Marginal bone loss around tissue level implants in the posterior part of the mandible / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To clarify the related factors of marginal bone loss (MBL) around tissue level implants in the posterior part of the mandible.</p><p><b>METHODS</b>A total of 116 tissue level implants were implanted in the mandibular posterior region of 76 patients. Patients' information, including general characteristics, implant characteristics, implant site characteristics, and prosthesis characteristics, was recorded. Their cone beam computed tomography data were measured immediately after implant placement, 3 months later, and 3 and 12 months after prosthesis loading. The measurement of MBL was conducted by One Volume Viewer software. SPSS 20.0 was used for statistic analysis.</p><p><b>RESULTS</b>Smoking, cortical bone thickness (CBT), collum angle (CA), and implant local sanitation showed significant differences with body mass loss (P<0.05). No significant differences were found among sex, age, length of implant, diameter of implants, implant systems, bone height, prosthesis type, and MBL (P>0.05).</p><p><b>CONCLUSION</b>The risk factors that caused MBL were smoking, thicker CBT, larger CA, and poor implant local sanitation. Among them, poor implant local sanitation had the highest correlation with MBL.</p>

Genome-wide research on fluid shear stress-sensitive signaling pathways in MC3T3-E1 cells / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To explore the differentially expressed genes and related signaling pathways in MC3T3-E1 osteo- blasts in response to suitable fluid shear stress values and action time with cDNA microarrays.</p><p><b>METHODS</b>MC3T3-E1 cells cultured on a cover slip were subjected to fluid shear stress using a parallel plate flow chamber. The harvested RNA was used for microarray hybridization comprising approximately 44 170 genes, as well as for the subsequent real-time quantitative polymerase chain reaction validation of expression levels for selected genes. Microarray results were analyzed by using both GO and Pathway analysis.</p><p><b>RESULTS</b>Microarray analysis indicated that 884 differentially expressed genes were found. Among these genes, 444 were upregulated, whereas 440 were downregulated. The Notch signal and RIG- I -like receptor signaling pathways were involved in the Pathway analysis. GO analysis mainly involved different functional classifications, such as prostaglandin biosynthesis, nitric oxide-mediated signal transduction, calcium mediated signal, and cellular immune response, among others.</p><p><b>CONCLUSION</b>The mechanism underlying the protective effect of fluid shear stress on MC3T3-E1 cells might be related to promoting cell survival- and inhibiting cell apoptosis-related signaling pathways and biological processes.</p>