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STATEMENT OF PROBLEM: Despite the extensive studies on and comparisons of different implant impression techniques for completely edentulous patients, studies on novel techniques that combine conventional impression making with digital scanning are lacking. PURPOSE: The primary aim of this study was to compare the accuracy of the impression scan body technique with conventional impression making and digital scanning for a completely edentulous mandibular arch. The secondary aim was to assess the relationship between different implant angulations and interimplant distances in relation to the recording accuracy. MATERIAL AND METHODS: An edentulous mandibular definitive cast (control) was designed with 5 implants placed at different angles and interimplant distances. Three recording techniques were tested: a conventional impression with splinted copings (conventional) (n=15), an impression scan body technique where impression scan bodies were attached to the splinted impression copings in a conventional elastomeric impression and then digitally scanned with an extraoral scanner (n=15), and an intraoral digital scanning technique (digital) (n=15). For comparison, the definitive cast and the conventional impression stone casts were digitized into standard tessellation language (STL) datasets using the extraoral scanner. The 3-dimensional (3D) deviations between the 3 test groups and the control were calculated by superimposing the STL datasets. The 3D deviations from the control were compared by using the Kruskal-Wallis test followed by the Dunn post hoc test (α=.05). The Mann-Whitney test was used to investigate the effect of implant angulation and interimplant distance on impression accuracy (α=.05). RESULTS: The conventional splinted-coping impression technique showed a mean 3D deviation of 0.408â¯mm. The impression scan body and intraoral digital scan showed similar mean 3D deviations, 0.219â¯mm and 0.257â¯mm, respectively (P=.334). Both techniques showed significantly lower 3D deviations than the conventional technique (P<.001). Implants at an angle of 5 degrees and 10 degrees showed a statistically significant difference (P=.010) with mean 3D deviations of 0.340â¯mm and 0.396â¯mm, respectively. Implants with 5-mm and 10-mm interimplant distance showed a significant difference (P<.001) with mean 3D deviations of 0.301â¯mm and 0.423â¯mm, respectively. CONCLUSIONS: The impression scan body technique is comparable with intraoral digital scanning for a completely edentulous arch. Increased implant angulation and increased interimplant distance significantly reduced the accuracy of implant impression making or scanning.
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STATEMENT OF PROBLEM: Duplicating mandibular movement with a semi-adjustable articulator has been reported to lack accuracy. However, although previous studies have analyzed articulator movement, few have compared excursive tooth contact on the articulator with tooth contact during actual mandibular movement. PURPOSE: The purpose of this clinical study was to evaluate the concordance of semi-adjustable articulator contacts with intraoral contacts during eccentric movements by using a T-scan occlusal analysis system. MATERIAL AND METHODS: Forty-two participants with normal occlusion and without signs of temporomandibular disorder were analyzed for the reproducibility of eccentric tooth contact on a semi-adjustable articulator. Maxillary casts made from irreversible hydrocolloid impressions were mounted on a semi-adjustable articulator with the facebow. The condylar inclination of the articulator was set by using interocclusal records. Three recordings of right and left excursive mandibular movement and protrusive mandibular movement were made in the supine position by using the T-scan v9.1. The same procedure was then performed with the articulator. The results of complete mandibular movement from T-scan measurements were divided into 4 time points for analysis: T0, T1, T2, and T3. The concordance of intraoral and articulator occlusal contacts was evaluated at each point, and the occlusal force for each tooth was compared. Overall concordance and concordance of the working and nonworking sides were also calculated. Repeated measures analysis of variance was used to analyze differences between the concordance of intraoral and articulator contacts according to mandibular movement direction, time, and working and nonworking sides (α=.01). RESULTS: For all teeth, concordance between the intraoral and articulator occlusal contacts during excursive mandibular movement was greatest at T0, decreasing at T1 and T2, and increasing at T3. No significant differences were found in the concordance among the right lateral, left lateral, and protrusive excursion (P>.01). The concordance of working side occlusal contacts during lateral excursion was significantly lower at T3 than that at T0 (P<.01). CONCLUSIONS: When comparing intraoral and articulator contacts during lateral eccentric mandibular movement, concordance was affected by time and working or nonworking side. Reproducibility of initial eccentric tooth contact on a semi-adjustable articulator appeared to be reliable. However, occlusal adjustment of the working side might be required after prosthesis delivery.
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Cryopreserved oocytes are inevitably exposed to cold stress, which negatively affects the cellular aspects of the oocytes. Lipidomic analysis of the oocytes reveals quantitative changes in lipid classes under conditions of cold stress, leading to potential freezing-vulnerability. We had previously shown that specific phospholipids are significantly downregulated in vitrified-warmed mouse oocytes compared to those in fresh oocytes. In this study, we examined whether supplementation of polyethylene glycol 8000 (PEG 8000) during vitrification influences the lipidome of the oocytes. We used liquid chromatography with tandem mass spectrometry (LC-MS/MS) to study the alteration in the lipidome in three groups of mouse oocytes: fresh, vitrified-warmed, and vitrified with PEG 8000-warmed during vitrification. In these groups, we targeted to analyze 21 lipid classes. We profiled 132 lipid species in the oocytes and statistical analyses revealed lipid classes that were up- or downregulated in these groups. Overall, our data revealed that several classes of lipids were affected during vitrification, and that oocytes vitrified with PEG 8000 to some extent alleviated the levels of changes in phospholipid and sphingolipid contents during vitrification. These results suggest that phospholipids and sphingolipids are influenced by PEG 8000 during vitrification and that PEG 8000 can be considered as a potential candidate for preserving membrane integrity during oocyte cryopreservation.
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Lipidômica , Vitrificação , Animais , Cromatografia Líquida , Criopreservação/métodos , Suplementos Nutricionais , Camundongos , Oócitos , Polietilenoglicóis , Espectrometria de Massas em TandemRESUMO
BACKGROUND: Ocular coloboma is an excavation of ocular structures that occurs due to abnormal fusion of the embryonic optic fissure. Further, cleft lip/palate (CL/P), a congenital midline abnormality, is caused by a defect in the fusion of the frontonasal, maxillary, and mandibular prominences. No study has reported the association between these two phenotypes in the absence of other systemic abnormalities. We present a case of ocular coloboma along with CL/P and without other neurological abnormalities. CASE PRESENTATION: A 5-year-old Asian boy presented with decreased visual acuity in his right eye. Physical examination revealed no abnormal findings except CL/P, which was surgically corrected at the age of 9 months. Best-corrected visual acuity was 20/60 in the right eye and 20/25 in the left eye. Anterior segment examination revealed iris coloboma in the inferior quadrant of his right eye as well as a large inferonasal optic disc and chorioretinal coloboma in the same eye. He was prescribed glasses based on his cycloplegic refractive errors and part-time occlusion of the left eye was recommended. After 3 months, best-corrected visual acuity improved to 20/30 in the right eye. CONCLUSION: The association of ocular coloboma should be kept in mind when encountering a patient with CL/P without other neurological or systemic abnormalities.
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Fenda Labial , Fissura Palatina , Coloboma , Disco Óptico , Pré-Escolar , Fenda Labial/complicações , Fissura Palatina/complicações , Coloboma/complicações , Coloboma/diagnóstico , Humanos , Lactente , MasculinoRESUMO
BACKGROUND: Cyanoacrylate closure for the treatment of incompetent saphenous veins does not cause thermal damage and demonstrates satisfactory outcomes with rapid recovery. However, the characteristics of phlebitis-like abnormal reaction (PLAR), the most common adverse event after cyanoacrylate closure, have not been clarified. Moreover, it differs from typical phlebitis after thermal ablation. The objective of our study is to investigate the clinical features of PLAR after cyanoacrylate closure and to report its management. METHODS: A total of 160 patients with 271 incompetent saphenous veins (great saphenous veins, 201; small saphenous veins, 70) underwent cyanoacrylate closure with the VenaSeal™ system. We defined PLAR as any unusual skin condition that develops suddenly, such as erythema, itching, swelling, and pain/tenderness, over the treated veins several days after cyanoacrylate closure. Oral antihistamines and intravenous dexamethasone were administered to manage PLAR. RESULTS: Of the 271 treated veins, 69 experienced PLAR (25.4%). The mean time of occurrence was 13.6 ± 4.6 days after treatment. The rate of occurrence of erythema, itching, swelling, and pain/tenderness were 92.2%, 91.2%, 66.2%, and 48.5%, respectively. The occurrence of PLAR was significantly higher for great saphenous veins than for small saphenous veins (P < 0.001). Occurrences were more frequent in cases with a suprafascial great saphenous vein of length >10 cm than in cases with a subfascial great saphenous vein (P = 0.001). The proportion of patients who reported swelling decreased by more than half after the administration of oral antihistamine. The pain score on the 10th day also decreased significantly after the administration of antihistamine (P = 0.006). CONCLUSIONS: PLAR must be distinguished from classic phlebitis. We believe that PLAR is a type IV hypersensitivity reaction due to a foreign body, and in our experience, antihistamines or steroids are effective for the prevention and management of PLAR.
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Cianoacrilatos/efeitos adversos , Reação a Corpo Estranho/induzido quimicamente , Hipersensibilidade Tardia/induzido quimicamente , Flebite/induzido quimicamente , Veia Safena , Adesivos Teciduais/efeitos adversos , Insuficiência Venosa/terapia , Administração Intravenosa , Administração Oral , Adulto , Idoso , Dexametasona/administração & dosagem , Feminino , Reação a Corpo Estranho/diagnóstico por imagem , Reação a Corpo Estranho/tratamento farmacológico , Reação a Corpo Estranho/fisiopatologia , Glucocorticoides/administração & dosagem , Antagonistas dos Receptores Histamínicos/administração & dosagem , Humanos , Hipersensibilidade Tardia/diagnóstico por imagem , Hipersensibilidade Tardia/tratamento farmacológico , Hipersensibilidade Tardia/fisiopatologia , Masculino , Pessoa de Meia-Idade , Flebite/diagnóstico por imagem , Flebite/tratamento farmacológico , Flebite/fisiopatologia , Estudos Prospectivos , Fatores de Risco , Veia Safena/diagnóstico por imagem , Veia Safena/fisiopatologia , Fatores de Tempo , Resultado do Tratamento , Insuficiência Venosa/diagnóstico por imagem , Insuficiência Venosa/fisiopatologia , Adulto JovemRESUMO
This paper introduces super absorbent polymer valves and colorimetric sensing reagents as enabling components of soft, skin-mounted microfluidic devices designed to capture, store, and chemically analyze sweat released from eccrine glands. The valving technology enables robust means for guiding the flow of sweat from an inlet location into a collection of isolated reservoirs, in a well-defined sequence. Analysis in these reservoirs involves a color responsive indicator of chloride concentration with a formulation tailored to offer stable operation with sensitivity optimized for the relevant physiological range. Evaluations on human subjects with comparisons against ex situ analysis illustrate the practical utility of these advances.
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Colorimetria/métodos , Microfluídica/métodos , Polímeros/química , Suor/química , Humanos , Dispositivos Lab-On-A-Chip , Pele/metabolismoRESUMO
Developing a monomeric form of an avidin-like protein with highly stable biotin binding properties has been a major challenge in biotin-avidin linking technology. Here we report a monomeric avidin-like protein-enhanced monoavidin-with off-rates almost comparable to those of multimeric avidin proteins against various biotin conjugates. Enhanced monoavidin (eMA) was developed from naturally dimeric rhizavidin by optimally maintaining protein rigidity during monomerization and additionally shielding the bound biotin by diverse engineering of the surface residues. eMA allowed the monovalent and nonperturbing labeling of head-group-biotinylated lipids in bilayer membranes. In addition, we fabricated an unprecedented 24-meric avidin probe by fusing eMA to a multimeric cage protein. The 24-meric avidin and eMA were utilized to demonstrate how artificial clustering of cell-surface proteins greatly enhances the internalization rates of assembled proteins on live cells.
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Avidina/química , Proteínas de Bactérias/química , Biopolímeros/química , Biotina/química , Ligação ProteicaRESUMO
The aim of our study was to evaluate the effect of cant correction in the anterior (AMXTOP) and posterior maxillary transverse occlusal planes (PMXTOP) on the change in lip cant (LC) using three-dimensional facial scan (FS) in conjunction with computed tomographic (CT) images. Thirty-five class III asymmetry patients treated with 2-jaw surgery were selected. Three-dimensional CT and three-dimensional FS images were taken before (T1) and after orthognathic surgery (T2). After obtaining the same head orientation between 2 images, bracket slot midpoints of the maxillary right and left canines as well as the first molars, point A, point B, and menton on three-dimensional CT images and the right and left lip commissures on three-dimensional FS images were located. Linear and angular variables of AMXTOP, PMXTOP, and LC were measured and statistically analyzed. At the T1 stage, linear and angular LC showed significant correlations with linear and angular cant of AMXTOP and PMXTOP, as well as menton deviation (all P < 0.001). During T1 to T2, significant linear and angular cant corrections were observed: ΔAMXTOP (1.3 mm, 1.9 degrees), ΔPMXTOP (1.9 mm, 1.7 degrees), and ΔLC (1.5 mm, 1.8 degrees) (all P < 0.001). Although angular change ratios of ΔLC/ΔAMXTOP and ΔLC/ΔPMXTOP did not exhibit a significant difference (1.0 vs 0.7), linear change ratio of ΔLC/ΔAMXTOP was higher than that of ΔLC/ΔPMXTOP (3.0 vs 0.5, P < 0.05). The vertical change in commissures was related to that in the maxillary right and left canines or maxillary right and left first molars and the extent of mandibular setback (all P < 0.01). To conclude, the use of three-dimensional FS images in conjunction with three-dimensional CT can provide more accurate information for changes in AMXTOP, PMXTOP, and LC.
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Fenda Labial/cirurgia , Assimetria Facial/cirurgia , Imageamento Tridimensional/métodos , Mandíbula/cirurgia , Maxila/cirurgia , Procedimentos Cirúrgicos Ortognáticos/métodos , Tomografia Computadorizada por Raios X/métodos , Adulto , Cefalometria/métodos , Fenda Labial/diagnóstico , Assimetria Facial/diagnóstico , Feminino , Humanos , Masculino , Adulto JovemRESUMO
To propel electronic skin (e-skin) to the next level by integrating artificial intelligence features with advanced sensory capabilities, it is imperative to develop stretchable memory device technology. A stretchable memory device for e-skin must offer, in particular, long-term data storage while ensuring the security of personal information under any type of deformation. However, despite the significance of these needs, technology related to stretchable memory devices remains in its infancy. Here, we report an intrinsically stretchable floating gate (FG) polymer memory transistor. The device features a dual-stimuli (optical and electrical) writing system to prevent easy erasure of recorded data. An FG comprising an intermixture of Ag nanoparticles and elastomer and with proper energy-band alignment between the semiconductor and dielectric facilitated sustainable memory performance, while achieving a high memory on/off ratio (>105) and a long retention time (106 s) with the ability to withstand 50% uniaxial or 30% biaxial strain. In addition, our memory transistor exhibited high mechanical durability over multiple stretching cycles (1000 times), along with excellent environmental stability with respect to factors such as temperature, moisture, air, and delamination. Finally, we fabricated a 7 × 7 active-matrix memory transistor array for personalized storage of e-skin data and successfully demonstrated its functionality.
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Transistores Eletrônicos , Dispositivos Eletrônicos Vestíveis , Armazenamento e Recuperação da Informação , Prata/química , Humanos , Elastômeros/química , Dispositivos de Armazenamento em Computador , Nanopartículas Metálicas/química , Desenho de EquipamentoRESUMO
Cherubism is a rare fibro-osseous condition characterized by bilateral expansion of the mandible and maxilla. Due to its rarity, treatment guidelines for cherubism have not been clearly established. Observation without surgical intervention is typically recommended, as cherubism often regresses spontaneously after puberty. However, a surgical intervention may be necessary if aggressive lesions lead to severe complications. In this report, we present a case involving surgical management of cherubism that did not spontaneously regress until early adulthood. An 18-year-old man was diagnosed with cherubism, presenting characteristic upward-looking eyes and a swollen face. He strongly desired surgical management. Gross contouring of the mandible was performed using an osteotome. Subsequently, delicate contouring was performed by bone burring and curettage. The remaining multiple locular bony defects were filled with demineralized bone matrix. No major complications, including infection and hematoma, occurred during the 8-month follow-up period. The facial contour remained stable without the aggravation of cherubism. The patient was satisfied with the cosmetic results. Considering that cherubism is a rare disease globally, with few reported cases in Korea, and that treatment guidelines are not clearly established, we anticipate that the results of this case will contribute to the development of future protocols for treating cherubism.
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Herein, dexamethasone (DEX) nanocrystalline suspension (NS)-embedded hydrogel (NS-G) was constructed using a hydroxypropyl methylcellulose (HPMC) polymer to enhance cochlear delivery and attenuate hearing loss following intratympanic (IT) injection. Hydrophobic steroidal nanocrystals were prepared using a bead milling technique and incorporated into a polysaccharide hydrogel. The NS-G system with HPMC (average molecular weight, 86,000 g/mol; 15 mg/mL) was characterized as follows: rod-shaped drug crystalline; particle size <300 nm; and constant complex viscosity ≤1.17 Pa·s. Pulverization of the drug particles into submicron diameters enhanced drug dissolution, while the HPMC matrix increased the residence time in the middle ear cavity, exhibiting a controlled release profile. The IT NS-G system elicited markedly enhanced and prolonged drug delivery (> 9 h) to the cochlear tissue compared with that of DEX sodium phosphate (DEX-SP), a water-soluble prodrug. In mice with kanamycin- and furosemide-induced ototoxicity, NS-G markedly enhanced hearing preservation across all frequencies (8-32 kHz), as revealed by an auditory brainstem response test, compared with both saline and DEX-SP. Moreover, treatment with NS-G showed enhanced anti-inflammatory effects, as evidenced by decreased levels of inflammation-related cytokines. Therefore, the IT administration of DEX NS-loaded HPMC hydrogels is a promising strategy for treating hearing loss.
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Cóclea , Dexametasona , Perda Auditiva , Hidrogéis , Derivados da Hipromelose , Injeção Intratimpânica , Nanopartículas , Dexametasona/química , Dexametasona/administração & dosagem , Animais , Derivados da Hipromelose/química , Hidrogéis/química , Nanopartículas/química , Camundongos , Cóclea/efeitos dos fármacos , Cóclea/patologia , Perda Auditiva/tratamento farmacológico , Perda Auditiva/induzido quimicamente , Liberação Controlada de Fármacos , Masculino , Sistemas de Liberação de Medicamentos/métodosRESUMO
The design and development of wound dressing with antioxidant and antibacterial properties to accelerate wound healing remain challenging. In this study, we synthesize a chitooligosaccharide-gentisic acid (COS-GSA) conjugate using the free-radical grafting method, and fabricate a poly(vinyl alcohol) (PVA)/chitosan (CH)/COS-GSA (PVA/CH/CG) hydrogel using a freeze-thaw method. We characterize the synthesized COS-GSA conjugates using through polyphenol assay, absorbance, and 1H NMR spectroscopy and evaluate their antioxidant properties. The COS-GSA conjugates are successfully synthesized and exhibit better antioxidant properties than pristine COSs. Subsequently, the fabricated hydrogel is characterized based on its morphological analysis, rheological properties, water contact angle, swelling, degradation, water retention properties, and COS-GSA release profiles. Finally, the biocompatibility of the fabricated hydrogel is evaluated on HDF and HaCaT cells through indirect and direct cytotoxicity. The PVA/CH/CG hydrogel exhibited significantly higher antioxidant properties (DPPH, 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), and hydrogen peroxide (H2O2) scavenging activities) and antibacterial activities (Staphylococcus aureus and Pseudomonas aeruginosa) compared to other fabricated hydrogels such as PVA, PVA/CH, and PVA/CH/COS (PVA/CH/C). These results provide evidence that PVA/CH/CG hydrogels with antioxidant, antibacterial, and non-cytotoxic properties have great potential for wound-dressing applications.
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Quitosana , Quitosana/química , Antioxidantes/farmacologia , Álcool de Polivinil/química , Hidrogéis/química , Peróxido de Hidrogênio , Antibacterianos/farmacologia , Antibacterianos/química , Bandagens , Água , EtanolRESUMO
This study demonstrated meso/micro/nano-ultraprecision machining through electrochemical reactions using intermittent DC pulses. The experiment focused on two machining methods: (1) pulse electrochemical polishing (PECP) of stainless steel, and (2) pulse electrochemical nano-patterning (PECNP) on a silicon (Si) surface, using atomic force microscopy (AFM) for fabrication. The dissolution reaction at the stainless steel surface following PECP produced a very clean, smooth workpiece. The advantages of the PECP process included improvements in corrosion resistance, deburring of the sample surface, and removal of hydrogen from the stainless steel surface as verified by time-of-flight secondary-ion mass spectrometry (TOF-SIMS). In PECNP, the electrochemical reaction generated within water molecules produced nanoscale oxide textures on a Si surface. Scanning probe microscopy (SPM) was used to evaluate nanoscale-pattern processing on a Si wafer surface produced by AFM-PECNP For both processes using pulse electrochemical reactions, three-dimensional (3-D) measurements and AFM were used to investigate the changes on the machined surfaces. Preliminary results indicated the potential for advancing surface polishing techniques and localized micro/nano-texturing technology using PECP and PECNP processes.
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Cristalização/métodos , Galvanoplastia/métodos , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Silício/química , Aço Inoxidável/química , Campos Eletromagnéticos , Substâncias Macromoleculares/química , Substâncias Macromoleculares/efeitos da radiação , Teste de Materiais , Conformação Molecular/efeitos da radiação , Nanoestruturas/efeitos da radiação , Tamanho da Partícula , Silício/efeitos da radiação , Aço Inoxidável/efeitos da radiação , Propriedades de Superfície/efeitos da radiaçãoRESUMO
This study investigated the oral symptoms and subjective health perceptions of Korean adolescents due to COVID-19. Data from the 17th Korea Youth Risk Behavior Survey (KYRBS; 2021) were analyzed, and 54,848 Korean middle and high school students were included in the study. Frequency, cross-tabulation, and logistic regression analyses were performed using IBM SPSS (v. 22.0; IBM Corp., Armonk, NY, USA). Statistical significance was set at p < 0.05. The survey results on subjective health perception showed that 64.8% considered themselves "healthy", 26.1% rated themselves "moderate" in health, and 9.26% rated themselves "unhealthy." When asked about brushing their teeth after lunch at school, students answered "no" more frequently than "yes". Participants provided significantly different responses to questions related to receiving "sealant treatment", "having broken teeth", "experiencing tooth pain when eating", "having throbbing tooth pain", and "having pain and bleeding in gums". Regarding the relationship between oral symptoms and subjective health perceptions due to COVID-19, students perceived themselves as healthy when they had no throbbing tooth pain, risk of pain, bleeding in the gums, or symptoms of toothache when eating. Results reveal a relationship between oral symptoms and subjective health perceptions due to COVID-19. Thus, appropriate oral health management for adolescents is needed in response to the COVID-related changes.
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PURPOSE: This narrative review aims to provide an overview of the mechanisms of 3D printing, the dental materials relevant to each mechanism, and the possible applications of these materials within different areas of dentistry. METHODS: Subtopics within 3D printing technology in dentistry were identified and divided among five reviewers. Electronic searches of the Medline (PubMed) database were performed with the following search keywords: 3D printing, digital light processing, stereolithography, digital dentistry, dental materials, and a combination of the keywords. For this review, only studies or review papers investigating 3D printing technology for dental or medical applications were included. Due to the nature of this review, no formal evidence-based quality assessment was performed, and the search was limited to the English language without further restrictions. RESULTS: A total of 64 articles were included. The significant applications, applied materials, limitations, and future directions of 3D printing technology were reviewed. Subtopics include the chronological evolution of 3D printing technology, the mechanisms of 3D printing technologies along with different printable materials with unique biomechanical properties, and the wide range of applications for 3D printing in dentistry. CONCLUSIONS: This review article gives an overview of the history and evolution of 3D printing technology, as well as its associated advantages and disadvantages. Current 3D printing technologies include stereolithography, digital light processing, fused deposition modeling, selective laser sintering/melting, photopolymer jetting, powder binder, and 3D laser bioprinting. The main categories of 3D printing materials are polymers, metals, and ceramics. Despite limitations in printing accuracy and quality, 3D printing technology is now able to offer us a wide variety of potential applications in different fields of dentistry, including prosthodontics, implantology, oral and maxillofacial, orthodontics, endodontics, and periodontics. Understanding the existing spectrum of 3D printing applications in dentistry will serve to further expand its use in the dental field. Three-dimensional printing technology has brought about a paradigm shift in the delivery of clinical care in medicine and dentistry. The clinical use of 3D printing has created versatile applications which streamline our digital workflow. Technological advancements have also paved the way for the integration of new dental materials into dentistry.
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BACKGROUND/AIM: We report an in vitro three-dimensional (3D) culture system optimized for the growth of HepG2 hepatocarcinoma cells. MATERIALS AND METHODS: The 3D culture system was fabricated based on polyethylene glycol (PEG)-based hydrogels; their mechanical strength was controlled by differences in the arm number and concentration of PEG-vinylsulfone. Moreover, cellular growth was evaluated after culturing HepG2 cells in PEG-based hydrogels with various mechanical strengths. RESULTS: HepG2 cell culture in the 3D PEG-based hydrogels induced the formation of spherical colonies. Moreover, the highest number of spherical colonies formed from HepG2 cells at the single-cell level, and the formation of spherical colonies with a uniform size was observed in HepG2 cells cultured in 5% (w/v) 8-arm PEG-based hydrogels. CONCLUSION: 5% (w/v) 8-arm PEG-based hydrogels may be developed as a 3D culture system optimized for stimulating the in vitro growth of HepG2 cells.
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Hidrogéis , Polietilenoglicóis , Humanos , Polietilenoglicóis/farmacologia , Células Hep G2 , Hidrogéis/farmacologia , Linhagem Celular , Técnicas de Cultura de Células/métodos , Materiais BiocompatíveisRESUMO
Microplastics (< 5 mm) have been found in marine ecosystems worldwide, even in Antarctic ecosystems. In this study, the stomach and upper intestines of 14 dead gentoo penguin (Pygoscelis papua) chicks were collected and screened for microplastics on King George Island, a gateway to Antarctic research and tourism. A total of 378 microplastics were identified by Fourier-transform infrared spectroscopy, with 27.0 ± 25.3 microplastics per individual. The detected number of microplastics did not increase with the mass of penguin chicks, suggesting no permanent accumulation of microplastics. However, the concentration of microplastics was much higher (9.1 ± 10.8 microplastics per individual within the size range 100-5000 µm) than the previously reported concentration in the penguin feces, and a greater number of smaller microplastics were found. Marine debris surveys near the breeding colony found various plastic (79.3%) to be the most frequent type of beached debris, suggesting that local sources of marine plastic waste could have contributed to microplastic contamination of penguin chicks being fed by parents that forage in nearby seas. This finding confirms the presence of microplastics in an Antarctic ecosystem and suggests the need for stronger waste management in Antarctica and a standardized scheme of microplastic monitoring in this once-pristine ecosystem.
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Spheniscidae , Animais , Microplásticos , Plásticos , Ecossistema , Regiões Antárticas , Galinhas , Trato Gastrointestinal , Monitoramento AmbientalRESUMO
The aim of this study was to investigate the surface characteristics and evaluate the bone-implant interfaces of injection molded zirconia implants with or without surface treatment and compare them with those of conventional titanium implants. Four different zirconia and titanium implant groups (n = 14 for each group) were prepared: injection-molded zirconia implants without surface treatment (IM ZrO2); injection-molded zirconia implants with surface treatment via sandblasting (IM ZrO2-S); turned titanium implants (Ti-turned); and titanium implants with surface treatments via sandblasting with large-grit particles and acid-etching (Ti-SLA). Scanning electron microscopy, confocal laser scanning microscopy, and energy dispersive spectroscopy were used to assess the surface characteristics of the implant specimens. Eight rabbits were used, and four implants from each group were placed into the tibiae of each rabbit. Bone-to-implant contact (BIC) and bone area (BA) were measured to evaluate the bone response after 10-day and 28-day healing periods. One-way analysis of variance with Tukey's pairwise comparison was used to find any significant differences. The significance level was set at α = 0.05. Surface physical analysis showed that Ti-SLA had the highest surface roughness, followed by IM ZrO2-S, IM ZrO2, and Ti-turned. There were no statistically significant differences (p > 0.05) in BIC and BA among the different groups according to the histomorphometric analysis. This study suggests that injection-molded zirconia implants are reliable and predictable alternatives to titanium implants for future clinical applications.
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Interface Osso-Implante , Lagomorpha , Animais , Humanos , Coelhos , Titânio , Próteses e Implantes , Assistência OdontológicaRESUMO
The associative phase behavior of cricket protein isolate (CPI) and sodium alginate (AL) in aqueous solutions was explored using turbidimetry, methylene blue spectroscopy, zeta potentiometry, dynamic light scattering, and confocal microscopy as a function of pH, biopolymer ratio, total biopolymer concentration (CT), and ionic strength. When both biopolymers had net-negative charges, soluble complexes formed between pH 6.0 and 8.0, however when both biopolymers had opposing net charges, insoluble complexes formed as complex coacervates below pH 5.5, defined as pHφ1, followed by precipitates below another critical pH 3.0 (pHp). Increasing the CPI:AL weight ratio or CT facilitated complex formation, and the addition of salts (NaCl/KCl) had a salt-enhancement and salt-reduction impact at low and high salt concentrations, respectively. Ionic interactions between oppositely charged CPI and AL were mainly responsible for the formation of their insoluble complexes, while hydrogen bonding and hydrophobic interactions also played significant roles.
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Alginatos , Gryllidae , Animais , Biopolímeros/química , Concentração de Íons de Hidrogênio , Cloreto de Sódio/química , ÁguaRESUMO
This study investigates the effects of professional ethics on the job satisfaction of dental technicians and dental hygienists among health and medical personnel. From 1 July to 30 September 2021, a survey was conducted with 178 dental technicians and dental hygienists. Frequency analysis, correlation analysis, and multiple regression analysis were performed. The collected data were processed using SPSS version 22.0 statistical program (IBM, Armonk, NY, USA). The significance level was set to 0.05. As factors influencing the professional ethics of dental technicians and dental hygienists, diligence, reduced leisure, work orientation, and time saving were found to affect job satisfaction. In addition to morality, various elements of professional ethics and their causal relationships with job satisfaction were investigated. In the future, in preparation for the increasing ethical problems in the medical environment, education on professional ethics should be standardized and conducted more systematically.