[Effect of zirconia abutment angulation on stress distribution in the abutment and the bone around implant: a finite element study].

PURPOSE: To investigate the effect of three different zirconia angular abutments on the stress distribution in bone and abutment using three-dimensional finite element analysis, and provide instruction for clinical application. METHODS: Finite element analysis (FEA) was applied to analyze the stress distribution of three different zirconia/titanium angular abutments and bone around implant. RESULTS: The maximum Von Minses stress that existed in abutment, bolt and bone of the angular abutment model was significantly higher than that existed in the straight abutment model. The maximum Von Minses stress that existed in abutment, bolt and bone of the 20 ° angular abutment model was significantly higher than that existed in 15 ° angular abutment model. There was no significant difference between zirconia abutment model and titanium abutment model. CONCLUSIONS: The abutment angulation has a significant influence on the stress distribution in the abutment, bolt and bone, and exacerbates as the angulation increases, which suggest that we should take more attention to the implant orientation and use straight abutment or little angular abutment. The zirconia abutment can be used safely, and there is no noticeable difference between zirconia abutment and titanium abutment on stress distribution.

[Evaluation of N2O inhalation and oral midazolam conscious sedation in pediatric dentistry of children with intellectual disability].

PURPOSE: To evaluate the effect of N2O inhalation and oral midazolam sedation on uncooperative patients with intellectual disability in pediatric dentistry. METHODS: N2O inhalation (35%-50%) and oral midazolam conscious sedation (dosages range: 0.50-0.75 mg/kg) were applied to 67 uncooperative pediatric patients with intellectual disability in outpatient department. The patients were divided into 2 groups: group A (N2O inhalation conscious sedation) and group B(oral midazolam conscious sedation).Treatment results and safety were statistically analyzed by Chi-square test with SPSSl3.0 software package. RESULTS: The mean success rate was 70%. The success rate in group B (75%) was higher than group A (67%). The overall incidence of adverse reactions was 13%(9/67). The adverse reaction rate in group B (25%) was significantly higher than group A (5%, P<0.05). CONCLUSIONS: N2O inhalation and oral midazolam conscious sedation are effective and safe in pediatric dental uncooperative patients with intellectual disability.

Postnatal high-protein diet improves learning and memory in premature rats via activation of mTOR signaling.

PURPOSE: The present study investigated whether a high-protein diet affects spatial learning and memory in premature rats via modulation of mammalian target of rapamycin (mTOR) signaling. METHODS: Pre- and full-term Sprague-Dawley pups were fed a normal (18% protein) or high-protein (30% protein) diet (HPD) for 6 or 8 weeks after weaning. Spatial learning and memory were tested in the Morris water maze at week 6 and 8. The activation of mTOR signaling pathway components was evaluated by western blotting. RESULTS: Spatial memory performance of premature rats consuming a normal and HPD was lower than that of full-term rats on the same diet at 6 weeks, and was associated with lower levels of ribosomal protein S6 kinase p70 subtype (p70S6K) and initiation factor 4E-binding protein 1 (4EBP1) phosphorylation in the hippocampus. Spatial memory was improved in 8-week-old premature rats on an HPD as compared to those on a normal diet. Premature rats on an HPD had p70S6K and 4EBP1 phosphorylation levels in the hippocampus that were comparable to those of full-term rats on an HPD. CONCLUSION: Long-term consumption of a protein-rich diet can restore the impairment in learning and memory in pre-term rats via upregulation of mTOR/p70S6K signaling.

[Clinical study of sinus elevation by hydraulic and implant placement followed by bone graft simultaneously].

PURPOSE: To evaluate the clinical results and technique of sinus membrane hydraulic elevation followed by bone graft and implant placement simultaneously. METHODS: Twenty-five patients were involved in the study (male:15, female: 10, age: 40-62 yrs). The mean residual ridge was (4.25±1.12) mm. Clinical examination were performed and radiographs were taken to evaluated the outcomes. RESULTS: The mean elevated height was (8.50±2.12) mm and 25 implants were placed. Only one implant was lost due to infection 3 weeks after operation because of diabetes. Only minor complications were observed postoperatively in the remaining patients. Twenty-four patients were satisfactorily restored with the follow-up period of 12-18 months. CONCLUSIONS: The technique of sinus membrane hydraulic elevation followed by bone graft and implant placement simultaneously displays minor complication, minimal discomfort and excellent success rate.

[Investigation of status of dental caries in children of primary school in Hangzhou city from 2009 to 2011].

PURPOSE: To investigate the status of dental caries in children of primary school in Hangzhou City from 2009 to 2011. METHODS: The status of dental caries was examined annually from 2009 to 2011, and the caries prevalence, filling rates, mean DMFT/dmft were recorded. SPSS 13.0 software package was used for statistical analysis. RESULTS: From 2009 to 2011, the caries prevalence of deciduous teeth were 49.27%, 48.09% and 48.33%, mean dmft were 2.78, 2.81 and 2.84, filling rates of deciduous teeth were 3.92%, 4.31% and 4.28%, respectively. No significant difference was found in the caries prevalence of temporary teeth, filling rates of temporary teeth, mean dmft. For the permanent teeth, the caries prevalence were 20.24%, 18.48% and 15.85%, mean DMFT were 0.46, 0.41 and 0.33, filling rates were 10.17%, 15.67% and 23.00%, respectively. From 2009 to 2011, the caries prevalence and mean DMFT of permanent teeth was decreased, while the filling rate was increased. CONCLUSIONS: In the past three years, the status of dental caries of permanent teeth shows a remarkable improving tendency in children of primary school in Hangzhou City. However, the status of dental caries of deciduous teeth presents no significant improvement.

Novel docosanoids inhibit brain ischemia-reperfusion-mediated leukocyte infiltration and pro-inflammatory gene expression.

Ischemic stroke triggers lipid peroxidation and neuronal injury. Docosahexaenoic acid released from membrane phospholipids during brain ischemia is a major source of lipid peroxides. Leukocyte infiltration and pro-inflammatory gene expression also contribute to stroke damage. In this study using lipidomic analysis, we have identified stereospecific messengers from docosahexaenoate-oxygenation pathways in a mouse stroke model. Aspirin, widely used to prevent cerebrovascular disease, activates an additional pathway, which includes the 17R-resolvins. The newly discovered brain messenger 10,17S-docosatriene potently inhibited leukocyte infiltration, NFkappaB, and cyclooxygenase-2 induction in experimental stroke and elicited neuroprotection. In addition, in neural cells in culture, this lipid messenger also inhibited both interleukin 1-beta-induced NFkappaB activation and cyclooxygenase-2 expression. Thus, the specific novel bioactive docosanoids generated in vivo counteract leukocyte-mediated injury as well as pro-inflammatory gene induction. These results challenge the view that docosahexaenoate only participates in brain damage and demonstrate that this fatty acid is also the endogenous precursor to a neuroprotective signaling response to ischemia-reperfusion.