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1.
J Mech Behav Biomed Mater ; 155: 106552, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38701678

RESUMO

This study aimed to evaluate and compare the mechanical properties of dental training teeth with subtractive and additive computer-aided design/computer-aided manufacturing (CAD/CAM) materials used to fabricate dental simulation models. Therefore, the three-axis load generated during cutting movements, including drilling and milling performed using a dental handpiece, was measured and compared. The samples were cut vertically downward by 1.5 mm, horizontally by 6 mm, and vertically upward at a constant speed (1 mm/s), while the rotational speed of the bur was maintained at 200,000 rotations per minute. A three-axis load cell was used to measure the X-, Y-, and Z-axis loads on the specimen. The median value of the X-, Y-, and Z-axis measurements and the resultant load during the vertical-downward, horizontal, and vertical-upward movements were compared using a one-way analysis of variance and Tukey's post hoc test. For vertical downward movement, the drilling force of the dental training teeth was lower than that of Vita Enamic® and similar to that of Lava™ Ultimate. In contrast to subtractive CAD/CAM blocks, the drilling force of the dental training teeth was higher than that of 3D-printed resin blocks. Regarding horizontal movement, the milling force of dental training teeth was lower than that of Vita Enamic®. In contrast, the milling force of Nissin was similar to that of Lava™ Ultimate, while that of Frasaco was lower. Furthermore, compared to additive CAD/CAM blocks, the milling force of the dental training teeth was higher than that of 3D-printed resin blocks. Regarding vertical upward movement, the resultant loads of dental training teeth was lower than that of Vita Enamic®. Similarly, the resultant load of Nissin was similar to that of Lava™ Ultimate, while that of Frasaco was lower. Additionally, compared to additive CAD/CAM blocks, the resultant loads of the dental training teeth were similar to those of the 3D-printed resin blocks.


Assuntos
Desenho Assistido por Computador , Fenômenos Mecânicos , Teste de Materiais , Testes Mecânicos , Dente/fisiologia
2.
Sci Rep ; 14(1): 9909, 2024 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-38688952

RESUMO

Three-dimensional (3D) printing, otherwise known as additive manufacturing in a non-technical context, is becoming increasingly popular in the field of dentistry. As an essential step in the 3D printing process, postwashing with organic solvents can damage the printed resin polymer and possibly pose a risk to human health. The development of water-washable dental resins means that water can be used as a washing agent. However, the effects of washing agents and washing times on the mechanical and biocompatibility properties of water-washable resins remain unclear. This study investigated the impact of different washing agents (water, detergent, and alcohol) and washing time points (5, 10, 20, and 30 min) on the flexural strength, Vickers hardness, surface characterization, degree of conversion, biocompatibility, and monomer elution of 3D printed samples. Using water for long-term washing better preserved the mechanical properties, caused a smooth surface, and improved the degree of conversion, with 20 min of washing with water achieving the same biological performance as organic solvents. Water is an applicable agent option for washing the 3D printing water-washable temporary crown and bridge resin in the postwashing process. This advancement facilitates the development of other water-washable intraoral resins and the optimization of clinical standard washing guidelines.


Assuntos
Materiais Biocompatíveis , Teste de Materiais , Impressão Tridimensional , Água , Água/química , Materiais Biocompatíveis/química , Teste de Materiais/métodos , Humanos , Resinas Sintéticas/química , Dureza , Coroas , Propriedades de Superfície
3.
Int J Med Sci ; 21(4): 644-655, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38464836

RESUMO

Vascular dementia (VD) is the second most prevalent dementia type, with no drugs approved for its treatment. Here, the effects of Banhabaekchulcheonma-Tang (BBCT) on ischemic brain injury and cognitive function impairment were investigated in a bilateral carotid artery stenosis (BCAS) mouse model. Mice were divided into sham-operated, BCAS control, L-BBCT (40 ml/kg), and H-BBCT (80 ml/kg) groups. BBCT's effects were characterized using the Y-maze test, novel object recognition test (NORT), immunofluorescence staining, RNA sequencing, and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology (GO) analyses. The NORT revealed cognitive function improvement in the H-BBCT group, while the Y-maze test revealed no significant difference among the four groups. The CD68+ microglia and GFAP+ astrocyte numbers were reduced in the H-BBCT group. Furthermore, H-BBCT treatment restored the dysregulation of gene expression caused by BCAS. The major BBCT targets were predicted to be cell division cycle protein 20 (CDC20), Epidermal growth factor (EGF), and tumor necrosis factor receptor-associated factor 1 (TRAF1). BBCT regulates the neuroactive ligand-receptor interaction and neuropeptide signaling pathways, as predicted by KEGG and GO analyses, respectively. BBCT significantly improved cognitive impairment in a BCAS mouse model by inhibiting microglial and astrocyte activation and regulating the expression of CDC20, EGF, TRAF1, and key proteins in the neuroactive ligand-receptor interaction and neuropeptide signaling pathways.


Assuntos
Lesões Encefálicas , Isquemia Encefálica , Estenose das Carótidas , Disfunção Cognitiva , Neuropeptídeos , Animais , Camundongos , Estenose das Carótidas/complicações , Estenose das Carótidas/tratamento farmacológico , Fator de Crescimento Epidérmico/metabolismo , Ligantes , Fator 1 Associado a Receptor de TNF/metabolismo , Disfunção Cognitiva/tratamento farmacológico , Disfunção Cognitiva/etiologia , Cognição , Modelos Animais de Doenças , Neuropeptídeos/metabolismo , Camundongos Endogâmicos C57BL
4.
J Mech Behav Biomed Mater ; 149: 106221, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-37976994

RESUMO

OBJECTIVES: This study evaluated the repairability of three-dimensional printed (3DP) denture bases based on different conventional relining materials and aging. MATERIAL AND METHODS: The groups for surface characterization (surface-roughness and contact-angle measurements) were divided based on the denture base and surface treatment. Shear bond strength test and failure-mode analysis were conducted by a combination of three variables: denture base, relining materials, and hydrothermal aging (HA). The initial characterization involved quantifying the surface roughness (n = 10) and contact angle (n = 10) of denture base specimens with and without sandblasting (SB) treatment. Four relining materials (Kooliner [K], Vertex Self-Curing [V], Tokuyama Rebase II (Normal) [T], and Ufi Gel Hard [U]) were applied to 3DP, heat-cured (HC), and self-cured (SC) denture-base resin specimens. Shear bond strength (n = 15) and failure-mode analyses (n = 15) were performed before and after HA, along with evaluations of the fractured surfaces (n = 4). Statistical analyses were performed using a two-way analysis of variance (ANOVA) for surface characterization, and a three-way ANOVA was conducted for shear bond strength. RESULTS: The surface roughness peaked in HC groups and increased after SB. The 3DP group displayed significantly lower contact angles, which increased after treatment, similar to the surface roughness. The shear bond strength was significantly lower for 3DP and HC denture bases than for SC denture bases, and peaked for U at 10.65 ± 1.88 MPa (mean ± SD). HA decreased the shear bond strength relative to untreated samples. Furthermore, 3DP, HC, and SC mainly showed mixed or cohesive failures with V, T, and U. K, on the other hand, trended toward adhesive failures when bonded with HC and SC. CONCLUSION: This study has validated the repairability of 3DP dentures through relining them with common materials used in clinical practice. The repairability of the 3DP denture base was on par with that of conventional materials, but it decreased after aging. Notably, U, which had a postadhesive application, proved to be the most effective material for repairing 3DP dentures.


Assuntos
Colagem Dentária , Bases de Dentadura , Teste de Materiais , Adesivos , Resistência ao Cisalhamento , Impressão Tridimensional , Propriedades de Superfície
5.
BMC Med ; 21(1): 491, 2023 12 12.
Artigo em Inglês | MEDLINE | ID: mdl-38082312

RESUMO

BACKGROUND: Major psychiatric disorders such as schizophrenia (SCZ) and bipolar disorder (BPD) are complex genetic mental illnesses. Their non-Mendelian features, such as those observed in monozygotic twins discordant for SCZ or BPD, are likely complicated by environmental modifiers of genetic effects. 5-Hydroxymethylcytosine (5hmC) is an important epigenetic mark in gene regulation, and whether it is linked to genetic variants that contribute to non-Mendelian features remains largely unexplored. METHODS: We combined the 5hmC-selective chemical labeling method (5hmC-seq) and whole-genome sequencing (WGS) analysis of peripheral blood DNA obtained from monozygotic (MZ) twins discordant for SCZ or BPD to identify allelic imbalances in hydroxymethylome maps, and examined association of allele-specific hydroxymethylation (AShM) transition with disease susceptibility based on Bayes factors (BF) derived from the Bayesian generalized additive linear mixed model. We then performed multi-omics integrative analysis to determine the molecular pathogenic basis of those AShM sites. We finally employed luciferase reporter, CRISPR/Cas9 technology, electrophoretic mobility shift assay (EMSA), chromatin immunoprecipitation (ChIP), PCR, FM4-64 imaging analysis, and RNA sequencing to validate the function of interested AShM sites in the human neuroblastoma SK-N-SH cells and human embryonic kidney 293T (HEK293T) cells. RESULTS: We identified thousands of genetic variants associated with AShM imbalances that exhibited phenotypic variation-associated AShM changes at regulatory loci. These AShM marks showed plausible associations with SCZ or BPD based on their effects on interactions among transcription factors (TFs), DNA methylation levels, or other epigenomic marks and thus contributed to dysregulated gene expression, which ultimately increased disease susceptibility. We then validated that competitive binding of POU3F2 on the alternative allele at the AShM site rs4558409 (G/T) in PLLP-enhanced PLLP expression, while the hydroxymethylated alternative allele, which alleviated the POU3F2 binding activity at the rs4558409 site, might be associated with the downregulated PLLP expression observed in BPD or SCZ. Moreover, disruption of rs4558409 promoted neural development and vesicle trafficking. CONCLUSION: Our study provides a powerful strategy for prioritizing regulatory risk variants and contributes to our understanding of the interplay between genetic and epigenetic factors in mediating SCZ or BPD susceptibility.


Assuntos
Esquizofrenia , Gêmeos Monozigóticos , Humanos , Teorema de Bayes , Alelos , Gêmeos Monozigóticos/genética , Células HEK293 , Metilação de DNA/genética , Esquizofrenia/genética , Predisposição Genética para Doença , Epigênese Genética/genética
6.
J Mech Behav Biomed Mater ; 143: 105906, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37178635

RESUMO

The use of digital manufacturing, particularly additive manufacturing using three-dimensional (3D) printing, is expanding in the field of dentistry. 3D-printed resin appliances must undergo an essential process, post-washing, to remove residual monomers; however, the effect of the washing solution temperature on the biocompatibility and mechanical properties remains unclear. Therefore, we processed 3D-printed resin samples under different post-washing temperatures (without temperature control (N/T), 30 °C, 40 °C, and 50 °C) for different durations (5, 10, 15, 30, and 60 min) and evaluated the degree of conversion rate, cell viability, flexural strength, and Vickers hardness. Increasing the washing solution temperature significantly improved the degree of conversion rate and cell viability. Conversely, increasing the solution temperature and time decreased the flexural strength and microhardness. This study confirmed that the washing temperature and time influence the mechanical and biological properties of the 3D-printed resin. Washing 3D-printed resin at 30 °C for 30 min was most efficient to maintain optimal biocompatibility and minimize changes of mechanical properties.


Assuntos
Impressão Tridimensional , Resinas Sintéticas , Teste de Materiais , Temperatura , Propriedades de Superfície
7.
J Prosthet Dent ; 129(1): 69-75, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35985854

RESUMO

STATEMENT OF PROBLEM: Despite the introduction of intraoral scanners (IOSs) with dual camera triangulation, only a few comparative clinical studies have evaluated their clinical performances in the digital workflow for cast-free restorations. PURPOSE: The purpose of this clinical trial was to assess the clinical efficacy of 2 different technology-based IOSs by evaluating the marginal and internal gaps of cast-free monolithic zirconia crowns fabricated by using a fully digital workflow. MATERIAL AND METHODS: A prospective randomized clinical trial was conducted in 35 participants requiring a single-unit restoration. One crown was fabricated from the scan data obtained with a confocal microscopy-based IOS (Group T), while the other was made with the scan data obtained from an IOS using dual camera triangulation (Group I). A replica technique was used to assess the marginal and internal gaps. The buccolingual and mesiodistal cross-sections were measured, and noninferiority trials were performed. RESULTS: A total of 39 teeth from 35 participants were restored with a single-unit crown. The marginal and axial wall gaps of the crowns in Group I was not inferior to that of the crowns in Group T (upper limit confidence interval [CI] <30). In contrast, the gap of the crowns at the line angle in Group T was inferior to that of the crowns in Group I (lower limit CI <-30). From an occlusal space perspective, the gap of the crowns in Group I was inferior to that of the crowns in Group T (upper limit CI >30). Twenty-five crowns were selected from Group I, and 14 crowns were selected from Group T for definitive placement. CONCLUSIONS: The marginal gap of the crown fabricated by using the scan data obtained from the dual camera triangulation-based IOS was noninferior to that obtained from the confocal microscopy-based IOS and was within the clinically applicable limit.


Assuntos
Desenho Assistido por Computador , Planejamento de Prótese Dentária , Humanos , Estudos Prospectivos , Adaptação Marginal Dentária , Técnica de Moldagem Odontológica , Coroas
8.
Artigo em Inglês | MEDLINE | ID: mdl-36554572

RESUMO

Insomnia is a common health problem that can lead to various diseases and negatively impact quality of life. Pharmacopuncture is a new type of acupuncture that involves applying herbal medicine extracts to acupoints. Korean medicine doctors frequently use it to treat insomnia disorder. However, there is insufficient evidence to support the effectiveness and safety of pharmacopuncture for insomnia disorder. We designed a pragmatic randomized controlled trial to compare the effectiveness of pharmacopuncture and acupuncture for insomnia disorder. This multi-site, randomized, acupuncture-controlled trial will enroll 138 insomnia patients. The subjects will be randomly assigned to one of two groups, pharmacopuncture or acupuncture, at a 2:1 ratio. For 4 weeks, the participants will receive ten sessions of pharmacopuncture or acupuncture treatment and will be followed up for 4 weeks after the treatment ends. The Pittsburgh Sleep Quality Index score is the primary outcome measure. Insomnia severity index score, sleep parameters recorded using actigraphy and sleep diaries, physical symptoms associated with insomnia, emotions, quality of life, medical costs, and safety are the secondary outcome measures. The findings of this trial willprovide evidence that will be useful in clinical decision-making for insomnia treatment strategies.


Assuntos
Terapia por Acupuntura , Acupuntura , Distúrbios do Início e da Manutenção do Sono , Humanos , Distúrbios do Início e da Manutenção do Sono/terapia , Qualidade de Vida , Terapia por Acupuntura/métodos , Sono , Resultado do Tratamento , Ensaios Clínicos Controlados Aleatórios como Assunto
9.
J Mech Behav Biomed Mater ; 136: 105537, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36327665

RESUMO

The aim of this study was to determine the color stability of 3D printed resin according to the post-curing conditions (polymerization conditions and temperature). Specimens were post-polymerized under different conditions of oxygen inhibition, such as on glycerin immersion (GLY), medium-low vacuum environment (VA), and oxygen contact (CON, the control group), and temperature (35 °C, 60 °C, and 80 °C). The degree of conversion (DC), water sorption (Wsp) and solubility (Wsl), surface roughness (Ra) were measured. Additionally, surface free energy (SFE), pH values of colorants were measured. Grape juice (grape), coffee, and curry were used as the colorants, and distilled water (DW) was used as a control. And the color value was measured before and after immersion using a spectrophotometer. Then, Calculated the color change. For statistical methods, The Shapiro-Wilk test performed to check for normality revealed that the data presented a normal distribution (p>0.05). ΔE values were analyzed using three-way ANOVA. DC, Wsp, Wsl, SFE, and Ra were analyzed using two-way ANOVA. To confirm the linear correlation, Pearson's correlation coefficient was determined. The threshold for significance (p) was set at 0.05 (95% confidence interval) for all tests. DC was the highest at 80 °C in the GLY group (95.08 ± 4.88%). And Wsl decreased with increasing temperature, and was lowest at 80 °C in the GLY group (0.46 ± 0.30 um/mm3). After the colorants were immersed for 30 days, as the temperature increased, ΔE decreased in the GLY group but not in the VA and CON groups, and was the lowest at 80 °C in the GLY group: (DW, 0.95 ± 0.45 [mean± SD]; grape, 6.45± 0.69; coffee, 4.50± 0.56; curry, 9.37± 1.40). There was also a significant inverse relation between DC and ΔE. A significant inverse relation was found between Wsl and DC, and a significant positive correlation was found between Wsl and ΔE. Wsp, SFE, and Ra did not affect color stability. In the post-polymerization process, increasing the temperature and GLY were effective in reducing ΔE, which was lowest at 80 °C in the GLY group. It was also observed that a complex mechanism between the DC, Wsl of 3D printed resin affects ΔE of the resin.


Assuntos
Café , Resinas Compostas , Cor , Temperatura , Polimerização , Teste de Materiais , Água , Impressão Tridimensional , Propriedades de Superfície
10.
Healthcare (Basel) ; 10(11)2022 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-36360498

RESUMO

(1) Insomnia is associated with poor quality of life and loss of productivity, and is a significant economic burden on society. Gamiguibi-tang (GGBT) is the most frequently prescribed herbal medicine for insomnia treatment. Hwangryunhaedok-tang (HHT) is used as an insured herbal medicine for insomnia in the Korean National Health Insurance (NHI) system. This study aims to evaluate the cost-effectiveness of GGBT versus HHT in patients with insomnia disorders based on clinical trial data; (2) Methods: The EuroQol five-dimension scale (EQ-5D) was used to estimate quality-adjusted life-years (QALY). Direct and non-direct medical costs and lost productivity costs were estimated. The cost-effectiveness of GGBT was compared with HHT treatments over six weeks from a societal perspective; (3) Results: A total of 81 patients who underwent GGBT (n = 56) and HHT (n = 25) treatment completed the clinical trial. The EQ-5D score improved significantly more in the GGBT than in the HHT group (0.02 vs. −0.03, p < 0.05). The QALYs for six weeks were slightly greater in GGBT (0.0997) than in the HHT group (0.0987); however, the total costs incurred were approximately 9% less in GGBT ($934) than in the HHT group ($1029). GGBT was found to be a more economically dominant treatment option compared to HHT for treating insomnia; (4) Conclusions: Among herbal medicines, GGBT may be a cost-effective option for treating insomnia from a societal perspective in Korea.

11.
Materials (Basel) ; 15(19)2022 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-36234230

RESUMO

This study evaluated the effects of the light intensity of curing and the post-curing duration on the mechanical properties and accuracy of the interim dental material. After designing the specimen, 3D printing was performed, and the light intensity was divided into groups G20, G60, G80, and G120 (corresponding to 1.4−1.6, 2.2−3.0, 3.8−4.4, and 6.4−7.0 mW/cm2, respectively), with no post-curing or 5, 10, or 20 min of post-curing being performed. The flexural properties, Vickers microhardness, degree of conversion (DC), and 3D accuracy were then evaluated. The flexural properties and Vickers microhardness showed a sharp increase at the beginning of the post-curing and then tended to increase gradually as the light intensity and post-curing time increased (p < 0.001). On the other hand, there was no significant difference between groups in the accuracy analysis of a 3D-printed three-unit bridge. These results indicate that the light intensity of the post-curing equipment influences the final mechanical properties of 3D-printed resin and that post-curing can be made more efficient by optimizing the light intensity and post-curing time.

12.
Dent Mater ; 38(11): 1812-1825, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36192277

RESUMO

OBJECTIVES: This study aimed to determine the effects of the postwashing method and time on the mechanical properties and biocompatibility of three-dimensional (3D) printed crown and bridge resin. METHODS: DLP (digital light processing)-printed specimens produced from Nextdent crown & bridge (C&B) resins were washed separately using an ultrasonic bath and rotary washer with TPM (tripropylene glycol monomethyl ether) for 3 min, 6 min, 10 min, 20 min, and 1 h. Postcuring was applied for 30 min to each specimen after the washing process. The flexural strength, Vickers hardness, water sorption and solubility, degree of conversion (DC), elution of residual monomers, and biocompatibility of the specimens were evaluated. RESULTS: The ultrasonic bath showed greater washing efficacy by reducing the residual HEMA (2-hydroxyethyl methacrylate) from 2.0634 ppm to 0.1456 ppm and reducing the residual TEGDMA (triethylene glycol dimethacrylate) from 1.4862 ppm to 0.1484 ppm. With prolonged washing, the flexural strength significantly decreased from 129.67 ± 6.66 MPa (mean±standard deviation) to 103.17 ± 7.20 MPa, while the Vickers hardness increased slightly for the first 6 min and then decreased thereafter significantly. The DC was 87.78 ± 1.34% after 3 min and then gradually decreased with extended washing time. The cytotoxicity significantly decreases with the increment of the washing time. SIGNIFICANCE: The washing effect on the elution of residual monomers was better for an ultrasonic bath than for a rotary washer. Extending the washing time reduces the mechanical properties and cytotoxicity of the Nextdent C&B resin.


Assuntos
Resinas Compostas , Coroas , Éteres , Teste de Materiais , Metacrilatos , Polietilenoglicóis , Ácidos Polimetacrílicos , Impressão Tridimensional , Água
13.
Proc Natl Acad Sci U S A ; 119(22): e2118124119, 2022 05 31.
Artigo em Inglês | MEDLINE | ID: mdl-35617426

RESUMO

Fragile X­associated tremor/ataxia syndrome (FXTAS) is a debilitating late-onset neurodegenerative disease in premutation carriers of the expanded CGG repeat in FMR1 that presents with a spectrum of neurological manifestations, such as gait ataxia, intention tremor, and parkinsonism [P. J. Hagerman, R. J. Hagerman, Ann. N. Y. Acad. Sci. 1338, 58­70 (2015); S. Jacquemont et al., JAMA 291, 460­469 (2004)]. Here, we performed whole-genome sequencing (WGS) on male premutation carriers (CGG55­200) and prioritized candidate variants to screen for candidate genetic modifiers using a Drosophila model of FXTAS. We found 18 genes that genetically modulate CGG-associated neurotoxicity in Drosophila, such as Prosbeta5 (PSMB5), pAbp (PABPC1L), e(y)1 (TAF9), and CG14231 (OSGEPL1). Among them, knockdown of Prosbeta5 (PSMB5) suppressed CGG-associated neurodegeneration in the fly as well as in N2A cells. Interestingly, an expression quantitative trait locus variant in PSMB5, PSMB5rs11543947-A, was found to be associated with decreased expression of PSMB5 and delayed onset of FXTAS in human FMR1 premutation carriers. Finally, we demonstrate evidence that PSMB5 knockdown results in suppression of CGG neurotoxicity via both the RAN translation and RNA-mediated toxicity mechanisms, thereby presenting a therapeutic strategy for FXTAS.


Assuntos
Ataxia , Síndrome do Cromossomo X Frágil , Complexo de Endopeptidases do Proteassoma , Tremor , Animais , Ataxia/genética , Modelos Animais de Doenças , Drosophila melanogaster , Proteína do X Frágil da Deficiência Intelectual/genética , Síndrome do Cromossomo X Frágil/genética , Humanos , Masculino , Complexo de Endopeptidases do Proteassoma/genética , Tremor/genética
14.
J Mech Behav Biomed Mater ; 130: 105170, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35334279

RESUMO

The photosensitive resin used in additive manufacturing is cured by free radical polymerization by UV irradiation. However, undesired reaction with oxygen during polymerization inhibits polymerization and results in an under-cured polymer. Therefore, in this study, the hypothesis that successful oxygen shielding in the post-polymerization step could affect the properties of the final polymer was tested. 3D printed specimens using denture base resin were post polymerized either by immersion in glycerin for oxygen shielding (GL group) or placed in a medium-low vacuum chamber at 5 × 10-2 Torr (VA group). Specimens cured with no additional conditioning served as the control (CON group). To consider the effect of temperature, all groups were additionally compared with 80 °C and without an increase in temperature (room temperature) during post-polymerization. Fourier transform infrared spectroscopy was used to measure the monomer conversion ratios between different groups. In addition, the mechanical properties were quantified by the micro-hardness, flexural strength, and elasticity of the surface, and the water sorption and solubility. Dynamic mechanical analysis (DMA) was conducted to observe the trend in storage and loss modulus between the groups against temperature. Differences in the surface as a function of the post-polymerization conditions were qualitatively observed by scanning electron microscopy (SEM). The result shows that oxygen shielding during post-polymerization showed an increase in the degree of conversion (DC) and hardness of the resin surface. The highest DC was observed for GL group specimens at both room temperature and 80 °C. This result was confirmed by the SEM micrographs of the resin surface, where the interface between the layers of the GL group structure becomes more robust. However, a difference was observed between the samples prepared at room temperature and 80 °C. The flexural modulus was highest in the GL group, followed by the VA group, and lowest in the CON group at 80 °C. No difference in water absorption was observed for any groups, but high water solubility was observed in the GL group at room temperature. Overall, more significant differences in the properties were observed for the samples post-polymerized at 80 °C than at room temperature. The results of DMA analysis to determine the glass transition temperature showed a similar trend in all groups, and the storage modulus and loss rate obtained in the same experiment decreased in the order of GL, CON, and VA. In conclusion, an oxygen shielded post-polymerization environment at elevated temperature effectively improves the mechanical properties of photosensitive resin.


Assuntos
Glicerol , Oxigênio , Resinas Compostas , Dureza , Teste de Materiais , Polimerização , Polímeros/química , Impressão Tridimensional , Propriedades de Superfície , Temperatura , Vácuo , Água/química
15.
J Mech Behav Biomed Mater ; 128: 105127, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35182913

RESUMO

This study analyzed the flexural properties, Vickers hardness, degree of conversion (DC), and cell viability of 3D printed crown and bridge resin postcured using various types of postcuring equipment (PCE). 3D printed specimens were postcured for various times using different types of 3D printing PCE [for 5, 15, and 30 min using LC 3D Print Box (LC), Form Cure (FC), Cure M (CM), and Veltz 3D (VE) devices] and the VALO handheld light-curing (VA) device for 20, 40, and 60 s. Neither the flexural strength (132.27-145.79 MPa) nor the flexural modulus (1.52-1.83 GPa) differed significantly when postcuring for 30 min using the LC, FC, CM, or VE device, or for 20, 40, or 60 s of postcuring using the VA device (p > 0.05). The Vickers hardness was highest after 30 min of postcuring for all groups, and varied significantly with the postcuring time in the LC (p < 0.001) and CM (p < 0.001) groups. DC was significantly higher for the 5-min CM group (84.97 ± 4.02%) than for the GS, 30-min FC, 5-min VE, and 20-s VA groups. Cell viability of the postcured resin specimens was 56.46-92.29%, and varied significantly in the CM and VE groups according to the postcuring time (p < 0.05). Confocal laser scanning microscopy observations showed well-developed cell morphology and numerous cell-cell contacts in all groups except the GS group. This study found that the use of different types of PCE did not significantly affect the flexural properties of 3D printed crown and bridge resin, whereas there were significant variations in DC, Vickers hardness, and cell viability.


Assuntos
Coroas , Resistência à Flexão , Resinas Compostas , Teste de Materiais , Impressão Tridimensional , Propriedades de Superfície
16.
Artigo em Inglês | MEDLINE | ID: mdl-35162777

RESUMO

Post-stroke insomnia (PSI) is a highly prevalent complication after stroke. Current evidence of psychotropic drug use for PSI management is scarce and indicates harmful adverse events (AEs). Traditional East Asian herbal medicine is a widely used traditional remedy for insomnia. However, so far, no study has systematically reviewed the efficacy and safety of traditional east asian herbal medicine (HM) for PSI. Therefore, we perform meta-analysis to evaluate the effectiveness and safety of HM for PSI. After a comprehensive electronic search of 15 databases, we review the randomized controlled trials (RCTs) of HM use as monotherapy for PSI. Our outcomes were the Pittsburgh sleep quality index and total effective rate. In total, 24 RCTs were conducted with 1942 participants. HM showed statistically significant benefits in sleep quality. It also appeared to be safer than psychotropic drugs in terms of AEs, except when the treatment period was two weeks. The methods used for RCTs were poor, and the quality of evidence assessed was graded "low" or "moderate." The findings of this review indicate that the use of HM as a monotherapy may have potential benefits in PSI treatment when administered as an alternative to conventional medications. However, considering the methodological quality of the included RCTs, we were uncertain of the clinical evidence. Further, well-designed RCTs are required to confirm these findings.


Assuntos
Medicamentos de Ervas Chinesas , Distúrbios do Início e da Manutenção do Sono , Acidente Vascular Cerebral , Gerenciamento de Dados , Medicamentos de Ervas Chinesas/uso terapêutico , Medicina Herbária/métodos , Humanos , Ensaios Clínicos Controlados Aleatórios como Assunto , Distúrbios do Início e da Manutenção do Sono/complicações , Distúrbios do Início e da Manutenção do Sono/etiologia , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/tratamento farmacológico
17.
J Prosthet Dent ; 127(6): 827-831, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33541819

RESUMO

In studies that assessed the accuracy of implant surgical guides, evaluations were based on the placement position of the implant by using a manufactured surgical guide. However, such assessments could involve errors that may occur during implant placement. Therefore, evaluating the 3-dimensional accuracy of the fabrication of the implant surgical guide itself is not enough. In the evaluation method described in this article, location-related information is obtained by connecting a scan body to the sleeve of the surgical guide instead of directly placing the implant. This helps to evaluate the accuracy of the surgical guide without errors in the placement of an implant.


Assuntos
Implantes Dentários , Cirurgia Assistida por Computador , Desenho Assistido por Computador , Tomografia Computadorizada de Feixe Cônico , Implantação Dentária Endóssea/métodos , Imageamento Tridimensional
18.
Hum Mol Genet ; 31(10): 1673-1680, 2022 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-34897434

RESUMO

RNA modifications affect many aspects of RNA metabolism and are involved in the regulation of many different biological processes. Mono-methylation of adenosine in the N1 position, N1-methyladensoine (m1A), is a reversible modification that is known to target rRNAs and tRNAs. m1A has been shown to increase tRNA structural stability and induce correct tRNA folding. Recent studies have begun to associate the dysregulation of epitranscriptomic control with age-related disorders such as Alzheimer's disease. Here, we applied the newly developed m1A-quant-seq approach to map the brain abundant m1A RNA modification in the cortex of an Alzheimer's disease mouse model, 5XFAD. We observed hypomethylation in both mitochondrial and cytosolic tRNAs in 5XFAD mice compared with wild type. Furthermore, the main enzymes responsible for the addition of m1A in mitochondrial (TRMT10C, HSD17B10) and cytosolic tRNAs (TRMT61A) displayed decreased expression in 5XFAD compared with wild-type mice. Knockdown of these enzymes results in a more severe phenotype in a Drosophila tau model, and differential m1A methylation is correlated with differences in mature mitochondrial tRNA expression. Collectively, this work suggests that hypo m1A modification in tRNAs may play a role in Alzheimer's disease pathogenesis.


Assuntos
Doença de Alzheimer , Doença de Alzheimer/genética , Doença de Alzheimer/metabolismo , Animais , Citosol/metabolismo , Metilação de DNA/genética , Camundongos , Processamento Pós-Transcricional do RNA/genética , RNA de Transferência/genética , RNA de Transferência/metabolismo
19.
Materials (Basel) ; 14(20)2021 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-34683773

RESUMO

During the three-dimensional (3D) printing process of a dental prosthesis, using photopolymer resin, partially polymerized resin is further cured through the postcuring process that proceeds after the printing, which improves the stability of the printed product. The mechanical properties of the end product are known to be poor if the postcuring time is insufficient. Therefore, this study evaluated the effect of the postcuring time of the 3D-printed denture base on its dimensional stability, according to the aging period. The 3D prints were processed after designing maxillary and mandibular denture bases, and after the following postcuring times were applied: no postcuring, and 5, 15, 30, and 60 min. The dimensional stability change of the denture base was evaluated and analyzed for 28 days after the postcuring process. The trueness analysis indicated that the mandibular denture base had lower output accuracy than the maxillary denture base, and the dimensional stability change increased as postcuring progressed. In the no postcuring group for the mandible, the error value was 201.1 ± 5.5 µm (mean ± standard deviation) after 28 days, whereas it was 125.7 ± 13.0 µm in the 60 min postcuring group. For both the maxilla and the mandible, shorter postcuring times induced larger dimensional stability changes during the aging process. These findings indicate that in order to manufacture a denture base with dimensional stability, a sufficient postcuring process is required during the processing stage.

20.
Materials (Basel) ; 14(20)2021 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-34683798

RESUMO

This study analyzed the surface roughness and waviness, Vickers hardness (VHN), and color changes of six types of 3D printed resins and computer-aided design/computer-aided manufacturing (CAD/CAM) materials after artificial toothbrushing. The average surface roughness height (Ra) change of Formlabs denture teeth A2 resin (FMLB) was not significant between after artificial toothbrushing (0.17 ± 0.02 µm and 0.17 ± 0.05 µm, respectively; mean ± standard deviation). However, the Ra value increased significantly in all remaining groups. Regarding waviness, polymethylmethacrylate (PMMA) had the largest increases in average waviness height (Wa) and maximum surface waviness height (Wz) between, before (0.43 ± 0.23 µm and 0.08 ± 0.02 µm), and after (8.67 ± 4.03 µm, 1.30 ± 0.58 µm) toothbrushing. There were no significant changes in Wa for Formlabs denture teeth A2 resin (FMLB) and NextDent C&B (NXT). After artificial toothbrushing, the dispersed-filler composite (DFC) group had the largest color difference (ΔE, of 2.4 ± 0.9), and the remaining materials had smaller changes than the clinical acceptance threshold of ΔE = 2.25. The VHN of FMLB and NXT were 9.1 ± 0.4 and 15.5 ± 0.4, respectively, and were not affected by artificial toothbrushing. The flexural strengths of the 3D printed materials were 139.4 ± 40.5 MPa and 163.9 ± 14.0 MPa for FMLB and NXT, respectively, which were similar to those of the polycarbonate and PMMA groups (155.2 ± 23.6 MPa and 108.0 ± 8.1 MPa, respectively). This study found that the evaluated 3D printed materials had mechanical and optical properties comparable to those of CAD/CAM materials and were stable even after artificial toothbrushing and hydrothermal aging.

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