Selective laser sintering and performances of porous titanium implants / 华西口腔医学杂志

OBJECTIVE@#This work aims to analyze the mechanical properties and biocompatibility of porous titanium (Ti) implants fabricated by selective laser sintering (SLS) and investigate the promotion of osseointegration by porous titanium implant combined with chitosan (CS)/hydroxyapatite(HA) composite coating.@*METHODS@#Ti6Al4V specimens were prepared, and CS/HA composite coating was fabricated on the surface of a portion of the specimens. The mechanical properties of the samples were observed by scanning electron microscope. MC3T3-E1 cells were cultured in vitro, and their biological properties in vitro were analyzed using live and dead viability cell staining method, methyl thiazolyl tetrazolium (MTT) staining, and alkaline phosphatase (ALP) level detection. The thread implant specimens were implanted in the femoral condyle of rabbits, and biological performance was evaluated in vivo.@*RESULTS@#Quasi-elastic gradient of porous specimens decreased with increasing porosity, and the quasi-elastic gradient were close to cortical and cancellous bone when the porosities were 30% and 70%. The specimens showed good biocompatibility. Combined with CS/HA coating, the implants promoted the proliferation and differentiation of MC3T3-E1 cells and facilitated the entry of bone tissue into pores and good osteogenesis.@*CONCLUSIONS@#The porous titanium implant exhibited favorable mechanical properties and biocompatibility. Combined with CS/HA coating, the implant exhibited bone inducibility, which leads to stable osteogenesis.

Differentially expressed genes and signalling pathways are involved in mouse osteoblast-like MC3T3-E1 cells exposed to 17-β estradiol / 国际口腔科学杂志·英文版

Oestrogen is essential for maintaining bone mass, and it has been demonstrated to induce osteoblast proliferation and bone formation. In this study, complementary DNA (cDNA) microarrays were used to identify and study the expression of novel genes that may be involved in MC3T3-E1 cells' response to 17-β estradiol. MC3T3-E1 cells were inoculated in minimum essential media alpha (α-MEM) cell culture supplemented with 17-β estradiol at different concentrations and for different time periods. MC3T3-E1 cells treated with 10⁻⁸ mol⋅L⁻¹ 17-β estradiol for 5 days exhibited the highest proliferation and alkaline phosphatase (ALP) activity; thus, this group was chosen for microarray analysis. The harvested RNA was used for microarray hybridisation and subsequent real-time reverse transcription polymerase chain reaction (RT-PCR) to validate the expression levels for selected genes. The microarray results were analysed using both functional and pathway analysis. In this study, microarray analysis detected 5403 differentially expressed genes, of which 1996 genes were upregulated and 3407 genes were downregulated, 1553 different functional classifications were identified by gene ontology (GO) analysis and 53 different pathways were involved based on pathway analysis. Among the differentially expressed genes, a portion not previously reported to be associated with the osteoblast response to oestrogen was identified. These findings clearly demonstrate that the expression of genes related to osteoblast proliferation, cell differentiation, collagens and transforming growth factor beta (TGF-β)-related cytokines increases, while the expression of genes related to apoptosis and osteoclast differentiation decreases, following the exposure of MC3T3-E1 cells to α-MEM supplemented with 17-β estradiol. Microarray analysis with functional gene classification is critical for a complete understanding of complementary intracellular processes. This microarray analysis provides large-scale gene expression data that require further confirmatory studies.

Clinical evaluation of masticatory function of implant supported dentures in partially edentulous patients / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the masticatory efficiency of implant supported dentures in partially edentulous patients and the patients' satisfaction on masticatory function.</p><p><b>METHODS</b>The masticatory efficiency of implant supported dentures of 22 patients were tested. The questionnaire of the patients' satisfaction about masticatory function had also been collected. The correlativity of the masticatory efficiency of implant supported dentures and the scores evaluated by patients on masticatory function were analyzed.</p><p><b>RESULTS</b>There were no differences in masticatory efficiency between implant supported denture and non-implant supported denture (natural teeth and porcelain-fused-to-metal fixed bridges). The patients gave high scores to the satisfaction about masticatory function in the questionnaire. But the test results of masticatory efficiency were not related with the scores evaluated by patients.</p><p><b>CONCLUSION</b>The implant supported denture could meet the requirement of normal masticatory function. The patients were satisfactory with the masticatory function of implant supported dentures, but the patients' subjective evaluation about masticatory function was probably influenced by varied factors.</p>

Investigation of the expression of calcitonin receptor mRNA in human osteoclasts on deciduous teeth / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the expression of calcitonin receptor mRNA in the osteoclasts of the resorbing deciduous teeth.</p><p><b>METHODS</b>After fixing the collected deciduous teeth, toluidine blue was performed and tartrate-resistant acid phosphatase (TRAP) staining was used to identify the osteoclasts on the resorbing surface of human deciduous teeth and in situ hybridization of calcitonin receptor mRNA to show its existence.</p><p><b>RESULTS</b>There were a number of TRAP positive osteoclasts on the root surface which showed the expression of calcitonin receptor mRNA.</p><p><b>CONCLUSION</b>On the resorbing surface of human deciduous teeth there are osteoclasts that express calcitonin receptor mRNA, so it is feasible to use this kind of osteoclast to test the effect of external factors on the expression of CTR mRNA.</p>