Objective:To study the perioral soft tissue characteristics of the subjects with ClassⅡDivisionⅠand various vertical pat-terns. Methods:Lateral cephalograms of 90 adults ( half men, half women) were divided into 3 groups based on GoGn-SN angle:low angle, normal angle and high angle(n=30). The perioral soft tissues were measured and compared for the determination of the vertical skeletal variables influencing soft tissue characteristics. Results: The subjects with low angle showed significantly smaller values than those with high angle for basic lower lip thickness and lower lip length(P<0. 05). Most measurements of soft tissue thickness were greater in men than in women in all groups, especially for basic upper lip thickness and upper lower lip thickness(P<0. 05). Conclu-sion:Orthodontists need to pay more attention to the differences of perioral soft tissue in the subjects with various vertical patters to ob-tain balance of the facial harmony in orthodontic treatment.

Objective: To explore the best indication for veneers and to improve the repair success rate by investigating the effects of different types of dentin exposure on the shear bond strength of cast porcelain veneers with two new veneer bonding systems. Methods: Bonding interfaces with 0%, 25%, 50%, 75% and 100% dentin exposure were designed and fabricated. The bonding interfaces were divided into groups A, B, C, D and E. Sixty 4-mm x 4-mm x 2-mm (length x width x thickness) ceramic specimens were bonded by using two bonding systems, The VN-A, VN-B, VN-C, VN-D and VN-E groups were bonded with Variolink bonding system, and the PF-A, PF-B, PF-C, PF-D and PF-E were bonded with Panavia F bonding system (six specimens per group). The bonded specimens were stored in a distilled water bath at (37 + 1)℃ for 24 hours. The fracture load was tested by a universal testing machine, and the fracture type was observed by scanning electron microscopy. Results : The VN-A (25.14 ± 3.40 MPa), VN-B (22.54 ± 4.48 MPa), VN-C (19.59 ± 2.21 MPa), PF-A (20.61 ± 2.42 MPa), PF-B (18.08 ± 4.11 MPa), PF-C (17.06 ± 2.29 MPa) groups’ shear bond strengths were above 17 MPa. The VN-A group had the highest shear bond strength value. There was no statistically significant difference in bond strength between the VN-A group and the VN-B and VN-C groups (P > 0.05) or the PF-A and PF-B groups (P > 0.05); however, the differences between VN-A and the VN-D and VN-E groups (P < 0.05) and between PF-A and the PF-C and PF-D and PF-E groups (P < 0.05) were statistically significant. The differences between the VN-A group and PF-A group (P < 0.05) were statistically significant. The fracture modes of the VN-A, PF-A, VN-B, PF-B, and VN-C groups mainly included resin cement cohesive failure and mixed failure; the VN-D, VN-E, PF-C, PF-D and PF-E groups were dominated by interface failure and mixed failure. Conclusion When the dentin exposure is greater than 50%, the shear bond strength value of the veneer was significantly affected. To obtain a better clinical effect, the dentin exposure rate should be less than 25%.

Porphyromonas gingivalis peptidylarginine deiminase (PPAD), an isoenzyme of animal endogenous peptidylarginine deaminase, is secreted by the Por system and catalyzes the citrullination of arginine. Recent studies have found that PPAD can affect the formation of Porphyromonas gingivalis biofilm and reduce the body′s immune defense function, which is related to the occurrence and development of many diseases such as periodontal diseases and rheumatoid arthritis. In this paper, we reviewed the molecular characteristics of PPAD, including the genetic and functional characteristics, as well as the mechanisms related to the inflammatory and autoimmune diseases. We also pointed some issues that should be pay attention to in the further study.

Objective:To explore the performance of the commonly used whole blood C-reactive protein (CRP) detection systems and give related recommendation on the performance requirements of detection systems.Methods:A total of 7 540 venous blood samples from 26 maternal, child and children′s hospitals were collected to conduct this multi-center study on the analytical performance of 5 commonly used whole blood CRP detection systems from March to April in 2019. The blank check, carryover, repeatability, intermediate precision, linearity, sample stability, influence of hematocrit/triglyceride/bilirubin, comparison with SIEMENS specific protein analyzer and trueness were evaluated. The 5 systems included BC-5390CRP autohematology analyzer, AstepPLUS specific protein analyzer, Ottoman-1000 Automated Specific Protein POCT Workstation, i-CHROMA Immunofluorometer equipment Reader and Orion QuikRead go detecting instrument. The 5 systems were labeled as a, b, c, d and e randomly.Results:Within the 5 systems, all values of blank check were less than 1.00 mg/L, the carryovers were lower than 1.00%. The repeatability of different ranges of CRP concentrations including 3.00-10.00, 10.00-30.00 and>30.00 mg/L were less than 10.00%, 6.00% and 5.00%, respectively, and the intermediate precision was less than 10.00%. The linearity correlation coefficients of the 5 systems were all above 0.975, while the slope was within 0.950-1.050. Whole blood samples were stable within 72 hours both at room temperature (18-25 ℃) and refrigerated temperature (2-8 ℃). The CRP results were rarely influenced by high triglyceride or bilirubin, except for the immmunoturbidimetric test based on microparticles coated with anti-human CRP F(ab) 2 fragments. When triglyceride was less than 15.46 mmol/L, the deviation of CRP was less than 10.00%. When bilirubin was less than 345.47 μmol/L, the deviation of CRP was less than 10.00%. CRP was more susceptible to Hct on the systems without Hct correction. The deviation of CRP between different Hct dilution concentration and 40% dilution concentration can reach as high as 67.48%. The correlation coefficients ( r) of 5 systems were all more than 0.975 in the range of 0-300.00 mg/L compared with Siemens specific protein analyzer. All systems passed the trueness verification using the samples with specified values of 12.89 and 30.60 mg/L. Conclusion:The performance of 5 systems can basically meet the clinical needs, but it is suggested that the whole blood CRP detection system without automatic Hct correction should be modified manually.

BACKGROUND:Three-dimensional(3D)printing is an emerging technology in the field of dentistry.It utilizes a layer-by-layer manufacturing technique to create scaffolds suitable for periodontal tissue engineering applications.Tissue scaffolds produced through 3D printing can possess controlled characteristics,including internal structure,porosity,and interconnectivity,making it an ideal strategy for periodontal tissue engineering. OBJECTIVE:To review the applications of 3D printed scaffolds in periodontal regeneration. METHODS:English search terms were"3D printing,periodontal tissue engineering,additive manufacturing,regenerative medicine,bioengineering,scaffold,bioprinting,periodontitis".Chinese search terms were"3D printing,additive manufacturing,periodontal tissue engineering,scaffolds,bio-inks,bioprinting,tissue engineering".Relevant literature published from 2000 to 2023 in PubMed and CNKI databases was retrieved and included in the review. RESULTS AND CONCLUSION:Over the past few decades,3D printing technology has made significant progress and breakthroughs in tissue engineering and biomedical fields.3D printing technology can provide highly personalized treatment programs,improve the suitability and therapeutic effect of therapeutic stents,and has broad application prospects in periodontal tissue engineering.In periodontal tissue engineering,3D printing applications can better mimic the complex structures of biological tissues and manufacture biocompatible scaffold materials with suitable mechanical and rheological properties.The layer-by-layer construction of tissue engineering scaffolds through 3D printing not only enables the creation of precise and intricate scaffold models for personalized treatment of periodontal disease but also facilitates the incorporation of complex microstructures and channels within the scaffolds to promote cell growth and tissue regeneration.