Accuracy of photogrammetry and conventional impression techniques for complete-arch implant rehabilitation: an in vitro comparative study / 中华口腔医学杂志

Objective: To compare the accuracy of photogrammetry and conventional impression techniques for complete-arch implant rehabilitation. Methods: An edentulous maxillary stone cast containing 8 screw-retained implant abutment replicas was derived from a 74-year-old male patient who visited the Department of Dental Implant Center, Capital Medical University School of Stomatology in September 2019. The stone cast was copied through the open-tray splinted impression, and the copied cast was used as the master cast for this study. The abutment-level impressions of master cast were made by photogrammetry (PG) and the conventional impression technique (CNV) by one attending doctor. Group PG: after which scan bodies were connected to each implant replica, a photogrammetry system was used to obtain digital impressions of the master cast (n=10); Group CNV: conventional open-tray splinted impression technique was performed to fabricate conventional definitive casts (n=10). After connecting the scan bodies onto each implant replicas, the master cast and the 10 definitive casts from group CNV were digitized with a laboratory reference scanner. All data of group PG, group CNV and mater cast were saved as ".stl" files. For all test scans and reference scan, the three-dimensional information of scan bodies were converted to implant abutment replicas using a computer aided design software (Exocad). The data of the group PG and the group CNV were respectively registered with the reference data (trueness analysis) and pairwise within group (precision analysis) for accuracy evaluation in a three-dimensional analysis software (Geomagic Control X). Results: The trueness and precision of group PG [(17.33±0.34) and (2.50±0.79) μm ] were significantly statistically better than those of group CNV [(24.30±4.16) and (26.12±4.54) μm] respectively (t=-5.29 and -34.35, P<0.001). Conclusions: For complete-arch implant abutment-level impression, photogrammetry produces significantly better accuracy than conventional impression technique.

Effect of Tongluo recipe on leptin and insulin in rat model of type 1 diabetes mellitus / 第二军医大学学报

Objective To study the effect of Tongluo recipe on leptin and insulin in rat model of type 1 diabetes mellitus. Methods A total of 30 adult male SD rats were equally randomized into the following 3 groups: normal control group, diabetes mellitus group and Tongluo recipe group. SD rats were administered intraperitoneally with STZ (60 mg/kg) to induce the model of type 1 diabetes mellitus. The rats in Tongluo recipe group were administered intragastrically with Tongluo recipe (1.0g·kg-1·d-1), and the other two groups were administered intragastrically with double distilled water in the same dosage. The body weight, white adipose tissue weight, fasting blood glucose, fasting insulin, total cholesterol, triglyceride, free fatty acid, and leptin levels were compared between each group 8 weeks later. The expression of leptin mRNA in white adipose tissue was examined. Results Compared with diabetes mellitus group, the body weight,fasting insulin, and leptin were significantly higher (P<0.05or0.01) in the Tongluo recipe group, the levels of fasting blood glucose, total cholesterol, and free fatty acid were significantly lower (P<0.05or0.01) in Tongluo recipe group, and the expression of leptin mRNA was significantly higher (P<0.05) in the Tongluo recipe group. Conclusion Tongluo recipe may correct the disturbance in the lipid and glucose metabolism by improving the low leptin and insulin levels in diabeticrats.

Adipokine signal transduction pathways and its secretion in obese patients / 第二军医大学学报

Adipose tissue is traditionally regarded only as an energy storage and a filler between tissues/organs. However, other important functions of adipose tissue begin to be discovered with the discovery of adipokines. Adipose tissue is also an endocrine organ, which secrets different kinds of adipokines, affecting the target organs through autocrine, paracrine and the blood circulation, and playing important roles in the pathogenesis of the obesity, insulin resistance and type 2 diabetes mellitus. This paper reviews the signal transduction pathways of adiponectin, leptin and resistin, and their changes during obesity.