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Bone is a complex tissue with unique properties such as high strength and regeneration capabilities while carrying out multiple functions. Bone regeneration occurs both in physiological situations (bone turnover) and in pathological situations (e.g. fractures), being performed by osteoblasts and osteoclasts. If this process is inadequate, fracture nonunion or aseptic loosening of implants occurs and requires a complex treatment. Exogenous factors are currently used to increase bone regeneration process when needed, such as bisphosphonates and vitamin D, but limitations do exist. Cannabinoid system has been shown to have positive effects on bone metabolism. Cannabinoids at bone level mainly act on two receptors called CB-1 and CB-2, but GPR55, GPR119, TPRV1, TPRV4 receptors may also be involved. The CB-2 receptors are found in bone cells at higher levels compared to other receptors. Endocannabinods represented by anandamide and 2-arachidonoylglycerol, can stimulate osteoblast formation, bone formation and osteoclast activity. CB-2 agonists including HU-308, HU-433, JWH133, and JWH015 can stimulate osteoblast proliferation and activity, while CB-2 antagonists such as AM630 and SR144528 can inhibit osteoclast differentiation and function. CB-1 antagonist AM251 has been shown to inhibit osteoclast differentiation and activity, while GPR55 antagonist cannabidiol increases osteoblast activity and decreases osteoclast function. An optimal correlation of dose, duration, moment of action, and affinity can lead to an increased bone regeneration capacity, with important benefits in many pathological situations which involve bone tissue. As adverse reactions of cannabinoids have not been described in patients under controlled medication, cannabinoids can represent future treatment for bone regeneration.
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Regeneración Ósea/fisiología , Huesos/metabolismo , Cannabinoides/metabolismo , Animales , Humanos , Osteoblastos/metabolismo , Osteoclastos/metabolismo , Receptor Cannabinoide CB2/metabolismoRESUMEN
This review intended to comparatively explain and present the most important medical use and biological impact of poly-lactides and lactide-based composites. The utilization and degradation of compounds based on lactic acid and polylactides is described in detail. Understanding the metabolism and degradation phenomenon and the factors that potentially influence it is key to modulating their properties as well as their characteristics driven from the fabrication procedures and the fields of use. All these are commented according to the clinician's criteria. The current debate on the advantages and shortcomings of various resorbable polymeric materials categories is also analyzed, from the perspective of the users of resorbable polylactide-based biomaterials. The scientific literature comprises either distinct chemical and physical or specific animal or medical description of resorbable materials; so that in compensation, the present review covers all topics for the most appropriate comprehensive update of the reader.
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Implantes Absorbibles , Poliésteres/administración & dosificación , Poliésteres/química , Animales , Materiales Biocompatibles/química , Materiales Biocompatibles/metabolismo , Humanos , Ácido Láctico/química , Poliésteres/metabolismoRESUMEN
Articular cartilage has a complex structure and metabolism which allow for a proper movement within joints. Nevertheless, several systemically administered pharmacological agents have been proved to improve the anabolic response in the case of cartilage lesions. Alendronate, glucosamine, chondroitin sulfate, hyaluronic acid, collagen hydrolysate, vitamin C, vitamin D, aspirin and strontium ranelate have shown positive results in clinical trials. On the other hand, calcitonin, risedronate, doxycycline, and celecoxib did not slow the progression of cartilage lesions in clinical trials. Other systemic drugs or supplements such as teriparatide, leptin, zoledronic acid, bevacizumab, atorvastatin, omega-3 fatty acid, naringin, MSM, selenium, zinc, magnesium, resveratrol, donepezil, naproxen, etodolac, ursodeoxycholic acid (UDCA), lithium chloride, and rebamipide showed positive results in in vitro and animal studies but clinical trials are needed to confirm the positive impact on cartilage repair. A number of molecules, not currently available on the market, have also shown promising results in cartilage healing, such as licofelone, sclerostin, cyclopamine, cyclodextrin polysulfate, AG-041R, osteoprotegerin, rhMK, ß-cryptoxanthine, NF-κb essential modulator binding domain (NBD), TGF-ß-neutralizing antibody, osteogenic protein-1 (BMP-7), fibroblast growth factor 2 (FGF2), and RhBMP-2. Currently available systemic drugs that impair cartilage healing are represented by corticosteroids, vitamin A, and fluoroquinolones.
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Osteoartritis/tratamiento farmacológico , Acetaminofén/uso terapéutico , Analgésicos no Narcóticos/uso terapéutico , Animales , Antiinflamatorios no Esteroideos/uso terapéutico , Capsaicina/uso terapéutico , Cartílago Articular/efectos de los fármacos , Cartílago Articular/metabolismo , Cartílago Articular/patología , Inhibidores de la Ciclooxigenasa 2/uso terapéutico , Suplementos Dietéticos , Humanos , Osteoartritis/metabolismo , Osteoartritis/patología , Ensayos Clínicos Controlados Aleatorios como AsuntoRESUMEN
OBJECTIVES: The aim of the present study is to evaluate the early and long-term postoperative dimensional changes of the muscles of the mandible in patients with orthognathic surgery for class II and class III malocclusions by using ultrasonography (US). MATERIAL AND METHODS: Twenty-six patients who underwent bimaxillary orthognathic surgery for class II or class III malocclusions (14 and 12 patients, respectively) were ultrasonographically examined. The length, width, and cross-sectional area of the masseter and suprahyoid muscles were measured at three different time points: T0 (preoperatively), T1 (early postoperatively at 1 month after the surgery), and T2 (late postoperatively at 9 months). A repeated measures ANOVA was used to calculate statistically significant dimensional changes of the mandibular muscles. RESULTS: Statistically significant dimensional changes were found postoperatively in class II malocclusion patients only. The digastric muscle showed higher values for the length and lower values for the width (p < .05) at T1. The geniohyoid muscles were higher in length at T1 and lower in cross-sectional area (CSA) (p < .05) at T2. A decreased measured length and an increased measured width were found in case of the mylohyoid muscle (p < .05) at T2. The early and long-term postoperative dimensional changes of the masseter muscle were not statistically significant. CONCLUSIONS: The mandibular muscles showed a variable adaptive response to the orthognathic surgery. US should be considered for the long-term follow-up of muscular dimensional changes in class II malocclusion patients. CLINICAL RELEVANCE: From a clinical perspective, US is a reliable, non-invasive, and widely available method, which allows monitoring the postoperative muscular changes occurring in class II malocclusion patients.
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Maloclusión de Angle Clase III , Maloclusión Clase II de Angle , Músculo Esquelético , Procedimientos Quirúrgicos Ortognáticos , Cefalometría , Estudios de Seguimiento , Humanos , Maloclusión Clase II de Angle/diagnóstico por imagen , Maloclusión Clase II de Angle/cirugía , Maloclusión de Angle Clase III/diagnóstico por imagen , Maloclusión de Angle Clase III/cirugía , Mandíbula/cirugía , Maxilar , Músculo Esquelético/anatomía & histología , Músculo Esquelético/fisiología , Osteotomía Le FortRESUMEN
BACKGROUND: An increasing number of CBCT units and a wide variability of radiation doses have been reported in dentistry lately. AIM: To estimate the effective, cumulative, and organ absorbed doses in children exposed to CBCT over 2 years. DESIGN: A prospective study was conducted in children who underwent CBCT diagnostic imaging with the ProMax3D machine. Organ and effective doses were calculated by Monte Carlo simulation using 5- and 8-year-old pediatric voxel phantoms. Extrapolation procedures were applied to estimate doses for other ages and CBCT protocols used in clinical conditions. RESULTS: The median effective dose was 137.9 µSv, and the median cumulative dose was 231.4 µSv. Statistically significant differences in the effective doses and cumulative doses were found for various indications of CBCT in children (P < 0.001). The median absorbed organ dose for brain and thyroid was significantly higher for the clinical condition that required large FOVs (2.5 mGy and 1.05 mGy, respectively) compared to medium (0.19 and 0.51 mGy) and small FOVs (0.07 and 0.24 mGy; P < 0.05). The radiation dose of salivary glands did not vary significantly with FOV. CONCLUSION: The results revealed the variation of CBCT doses and the influence of FOV size in pediatric exposure.
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Tomografía Computarizada de Haz Cónico , Método de Montecarlo , Dosis de Radiación , Radiografía Dental , Encéfalo/diagnóstico por imagen , Niño , Preescolar , Tomografía Computarizada de Haz Cónico/instrumentación , Femenino , Humanos , Masculino , Fantasmas de Imagen , Estudios ProspectivosRESUMEN
Titanium implants are widely used on an increasing number of patients in orthopedic and dental medicine. Despite the good survival rates of these implants, failures that lead to important socio-economic consequences still exist. Recently, research aimed at improving implant fixation, a process called osseointegration, has focused on a new, innovative field: systemic delivery of drugs. Following implant fixation, patients receive systemic drugs that could either impair or enhance osseointegration; these drugs include anabolic and anti-catabolic bone-acting agents in addition to new treatments. Anabolic bone-acting agents include parathyroid hormone (PTH) peptides, simvastatin, prostaglandin EP4 receptor antagonist, vitamin D and strontium ranelate; anti-catabolic bone-acting agents include compounds like calcitonin, biphosphonates, RANK/RANKL/OPG system and selective estrogen receptor modulators (SERM). Examples of the new therapies include DKK1- and anti-sclerostin antibodies. All classes of treatments have proven to possess positive impacts such as an increase in bone mineral density and on osseointegration. In order to prevent complications from occurring after surgery, some post-operative systemic drugs are administered; these can show an impairment in the osseointegration process. These include nonsteroidal anti-inflammatory drugs, proton pump inhibitors and selective serotonin reuptake inhibitors. The effects of aspirin, acetaminophen, opioids, adjuvants, anticoagulants and antibiotics in implant fixations are not fully understood, but studies are being carried out to investigate potential ramifications. It is currently accepted that systemic pharmacological agents can either enhance or impair implant osseointegration; therefore, proper drug selection is essential. This review aims to discuss the varying effects of three different classes of treatments on improving this process.
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Oseointegración/efectos de los fármacos , Prótesis e Implantes , Titanio , Anabolizantes/farmacología , Analgésicos/efectos adversos , Animales , Conservadores de la Densidad Ósea/farmacología , Humanos , Modelos BiológicosRESUMEN
Craniofacial bone structures are frequently and extensively affected by trauma, tumors, bone infections and diseases, age-related degeneration and atrophy, as well as congenital malformations and developmental anomalies. Consequently, severe encumbrances are imposed on both patients and healthcare systems due to the complex and lengthy treatment duration. The search for alternative methods to bone transplantation, grafting and the use of homologous or heterologous bone thus responds to one of the most significant problems in human medicine. This review focuses on the current consensus of bone-tissue engineering in the craniofacial area with emphasis on drug-induced stem cell differentiation and induced bone regeneration.
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Regeneración Ósea/efectos de los fármacos , Sistemas de Liberación de Medicamentos , Cráneo/efectos de los fármacos , Ingeniería de Tejidos/métodos , Animales , Trasplante Óseo/métodos , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/efectos de la radiación , Humanos , Cráneo/patología , Cráneo/trasplante , Células Madre/citología , Células Madre/efectos de los fármacos , Andamios del TejidoRESUMEN
BACKGROUND: We aimed to demonstrate that DF stem cells from impacted molars and canines can be used to improve bone regeneration on titanium implants surfaces. This study highlights the presence of stem cells in DF, their potential to adhere and differentiate into osteoblasts on different types of titanium surfaces. RESULTS: Isolated cells from the harvested DF tissue from impacted canine/molars, expressed stem cells markers. Differentiation into bone cells was induced in presence or absence of BMP-2 and TGFß1. The presence of growth factors until 28 days in medium maintained the cells in an earlier stage of differentiation with a lower level of specific bone proteins and a higher expression of alkaline phosphatase (ALP). Influence of titanium implants with different bioactive coatings, hydroxyapatite (TiHA) and with silicatitanate (TiSiO2), and porous Ti6Al7Nb implants as control (TiCtrl), was studied in terms of cell adhesion and viability. Ti HA implants proved to be more favorable for adhesion and proliferation of DF stem cells in first days of cultivation. The influence of titanium coatings and osteogenic differentiation mediums with or without growth factors were evaluated. Additional BMP-2 in the medium did not allow DF stem cells to develop a more mature phenotype, leaving them in a pre-osteogenic stage. The best sustained mineralization process evaluated by immuno-cytochemical staining, scanning electron microscopy and Ca(2+) quantification was observed for TiHA implants with a higher expression of ALP, collagen and Ca(2+) deposition. Long term culturing (70 days) on titanium surfaces of DF stem cells in standard medium without soluble osteogenic inducers, indicated that HA coating is more favorable, with the acquisition of a more mature osteoblastic phenotype as shown by immunocytochemical staining. These findings demonstrated that even in absence of exogenous osteogenic factors, TiHA implants and in a lesser extent TiCtrl and TiSiO2 implants can induce and sustain osteogenic differentiation of DF stem cells, by their chemical and topographical properties. CONCLUSIONS: Our research demonstrated that DF stem cells have a spontaneous tendency for osteogenic differentiation and can be used for improving bone regeneration on titanium implants surfaces.
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Regeneración Ósea/fisiología , Implantes Dentales , Saco Dental/citología , Células Madre/citología , Titanio , Adolescente , Adulto , Fosfatasa Alcalina/metabolismo , Diferenciación Celular/fisiología , Células Cultivadas , Materiales Biocompatibles Revestidos/química , Materiales Biocompatibles Revestidos/metabolismo , Diente Canino/citología , Durapatita/química , Femenino , Humanos , Células Madre Mesenquimatosas/citología , Diente Molar/citología , Osteoblastos/citología , Osteoblastos/fisiología , Osteogénesis , Adulto JovenRESUMEN
The purpose of this study was to evaluate the biocompatibility of some composites consisting of different proportions of graphene in combination with gold nanoparticles (AuNPs) and nanostructured hydroxyapatite (HA) on osteoblast viability, proliferation and differentiation. Au/HA@graphene composites synthesized by the catalytic chemical vapor deposition induction heating method with acetylene as the carbon source and over an Au/HA catalyst, were characterized by transmission electron microscopy, thermogravimetric analysis and Raman spectroscopy and showed that the few-layer graphene was grown over the Au/HA catalyst. The cytocompatibility study was performed using the fluorescein diacetate assay for assessment of the viability and proliferation of osteoblasts cultivated in the presence of HA, Au/HA and Au/HA@graphene composites as colloidal suspensions or as substrates. The most favorable composites for cell adhesion and proliferation were HA, Au/HA and Au/HA composites with 1.6% and 3.15% concentration of graphenes. Immunocytochemical staining performed after 19 days of osteoblasts cultivation on substrates showed that the graphene composites induced low expression of alkaline phosphatase compared to the control group and HA and Au/HA substrates. The presence of graphene in the substrate composition also induced an increased level of intracellular osteopontin and cytoskeleton reorganization (actin-F) depending on graphene concentration, suggesting cell activation, increased cellular adhesion and acquisition of a mechanosensorial osteocyte phenotype.
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Materiales Biocompatibles/toxicidad , Resinas Compuestas/toxicidad , Durapatita/toxicidad , Oro/toxicidad , Grafito/toxicidad , Nanopartículas del Metal/toxicidad , Osteoblastos/efectos de los fármacos , Adhesión Celular/efectos de los fármacos , Diferenciación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Humanos , Ensayo de MaterialesRESUMEN
OBJECTIVE: The aim of this study was to evaluate the color stability in relation to the opacity of the nanocomposite Filtek Ultimate (3M ESPE), by immersing the specimens in different types of natural and artificial staining solutions. MATERIAL AND METHODS: Eighty disks of the shades A1 body (A1B), A1 dentine (A1D), A1 enamel (A1E), and white enamel (WE) (n = 4) of the nanocomposite Filtek Ultimate (3M ESPE) were immersed in staining solutions Orange II, Amaranth, coffee, tea, and artificial saliva. Color coordinates Commission Internationale de l'éclairage (CIE) L*a*b* were collected before and after immersion at 4, 6, 12, 24 h and 7 days. Two-way repeated measurements ANOVA was used in order to assess the effect of immersion time, staining solutions, and materials on CIE L*a*b* parameters, translucency parameter (TP), and color difference (ΔE*). For comparisons between staining solutions and materials, pairwise contrasts adjusted by Bonferroni method were used. RESULTS: The color difference (ΔE*) after 7 days of immersing in staining solution ranged between 0.9 and 15.8. The highest ΔE* after 7 days was obtained for WE, followed by A1E, A1B, and A1D (for all of the immersion solutions, except coffee). There were differences among staining solutions regarding the induced color changes. Coffee induced the most pronounced color differences. However, Orange II, Amaranth, and artificial saliva generated similar behavior in time, for all tested materials. CONCLUSIONS: No statistically significant differences were found among various opacities of Filtek Ultimate regarding the ΔE*, TP, ΔL*, and Δb* overtime. In contrast, Δa* was significantly affected by the type of material. CLINICAL RELEVANCE: The purpose of this study was to predict the color change of different layers of composites, in cases of complex stratified dental restorations.
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Resinas Compuestas/química , Nanocompuestos/química , Color , Ensayo de MaterialesRESUMEN
OBJECTIVES: The present study evaluated the clinical validity of cone-beam computed tomography (CBCT) scans in comparison to panoramic radiographs regarding preoperative implant planning in combination with sinus grafting procedures. MATERIALS AND METHODS: Preoperative assessment of the maxillary sinuses and implant planning using panoramic radiographs and CBCT scans was performed on 16 sinuses (13 patients) and comprised choice of treatment, timing of implant placement, sinus morphology, level of confidence, complication prediction and graft volume assessment. Six examiners were involved in the study. RESULTS: In the majority of cases there was a concordance between the treatment type based on either panoramic radiographs or CBCT. If any difference was found, this was due to an overestimation of bone quantity and quality on panoramic radiographs. The assessment of sinus morphology showed a significantly higher detection rate of sinus mucosal hypertrophy on CBCT. The most appealing result is a significant increase in surgical confidence and a significantly better prediction of complications when using CBCT. CONCLUSIONS: A preoperative planning based on CBCT seems to improve sinus diagnostics and surgical confidence.
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Tomografía Computarizada de Haz Cónico , Implantes Dentales , Seno Maxilar/diagnóstico por imagen , Seno Maxilar/cirugía , Radiografía Panorámica , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias , Periodo Posoperatorio , Periodo PreoperatorioRESUMEN
Although experimental studies in vitro and vivo have been numerous, the effect of laser wavelength irradiation on human fibroblast cell culture is poorly understood. This emphasizes the need of additional cellular and molecular research into laser influence with low energy and power. The aim of this study was to assess the influence of three different laser wavelengths on the human skin fibroblasts cell culture. We wanted to evaluate if near infrared lasers had any influence in healing of wounds by stimulating mitochondrial activity of fibroblasts. The cells were irradiated using 830-, 980- and 2,940-nm laser wavelengths. The irradiated cells were incubated and their mitochondrial activity was assessed by the MTT assay at 24, 48 and 72 h. Simultaneously, an apoptosis assay was assessed on the irradiated fibroblasts. It can be concluded that laser light of the near-infrared region (830 and 980 nm) influences fibroblasts mitochondrial activity compared to the 2,940-nm wavelength which produces apoptosis.
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Fibroblastos/efectos de la radiación , Terapia por Láser/métodos , Apoptosis/efectos de la radiación , Células Cultivadas , Relación Dosis-Respuesta en la Radiación , Humanos , Rayos Infrarrojos , Mitocondrias/metabolismo , Mitocondrias/efectos de la radiación , Cicatrización de Heridas/efectos de la radiaciónRESUMEN
OBJECTIVES: This study aims to assess the disk morphology and the condyle position in subjects with temporomandibular (TMJ) disk displacements on sagittal and coronal magnetic resonance imaging (MRI). MATERIALS AND METHODS: Seventy-four TMJs (from 37 patients) with positive clinical TMD symptoms according to the RDC/TMD axis I protocol were evaluated by 1.5 T MRI. Disk position, disk morphology, sagittal and coronal condyle position, joint effusion, joint space, and coronal condyle angulation were evaluated. Multivariate logistic regression was used to explore the relationship between disk displacement and MRI variables. RESULTS: Disk displacement with reduction (DDR) was found in 36.48 % and without reduction (DDwR), in 21.62 % of the joints. Disk displacement was anterior in 35.1 %, anterior-medial in 13.5 %, and anterior-lateral in 9.45 % of cases. The thickened posterior band (94.48 OR, p = 0.001) and the posterior condyle position (4.57 OR, p = 0.03) were more likely found on sagittal MRI in disk displacements. On coronal slices, the disk displacement was significantly associated with the distance from the most medial condyle point to the midplane (p < 0.05). CONCLUSIONS: Disk displacement is associated with changes of disk shape, disk dimension, and condyle position on sagittal MRI. A significant variation of the distance from the most medial condyle point to the midplane in disk displacement was found on coronal MRI. CLINICAL RELEVANCE: Our study highlights the existence of changes on coronal MRI in TMD patients which should be assessed for better understanding of the clinical evolution of temporomandibular disorders.
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Trastornos de la Articulación Temporomandibular/patología , Articulación Temporomandibular/patología , Adolescente , Adulto , Femenino , Humanos , Luxaciones Articulares/patología , Modelos Logísticos , Imagen por Resonancia Magnética/métodos , Masculino , Cóndilo Mandibular/patología , Persona de Mediana Edad , Estudios Prospectivos , Estadísticas no Paramétricas , Disco de la Articulación Temporomandibular/patología , Adulto JovenRESUMEN
Guided bone regeneration is frequently used to reconstruct the alveolar bone to rehabilitate the mastication using dental implants. The purpose of this article is to research the properties of eggshell membrane (ESM) and its potential application in tissue engineering. The study focuses on the structural, mechanical, and histological characteristics of ESM extracted from Gallus domesticus eggs and to compare them to a commercially available porcine pericardium membrane (Jason® membrane, botiss biomaterials GmbH, Zossen, Germany). Thus, histology was performed on the ESM, and a comparison of the microstructure through scanning electron microscopy and atomic force microscopy (AFM) was conducted. Also, mechanical tensile strength was evaluated. Samples of ESM were prepared and treated with alcohol for fixation and disinfection. Histological analysis revealed that the ESM architecture is constituted out of loose collagen fibers. However, due to the random arrangement of collagen fibers within the membrane, it might not be an effective barrier and occlusive barrier. Comparative analyses were performed between the ESM and the AFM examinations and demonstrated differences in the surface topography and mechanical properties between the two membranes. The ESM exhibited rougher surfaces and weaker mechanical cohesion attributed to its glycoprotein content. The study concludes that while the ESM displays favorable biocompatibility and resorb ability, its non-uniform collagen arrangement limits its suitability as a guided bone regeneration membrane in the current non-crosslinked native form. Crosslinking techniques may enhance its properties for such applications. Further research is needed to explore modifications and processing methods that could leverage the ESM's unique properties for tissue engineering purposes.
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The goal of the current study was to determine the mechanical proprieties of polymethylmethacrylate (PMMA) and the improved compound, the graphene-based PMMA, with Zn and Ag and to compare the results. Scanning electron microscopy analysis of the samples before and after the mechanical test was conducted. The compression behavior, flexural properties, tensile strength, and shape of the samples were all investigated and compared between the variants of PMMA. Commercially available polymethylmethacrylate was used (Orthocryl®-Dentaurum, Ispringen, Germany) with the salt and pepper technique according to the manufacturer's instructions to produce 20 samples for each mechanical trial with standard cylinders (4 mm diameter × 8 mm length) for compression, parallelepipedal prisms for flexing (2 mm × 2 mm × 25 mm) and flat samples for traction. There was no statistical difference in the mechanical proprieties of the samples evaluated, although there were values that could suggest significance. The graphene-based PMMA demonstrated good mechanical proprieties, like the commercially available PMMA, and appears promising for future clinical use based on its multiple advantages.
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Objective: The objective of this study was to identify and summarize the characteristic features of eggshell for regeneration purpose in oral surgery procedures. Methods: A review of literature was undertaken based on the PubMed database. A search to reveal the current state of knowledge and the current uses of the eggshell as a biomaterial was performed. The characteristics of the materials, the specific use, the procedure and the outcome were extracted from the articles. Results: The materials have been found to be used in humans, animals, and in vitro studies. There is a wide use regarding oral surgery especially in experimental models. There have also been attempts to enhance certain properties and improve the capabilities of eggshell as a biomaterial. There is yet a commercial product to be developed and approved for human use. Conclusions: Eggshell can be an important biowaste which can be of use in guided bone regeneration procedures, but it has not yet entered the commercial phase and approval through official regulation channels.
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Guided bone regeneration (GBR) utilizing eggshell membrane (ESM) as a potential biomaterial for dental implant therapy augmentation was explored in this study. ESM, an environmentally friendly waste product, possesses collagen-rich characteristics. The biocompatibility and histological responses of ESM were investigated in a rat model. Twelve young adult Wistar rats were used in this study. ESM samples were implanted in subcutaneous and intramuscular pockets, and samples were collected at 48 hours, 4 weeks, and 8 weeks post-implantation. Histological analysis revealed the changes in ESM over time. Results showed that ESM maintained its structural integrity, induced a moderate cellular response, and exhibited slow degradation, indicating potential biocompatibility. However, the lack of organized collagen arrangement in ESM led to the formation of irregular and polymorphic spaces, allowing cell migration. Encapsulation of ESM by newly proliferating collagen fibers and multinucleated giant cells was observed at later time points, indicating a foreign body reaction. Crosslinking might improve its performance as a separation membrane, as it has the potential to resist enzymatic degradation and enhance biomechanical properties. In conclusion, ESM demonstrated biocompatibility, slow degradation, and lack of foreign body reaction. While not suitable as a complete separation membrane due to irregular collagen arrangement, further research involving crosslinking could enhance its properties, making it a viable option for guided bone regeneration applications in dental implant therapy. This study highlights the potential of repurposing waste materials for medical purposes and underscores the importance of controlled collagen structure in biomaterial development.
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Implantes Dentales , Ratas , Animales , Ratas Wistar , Membranas Artificiales , Cáscara de Huevo , Colágeno , Regeneración Ósea , Materiales Biocompatibles , Reacción a Cuerpo ExtrañoRESUMEN
Dental 3D-printing technologies, including stereolithography (SLA), polyjet (triple-jetting technology), and fusion deposition modeling, have revolutionized the field of orthodontic occlusal splint manufacturing. Three-dimensional printing is now currently used in many dental fields, such as restorative dentistry, prosthodontics, implantology, and orthodontics. This study aimed to assess the mechanical properties of 3D-printed materials and compare them with the conventional polymethylmethacrylate (PMMA). Compression, flexural, and tensile properties were evaluated and compared between PMMA samples (n = 20) created using the "salt and pepper" technique and digitally designed 3D-printed samples (n = 20). The samples were subjected to scanning electron microscope analysis. Statistical analysis revealed that the control material (PMMA) exhibited a significantly higher Young's modulus of compression and tensile strength (p < 0.05). In the flexural tests, the control samples demonstrated superior load at break results (p < 0.05). However, the 3D-printed samples exhibited significantly higher maximum bending stress at maximum load (MPa) (p < 0.05). Young's modulus of tensile testing (MPa) was statistically significant higher for the control samples, while the 3D-printed samples demonstrated significantly higher values for elongation at break (p < 0.05). These findings indicate that 3D-printed materials are a promising alternative that can be effectively utilized in clinical practice, potentially replacing traditional heat-cured resin in various applications.
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PURPOSE: The aim of this study was to assess quantitatively whether a symmetric reconstruction of the calvaria could be achieved using 3-dimensional (3D) custom-made implants and to examine any complications caused by the cranioplasty. PATIENTS AND METHODS: Custom-made cranial implants were produced using data obtained from computed tomographic scanning of the defect using computer-aided design and rapid prototyping techniques. Polymethylmethacrylate was used as the reconstruction material and the implant was cast from a silicone rubber mold. These implants were used in 10 patients (9 men and 1 woman) who previously received a craniectomy. The symmetry gained after cranioplasty was quantified by volumetric analysis using 3D reconstructed postoperative computed tomographic imaging. Any complications after cranioplasty also were recorded. RESULTS: The average follow-up was 42.5 months (range, 7 to 85 mo). The esthetic appearance of all patients was much improved. When the volume of the reconstructed right calvaria was compared with the left calvaria, the difference was not statistically significant (P > .05). There were 2 cases of complications. One exhibited a transient seroma collection. Another had a wrinkle formation in the forehead. No infectious episodes or signs of plate rejection were encountered. CONCLUSIONS: The custom-made implants for cranioplasty showed a significant improvement in morphology. The implants may be very useful for repairing large and complex-shaped cranial defects. The technique may be useful for the bone reconstruction of other sites.
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Craneotomía/métodos , Procedimientos de Cirugía Plástica/métodos , Prótesis e Implantes , Adulto , Materiales Biocompatibles/química , Diseño Asistido por Computadora , Estética , Femenino , Estudios de Seguimiento , Frente/patología , Humanos , Imagenología Tridimensional/métodos , Masculino , Persona de Mediana Edad , Modelos Anatómicos , Polimetil Metacrilato/química , Complicaciones Posoperatorias , Diseño de Prótesis , Implantación de Prótesis/métodos , Seroma/etiología , Piel/patología , Cráneo/lesiones , Cráneo/cirugía , Neoplasias Craneales/cirugía , Accidente Cerebrovascular/cirugía , Tomografía Computarizada Espiral/métodos , Interfaz Usuario-Computador , Adulto JovenRESUMEN
This study aimed to review the literature related to the intrusion of maxillary posterior teeth in subjects needing pre-prosthetic restoration or orthodontic treatment due to anterior open bite, and to report a thin alveolar biotype case needing a pre-prosthetic intrusion of maxillary teeth by introducing a novel, personalized method of intrusion measurement. An electronic search was conducted between February 2022 and March 2022 in the following databases: PubMed, Scopus, Embase, Web of Science, and Lilacs; the terms "tooth movement techniques", "orthodontic anchorage procedures", "tooth intrusion", "intrusion", "molar", "premolar", and "human" were surveyed. Eighteen articles were included in this review; the mean amount of intrusion ranged from between 2.1 ± 0.9 mm and 4.57 ± 0.98 mm (being mostly 2-3 mm). The intrusion force varied between 100 and 500 g; 10 articles reported miniscrews (MS), 7 reported zygomatic plates (ZP), and 1 publication reported both anchorage types. The average treatment time was 6.9 months for MS and 7.9 months for ZP. Levelling the occlusal plane by intrusion of the upper posterior teeth can be achieved by skeletal anchorage. The stability of the obtained results, shortening treatment time, and controlling treatment outcome are the main goals for a complex surgical and orthodontic treatment approach.