The paravertebral lymphatic system is involved in the resorption of the herniated nucleus pulposus and the regression of inflammation associated with disc herniation.

OBJECTIVE: To investigate the role of the paravertebral lymphatic system in the nucleus pulposus herniation (NPH) resorption and the inflammation regression. DESIGN: Clinical specimens (n = 10) from patients with lumbar disc herniation (LDH) were collected, C57BL/6 (n = 84) and conditional Vegfr3 knockout mice (n = 14) were used. Immunofluorescence staining detected lymphatic vessels (LVs) and NP cells. Near-infrared imaging assessed lymphatic drainage function, and Alcian Blue/Orange determined inflammation. RESULTS: Lymphangiogenesis was observed in the herniated NP of patients with LDH, and the proportion of capillary LVs was higher than that of collecting LVs (mean 68.2% [95% confidence interval: 59.4, 77.1]). In NPH mice, NP cells were detected in paravertebral tissue (38.6 [32.0, 45.2]) and draining lymph nodes (dLN) at 4 h (76.9 [54.9, 98.8]). A significant increase of NP cells in dLNs was observed at 24 h (157.1 [113.7, 200.6]). Most of the herniated NP cells were cleared in paravertebral tissue after 1 week (7.5 [4.4, 10.6]), but disc inflammation peaked at 1 week (19.9% [14.7, 25.1]), along with persistent lymphangiogenesis (9.5 [7.2, 11.8]). However, conditional Vegfr3 knockout mice exhibited impaired lymphangiogenesis (5.7 [4.4, 7.0]) and herniated NP cell clearance (6.1 [1.8, 10.5]) during NPH, leading to exacerbated disc inflammation (23.7% [19.3, 28.2]). CONCLUSION: The paravertebral lymphatic system is involved in the NPH resorption and inflammation regression. Promoting lymphangiogenesis may be a novel strategy for facilitating NPH resorption and inflammation regression in patients with LDH.

Study on the mechanism of action of Saposhnikovia divaricata and its key phytochemical on rheumatoid arthritis based on network pharmacology and bioinformatics.

ETHNOPHARMACOLOGICAL RELEVANCE: Saposhnikovia divaricata (Turcz.) Schischk (SD; called "fangfeng" in China) has been widely used in the clinical treatment of rheumatoid arthritis (RA) and has shown well therapeutic effects, but the specific mechanisms of action of its bioactive phytochemicals remain unclear. AIM OF THE STUDY: This study aimed to investigate the molecular biological mechanism of SD in treating RA through a pharmacology-based strategy. The SD-specific core ingredient Prangenidin was screened for further in-depth study. MATERIALS AND METHODS: The bioactive phytochemicals of SD and potential targets for the treatment of RA were screened by network pharmacology, and phytochemicals-related parameters such as pharmacology, and toxicology were evaluated. The protein interaction network was established to screen the core targets, and the correlation between the core targets and RA was further validated by bioinformatics strategy. Finally, molecular docking of core components and corresponding targets was performed. The in vitro experiments were performed to elucidate the regulation of Prangenidin on MH7A cells and on the PI3K/AKT pathway, and the in vivo therapeutic effect of Prangenidin was validated in collagen-induced arthritis (CIA) mice. RESULTS: A total of 18 bioactive phytochemicals and 66 potential target genes intersecting with the screened RA disease target genes were identified from SD. Finally, core ingredients such as wogonin, beta-sitosterol, 5-O-Methylvisamminol, and prangenidin and core targets such as PTGS2, RELA, and AKT1 were obtained. The underlying mechanism of SD in treating RA might be achieved by regulating pathways such as PI3K/AKT, IL-17 pathway, apoptosis, and multiple biological processes to exert anti-inflammatory and immunomodulatory effects. Molecular docking confirmed that all core ingredients and key targets had great docking activity. Prangenidin inhibited viability, migration, and invasion, and induced apoptosis in MH7A cells. Prangenidin also reduced the production of IL-1ß, IL-6, IL-8, MMP-1, and MMP-3. Molecular analysis showed that Prangenidin exerts its regulatory effect on MH7A cells by inhibiting PI3K/AKT pathway. Treatment with Prangenidin ameliorated synovial inflammation in the joints of mice with CIA. CONCLUSION: Our findings provide insights into the therapeutic effects of SD on RA, successfully predicting the effective ingredients and potential targets, which could suggest a novel theoretical basis for further exploration of its molecular mechanisms. It also revealed that Prangenidin inhibited viability, migration, invasion, cytokine, and MMPs expression, and induced apoptosis in RA FLSs via the PI3K/AKT pathway.

[Robot-assisted PVP for the treatment of osteoporotic fractures of the upper thoracic vertebra].

OBJECTIVE: To investigate the clinical effect of "Tianji" orthopedic robot-assisted percutaneous vertebro plasty(PVP) surgery in the treatment of upper thoracic osteoporotic fracture. METHODS: A retrospective analysis was performed on 32 patients with upper thoracic osteoporotic fracture who underwent PVP surgery in Shenzhen Hospital of Traditional Chinese Medicine from August 2016 to June 2022. There were 8 males and 24 females, ranging in age from 58 to 90 years old, with a mean of (67.75±12.27) years old. Fifteen patients were treated with robot-assisted PVP surgery (robot group), including 3 males and 12 females, with an average age of (68.5±10.3) years. Fracture location:1 case of T2 fracture, 1 case of T3 fracture, 3 cases of T4 fracture, 3 cases of T5 fracture, and 7 cases of T6 fracture. The follow-up period ranged from 1.0 to 3.0 months, with a mean of (1.6±0.7) months. Seventeen patients underwent routine PVP surgery (conventional group), including 5 males and 12 females, with an average age of (66.8±11.6) years old. Fracture location:1 case of T1 fracture, 5 cases of T4 fracture, 2 cases of T5 fracture and 9 cases of T6 fracture. The follow-up period ranged from 0.5 to 4.0 months, with a mean of (1.5±0.6) months. Preoperative and postoperative visual analogue scale(VAS) and Oswestry disability index(ODI) scores were compared between the two groups, and the number of punctures, perspective times, operation time, intraoperative blood loss, bone cement distribution, bone cement leakage, and intraoperative radiation dose were compared between the two groups. RESULTS: Number of punctures times, perspective times, operation time, intraoperative blood loss, bone cement distribution, bone cement leakage and intraoperative radiation dose in the robot group were all significantly better than those in the conventional group(P<0.05). VAS of 2.03±0.05 and ODI of (22.16±4.03) % in the robot group were significantly better than those of the robot group before surgery, which were (8.67±0.25) score and (79.40±7.72)%(t=100.869, P<0.001;t=25.456, P<0.001). VAS of 2.17±0.13 and ODI of (23.88±6.15)% in the conventional group were significantly better than those before surgery, which were (8.73±0.18) score and (80.01±7.59)%(t=121.816, P<0.001;t=23.691, P<0.001). There was no significant difference in VAS and ODI between the two groups after operation (t=-3.917, P=0.476;t=-0.922, P=0.364). CONCLUSION: Robot-assisted PVP in the treatment of upper thoracic osteoporotic fractures can further improve surgical safety, reduce bone cement leakage, and achieve satisfactory clinical efficacy.

Treatment of degenerative lumbar scoliosis using transforaminal lumbar interbody fusion based on the concept of intervertebral correction.

PURPOSE: The study aimed to examine the outcomes of posterior approach transforaminal lumbar interbody fusion (TLIF) in the treatment of degenerative lumbar scoliosis (DLS) based on the concept of intervertebral correction. METHODS: A retrospective analysis was performed on 76 surgical patients (36 males and 40 females) who underwent posterior TLIF and internal fixation based on the concept of intervertebral correction in Shenzhen Traditional Chinese Medicine Hospital from February 2014 to March 2021.The operation duration, intraoperative blood loss, incision length, and complications were recorded. Clinical efficacy was evaluated preoperatively and postoperative time points through the visual analog scale (VAS) and the Oswestry disability index (ODI). The changes in the coronal scoliosis curve (Cobb angle), coronal balance distance (CBD), the sagittal vertical axis (SVA), lumbar lordosis (LL), and pelvic tilt angle (PT) were assessed perioperatively at the last follow-up. RESULTS: All patients successfully underwent the operation. The average operation duration was 243.81 ± 35.35 (220 - 350) min; the average intraoperative blood loss was 836.27 ± 50.28 (700 - 2500) mL; the average incision length was 8.30 ± 2.33 (8 - 15) cm. The total complication rate was 18.42% (14/76). The VAS score of low back pain, lower extremity pain, and ODI score of patients at the last follow-up was significantly improved compared with those before the operation (P < 0.05). At the last follow-up, the Cobb Angle, CBD, SVA, and PT of patients were significantly lower than those before the operation (P < 0.05), and LL was higher than those before the operation (P < 0.05). CONCLUSION: TLIF based on the concept of intervertebral correction for the treatment of DLS may provide favourable clinical outcomes.

[Characterization and osteogenic activity of FSP-modified TiNbTaZr/Zn].

PURPOSE: To investigate whether Ti-35Nb-2Ta-3Zr/Zn (TNTZ/Zn) composite material processed by friction stir processing has osteogenic activity. METHODS: Zn was added to the surface of TNTZ alloy by friction stir processing. The control group was TNTZ(TNTZ without FSP), the experimental groups was FSP(FSP without Zn), TNTZ/Zn-0.5 (0.5 mm pre-made holes) and TNTZ/Zn-1(1 mm pre-made holes). Surface characterization was performed by scanning electron microscope and X-ray diffraction. Alkaline phosphatase(ALP) activity of co-cultured rat bone marrow stromal stem cells (BMSCs) and COL-1α, OPN and OCN gene expression were detected by real-time quantitative PCR. SAS version 8.2 software was used for data analysis. RESULTS: Zn nanoparticles on the surface of the TNTZ/Zn-1 group were distributed homogeneously, with a diameter range of 70-80 nm. Compared with TNTZ group, the activity of ALP in TNTZ/Zn-0.5 and TNTZ/Zn-1 groups was up-regulated (P<0.05 and P<0.01). Compared with TNTZ group, ALP, COL-1α, OPN and OCN gene expression increased in TNTZ/Zn-0.5 and TNTZ/Zn-1 group, and the difference was statistically significant (P<0.05). CONCLUSIONS: Through FSP, Zn can be successfully integrated onto the surface of TNTZ alloy with nano-scale microstructures. TNTZ/Zn composite material can effectively induce bone formation and is a potential implant material.

Appetite Suppression and Interleukin 17 Receptor Signaling Activation of Colonic Mycobiota Dysbiosis Induced by High Temperature and High Humidity Conditions.

It is known that the microbiome affects human physiology, emotion, disease, growth, and development. Most humans exhibit reduced appetites under high temperature and high humidity (HTHH) conditions, and HTHH environments favor fungal growth. Therefore, we hypothesized that the colonic mycobiota may affect the host's appetite under HTHH conditions. Changes in humidity are also associated with autoimmune diseases. In the current study mice were fed in an HTHH environment (32°C ± 2°C, relative humidity 95%) maintained via an artificial climate box for 8 hours per day for 21 days. Food intake, the colonic fungal microbiome, the feces metabolome, and appetite regulators were monitored. Components of the interleukin 17 pathway were also examined. In the experimental groups food intake and body weight were reduced, and the colonic mycobiota and fecal metabolome were substantially altered compared to control groups maintained at 25°C ± 2°C and relative humidity 65%. The appetite-related proteins LEPT and POMC were upregulated in the hypothalamus (p < 0.05), and NYP gene expression was downregulated (p < 0.05). The expression levels of PYY and O-linked ß-N-acetylglucosamine were altered in colonic tissues (p < 0.05), and interleukin 17 expression was upregulated in the colon. There was a strong correlation between colonic fungus and sugar metabolism. In fimo some metabolites of cholesterol, tromethamine, and cadaverine were significantly increased. There was significant elevation of the characteristic fungi Solicoccozyma aeria, and associated appetite suppression and interleukin 17 receptor signaling activation in some susceptible hosts, and disturbance of gut bacteria and fungi. The results indicate that the gut mycobiota plays an important role in the hypothalamus endocrine system with respect to appetite regulation via the gut-brain axis, and also plays an indispensable role in the stability of the gut microbiome and immunity. The mechanisms involved in these associations require extensive further studies.

Curcumol Alleviates the Inflammation of Nucleus Pulposus Cells via the PI3K/Akt/NF-κB Signaling Pathway and Delays Intervertebral Disk Degeneration.

BACKGROUND: Intervertebral disk degeneration (IVDD) is closely associated with inflammatory environments. Curcumol has been shown to alleviate inflammation in various disease models, but its effects on IVDD remain unclear. In this study, we sought to determine the mechanism of curcumol in tumor necrosis factor (TNF)-α-induced nucleus pulposus cells and a mouse IVDD model. METHODS: Nucleus pulposus cells were pretreated with curcumol and then exposed to TNF-α. Cell viability was analyzed using CCK-8, and the messenger ribonucleic acid and protein levels of inflammatory cytokines and PI3K/Akt/NF-κB-related signaling molecules were detected using real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and western blotting. The mouse IVDD model was established by puncturing the C6/7 level of the caudal spine, and then it was treated with curcumol after surgery. Alcian blue/orange G staining was performed to evaluate the severity of intervertebral disk damage, and immunohistochemistry was performed to detect the expression of TNF-α. Toxicologic effects of curcumol were measured by performing hematoxylin-eosin staining and enzyme-linked immunosorbent assay. RESULTS: Curcumol reduced IL-1ß, IL-6, and TNF-α production in NPCs, and the phosphorylation of proteins in the PI3K/Akt/NF-κB signaling pathway was also decreased. The PI3K/Akt/NF-κB-related signaling molecules decreased when TNF-α-induced NPCs were treated with a PI3K inhibitor; however, curcumol did not reverse these effects. In vivo, curcumol ameliorated the progression of IVDD at the early stage and did not exert toxicologic effects. CONCLUSIONS: These results suggest a potential therapeutic use of curcumol to alleviate inflammation via the PI3K/Akt/NF-κB signaling pathway and delay the progression of IVDD.

A novel and injectable strontium-containing hydroxyapatite bone cement for bone substitution: A systematic evaluation.

Reconstruction of bone defects is still a challenge. In this study, we developed and systematically evaluated a novel injectable strontium-containing hydroxyapatite (Sr-HA) bone cement in which Sr-HA powder included 5% Sr and was mixed with a setting liquid that included 5% potassium citrate. This Sr-HA cement was mainly composed of HA and α-tricalcium phosphate (TCP) and exhibited favorable injectability (100%), setting times (the initial setting time was 240 s and the final setting time was 420 s), compressive strength (73.4 MPa), maximal load and maximum bending stress, and excellent radiopacity. In addition, the Sr-HA cement also had excellent biocompatibility that exhibited low cytotoxicity for cell proliferation and no obvious disturbing effect on the osteogenic differentiation of periodontal ligament stem cells (DLSCs) and dental pulp stem cells (DPSCs). However, the Sr-HA cement could slightly promote the osteogenic differentiation of MC3T3 cells, which also implied that it would promote osseointegration between the cement and surrounding bone but would not obviously disturb the biological behavior of DLSCs and DPSCs. An in vivo study further confirmed that Sr-HA cement exhibited favorable osseointegration with the maxilla and tibia. All these findings implied that the novel Sr-HA cement was a suitable bone substitution for bone defects.

A Review on Design and Mechanical Properties of Additively Manufactured NiTi Implants for Orthopedic Applications.

NiTi alloy has a wide range of applications as a biomaterial due to its high ductility, low corrosion rate, and favorable biocompatibility. Although Young's modulus of NiTi is relatively low, it still needs to be reduced; one of the promising ways is by introducing porous structure. Traditional manufacturing processes, such as casting, can hardly produce complex porous structures. Additive manufacturing (AM) is one of the most advanced manufacturing technologies that can solve impurity issues, and selective laser melting (SLM) is one of the well-known methods. This paper reviews the developments of AM-NiTi with a particular focus on SLM-NiTi utilization in biomedical applications. Correspondingly, this paper aims to describe the three key factors, including powder preparation, processing parameters, and gas atmosphere during the overall process of porous NiTi. The porous structure design is of vital importance, so the unit cell and pore parameters are discussed. The mechanical properties of SLM-NiTi, such as hardness, compressive strength, tensile strength, fatigue behavior, and damping properties and their relationship with design parameters are summarized. In the end, it points out the current challenges. Considering the increasing application of NiTi implants, this review paper may open new frontiers for advanced and modern designs.

3D Printing Technologies in Metallic Implants: A Thematic Review on the Techniques and Procedures.

Additive manufacturing (AM) is among the most attractive methods to produce implants, the processes are very swift and it can be precisely controlled to meet patient's requirement since they can be produced in exact shape, dimension, and even texture of different living tissues. Until now, lots of methods have emerged and used in this field with diverse characteristics. This review aims to comprehensively discuss 3D printing (3DP) technologies to manufacture metallic implants, especially on techniques and procedures. Various technologies based on their main properties are categorized, the effecting parameters are introduced, and the history of AM technology is briefly analyzed. Subsequently, the utilization of these AM-manufactured components in medicine along with their effectual variables is discussed, and special attention is paid on to the production of porous scaffolds, taking pore size, density, etc., into consideration. Finally, 3DP of the popular metallic systems in medical applications such as titanium, Ti6Al4V, cobalt-chromium alloys, and shape memory alloys are studied. In general, AM manufactured implants need to comply with important requirements such as biocompatibility, suitable mechanical properties (strength and elastic modulus), surface conditions, custom-built designs, fast production, etc. This review aims to introduce the AM technologies in implant applications and find new ways to design more sophisticated methods and compatible implants that mimic the desired tissue functions.

TC4/Ag Metal Matrix Nanocomposites Modified by Friction Stir Processing: Surface Characterization, Antibacterial Property, and Cytotoxicity in Vitro.

Numerous antibacterial biomaterials have been developed, but a majority of them suffer from poor biocompatibility. With the purpose of reducing biomaterial-related infection and cytotoxicity, friction stir processing (FSP) was employed to embed silver nanoparticles (Ag NPs) in a Ti-6Al-4V (TC4) substrate. Characterization using scanning electron microscopy, transmission electron microscopy, and three-dimensional atom probe tomography illustrates that NPs are distributed more homogeneously on the surface of TC4 as the groove depth increases, and silver-rich NPs with a size from 10 to 20 nm exist as metallic silver diffused into the substrate, where the silver content is 4.3-5.6%. Electrochemical impedance spectroscopy shows that both FSP and the addition of silver have positive effects on corrosion resistance. The modified samples effectively inhibit both Staphylococcus aureus and Escherichia coli strains and slightly reduce their adhesion while not displaying any cytotoxicity to bone mesenchymal stem cells in vitro. The antibacterial effect is independent of Ag-ion release and is likely due to the number of embedded silver NPs on the surface, which directly contact and subsequently destroy the cell membrane. Our study shows that the TC4/Ag metal matrix nanocomposite is a potential infection-related biomaterial and that embedding Ag NPs tightly on a biomaterial surface is an effective strategy for striking a balance between the antibacterial effect and biocompatibility, providing an innovative approach for accurately controlling the cytotoxicity of infection-related biomaterials.

[Experimental evaluation of the spraying disinfection efficiency on dental models].

PURPOSE: To evaluate the disinfect effect after spraying a new kind of disinfectant on the dental plaster models. METHODS: The germ-free plaster samples, which were smeared with bacteria compound including Staphylococcus aureus, Escherichia coli, Saccharomyces albicans, Streptococcus mutans and Actinomyces viscosus were sprayed with disinfectants (CaviCide) and glutaraldehyde individually. In one group(5 minutes later) and another group(15 minutes later), the colonies were counted for statistical analysis after sampling, inoculating, and culturing which were used for evaluation of disinfecting efficiency. ANOVA was performed using SPSS12.0 software package. RESULTS: All sample bacteria were eradicated after spraying disinfectants(CaviCide) within 5 minutes and effective bacteria control was retained after 15 minutes. There was significant difference between the disinfecting efficiency of CaviCide and glutaraldehyde. CONCLUSIONS: The effect of disinfection with spraying disinfectants (CaviCide) on dental models is quick and effective.

[The effect of different retention pin on the shear force of anterior base plate].

PURPOSE: The purpose of this study was to compare the effect of enhancement by different shape retention nails on the anterior region resin denture base through shear strength measurements. METHODS: 24 specimens with the same size and thickness were divided into 4 groups by the shape of retention nails. Three experimental groups of the resin denture base specimen were placed a retention nail with different shape, Δtype, V type and I type. Another group of 6 specimens without nail was used as control. All the samples' shear forces were tested by universal mechanical testing machine, and the data was statistically analyzed by SPSS 10.1 software package. RESULTS: The shear forces of Δtype group, V type group, the I type group and control group, were respectively (326.80±64.17) N, (225.07±31.76) N, (182.85±15.18) N, and (116.67soil 4.35) N. According to the statistical results, the difference of shear forces had no significant difference (P>0.05) between I type and V type, although the shear forces of these two groups were significantly greater than the control group (P<0.05). The shear forces of Δ type group were significantly greater than the other three groups (P<0.05). CONCLUSIONS: The retention nail of Δ shape can significantly enhance the anti-shear ability of resin denture base.

[Fabrication and physical properties of porous individual beta-TCP scaffold to reconstruct residual alveolar ridge in dog].

PURPOSE: To fabricate porous individual beta-tricalcium phosphate scaffold and test its properties in dog. METHODS: A model of residual alveolar ridge in mandible of a dog was made and CT scanned after 3 months.The data of CT was transformed to 3-D format by MIMICS 7.0 and was made to resin model by rapid prototype technique.The residual alveolar ridge was reconstructed using silicon rubber, and its impression was made.Porous individual beta-tricalcium phosphate scaffold and 5 samples were fabricated for precision and properties test.Porosity, water absorbing capacity and compressive strength of samples were tested with crystalling phase and pore structure were analysed by XRD and scanning electron microscope. RESULTS: We successfully fabricated a scaffold which fit the resin model well and consisted of beta-TCP. Its porosity was 74%,water absorbing capacity was 48%,compressive strength was 4 MPa,diameter of pore was 150 to 400 microm,connecting diameter was 40 microm. CONCLUSIONS: We can fabricate individual beta-TCP scaffold which fit the model well by combination of traditional method and rapid prototype technique.Supported by Shanghai Leading Academic Discipline Project(Grant No.T0202).

[Advances in research and application of beta-tricalcium phosphate, collagen and beta-tricalcium phosphate/collagen composite in bone tissue engineering].

Bone defects in oral and maxillofacial region was a common problem. To repair the defect, bone grafts including autograft, allograft and artificial bone graft were used in clinic despite of their disadvantages. Nowadays, bone tissue engineering has become a commonly used method to repair bone defect. This paper reviewed the application of beta-TCP, collagen and beta-TCP/collagen composite in bone tissue engineering. It was concluded that beta-TCP/collagen composite was a promising materials in bone tissue engineering.

[Culture and characteristics of porcine dental papilla cells (pDPCs) in vitro].

PURPOSE: To culture porcine dental papilla cells (pDPCs) and to study the cytobiological characteristics of the cells in vitro. METHODS: Dental papillae were collected from postnatal (1-3 days) pigs, then the pDPCs were isolated and cultured through the method of enzyme-digestion. Vimentin and cytokeratin (CK) were used to demonstrate the cells' mesenchymal derivation. Collagen I collagen III and dentin sialoprotein (DSP) were detected in pDPCs by immunohistochemistry. RESULTS: The pDPCs were well cultured in the medium of DMEM/F12 containing 10% FBS in vitro. Vimentin was positively expressed in pDPCs but CK was not. Collagen I, collagen III, and DSP were all positive in the plasma of the pDPCs. CONCLUSIONS: The pDPCs were successfully isolated and cultured in vitro. The pDPCs come from mesenchymal tissue and have the capability of synthesizing extracellular matrix (collagen I, collagen III, and DSP) of dentin-pulp complex. This study indicated that the pDPCs may have the potential to be used as seed cell in regeneration of dentin-pulp complex.

[Comparison of the cytotoxicity in vitro among six types of nano-silver base inorganic antibacterial agents].

OBJECTIVE: To evaluate the biocompatibility of nano-silver base inorganic antibacterial agents and compare the cytotoxicity in vitro among six types of nano-silver base inorganic antibacterial agents. METHODS: FUMAT T200-4, HN300, Novaron, Kangwang, MOD and SR1000 were diluted to different concentrations, such as 100 g/L, 50 g/L, 25 g/L and 12.5 g/L. The cytotoxicity in vitro of these agents on rat's fibroblast was assayed with MTT method. And the grades of cytotoxicity were compared. RESULTS: High concentrations of nano-silver base inorganic antibacterial agents had cytotoxic effects on rat's fibroblasts L-929. As the concentration decreased, the cytotoxicity decreased. No cytotoxic effects were observed at or below the concentration of 25 g/L. FUMAT T200-4, Kongwang and SR1000, with the carrier of phosphate zirconium, had less cytotoxity than the others. CONCLUSIONS: Nano-Silver base inorganic antibacterial agents, such as FUMAT T200-4, Kangwang, SR1000, have good biocompatibility. And they have the possibility of clinical application. The safe concentration of these agents is at or below 25 g/L.

[The use of computer-aided colorimeter in porcelain-fused-to-metal (PFM) crowns among patients with special colored teeth].

PURPOSE: To evaluate the roll of ShadeEye-NCC, a computer-aided colorimeter, in Porcelain-Fused-to-Metal crowns among patients with special colored Teeth. METHODS: The first step was to choose the proper patients. The next was to use the colorimeter to measure the base shade of tooth and fabricate the PFM crowns according to the recipe given by the colorimeter. At last, the effects of the PFM crowns were evaluated subjectively by patients and doctor. RESULTS: The satisfaction rates of patients and doctor were 83.7% and 81.4% respectively, there was no significant difference between the two rates. CONCLUSIONS: The computer-aided colorimeter can offer good base shade recipe for fabricating PFM crowns of patients with special colored teeth.

[In vitro study on the cytotoxicity of strontium substituted hydroxyapatite].

OBJECTIVE: To evaluate the cytotoxicity of strontium substituted hydroxyapatite. METHODS: Cell Relative Growth Rate(RGR) method, MTT assay and Flow Cytometry(FCM) method were used, and the strontium substituted hydroxyapatite contained different strontium concentration(0%,1%,5%,10%,100%). RESULTS: It was found that there's no apparent cytotoxicity of all the strontium substituted hydroxyapatite,but the cytotoxicity increased as the strontium concentration raised. As the FCM method appeared, there was no apparent difference between the pure hydroxyapatite and 1%,5% strontium substituted hydroxyapatite. CONCLUSION: Strontium substituted hydroxyapatite has good biocompatibility, and 10%,100% strontium substituted hydroxyapatite has weak cytotoxicity.