ABSTRACT
BACKGROUND: Tendon-to-bone healing is a complex and slow process, which often hinders the therapeutic outcomes. To enhance the tendon-to-bone healing, increasing cell bioactivity on the contact surface is a new strategy. Hypoxia-inducible factor 1α (HIF-1α) can induce the formation of blood vessel and bone tissue via many ways.However,it is unclear whether HIF-1α can strengthen differentiation of human amniotic mesenchymal stem cells (hAMSCs) induced by Scleraxis, a specific marker of tendon, and can be used in tendon and bone repair. OBJECTIVE: To investigate the ability of HIF-1α in enhancing Scleraxis to modify hAMSCs aiming to promote tendon-to-bone healing and its molecular mechanism. METHODS: Passage 3 hAMSCs were infected with AdHIF-1α, AdScx, AdGFP and AdHIF-1α+AdScx. The expressions of related genes of tendon, cartilage and bone tissue were detected at 3 and 7 days after infection. RESULTS AND CONCLUSION: Under the inverted phase contrast microscopy, the passage 3 hAMSCs were in spindle shape and presented with vortex-like adherent growth. Under the transmission electron microscopy, hAMSCs were in oval shape and had clear structure, with abundant endoplasmic reticulum and mitochondria. Fluorescence photographs were taken at 24 hours after adenovirus infection, showing about 50% red fluorescence expression in the AdHIF-1α group, while about 70% green fluorescence expression in the AdScx and AdGFP groups. Real time-PCR results showed that at 3 and 7 days after infection, the mRNA expressions of collagen type I, Fibronectin, RUNX2, VEGF and ALP in the AdHIF-1α+AdScx group, AdHIF-1α group and AdScx group were higher than those in the AdGFP group (P < 0.05); the mRNA expressions of collagen type I, Fibronectin, RUNX2, VEGF and ALP in the AdHIF-1α+AdScx group were significantly higher than those in the AdScx group (P < 0.05). Fluorescence immunohistochemistry results showed that the expression of collagen type I in the AdHIF-1α+AdScx group at 7 days after infection was higher than that at 3 days after infection. To conclude, HIF-1α can enhance the ability of Scleraxis to modify hAMSCs to promote tendon-to-bone healing by upregulating the expressions of molecular markers of tenocytes, chondrocytes and osteocytes.
ABSTRACT
<p><b>OBJECTIVE</b>To study the effect of different optical impression methods in Cerec 3D/Inlab MC XL system on marginal and internal fit of all-ceramic crowns.</p><p><b>METHODS</b>A right mandibular first molar in the standard model was used to prepare full crown and replicated into thirty-two plaster casts. Sixteen of them were selected randomly for bonding crown and the others were used for taking optical impression, in half of which the direct optical impression taking method were used and the others were used for the indirect method, and then eight Cerec Blocs all-ceramic crowns were manufactured respectively. The fit of all-ceramic crowns were evaluated by modified United States Public Health Service (USPHS) criteria and scanning electron microscope (SEM) imaging, and the data were statistically analyzed with SAS 9.1 software.</p><p><b>RESULTS</b>The clinically acceptable rate for all marginal measurement sites was 87.5% according to USPHS criteria. There was no statistically significant difference in marginal fit between direct and indirect method group (P > 0.05). With SEM imaging, all marginal measurement sites were less than 120 microm and no statistically significant difference was found between direct and indirect method group in terms of marginal or internal fit (P > 0.05). But the direct method group showed better fit than indirect method group in terms of mesial surface, lingual surface, buccal surface and occlusal surface (P < 0.05). The distal surface's fit was worse and the obvious difference was observed between mesial surface and distal surface in direct method group (P < 0.01).</p><p><b>CONCLUSION</b>Under the conditions of this study, the optical impression method had no significant effect on marginal fit of Cerec Blocs crowns, but it had certain effect on internal fit. Overall all-ceramic crowns appeared to have clinically acceptable marginal fit.</p>
Subject(s)
Humans , Ceramics , Computer-Aided Design , Crowns , Dental Porcelain , Dental Prosthesis DesignABSTRACT
<p><b>OBJECTIVE</b>To analyze the use situation of finished resin teeth for the different location, and to provide reference for manufacturers of finished resin teeth and all the buyers.</p><p><b>METHODS</b>To analyze the use situation of finished resin teeth in the Dental Laboratory of the Affiliated Hospital of Stomatology of Chongqing Medical University from January 2006 to December 2008 by using statistic methods.</p><p><b>RESULTS</b>During the use of 55,787 finished resin teeth, the study found some rules. (1) The top use of finished resin teeth was D6 with the percentage of 5.31%, and the lowest use of finished resin teeth was D3 with the percentage of 1.94%. (2) Except the maxillary canines and the mandibular lateral incisors, there was no significant difference between the usage of other same name finished resin teeth (P > 0.05). (3) Among all finished resin teeth, the usage of section B exceeded section A, and the usage of maxillary finished resin teeth exceeded mandibular finished resin teeth (P < 0.05). (4) The use of the complete denture and single complete denture was about 1/3 of the total usage of finished resin teeth. (5) Except the use situation of complete denture and single complete denture, the frequency of simultaneously using mandibular left and right central incisors was the most with the percentage of 81.46%, for the frequency of simultaneously using maxillary left and right canines was 43.26% of the total, which was the lowest.</p><p><b>CONCLUSION</b>There is significant difference in the use frequency of finished resin teeth for different location. For such reason, the manufacturers should produce finished resin teeth pro rata as well as the buyers for their purchase.</p>