts.


Asunto(s)
Diente Premolar/diagnóstico por imagen , Técnica de Perno Muñón , Microtomografía por Rayos X/métodos , Humanos
4.
Discov Med ; 36(188): 1772-1779, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39327240

RESUMEN

Aging is frequently associated with a progressive increase in chronic low-grade inflammation, known as "inflammaging". Numerous studies have shown that inflammaging is closely linked to the development of several age-related diseases. However, the underlying mechanism and its causal role are still not fully understood despite this association. In the complex context of aging, mesenchymal stem cells (MSCs) undergo changes in behavior and functionality. This narrative topical review examines the recent advances in aging research, specifically focusing on the role of inflammaging and related mechanisms that contribute to age-related chronic diseases. The authors critically investigated whether and how inflammaging, epigenetic damage, mitochondrial changes, and macrophage alterations may influence stem cell behavior, highlighting the interplay between these factors and their potential therapeutic implications. By elucidating the mechanisms underlying these processes, we can gain valuable insights into the maintenance and regeneration of stem cell populations, providing the basis for novel therapeutic strategies targeting age-related decline and disease progression.


Asunto(s)
Envejecimiento , Epigénesis Genética , Inflamación , Macrófagos , Mitocondrias , Humanos , Macrófagos/metabolismo , Macrófagos/patología , Mitocondrias/metabolismo , Mitocondrias/genética , Mitocondrias/patología , Inflamación/patología , Inflamación/genética , Envejecimiento/genética , Envejecimiento/patología , Envejecimiento/fisiología , Células Madre Mesenquimatosas/metabolismo , Células Madre Mesenquimatosas/patología , Animales
5.
Dent Mater ; 2024 10 01.
Artículo en Inglés | MEDLINE | ID: mdl-39358191

RESUMEN

OBJECTIVES: This study investigated the impact of some specific experimental calcium phosphate cements doped with different fluoride salts (FDCPCs) concentrations on the basal functions of human Dental Pulp Stem Cells (hDPSCs). Furthermore, this study also examined the migration, as well as the mineralisation through osteogenic differentiation. METHODS: Experimental FDCPCs were formulated using different concentrations of calcium/sodium fluoride salts [(5 wt%: VS5F), (10 wt%: VS10F), (20 wt%: VS20F)]. A fluoride-free calcium phosphate (VS0F) was used as a control. The hDPSCs were assessed to evaluate their self-renewal and migration activity in the presence of eluates of the different FDCPCs. A viability assay in osteogenic conditions was carried out, along with the differentiation potential through Alkaline Phosphatase Activity (ALP), and Alizarin Red Staining (ARS). Moreover, the gene expression of specific markers (RUNX2, ALP, COL1α1, OCN, OPN, DSPP, MEPE, and DMP-1) was also evaluated. RESULTS: All the tested FDCPD had no influence on cell migrations, but they caused a decrease in cell viability in osteogenic conditions when not diluted. Conversely, the eluants of VS20F showed a positive effect on stem cell differentiation. This result was corroborated through ALP activity, ARS assay. Moreover, upregulation of specific gene markers such as RUNX2, DMP-1, and DSPP was observed in hDPSCs, especially when treated with VS20F. SIGNIFICANCE: The experimental FDCPC tested in this study exhibits a dose-dependent capacity to promote mineralisation in osteogenic environment. The FDCPC-VS20F seems to be the most promising experimental material suitable for developing of pulp-capping materials with osteogenic and bioactive properties.

6.
J Biotechnol ; 393: 7-16, 2024 Sep 20.
Artículo en Inglés | MEDLINE | ID: mdl-39033880

RESUMEN

Periodontitis (PDS) is a chronic inflammatory disease initiated by a dysbiosis of oral pathogenic bacterial species, such as Porphyromonas gingivalis (Pg). These bacteria can penetrate the bloodstream, releasing various endo and exotoxins that fuel the infection, and stimulate toxic inflammation in different compartments, including the brain. However, the specific mechanisms by which PDS/Pg contribute to brain disorders, such as Alzheimer's disease (AD), remain unclear. This study assessed the effects of Pg's virulence factors - lipopolysaccharide (LPS-Pg) and gingipains (gps) K (Kgp) and Rgp - on SH-SY5Y cells. Our results demonstrated that LPS-Pg activated signaling through the Toll-like receptor (TLR)-2/4 induced a significant downregulation of G protein-coupled receptor kinase 5 (GRK5). Additionally, LPS-Pg stimulation resulted in a robust increase in Tau phosphorylation (pTau) and p53 levels, while causing a marked reduction in Bcl2 and increased cell death compared to unstimulated cells (Ns). LPS-Pg also elevated inducible nitric oxide synthase (iNOS) expression, leading to oxidative damage. In cells overexpressing GRK5 via Adenovirus, LPS-Pg failed to increase iNOS and pTau levels compared to GFP control cells. High GRK5 levels also prevented the nuclear accumulation of nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB). Furthermore, the overexpression of a GRK5 mutant form lacking the nuclear localization signal (ΔNLS) nearly abolished LPS-Pg induced p53 and iNOS upregulation. Finally, we tested whether Kgp and Rgp mediated similar effects and our data showed that both gps caused a marked downregulation of GRK5 leading to increased p53 and pTau levels. In conclusion, this study provides further insight into the toxic effects elicited by Pg in cells and suggests that preventing GRK5 deficiency may be a valid strategy to mitigate Pg-induced toxic effects (i.e. cell death, oxidative damage, and Tau hyperphosphorylation) in SH-SY5Y cells, which are typical molecular hallmarks of neurodegenerative disorders.


Asunto(s)
Quinasa 5 del Receptor Acoplado a Proteína-G , Lipopolisacáridos , Porphyromonas gingivalis , Factores de Virulencia , Humanos , Línea Celular Tumoral , Quinasa 5 del Receptor Acoplado a Proteína-G/metabolismo , Quinasa 5 del Receptor Acoplado a Proteína-G/genética , Cisteína-Endopeptidasas Gingipaínas/metabolismo , Neuroblastoma , Óxido Nítrico Sintasa de Tipo II/metabolismo , Óxido Nítrico Sintasa de Tipo II/genética , Fosforilación , Porphyromonas gingivalis/patogenicidad , Transducción de Señal , Proteínas tau/metabolismo , Receptor Toll-Like 2/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Factores de Virulencia/metabolismo , Factores de Virulencia/genética
7.
J Clin Med ; 12(11)2023 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-37297998

RESUMEN

Over the past few decades, life expectancy has been increasing in several countries [...].

8.
Dent Mater ; 39(4): 391-401, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36907820

RESUMEN

OBJECTIVES: This study aimed at evaluating the cytotoxicity, chemical and structural properties of experimental fluoride-doped calcium-phosphates as potential remineralising materials for dental applications. METHODS: Experimental calcium phosphates were formulated using ß-tricalcium phosphate, monocalcium phosphate monohydrate, calcium hydroxide, and different concentrations of calcium/sodium fluoride salts [(5 wt%: VSG5F), (10 wt%: VSG10F), (20 wt%: VSG20F)]. A fluoride-free calcium phosphate (VSG) was used as control. Each tested material was immersed in simulated body fluid (SBF), (24 h, 15 and 30 days) to assess their ability to crystallise into apatite-like. Cumulative fluoride release was assayed up to 45 days. Moreover, each powder was placed into a medium containing human dental pulp stem cells (200 mg/mL) and their cytotoxicity was analysed using the 3-(4,5-dimethylthiazol-2-yl)- 2,5-diphenyltetrazolium bromide (MTT) assay (24 h, 48 h and 72 h incubation). These latter results were statistically analysed by ANOVA and Tukey's test (α = 0.05). RESULTS: All the experimental VSG-F materials produced fluoride-containing apatite-like crystals after SBF immersion. VSG20F presented prolonged release of fluoride ions into the storage media (45d). VSG, VSG10F and VSG20F showed a significant cytotoxicity at dilution of 1:1, while at 1:5, only VSG and VSG20F demonstrated a reduction in cell viability. At lower dilutions (1:10, 1:50 and 1:100) all specimens showed no significant toxicity to hDPSCs, but an increase in cell proliferation. SIGNIFICANCE: The experimental fluoride-doped calcium-phosphates are biocompatible and possess a clear ability to evoke fluoride-containing apatite-like crystallisation. Hence, they may be promising remineralising materials for dental applications.


Asunto(s)
Calcio , Fosfatos , Humanos , Fosfatos/química , Calcio/química , Fosfatos de Calcio/química , Apatitas/química , Fluoruros/análisis
9.
Materials (Basel) ; 15(3)2022 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-35161083

RESUMEN

Physical and mechanical properties of continuous carbon or glass fiber reinforced endodontic posts are relevant to increase the retention and resistance of the tooth-restoration system. Hollow posts have been recently designed for delivering the luting cement through the post hole, thus enhancing the post-dentin interface by reducing the risk of air bubbles formation. Methods: Three type of endodontic posts, a carbon fiber hollow post, a glass fiber hollow post and a compact glass fiber post were investigated. Mechanical properties of these posts were assessed through bending tests. Teeth were subjected to fatigue cycling and the strength of restored teeth was detected through static tests. Failure modes were investigated through optical and scanning electron microscopy. Results show that composite posts increase the mechanical stability by more than 100% compared to premolars restored with particulate composite. Carbon fiber posts retain the highest strength (1467 N ± 304 N) among the investigated post and core restoration, but an unfavorable type of fracture has been observed, preventing the tooth re-treatment. Instead, more compliant posts (i.e., glass fiber reinforced composite, providing a strength of 1336 N ± 221 N), show a favorable mode of fracture that allows the re-treatment of teeth in the case that failure occurs. Glass fiber hollow posts show a good trade-off between strength and a favorable type of fracture.

10.
J Clin Med ; 11(14)2022 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-35887779

RESUMEN

Vital pulp therapy (VPT) has been recently proposed as an alternative approach even in symptomatic mature permanent teeth with deep caries' lesions, aiming to maintain the pulp vitality over time and/or to avoid non-surgical root canal therapy (NSRCT). However, to date, the diagnosis of reversible or irreversible pulpitis is only based on clinical pain quantity and quality, without precisely reflecting the pulp inflammation status. Therefore, the aim of the present study was to provide an overview based on the current scientific literature to demonstrate the clinical effectiveness of VPT on mature permanent teeth, validating the use of hydraulic calcium silicate-based cements and their role in pain management. VPT may be successfully applied not only in mature permanent teeth diagnosed with reversible pulpitis, but also in permanent dental elements with signs and symptoms of irreversible pulpitis. Hydraulic cements showed favorable outcomes in terms of decrease of pro-inflammatory mediators and of post-operative pain. Pain plays a central role in the chance to perform VPT in mature permanent teeth, since it may be considered as a pre-operative diagnostic criterion as well as a treatment success parameter. In addition, proper assessment of pulp inflammation and choice of appropriate materials are key factors in enhancing VPT success.

11.
Dent Mater ; 37(9): e455-e484, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34148785

RESUMEN

OBJECTIVE: To conduct a systematic review and meta-analysis to assess if the presence of an endodontic post may increase the fracture resistance of endodontically-treated maxillary premolars directly restored with composite. METHODS: A comprehensive systematic literature search according to the PRISMA statement was conducted to assess in vitro studies including endodontically-treated maxillary premolars, restored with different type of posts supporting direct composite reconstructions. Two groups of meta-analyses were performed using fixed effects model and additional Trial Sequential Analysis (TSA) was carried out. Moreover, risk of bias was conducted and quality of evidence for any performed meta-analysis was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE). RESULTS: Twenty-four articles met the inclusion criteria and 13 studies also underwent quantitative evaluation. Fracture resistance of endodontically-treated premolars restored with fiber posts was significantly less than sound teeth (p value: < 0.00001), however endodontically-treated premolars with a fiber post provided an increase in fracture resistance when compared to equivalent teeth restored without post (p value: 0.003). TSA revealed high power of both meta-analyses. Moderate risk of bias was reported in 23/24 studies; only 1 study showed high risk of bias. GRADE system showed moderate strength of evidence due to the presence of a study with high risk of bias and to wide confidence intervals. SIGNIFICANCE: Within the limitation of the present systematic review and meta-analysis, it can be concluded that endodontically-treated maxillary premolars restored with a fiber post and direct composite restoration demonstrated increased fracture resistance when compared to equivalent teeth without post.


Asunto(s)
Técnica de Perno Muñón , Fracturas de los Dientes , Diente no Vital , Diente Premolar , Resinas Compuestas , Análisis del Estrés Dental , Humanos
12.
Dent Mater ; 37(11): 1734-1750, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34561100

RESUMEN

OBJECTIVE: To assess the microtensile bond strength (MTBS) and interfacial characteristics of universal adhesives applied on dentine air-abraded using different powders. The analysis includes the cytotoxicity of the powders and their effect on odontogenic gene expression. METHODS: Sound human dentine specimens were air-abraded using bioglass 45S5 (BAG), polycarboxylated zinc-doped bioglass (SEL), alumina (AL) and submitted to SEM analysis. Resin composite was bonded to air-abraded or smear layer-covered dentine (SML) using an experimental (EXP) or a commercial adhesive (ABU) in etch&rinse (ER) or self-etch (SE) modes. Specimens were stored in artificial saliva (AS) and subjected to MTBS testing after 24 h and 10 months. Interfacial nanoleakage assessment was accomplished using confocal microscopy. The cytotoxicity of the powders was assessed, also the total RNA was extracted and the expression of odontogenic genes was evaluated through RT-PCR. RESULTS: After prolonged AS storage, specimens in the control (SML) and AL groups showed a significant drop in MTBS (p > 0.05), with degradation evident within the bonding interface. Specimens in BAG or SEL air-abraded dentine groups showed no significant difference, with resin-dentine interfaces devoid of important degradation. The metabolic activity of pulp stem cells was not affected by the tested powders. SEL and BAG had no effect on the expression of odontoblast differentiation markers. However, AL particles interfered with the expression of the odontogenic markers. SIGNIFICANCE: The use of bioactive glass air-abrasion may prevent severe degradation at the resin-dentine interface. Unlike alumina, bioactive glasses do not interfere with the normal metabolic activity of pulp stem cells and their differentiation to odontoblasts.


Asunto(s)
Recubrimiento Dental Adhesivo , Recubrimientos Dentinarios , Resinas Compuestas , Cementos Dentales , Dentina , Expresión Génica , Humanos , Ensayo de Materiales , Cementos de Resina , Propiedades de Superficie , Resistencia a la Tracción
13.
J Appl Biomater Biomech ; 8(3): 146-52, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-21337305

RESUMEN

PURPOSE: The importance of polymer-based composite materials to make multifunctional substrates for tissue engineering and the strategies to improve their performances have been stressed in the literature. Bioactive features of sol-gel synthesized poly(ε-caprolactone)/TiO2 or poly(ε-caprolactone)/ZrO2 organic-inorganic hybrid materials are widely documented. Accordingly, the aim of this preliminary research was to develop advanced composite substrates consisting of a poly(ε-caprolactone) matrix reinforced with sol-gel synthesized PCL/TiO2 or PCL/ZrO2 hybrid fillers. METHODS: Micro-computed tomography and atomic force microscopy analyses allowed to study surface topography and roughness. On the other hand, mechanical and biological performances were evaluated by small punch tests and Alamar Blue™ assay, respectively. RESULTS: Micro-computed tomography and atomic force microscopy analyses highlighted the effect of the preparation technique. Results from small punch tests and Alamar Blue™ assay evidenced that PCL reinforced with Ti2 (PCL=12, TiO2=88 wt%) and Zr2 (PCL=12, ZrO2=88 wt%) hybrid fillers provided better mechanical and biological performances. CONCLUSIONS: PCL reinforced with Ti2 (PCL=12, TiO2=88 wt%) and Zr2 (PCL=12, ZrO2=88 wt%) hybrid fillers could be considered as advanced composite substrates for hard tissue engineering.


Asunto(s)
Poliésteres/química , Ingeniería de Tejidos/métodos , Titanio/química , Circonio/química , Geles/química , Compuestos Inorgánicos/química , Microscopía de Fuerza Atómica , Compuestos Orgánicos/química , Polimetil Metacrilato/química
15.
Dent J (Basel) ; 8(2)2020 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-32260114

RESUMEN

Regenerative dentistry represents a novel interdisciplinary approach involving biomaterials, several molecules and mesenchymal stem cells (MSCs), preferably derived from oral tissues. The pivotal role of MSCs depends on the fact that they can differentiate into different cell lineages and have the strategic role to release bioactive substances that stimulate the renewal and regeneration of damaged tissues. The role of regenerative dentistry is promising in all the branches of dentistry: the most intriguing application is related to the management of endodontic and periodontal defects, overcoming the surgical approach and the implantology as a consequence of a poorly efficient therapeutic plan.

16.
J Clin Med ; 9(12)2020 Nov 28.
Artículo en Inglés | MEDLINE | ID: mdl-33260782

RESUMEN

The implementation of hydraulic calcium silicate-based endodontic cements (HCSCs) in biologically based endodontic procedures for the primary dentition has been recently investigated, focusing on the biological response of stem cells from human exfoliated deciduous teeth (SHEDs) towards them. The present systematic review aimed to present a qualitative synthesis of the available literature consisting of in vitro assays, which assessed the cytocompatibility and bioactive properties of HCSCs in direct contact with SHEDs. Following the PRISMA statement, an electronic database search was carried out in Medline, Scopus, Embase, Web of Science, and SciELO on March 31st and updated on November 16th, 2020. In vitro studies evaluating the biological response of SHEDs to the treatment with HCSCs were eligible. Within the term biological response, assays assessing the cytocompatibility (i.e., cell viability, migration, proliferation), cell plasticity or differentiation (i.e., osteo/odontogenic marker expression), and bioactivity or biomineralization (i.e., mineralized nodule formation) were included. A total of seven studies were included after the selection process. The study sample comprised an extensive range of cell viability, migration, proliferation, adhesion, and bioactivity assays regarding the biological response of SHEDs towards five different commercially available HCSCs (MTA, ProRoot MTA, Biodentine, iRoot BP Plus, and Theracal LC). Biodentine, MTA, and iRoot BP Plus showed significant positive results in cytocompatibility and bioactivity assays when cultured with SHEDs. The results from in vitro assays assessing the cytocompatibility and bioactivity of the HCSCs MTA, Biodentine, and iRoot BP Plus towards SHEDs support their use in vital pulp treatment for the primary dentition.

17.
Materials (Basel) ; 13(24)2020 Dec 11.
Artículo en Inglés | MEDLINE | ID: mdl-33322480

RESUMEN

Background: The aim of this study was to investigate cuspal deflection caused by material shrinkage and temperature rise occurring in the pulp chamber during photopolymerization. The aim of this study was also to investigate the effect of flowable and packable bulk-fill composites on cuspal deflection occurring in mesio-occlusal-distal (MOD) cavities restored through the bulk-fill or through the incremental layering technique. Additionally, mechanical and thermal properties of bulk-fill composites were considered. Methods: Two bulk-fill composites (high-viscosity and low-viscosity), largely differing in material composition, were used. These composites were characterized through linear shrinkage and compressive test. Cuspal deformation during restoration of mesio-occlusal-distal cavities of human premolars was evaluated using both the bulk-fill and the incremental layering techniques. Temperature rise was measured through thermocouples placed 1 mm below the cavity floor. Results: Shrinkage of the flowable composite was significantly higher (p < 0.05) than that of packable composite, while mechanical properties were significantly lower (p < 0.05). For cusp distance variation, no significant difference was observed in cavities restored through both restorative techniques, while temperature rise values spanned from 8.2 °C to 11.9 °C. Conclusions: No significant difference in cusp deflection between the two composites was observed according to both the restorative techniques. This result can be ascribed to the Young's modulus suggesting that the packable composite is stiffer, while the flowable composite is more compliant, thus balancing the cusp distance variation. The light curing modality of 1000 mW/cm2 for 20 s can be considered thermally safe for the pulp chamber.

18.
J Appl Biomater Biomech ; 7(2): 132-40, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-20799174

RESUMEN

PURPOSE: The effects of light curing units (LCU) and energy doses on the chemical and physical properties of a dental composite were investigated. METHODS: The effects on the chemical and physical properties of a bisphenol A diglycidylether methacrylate (Bis-GMA) based dental restorative material were evaluated through photospectrometry, differential scanning calorimetry, and mechanical measurements. RESULTS: The light curing conditions associated with direct and indirect restorations were replicated in vitro using optical investigation techniques. A slight attenuation resulted independently of the LCU and a strong attenuation was measured for the cement luting a thick inlay, as well as for the deepest layer of a composite filling increment. Calorimetric measurements indicated that the curing degree is very sensitive to the light energy dose rather than to the LCU. Mechanical testing showed a transient phase during which properties increased. The delay of the composite in reaching adequate properties is strongly dependent on the energy dose. CONCLUSIONS: It is recommended that composites subject to unfavorable light curing conditions undergo a prolonged light curing process.

19.
Histol Histopathol ; 34(11): 1195-1203, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31169298

RESUMEN

Regenerative dentistry is attracting growing interest in the scientific community, mainly because of its translational and promising therapeutic approach. The latest research carried out by the scientific community are aimed at triggering the local cellular response, in order to induce a physiological self-repairing of damaged oral tissues. Such physiological processes mainly involve the activation of local stem cell populations: mesenchymal stem cells, in fact, retain the ability to proliferate and to differentiate towards functional mature elements, thus leading towards healing of damaged tissues. Glycogen Synthase Kinase-3 (GSK-3) is a key-regulator of the Wnt/ß-catenin pathway; it phosphorylates ß-catenin, that then is degraded in the cytosol. The activation of such signalling, mediated by Wnt ligand/receptor association, inhibits GSK-3, leading to translocation of ß-catenin to the nucleus and to gene transcription. Selective inhibitors of GSK-3 have been linked to the activity of Wnt signalling and to the regeneration of injured tissues, including complex dental and oral structures. Small Molecule GSK-3 Antagonists are the most interesting class of molecules acting with a "Bystander effect": reducing local inflammation and local bone resorption and triggering the activity and differentiation of resident "sleeping" MSCs. The aim of this narrative topical review is to describe the current knowledge on the role of small molecule GSK-3 antagonists in regenerative dentistry, with strategic insights towards the translational applications in nanomaterials in dentistry and in dental repairing.


Asunto(s)
Odontología , Glucógeno Sintasa Quinasa 3 , Inflamación/metabolismo , Regeneración/fisiología , Vía de Señalización Wnt/inmunología , Células de la Médula Ósea/citología , Células de la Médula Ósea/metabolismo , Resorción Ósea , Diferenciación Celular , Odontología/métodos , Odontología/tendencias , Glucógeno Sintasa Quinasa 3/antagonistas & inhibidores , Glucógeno Sintasa Quinasa 3/inmunología , Glucógeno Sintasa Quinasa 3/metabolismo , Humanos , Células Madre Mesenquimatosas/citología , Células Madre Mesenquimatosas/metabolismo , Células Madre/citología , Células Madre/metabolismo , beta Catenina/metabolismo
20.
Materials (Basel) ; 12(14)2019 Jul 18.
Artículo en Inglés | MEDLINE | ID: mdl-31323844

RESUMEN

Nowadays, the research of smart materials is focusing on the allotropics, which have specific characteristics that are useful in several areas, including biomedical applications. In recent years, graphene has revealed interesting antibacterial and physical peculiarities, but it has also shown limitations. Black phosphorus has structural and biochemical properties that make it ideal for biomedical applications: 2D sheets of black phosphorus are called Black Phosphorene (BP), and it could replace graphene in the coming years. BP, similar to other 2D materials, can be used for colorimetric and fluorescent detectors, as well as for biosensing devices. BP also shows high in vivo biodegradability, producing non-toxic agents in the body. This characteristic is promising for pharmacological applications, as well as for scaffold and prosthetic coatings. BP shows low cytotoxicity, thus avoiding the induction of local inflammation or toxicity. As such, BP is a good candidate for different applications in the biomedical sector. Properties such as biocompatibility, biodegradability, and biosafety are essential for use in medicine. In this review, we have exploited all such aspects, also comparing BP with other similar materials, such as the well-known graphene.

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