Precise implant insertion technology for measuring dental implant placement / 华西口腔医学杂志

Identifying the ideal implantation site is important for the long-term stability and effectiveness of follow-up restorations. Implant surgical guide and navigation are used to determine the implantation site in clinic and improve the precision of implantation. However, due to difficulties in digital methods, such as multiple procedures, high cost, and actual accuracy of more than 1 mm, many physicians still prefer to operate with free hand. In preoperative, intraoperative, and postoperative procedures, time-saving and practical methods for implant site evaluation are lacking. In many cases, oral physicians found that the position deviates only by cone beam CT, which was costly to modify the position. In this article, we presented a precise implantation insertion technology that is guided by a measurable technique throughout the implantation application for all implant systems. This method was guided by a dynamic control measuring ruler, which functions together with the measuring and intraoperative locating rulers. The 3D space of the operative area was measured by a measuring ruler prior to operation, and the implant plan and quantitative guidance design were conducted according to the measured and cone beam CT data. The whole implantation process was guided by the dynamic control measuring ruler, and measuring verification results were also considered. This method can realize the quantification of the entire preoperative space analysis, intraoperative precise implantation guidance, and postoperative site measurement and evaluation. This practical technique also helps to adjust the position, improve the implantation accuracy and is suitable in generalizing dental implantation.

Precise tooth preparation technique guided by 3D printing guide plate with quantitative hole / 华西口腔医学杂志

The minimum amount of tooth preparation that can be fully controlled is crucial in achieving long-term, stable, and effective aesthetic restoration, which is also a major difficulty in aesthetic restoration. The tooth preparation can be imple-mented efficiently and accurately through digital technology based on the fixed-deep hole guiding technology. Prior the actual tooth preparation, the technology first designs the virtual contour, layering, and virtual occlusion of the prosthesis on the computer. Then, virtual tooth preparation is carried out by cutting back according to the virtual prosthesis. Next, the virtual drilling operation plan is designed according to the shape of the virtual tooth preparation and the contour of the abutment tooth. Finally, the tooth preparation guide plate is designed and printed in 3D. It realizes the whole process of quantitative and precise guidance of dental preparation, visualizes the restoration space, reduces the clinical operation time, and guarantees the quality of dental preparation. It also promotes the improvement of the teaching quality of digital practical exercises.

Application of 3D printing in aesthetic oral rehabilitation / 华西口腔医学杂志

3D printing technology can be used in prosthodontics to obtain detailed structures. The technique offers a possible supersession for the most conventional restorations technologies. Contemporary aesthetic restorations encounter difficulties in the consistency between the analysis and design stages and the clinical implementation stage. 3D printing transfers aesthetic designs to customize the finial restoration fabrication, which could be an appropriate optimization to the aformentioned problem. Meanwhile, 3D printing technology can be employed to manufacture target restoration space guide (TRS guide), which is a blueprint for the aesthetic ceramic restorations and presents a general functional and aesthetic situation of patients. The guidance provided by TRS guide ensures precision and minimal invasive operation in aesthetic restorations. These new digital technologies have revolutionized aesthetic rehabilitation. This paper introduces the application of 3D printing in aesthetic oral rehabilitation.

Pharmacokinetics of Tongmai granule in acute myocardialischemic model beagles / 中国中药杂志

Tongmai granule (TM) is composed of Puerariae Lobatae Radix (Gegen), Salviae Miltiorrhizae Radix et Rhizoma(Danshen) and Chuanxiong Rhizoma(Chuanxiong). It has been used to treat ischemic cardio-cerebrovascular diseases for decades. For the purpose of elucidating its pharmacodynamic material foundation, the absorption and pharmacokinetic property of TM were investigated in acute myocardial ischemic model beagles. All serum samples were extracted before analysis with ethyl acetate after being acidified by hydrochloric acid. Under negative ESI detection mode, the chromatographic separation was carried out with monolithic C₁₈ column for gradient elution. A simultaneous quantitative analysis was made on 15 polyphenols, including 8 from Gegen, 5 from Danshen and 2 from Chuanxiong, in 8.5 min. The validation result demonstrated the specificity, accuracy and precision of the method in line with the bioanalysis requirements. After TM solution was administrated to acute myocardial ischemic model beagles through duodenum injection, serum samples were collected after 6 h. The quantitative detection proved the prompt absorption of TM, all of the components were detectable in the blood samples 5 min later, and reached peak respectively at 0.18-3.83 h after administration. The components presented large variabilities. The most components were exposed in serum with puerarin and salvianic acid A, followed by 3'-methoxypuerarin, mirificin, and 3'-hydroxypuerarin. The study proves puerarin and salvianic acid A are dominating active components of TM in acute myocardial ischemic model beagles.

Effects of selenium and protein on cardiac morphology and expression of cellular glutathione peroxidase and mitochondrial thioredoxin reductase in rat myocardium / 中国地方病学杂志

Objective To study the effects of selenium(Se) and protein on cardiac morphology and expression of cellular glutathione peroxidase(GPX1 ) and mitochondrial thioredoxin reductase(TR2) in rat myocardial tissue.MethodsSixty healthy weaning male Wistar rats were randomly divided into four groups by two factors two levels factorial design(n =15).Drinking water was divided into two levels of Se-deficient(0 mg/L) and Se-adequate (0.25 mg/L); diet was divided into two levels of protein-deficeient (10％ protein and 0.008 mg/kg Se) and protein-adequate(20％ protein and 0.015 - 0.026 mg/kg Se).The rats were killed after feeding for one year.Pathological changes in myocardial tissues were observed under light microscope.The expression of GPX1 and TR2 in rat myocardial tissue was detected by immunohistochemistry and Western blotting.Results Compared between groups,the difference of the rate of myocardial necrosis in rats was statistically significant(x2 =11.04,P ＜ 0.05),in which Se-deficient protein-deficient group [66.7％ (8/12) ] was significantly higher than Se-adequate proteinadequate group [ 7.1％ ( 1 / 14),x2 - 11.06,P ＜ 0.05 ].GPX 1 positive rates in Se-deficient protein-deficient group,Se-adequate protein-deficient group,Se-deficient protein-adequate group and Se-adequate protein-adequate group were 0(0/12),81.8％(9/11 ),10.0％(1/10) and 100.0％(14/14),respectively,in rat myocardial tissue determined by immunohistochemistry.Of which,Se-adequate protein-deficient group and Se-adequate protein-adequate group were significantly higher than Se-deficient protein-deficient group and Se-deficient protein-adequate group(x2 =12.88,8.14 and 35.89,32.60,all P ＜ 0.05).The positive expression rates of TR2 in rats myocardial tissue of the four groups were 0(0/12),81.8％(9/11),0(0/10) and 100.0％(14/14),respectively.Of which,Se-adequate proteindeficient group and Se-adequate protein-adequate group were significantly higher than Se-deficient protein-deficient group and Se-deficient protein-adequate group (x2 =28.67,18.25 and 35.89,32.60,all P ＜ 0.05).The four groups'results of the overall mean of the relatively value of protein expression of GPX1 in cardiac tissue by Western blotting were 0.87 ± 0.13,1.18 ± 0.13,0.95 ± 0.13 and 1.74 ± 0.23,respectively.Through analysis of variance of factorial design,the effects of Se and protein on protein expression of GPX1 in the heart were statistically significant(F=124.93,43.16,all P＜ 0.05).And there was interaction between them(F=24.10,P＜ 0.05).The four groups'results of the overall mean of the relatively value of protein expression of TR2 in cardiac tissue by Western blotting were 0.63 ± 0.19,0.97 ± 0.24,0.55 ± 0.08 and 1.03 ± 0.31,respectively.Through analysis of variance of factorial design,the effect of Se on expression of TR2 in the heart was statistically significant(F =36.97,P ＜ 0.05).Conclusions Adequate Se and protein diet can increase the levels of GPX1 and TR2 in the heart compared to deficient Se and protein diet,can enhance anti-oxidizing ability,protect the myocardial endothelial cells,reduce degree of myocardial injury,and the combined effects of both are better.

Survey of the awareness of Keshan disease and its influencing factors on the residents in a Keshan disease area, Fuyu County of Heilongjiang Province / 中国地方病学杂志

Objective To explore the inhabitants' knowledge about Keshan disease(KD) in endemic area in Heilongjiang Province and analyze its influencing factors. Methods Yongjin Village, a national KD monitoring site in Fanrong Township of Fuyu County in Heilongjiang Province,was selected as an investigating spot. Specially designed questionnaire was applied in the investigation, which included three aspects, demographical information (gender, age, educational level, etc.), KD-related knowledge survey (KD prevention measures including a healthy diet supplementing selenium, preventing microbial infection, inducers such as climate change, fatigue, cold, mental shock, overeating) and KD controlling measures (take prescribed medicine, dietetic regulation and regular exercise, etc.) Results Seventy-senven point six percent(272/352) knew the disease by the name in the endemic area, while only 29.7% (81/272)and 30.8% (84/272)were aware the preventive measures and inducers , respectively. The awareness rates of KD preventive measures and inducers among the KD patients were 6/17 and 9/17 respectively. The influencing factors of the awareness rate of KD name were gender, vocation and the state of education (χ2 value were 9.838,9.878,12.462, all P < 0.05). However, factors influencing the awareness rates of preventive measures were gender and the state of education(χ2 value were 7.400,20.251, both P < 0.05). Conclusions The awareness rates of KD preventive measures and inducers axe low in the endemic area. The major factors influencing the awareness rate of KD are gender and the educational degree.