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1.
J Esthet Restor Dent ; 35(4): 621-624, 2023 06.
Artículo en Inglés | MEDLINE | ID: mdl-36810946

RESUMEN

OBJECTIVE: To detail a technique for bonding periodontal splint precisely in a digital workflow. CLINICAL CONSIDERATIONS: Periodontal splinting can be considered to stabilize the mobile teeth, especially for mandibular anterior teeth. Reliable bonding of periodontal splints is a prerequisite for successful clinical performance. However, when bonding the indirect splint to place or making direct splint intraorally, there is a significant risk of mobile teeth drifting away from the splint. To guide accurate insertion of periodontal splint with no risk of displacement of mobile teeth, a guide device fabricated by digital workflow is introduced in this article. CONCLUSIONS: Periodontal compromised teeth can be provisionally fixed during splinting, with the help of the guided device, and precise bonding of the splint is readily accomplished by using such digital workflow. This technique is not only applicable to the lingual splints, but also suitable for the labial ones. CLINICAL SIGNIFICANCE: The use of a guided device, after being digitally designed and fabricated, enables to stabilize the mobile teeth, in case of any displacement during splinting. It is straightforward, and beneficial to reduce the risk of complications, such as debonding of the splint, and secondary occlusal trauma.


Asunto(s)
Ferulas Periodontales , Movilidad Dentaria , Humanos , Flujo de Trabajo , Movilidad Dentaria/terapia , Férulas (Fijadores)
2.
J Prosthet Dent ; 127(5): 703-708, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-33441258

RESUMEN

A digitally guided triple technique for bone reduction, implant placement, and immediate interim prostheses in complete-arch implant surgery is presented. This technique integrates bone reduction and implant placement information into a dual-function surgical template and introduces a digital approach to fabricating immediate interim implant-supported fixed dental prostheses with the same occlusal relationship as the one evaluated with diagnostic removable prostheses.


Asunto(s)
Implantes Dentales , Carga Inmediata del Implante Dental , Prótesis Dental de Soporte Implantado , Carga Inmediata del Implante Dental/métodos
3.
Bull Environ Contam Toxicol ; 106(1): 165-174, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32468076

RESUMEN

Adsorbents with the combination of magnetic separation and removal performance are expected for reducing the adverse impact of nuclear pollution. In this study, the core-shell Fe3O4@polydopamine (Fe3O4@PDA) was successfully synthesized and used for removal of uranium (U(VI)) ion from aqueous solution. The abundant N-containing groups derived from PDA exist as the chelate sites for U(VI) and contribute greatly for U(VI) removal. Experimental results show that Fe3O4@PDA (56.39 mg g-1) exhibits greater sorption capacity for U(VI) removal compared with the pure Fe3O4 (9.17 mg g-1). The sorption isotherm can be well fitted with Freundlich model and the sorption process is endothermic and spontaneous. The removal of U(VI) can be explained by the complexation of U(VI) with -NH-, -NH2 and C-O in the surface of Fe3O4@PDA by X-ray photoelectron spectroscopy (XPS) analysis.


Asunto(s)
Uranio , Adsorción , Indoles , Polímeros , Uranio/análisis
4.
J Nanobiotechnology ; 18(1): 118, 2020 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-32854720

RESUMEN

BACKGROUND: Developing a universal strategy to improve the specificity and sensitivity of PEGylated nanoaparticles (PEG-NPs) for assisting in the diagnosis of tumors is important in multimodality imaging. Here, we developed the anti-methoxypolyethylene glycol (mPEG) bispecific antibody (BsAb; mPEG × HER2), which has dual specificity for mPEG and human epidermal growth factor receptor 2 (HER2), with a diverse array of PEG-NPs to confer nanoparticles with HER2 specificity and stronger intensity. RESULT: We used a one-step formulation to rapidly modify the nanoprobes with mPEG × HER2 and optimized the modified ratio of BsAbs on several PEG-NPs (Lipo-DiR, SPIO, Qdot and AuNP). The αHER2/PEG-NPs could specifically target MCF7/HER2 cells (HER2++) but not MCF7/neo1 cells (HER2+/-). The αHER2/Lipo-DiR and αHER2/SPIO could enhance the sensitivity of untargeted PEG-NPs on MCF7/HER2 (HER2++). In in vivo imaging, αHER2/Lipo-DiR and αHER2/SPIO increased the specific targeting and enhanced PEG-NPs accumulation at 175% and 187% on 24 h, respectively, in HER2-overexpressing tumors. CONCLUSION: mPEG × HER2, therefore, provided a simple one-step formulation to confer HER2-specific targeting and enhanced sensitivity and contrast intensity on HER2 positive tumors for multimodality imaging.


Asunto(s)
Anticuerpos Biespecíficos , Neoplasias de la Mama , Sistemas de Liberación de Medicamentos/métodos , Receptor ErbB-2 , Anticuerpos Biespecíficos/química , Anticuerpos Biespecíficos/farmacocinética , Neoplasias de la Mama/diagnóstico por imagen , Neoplasias de la Mama/metabolismo , Línea Celular Tumoral , Medios de Contraste/química , Medios de Contraste/metabolismo , Femenino , Humanos , Células MCF-7 , Imagen Multimodal , Nanopartículas/química , Nanopartículas/metabolismo , Polietilenglicoles/química , Receptor ErbB-2/química , Receptor ErbB-2/metabolismo
5.
CMAJ ; 191(33): E909-E915, 2019 08 19.
Artículo en Inglés | MEDLINE | ID: mdl-31427355

RESUMEN

BACKGROUND: Temporomandibular disorders (TMDs) are a family of pain-related disorders associated with impaired function in the jaw, temporomandibular joint and muscles of mastication. Our objectives were to evaluate the association between chronic TMD and gastresophageal reflux disease (GERD) and to determine whether mental disorders or undermined sleep mediates this association. METHODS: We conducted a case-control study involving 1522 consecutive adult patients with chronic TMD and 1522 matched controls from 2 hospitals in China. All participants were aged between 18 and 70 years and were recruited from July 2017 to April 2018 Chronic TMD was diagnosed by trained dentists using the criteria in the Orofacial Pain Prospective Evaluation and Risk Assessment Study. Trained gastroenterologists made blinded diagnoses of GERD according to the Montreal definition and classification (at least 2 d of mild symptoms, or 1 d of moderate or severe symptoms per week). We used validated questionnaires to evaluate psychological status and sleep quality. RESULTS: Of the study participants, we identified 132 patients and 61 controls with GERD. Using conditional logistic regression analysis, we identified GERD as a risk factor for TMD (odds ratio 2.74, 95% confidence interval 1.88 to 3.98). Mediation analyses identified that somatization, anxiety and undermined sleep moderately mediated the relation between TMD and GERD. INTERPRETATION: Our study suggests that symptomatic GERD is associated with chronic, painful TMD, and somatization, anxiety and undermined sleep mediate this association to a certain extent. Due consideration should be given to the evaluation and management of gastrointestinal symptoms and mental disorders in the combined therapy for painful TMD.


Asunto(s)
Reflujo Gastroesofágico/complicaciones , Trastornos Mentales/complicaciones , Trastornos del Sueño-Vigilia/complicaciones , Trastornos de la Articulación Temporomandibular/etiología , Adolescente , Adulto , Anciano , Estudios de Casos y Controles , Enfermedad Crónica , Femenino , Humanos , Masculino , Persona de Mediana Edad , Factores de Riesgo , Trastornos de la Articulación Temporomandibular/psicología , Adulto Joven
6.
J Adhes Dent ; 20(3): 249-259, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29904751

RESUMEN

PURPOSE: The present study evaluated the influence of air entrapment within demineralized dentin on bond strength, nanoleakage, and degree of conversion. MATERIALS AND METHODS: A vacuum pump with adjustable pressure was used to control the gaseous pressure of a sealed container during the application of a two-step etch-and-rinse adhesive to demineralized dentin. Atmospheric pressure was used as control, and reduced pressures (0.08, 0.06, 0.04 MPa) as experimental variables. Simulated pulpal pressure was adopted during the bonding procedures. After making composite buildups and 24-h water storage, 48 specimens were occlusogingivally sectioned into beams for microtensile bond strength testing, interfacial morphology observation, and nanoleakage evaluation immediately (6 for each group) or after artificial aging (6 for each group); 20 specimens (5 for each group) were occlusogingivally sectioned into slices for degree of conversion testing. Failure modes were compared using the chi-squared test. The other data were analyzed using ANOVA. RESULTS: When air within composite-dentin interface was thinned with reduced pressures, more thorough adhesive infiltration was achieved, and less distinct nanoleakage as well as higher bond strength were observed compared with control groups, regardless of artificial aging. Mixed failure was predominantly identified, and its percentage was higher in the reduced pressure groups than in the controls. Adhesive application at reduced pressure improved the degree of conversion. CONCLUSION: Air entrapment in the demineralized dentin adversely affects composite-dentin bonds. Adhesive application at reduced pressure is helpful for reducing entrapped air, thereby improving the durability of composite-dentin bonds.


Asunto(s)
Recubrimiento Dental Adhesivo , Recubrimientos Dentinarios , Resinas Compuestas , Dentina , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Cementos de Resina , Propiedades de Superficie , Resistencia a la Tracción
7.
Anal Chem ; 89(11): 6082-6090, 2017 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-28485140

RESUMEN

Sensitive quantification of the pharmacokinetics of poly(ethylene glycol) (PEG) and PEGylated molecules is critical for PEGylated drug development. Here, we developed a sensitive sandwich enzyme-linked immunosorbent assay (ELISA) for PEG by tethering an anti-PEG antibody (AGP3) via tethers with different dimensions on the surface of 293T cells (293T/S-αPEG, short-type cells; 293T/L-αPEG, long-type cells; 293T/SL-αPEG, hybrid-type cells) to improve the binding capacity and detection limit for free PEG and PEGylated molecules. The binding capacity of hybrid-type cells for PEG-like molecules (CH3-PEG5K-FITC (FITC = fluorescein isothiocyanate) and eight-arm PEG20K-FITC) was at least 10-80-fold greater than that of 293T cells expressing anti-PEG antibodies with uniform tether lengths. The detection limit of free PEG (OH-PEG3K-NH2 and CH3-PEG5K-NH2) and PEG-like molecule (CH3-PEG5K-FITC, CH3-PEG5K-SHPP, and CH3-PEG5K-NIR797) was14-137 ng mL-1 in the hybrid-type cell-based sandwich ELISA. 293T/SL-αPEG cells also had significantly higher sensitivity for quantification of a PEGylated protein (PegIntron) and multiarm PEG macromolecules (eight-arm PEG20K-NH2 and eight-arm PEG40K-NH2) at 3.2, 16, and 16 ng mL-1, respectively. Additionally, the overall binding capacity of 293T/SL-αPEG cells for PEGylated macromolecules was higher than that of 293T/S-αPEG or 293T/L-αPEG cells. Anchoring anti-PEG antibodies on cells via variable-length tethers for cell-based sandwich ELISA, therefore, provides a sensitive, high-capacity method for quantifying free PEG and PEGylated molecules.


Asunto(s)
Anticuerpos/metabolismo , Membranas/metabolismo , Polietilenglicoles/análisis , Reactivos de Enlaces Cruzados/química , Ensayo de Inmunoadsorción Enzimática , Células HEK293 , Humanos
8.
Psychiatry Clin Neurosci ; 69(12): 752-62, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26129934

RESUMEN

AIMS: Childhood obstructive sleep apnea syndrome (OSA) affects not only the children's physical health, but also their mental development, behavioral problems and learning difficulties. Therefore, an early diagnosis is important. However, the assessment tools of polysomnography are demanding. The Obstructive Sleep Apnea Questionnaire-18 (OSA-18) is designed to screen OSA and has good reliability and validity. The goal of this study was to validate the Chinese version of the OSA-18, to analyze the frequency of symptoms and find the most common symptoms of OSA in Taiwanese children. METHODS: We validated the OSA-18 in an ethnic Chinese group and compared the treatment outcomes to show the sensitivity of the questionnaire. The caregivers completed the questionnaire twice at an interval of 4 weeks to test reliability. In the validation study, we included 88 OSA children. The OSA-18 and follow-up polysomnography were performed before and 6 months after adenotonsillectomy. RESULTS: Results showed the excellent test-retest reliability (r = 0.84**) of the OSA-18. There was a statistically significant correlation between the OSA-18 and, respectively, the Apnea-Hypopnea Index (r = 0.29*), and the Hypopnea Index (r = 0.29*). Quality of life showed a significant correlation with the Apnea Index (r = 0.43**), central apnea count (r = 0.50***), and mixed apnea count (r = 0.36*). The cut-off point of the OSA-18 total scores for detecting pediatric OSA in children aged 6-12 years was 66. The common symptoms of pediatric OSA were poor attention span, loud snoring, caregiver worried about child's health, difficulty awakening, and mouth breathing. CONCLUSIONS: Our results show that the Chinese version of the OSA-18 is a reliable and valid instrument. The questionnaire also showed improvement in the quality of life of OSA children post-adenotonsillectomy.


Asunto(s)
Apnea Obstructiva del Sueño/diagnóstico , Adenoidectomía , Niño , Femenino , Humanos , Masculino , Polisomnografía , Reproducibilidad de los Resultados , Sensibilidad y Especificidad , Apnea Obstructiva del Sueño/cirugía , Encuestas y Cuestionarios , Taiwán , Tonsilectomía , Resultado del Tratamiento
9.
Mol Pharm ; 11(7): 2213-23, 2014 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-24164427

RESUMEN

Cancer nanotherapeutics are rapidly progressing and being implemented to solve several limitations of conventional drug delivery systems. In this paper, we report a novel strategy of preparing methotrexate (MTX) nanoparticles based on chitosan (CS) and methoxypoly(ethylene glycol) (mPEG) used as nanocarriers to enhance their targeting and prolong blood circulation. MTX and mPEG-conjugated CS nanoparticles (NPs) were prepared and evaluated for their targeting efficiency and toxicity in vitro and in vivo. The MTX-mPEG-CS NP size determined by dynamic light scattering was 213 ± 2.0 nm with a narrow particle size distribution, and its loading content (LC %) and encapsulation efficiency (EE) were 44.19 ± 0.64% and 87.65 ± 0.79%, respectively. In vitro release behavior of MTX was investigated. In vivo optical imaging in mice proved that MTX was released from particles subsequently and targeted to tumor tissue, showing significantly prolonged retention and specific selectivity. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay obviously indicated that the higher inhibition efficiency of MTX-mPEG-CS NPs meant that much more MTX was transferred into the tumor cells. A significant right-shift in the flow cytometry (FCM) assay demonstrated that MTX-loaded nanoparticles were far superior to a pure drug in the inhibition of growth and proliferation of Hela cells. These results suggest that MTX-mPEG-CS NPs could be a promising targeting anticancer chemotherapeutic agent, especially for cervical carcinoma.


Asunto(s)
Quitosano/química , Metotrexato/química , Metotrexato/farmacología , Nanopartículas/química , Neoplasias/tratamiento farmacológico , Polietilenglicoles/química , Animales , Antineoplásicos/química , Antineoplásicos/farmacología , Línea Celular Tumoral , Portadores de Fármacos/química , Sistemas de Liberación de Medicamentos/métodos , Células HeLa , Humanos , Masculino , Ratones , Tamaño de la Partícula
10.
Colloids Surf B Biointerfaces ; 234: 113734, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38181690

RESUMEN

Metal-based nanomaterials have remarkable bactericidal effects; however, their toxicity cannot be disregarded. To address this concern, we developed a simple synthesis route for antibacterial catheters using metal-based nanomaterials to reduce toxicity while harnessing their excellent bactericidal properties. The grafting agent (3-aminopropyl)triethoxysilane (APTES) forms -NH2 groups on the catheter surface, onto which copper ions form a nanomaterial complex known as Cu2(OH)3(NO3) (defined as SA-Cu). The synthesized SA-Cu exhibited outstanding contact antibacterial effects, as observed through scanning electron microscopy (SEM), which revealed cell membrane crumbing and bacterial rupture on the catheter surface. Furthermore, SA-Cu exhibited excellent biosafety characteristics, as evidenced by the cell counting kit-8 (CCK-8) assay, which showed no significant cytotoxicity. SA-Cu demonstrated sustained antimicrobial capacity, with in vivo experiments demonstrating over 99% bactericidal efficacy against methicillin-resistant Staphylococcus aureus (MRSA) for two weeks. The transcriptome sequencing results suggested that SA-Cu may exert its bactericidal effects by interfering with histidine and purine metabolism in MRSA. This study presents a straightforward method for synthesizing antimicrobial silicone catheters containing copper nanomaterials using copper ions.


Asunto(s)
Antiinfecciosos , Staphylococcus aureus Resistente a Meticilina , Nanoestructuras , Humanos , Cobre/farmacología , Absceso , Siliconas , Antibacterianos/farmacología , Catéteres , Iones
11.
Appl Microbiol Biotechnol ; 97(11): 5079-87, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23615742

RESUMEN

Photodynamic antimicrobial chemotherapy (PACT) is proposed as a potential candidate to inactivate pathogens in localized infections due to the rapid evolution of bacterial resistance. The treatment modality utilizes nontoxic agents called photosensitizers and harmless visible light to generate reactive oxygen species which result in microbial cells' killing. Hematoporphyrin monomethyl ether (HMME) as a novel and affordable photosensitizer has been used in treating various clinical diseases for years, but few applications in infection. In this report, we studied the bactericidal effects of the HMME-mediated photodynamic reaction on the pathogenic microbes in supragingival plaque which can lead to many oral infectious diseases such as caries, gingivitis, and so on. Our findings demonstrated that HMME promoted an effective action in bacterial reduction with the application of laser energy. Moreover, the antimicrobial activities were dramatically enhanced as the HMME concentration and exposure time were increased, but reached a plateau when matched the appropriate agent concentration and illumination. It was found that the survival fraction of microorganisms is exponentially dependent on the product of HMME concentration and irradiation time. These promising results suggest the HMME may be an excellently cost-effective photosensitizing agent for mediating PACT in the treatment of supragingival plaque-related diseases. An optimized HMME concentration and irradiation time has been found to achieve the best results under our experimental conditions. The high HMME concentration matching short curative time, or vice versa, can achieve the similar therapeutic effect, which may provide more flexible treatment plans according to specific conditions.


Asunto(s)
Bacterias/aislamiento & purificación , Placa Dental/microbiología , Hematoporfirinas/farmacología , Luz , Viabilidad Microbiana/efectos de los fármacos , Viabilidad Microbiana/efectos de la radiación , Fármacos Fotosensibilizantes/farmacología , Bacterias/efectos de los fármacos , Bacterias/efectos de la radiación , Relación Dosis-Respuesta a Droga , Humanos , Rayos Láser , Trastornos por Fotosensibilidad , Factores de Tiempo
12.
J Dent ; 125: 104247, 2022 10.
Artículo en Inglés | MEDLINE | ID: mdl-35917996

RESUMEN

OBJECTIVES: To perform systematic review and quantitative analysis of the literature on the association between gastro-oesophageal reflux disease (GERD) and dental erosion in children. METHODS: Databases were searched for randomised controlled trials, cohort studies, cross-sectional surveys and case-control studies that evaluated the association between GERD and dental erosion in children aged 1-18 years, without limitations on the language or year of publication. Data were pooled in random effects models. Data sources included Embase, MEDLINE, Web of Science, Trip Pro, Cochrane Library, the International Clinical Trials Registry Platform, ClinicaTrials.gov, Open Grey, Proquest Dissertations and Thesis and Google Scholar from inception to June 9, 2022. RESULTS: Thirteen studies were included, of which twelve were used for meta-analysis. There were strong associations between GERD and enamel erosion with the subject as unit (odds ratio 4.46; 95% confidence interval (CI) 1.93-10.30; n = 6774); dentine erosion with the subject as unit (odds ratio 13.39; 95% CI 4.17-42.94; n = 371); enamel erosion with the tooth as unit (odds ratio 3.29; 95% CI 1.36-7.95; n = 4637); as well as dentine erosion with the tooth as unit (odds ratio 5.91; 95% CI, 2.35-14.86; n = 4637). In cohort studies, GERD was associated with a higher risk of enamel erosion with the subject as a unit (relative risk 1.88, 95% CI 1.22-2.92; n = 1411). CONCLUSIONS: Gastro-oesophageal reflux disease is associated with dental erosion in children. The heterogeneity of GERD definition should be considered when interpreting the present work. CLINICAL SIGNIFICANCE: There is a positive association between GERD and dental erosion in children. Dentists should emphasise timely detection and management of the underlying factors of dental erosion in GERD. Future studies should define paediatric GERD according to a universal guideline to better enhance patient care.


Asunto(s)
Reflujo Gastroesofágico , Estudios de Casos y Controles , Niño , Estudios Transversales , Reflujo Gastroesofágico/complicaciones , Humanos , Oportunidad Relativa
13.
Polymers (Basel) ; 14(14)2022 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-35890611

RESUMEN

BACKGROUND: In this study, we evaluated the effect of periodontal splints made from different materials on the stress distributions in compromised periodontal tissues and cement layers, using a computer simulation of mastication. METHODS: Twenty-five 3D models were created for a segment of mandibular teeth with different periodontal splints bilaterally extended to the canines. The models were divided into five groups according to the different materials and thicknesses (mm) of the splints: the non-splinted group, PEEK 0.7 group, PEEK 1.0 group, FRC group, and titanium group. Each group was subdivided based on five bone loss levels. Tooth 41 of each model was subjected to vertical and oblique (θ = 45°) static loads of 100 N, respectively, onto the incisal edge. The von Mises stresses and maximum principal stress were analyzed using Abaqus software. RESULTS: Oblique loading resulted in higher stresses on periodontal tissues, cement layers, and splints than those caused by vertical loading. The lower the supporting bone level, the greater the stress difference between the splinted groups and the non-splinted group. In model 133,331, with severe bone loss, the maximum von Mises stress values on the alveolar bone in tooth 41 under oblique loading dramatically decreased from 406.4 MPa in the non-splinted group to 28.62 MPa in the PEEK group and to 9.59 MPa in the titanium group. The four splinted groups presented similar stress distributions in periodontal tissues. The lowest stress level on the splint was observed in the PEEK 0.7 group, and the highest stress level was transferred to the cement layer in this group. Stress concentrations were primarily exhibited at the connectors near the load-carrying area. CONCLUSIONS: The tested splinted groups were all effective in distributing the loads on periodontal tissues around splinted teeth with similar patterns. Using splinting materials with low elastic moduli reduced the stress concentration at the splint connectors, whereas the tensile stress concentration was increased in the cement layer. Thus, the use of adhesive cement with a higher elastic modulus is recommended when applying less rigid PEEK splints.

14.
Artículo en Inglés | MEDLINE | ID: mdl-36231969

RESUMEN

BACKGROUND: The present study aimed to investigate the prevalence of peri-implant disease and identify potential disease risk factors in western China. METHODS: The present retrospective study was conducted in 131 consecutive patients receiving 248 dental implants treated with implant-supported prostheses with a mean follow-up of 2.52 years. Several patient-related, implant-related, and oral hygiene maintenance factors were analyzed. RESULTS: Peri-implant disease developed in 68 (51.91%) patients and 110 (44.35%) implants. The prevalence of peri-implant mucositis and peri-implantitis were 45.80% and 7.63%, respectively, at the subject level, and 36.69% and 7.66%, respectively, at the implant level. Multivariate analysis exhibited that male [odds ratio (OR) = 1.91; 95% confidence interval (CI): 1.02-3.57; p = 0.04], implant length < 10mm (OR = 7.87; 95% CI:1.62-38.46; p = 0.01), poor proximal contact of the prosthesis (OR = 1.90; 95% CI: 1.06-3.42; p = 0.03), tooth brushing once a day (OR = 3.11; 95% CI: 1.26-7.68; p = 0.04) and moderate periodontitis (OR = 13.00; 95% CI: 4.38-38.60; p < 0.01) were independent risk factors for peri-implant disease.


Asunto(s)
Implantes Dentales , Periimplantitis , Estudios de Casos y Controles , Implantes Dentales/efectos adversos , Humanos , Masculino , Periimplantitis/epidemiología , Periimplantitis/etiología , Prevalencia , Estudios Retrospectivos , Factores de Riesgo
15.
Polymers (Basel) ; 14(21)2022 Oct 31.
Artículo en Inglés | MEDLINE | ID: mdl-36365609

RESUMEN

The high-performance thermoplastic polyetheretherketone (PEEK) has excellent mechanical properties, biocompatibility, chemical stability, and radiolucency. The present article comprehensively reviews various applications of PEEK in removable dental prostheses, including in removable partial dentures (RPDs) (frameworks and clasps), double-crown RPDs, and obturators. The clinical performance of PEEK in removable dental prostheses is shown to be satisfactory and promising based on the short-term clinical evidence and technical complications are scarce. Moreover, the accuracy of RPDs is a vital factor for their long-term success rate. PEEK in removable dental prostheses is fabricated using the conventional lost-wax technique and CAD/CAM milling, which produces a good fit. Furthermore, fused deposition modeling is considered to be one of the most practical additive techniques. PEEK in removable prostheses produced by this technique exhibits good results in terms of the framework fit. However, in light of the paucity of evidence regarding other additive techniques, these manufacturers cannot yet be endorsed. Surface roughness, bacterial retention, color stability, and wear resistance should also be considered when attempting to increase the survival rates of PEEK removable prostheses. In addition, pastes represent an effective method for PEEK polishing to obtain a reduced surface roughness, which facilitates lower bacterial retention. As compared to other composite materials, PEEK is less likely to become discolored or deteriorate due to wear abrasion.

16.
Carbohydr Polym ; 296: 119917, 2022 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-36087973

RESUMEN

Low-temperature two-step concentrated H2SO4 was discovered to be a solvent with high cellulose solubility [>300 g/L (17 wt%)], fast cellulose dissolution, high regeneration yield (>0.92 g/g), and cellulose being mouldable during regeneration. The superior performance was enabled by the much better compatibility of cellulose with lower concentrated H2SO4 at low temperature, compared with that of high concentrated H2SO4. The regenerated cellulose was characterized by mostly unchanged composition and highly tunable degree of polymerization (DP). The H2SO4 starting content, cotton fibre temperature, dissolution temperature, regeneration temperature, regeneration bath and storage time were factors determining the DP of regenerated cellulose, which could be equivalent to 4-90 % of the original cotton. These advantages of the solvent enabled versatile application in fabrication of extra strong cellulose hydrogels, manufacture of strong cellulose fibres, preparation of various homogenous composites which would be prepared with much more difficulty by using other solvents, and facile manufacture of cellooligosaccharides.


Asunto(s)
Celulosa , Celulosa/química , Polimerizacion , Solubilidad , Solventes/química , Temperatura
17.
J Mater Sci Mater Med ; 22(11): 2403-11, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21979164

RESUMEN

Proanthocyanidin-based preconditioners were prepared by adding powdered proanthocyanidins-rich grape seed extract to various solvents at different concentrations. Demineralized dentin specimens were preconditioned for 20, 30, 60 or 120 s, followed by the evaluation of their cross-linking degree, mechanical properties and micromorphology. The cross-linking degree of the demineralized dentin collagen exhibited concentration- and time- dependent increase after preconditioning treatment, irrespective of the preconditioner and the solvent. When treated for the same exposure time, specimens after 15% proanthocyanidins preconditioning resulted in the highest mean ultimate tensile strength compared with all the other groups tested. Five percent glutaraldehyde control group produced the highest cross-linking degree, but the ultimate tensile strength was lower than that of 15% proanthocyanidins group. The field emission scanning electron microscopy confirmed that the demineralized dentin collagen was in a homogeneous and regular arrangement after preconditioning and maintained expanding, regardless of the surface moisture conditions.


Asunto(s)
Dentina/química , Proantocianidinas/química , Fenómenos Biomecánicos , Historia del Siglo XIX , Humanos , Resistencia a la Tracción , Diente/química
18.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 39(1): 58-63, 2021 Feb 01.
Artículo en Inglés, Zh | MEDLINE | ID: mdl-33723938

RESUMEN

OBJECTIVES: This study aimed to investigate the association between periodontal indexes and biomarkers in gingival crevicular fluid (GCF) and preterm birth (PTB) in pregnancy, as well as to assess the clinical value of these indexes as predictors of PTB. METHODS: A nested case-control study was conducted. A total of 300 systematically healthy pregnant women were selected within 36 weeks of gestation and grouped according to the enrolled weeks. Periodontal indexes, including probing depth (PD), bleeding index (BI), gingival index (GI), and five biomarkers in GCF, including interleukin (IL)-1ß, IL-6, tumor necrosis factor-α (TNF-α), prostaglandin E2 (PGE2), and 8-hydroxy-2-deoxyguanosine (8-OHdG) were measured at the enrolled date. The detailed birth outcome was recorded. RESULTS: Only women at 24-28 weeks of gestation per PTB case (four full-term births) were selected as controls subjects, PTB displayed significantly greater GI, BI, and 8-OHdG (P<0.05). Logistic regression analysis revealed that BI and 8-OHdG were the dependent risk factors of PTB (OR=5.90, P=0.034; OR=1.18, P=0.045, respectively). The areas under the receiver operating characteristic curve (ROC) of BI and 8-OHdG were 0.80 and 0.69, and that of the combined detection was 0.82, which was larger than the individual detection, although the differences were not significant (P>0.05). CONCLUSIONS: Increased BI and 8-OHdG at 24-28 weeks of gestation are risk factors for PTB. Their combined detection may have some value in the prediction of PTB, but further studies with a larger sample size are needed to explore it and thus provide experiment evidence for establishing an early warning system for PTB in pregnant women with periodontal disease.


Asunto(s)
Líquido del Surco Gingival , Nacimiento Prematuro , Biomarcadores , Estudios de Casos y Controles , Femenino , Humanos , Recién Nacido , Índice Periodontal , Embarazo
19.
Langmuir ; 26(10): 7349-54, 2010 May 18.
Artículo en Inglés | MEDLINE | ID: mdl-20121266

RESUMEN

This study demonstrates that collagen, the most abundant protein in animals, exists as a distribution of nanoscale morphologies in teeth, bones, and tendons. This fundamental characteristic of Type I collagen has not previously been reported and provides a new understanding of the nanoscale architecture of this ubiquitous and important biological nanomaterial. Dentin, bone, and tendon tissue samples were chosen for their differences in cellular origin and function, as well as to compare mineralized tissues with a tissue that lacks mineral in a normal physiological setting. A distribution of morphologies was present in all three tissues, confirming that this characteristic is fundamental to Type I collagen regardless of the presence of mineral, cellular origin of the collagen (osteoblast versus odontoblast versus fibroblast), anatomical location, or mechanical function of the tissue.


Asunto(s)
Huesos/química , Colágeno Tipo I/química , Nanoestructuras/química , Tendones/química , Diente/química , Animales , Masculino , Ratones , Ratones Endogámicos
20.
Sci Total Environ ; 708: 134575, 2020 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-31806329

RESUMEN

This study investigated the modification of moso bamboo biochar with polyethyleneimine (PEI) for the efficient enrichment of U(VI) in aqueous solution. The alkali/acid treated biochars with amine groups (PEI-alkali-biochar or PEI-acid-biochar) were characterized by SEM, BET, TGA, FTIR and XPS. The effects of contact time, U(VI) concentration, pH and ionic strength on U(VI) adsorption by PEI-alkali/acid-biochar were studied. U(VI) adsorption process on PEI-alkali/acid-biochar obeys pseudo-second-order model. Intraparticle diffusion model was used to investigate the controlled factors of the adsorption process. The fitting of Langmuir model gives the maximum adsorption capacities of 212.7 mg/g for PEI-alkali-biochar and 185.6 mg/g for PEI-acid-biochar, which are almost 9-10 times higher than that of pristine biochar (20.1 mg/g). The thermodynamic parameters illustrate that U(VI) adsorption on PEI-alkali/acid-biochar is an exothermic and spontaneous process. The FTIR and XPS analyses imply that U(VI) adsorption by PEI-alkali/acid-biochar is mainly controlled by complexation between U(VI) and amine groups. PEI-alkali/acid-biochar could be considered as a low-cost and outstanding material for U(VI) removal from radionuclide wastewater in practical application.


Asunto(s)
Carbón Orgánico , Adsorción , Cinética , Polietileneimina , Porosidad , Sasa , Contaminantes Químicos del Agua
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