[Precise tooth preparation technique guided by 3D printing guide plate with quantitative hole].

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.

[Precise implant insertion technology for measuring dental implant placement].

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.

[Application of 3D printing in aesthetic oral rehabilitation].

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.

Rapid Determination of 30 Polyphenols in Tongmai Formula, a Combination of Puerariae Lobatae Radix, Salviae Miltiorrhizae Radix et Rhizoma, and Chuanxiong Rhizoma, via Liquid Chromatography-Tandem Mass Spectrometry.

Tongmai formula (TMF) is a herbal preparation composed of three traditional Chinese medicinal materials: Puerariae Lobatae Radix (Gegen), Salviae Miltiorrhizae Radix et Rhizoma (Danshen) and Chuanxiong Rhizoma (Chuanxiong). It has been used to treat cardiovascular diseases for decades. To develop a reliable and convenient analytical method for a comprehensive determination of polyphenols in TMF and the ascertainment of their chemical correlations with its herbal components, a method combining high-performance liquid chromatography with electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) was developed and validated for rapid determination of 30 polyphenols in TMF and its three herbal components. The chromatographic separation was carried out on a Chromolith Fastgradient RP-18 endcapped 50-2 column using an optimized gradient elution. Statistical analysis of obtained data demonstrated that the method had a desirable linearity, precision, and accuracy, as well as excellent sensitivity. The obtained results indicated that, among the 30 polyphenols in TMF, 22 originated from Gegen, 6 originated from Danshen, and 2 originated from Chuanxiong. The major polyphenols in TMF have been identified as puerarin, mirificin, salvianolic acid B, salvianic acid A, 3'-hydroxypuerarin, 3'-methoxypuerarin, and salvianolic acid A, with a combined contribution of 19.2% of the preparation. The development and validation of this method will greatly facilitate future pharmacological studies of TMF and its herbal components, as well as polyphenols in cardiovascular therapies.

[Pharmacokinetics of Tongmai granule in acute myocardialischemic model beagles].

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.