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Objective@# To investigate the effects of different glucose concentration on the proliferation and osteogenic differentiation of human bone marrow mesenchymal stem cells (hBMSC) in vivo@*Methods@#Cultured with basal medium containing different glucose concentrations, CCK-8 cell proliferation was detected at 1, 4, 7, 10 days. The osteogenic differentiation of human bone marrow mesenchymal stem cells was observed at 7 d, which was induced by osteogenic differentiation medium with different concentration of glucose. The expressions of alkaline phosphatase (ALP), osteocalcin (OC) and collagen type I (Col-1) gene were detected by real-time fluorescence quantitative PCR. Mineralized nodule formation was displayed by calciumalizarin red staining on the seventh day.@*Results @#10 mM glucose stimulated proliferation of hBMSC, while the higher (>30 mM) inhibited the proliferation (P < 0.05); Osteogenic induction can induce osteogenic differentiation of hBMSC, but the increase of glucose concentration will decrease the formation of mineralized nodules of hBMSC, inhibit the expression of osteogenic marker genes ALP, OC and Col-1 (P < 0.05).@*Conclusion@#The expression of Col-1, ALP and OC in osteoblast was down-regulated by high glucose, and the hBMSC proliferation was inhibited. At the same time, high glucose can reduce the osteogenic mineralization ability of stem cells and indirectly affect bone formation and metabolism.
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PURPOSE: Early marginal bone loss around dental implants has been found during the bone healing period before stage II surgery despite a lack of apparent cause, and the etiology of this bone loss is unclear. This study was designed to investigate whether interleukin-1 gene polymorphism is associated with the marginal bone loss around the implants before stage II. MATERIALS AND METHODS: One hundred forty-three implants were placed in 59 patients. The patients were divided into 2 groups: 1) test group: with 1 or more marginal bone loss greater than 0.5 mm; and 2) control group: with marginal bone resorption less than 0.5 mm. Polymorphisms of the IL-1alpha and IL-1beta genes (IL-1A-889, IL-1B-511, and IL-1B+3954) were detected by restriction fragment length polymorphism using Ncol, AvaI, and TaqI digestion after polymerase chain reactions. RESULTS: The frequency of IL-1B-511 II/II was significantly higher among patients in early marginal bone loss (+) group than those in early marginal bone loss (-) group (P < .05). Multiple logistic regressions showed the OR of the II/II versus the I/I+I/II of the IL-1B-511 genotype was 3.933 between the 2 groups. The difference was statistically significant (P < .05). There was no significant difference between the other risk factors. CONCLUSION: These results suggest that the IL-1B-511 II/II genotype in individuals is associated with early marginal bone loss around implants.
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Pérdida de Hueso Alveolar/inmunología , Implantes Dentales , Interleucina-1/genética , Interleucina-1beta/genética , Polimorfismo Genético/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Pérdida de Hueso Alveolar/diagnóstico por imagen , Pérdida de Hueso Alveolar/genética , Cromosomas Humanos Par 2/genética , Exones/genética , Femenino , Frecuencia de los Genes/genética , Genotipo , Humanos , Interleucina-1alfa/genética , Masculino , Persona de Mediana Edad , Oseointegración/fisiología , Regiones Promotoras Genéticas/genética , Radiografía Panorámica , FumarRESUMEN
OBJECTIVE: To study the movement of long axis and the distribution of principal stress in the abutment teeth in removable partial denture which is retained by use of conical telescope. METHODS: An ideal three dimensional finite element model was constructed by using SCT image reconstruction technique, self-programming and ANSYS software. The static loads were applied. The displacement of the long axis and the distribution of the principal stress in the abutment teeth was analyzed. RESULTS: There is no statistic difference of displacenat and stress distribution among different three-dimensional finite element models. Generally, the abutment teeth move along the long axis itself. Similar stress distribution was observed in each three-dimensional finite element model. The maximal principal compressive stress was observed at the distal cervix of the second premolar. CONCLUSION: The abutment teeth can be well protected by use of conical telescope.
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Coronas , Análisis del Estrés Dental/métodos , Bases para Dentadura/normas , Retención de Dentadura/instrumentación , Pilares Dentales , Diseño de Dentadura , Dentadura Parcial Removible/normas , Análisis de Elementos Finitos , Humanos , Programas InformáticosRESUMEN
OBJECTIVE: To compare the tilted abutment teeth restored with or without fixed bridge on stress distribution by anisotropic finite element method when the vertical and the oblique loads are simulated. METHODS: Three-dimensional finite element model was constructed by using SCT image reconstruction technique, self-programming and ANSYS software with the anisotropic elasticity data. The static loads were simulated according to the restored and unrestored situation. The stress distribution and stress level of the second molar was recorded. RESULTS: When the vertical static load was simulated, the stress distribution of the tilted abutment teeth was much improved. Tensile stresses appeared dominantly on the mesial apex of the second molar (31.0 Mpa) before restoration and on the distal apex of the second molar (20.2 Mpa) after restoration. When the oblique load was simulated, the stress distribution changed a little. CONCLUSION: The stress distribution of the tilted abutment can be improved by restorative techniques with the use of fixed bridge; however, the clinician should lower the height of the cusp to reduce the oblique load of the abutment.