Identification of ROS and KEAP1-related genes and verified targets of α-hederin induce cell death for CRC.

In this study, we analyzed and verified differentially expressed genes (DEGs) in ROS and KEAP1 crosstalk in oncogenic signatures using GEO data sets (GSE4107 and GSE41328). Multiple pathway enrichment analyses were finished based on DEGs. The genetic signature for colorectal adenocarcinoma (COAD) was identified by using the Cox regression analysis. Kaplan-Meier survival and receiver operating characteristic curve analysis were used to explore the prognosis value of specific genes in COAD. The potential immune signatures and drug sensitivity prediction were also analyzed. Promising small-molecule agents were identified and predicted targets of α-hederin in SuperPred were validated by molecular docking. Also, expression levels of genes and Western blot analysis were conducted. In total, 48 genes were identified as DEGs, and the hub genes such as COL1A1, CXCL12, COL1A2, FN1, CAV1, TIMP3, and IGFBP7 were identified. The ROS and KEAP1-associated gene signatures comprised of hub key genes were developed for predicting the prognosis and evaluating the immune cell responses and immune infiltration in COAD. α-hederin, a potential anti-colorectal cancer (CRC) agent, was found to enhance the sensitivity of HCT116 cells, regulate CAV1 and COL1A1, and decrease KEAP1, Nrf2, and HO-1 expression significantly. KEAP1-related genes could be an essential mediator of ROS in CRC, and KEAP1-associated genes were effective in predicting prognosis and evaluating individualized CRC treatment. Therefore, α-hederin may be an effective chemosensitizer for CRC treatments in clinical settings.

Nomogram to predict severe retinopathy of prematurity in Southeast China.

AIM: To define the predictive factors of severe retinopathy of prematurity (ROP) and develop a nomogram for predicting severe ROP in southeast China. METHODS: Totally 554 infants diagnosed with ROP hospitalized in the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University and hospitalized in Taizhou Women and Children's Hospital were included. Clinical data and 43 candidate predictive factors of ROP infants were collected retrospectively. Logistic regression model was used to identify predictive factors of severe ROP and to propose a nomogram for individual risk prediction, which was compared with WINROP model and Digirop-Birth model. RESULTS: Infants from the Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University (n=478) were randomly allocated into training (n=402) and internal validation group (n=76). Infants from Taizhou Women and Children's Hospital were set as external validation group (n=76). Severe ROP were found in 52 of 402 infants, 12 of 76 infants, and 7 of 76 infants in training group, internal validation group, and external validation group, respectively. Birth weight [odds ratio (OR), 0.997; 95% confidence interval (CI), 0.996-0.999; P<0.001], multiple births (OR, 1.885; 95%CI, 1.013-3.506; P=0.045), and non-invasive ventilation (OR, 0.288; 95%CI, 0.146-0.570; P<0.001) were identified as predictive factors for the prediction of severe ROP, by univariate analysis and multivariate analysis. For predicting severe ROP based on the internal validation group, the areas under receiver operating characteristic curve (AUC) was 78.1 (95%CI, 64.2-92.0) for the nomogram, 32.9 (95%CI, 15.3-50.5) for WINROP model, 70.2 (95%CI, 55.8-84.6) for Digirop-Birth model. In external validation group, AUC of the nomogram was also higher than that of WINROP model and Digirop-Birth model (80.2 versus 51.1 and 63.4). The decision curve analysis of the nomogram demonstrated better clinical efficacy than that of WINROP model and Digirop-Birth model. The calibration curves demonstrated a good consistency between the actual severe ROP incidence and the predicted probability. CONCLUSION: Birth weight, multiple births, and non-invasive ventilation are independent predictors of severe ROP. The nomogram has a good ability to predict severe ROP and performed well on internal validation and external validation in southeast China.

Exploring the anatomical factors influencing testes elasticity via ultrasound shear wave elastography: Preliminary results

Purpose: The aim of this study is to evaluate the anatomical factors influencing elasticity values of normal testicular parenchyma using shear wave elastography (SWE). Methods: This study examined 68 healthy male volunteers (117 testes in which standard transverse axis ultrasonography views could be obtained) via conventional scrotal ultrasonography and SWE. Both the mean (EMean) and standard deviation (ESD) elasticity values were acquired. Results: In the standard transverse axis view of the rete testis at the mid-lateral edge of the testes, the EMean values in 2mm the testicular parenchyma from the rete testis and the testicular capsule at the same level as the rete testis were all significantly larger than in the central zone (P<0.001, P<0.001, respectively). The EMean value in the testicular parenchyma 2mm from the testicular capsule on the line formed approximately 45° below the horizontal line of the rete testis was significantly larger than in the rete testis approximately 45° above the horizontal line (P<0.001). In two standard transverse axis views, the ESD values in other regions were significantly larger than those in the central zones (all P<0.001). Also, the EMean values in the transmediastinal arteries were larger than those of the surrounding normal testicular parenchyma (P<0.001). Conclusion: Based on SWE, factors including the testicular capsule, the density of testicular fibrous septa, the depth of the Q-Box™, and the transmediastinal artery may influence the testes elasticity measurement. (AU)

Exploring the anatomical factors influencing testes elasticity via ultrasound shear wave elastography: Preliminary results.

PURPOSE: The aim of this study is to evaluate the anatomical factors influencing elasticity values of normal testicular parenchyma using shear wave elastography (SWE). METHODS: This study examined 68 healthy male volunteers (117 testes in which standard transverse axis ultrasonography views could be obtained) via conventional scrotal ultrasonography and SWE. Both the mean (EMean) and standard deviation (ESD) elasticity values were acquired. RESULTS: In the standard transverse axis view of the rete testis at the mid-lateral edge of the testes, the EMean values in 2mm the testicular parenchyma from the rete testis and the testicular capsule at the same level as the rete testis were all significantly larger than in the central zone (P<0.001, P<0.001, respectively). The EMean value in the testicular parenchyma 2mm from the testicular capsule on the line formed approximately 45° below the horizontal line of the rete testis was significantly larger than in the rete testis approximately 45° above the horizontal line (P<0.001). In two standard transverse axis views, the ESD values in other regions were significantly larger than those in the central zones (all P<0.001). Also, the EMean values in the transmediastinal arteries were larger than those of the surrounding normal testicular parenchyma (P<0.001). CONCLUSION: Based on SWE, factors including the testicular capsule, the density of testicular fibrous septa, the depth of the Q-Box™, and the transmediastinal artery may influence the testes elasticity measurement.

Triterpenoids of Rhus chinensis Supressed Colorectal Cancer Progress by Enhancing Antitumor Immunity and CD8 + T Cells Tumor Infiltration.

The absence of CD8+ T cells in the tumor center has become a major obstacle in the immunotherapy of colorectal cancer. Therefore, new therapeutic strategies are urgently needed to promote the accumulation of CD8+ T cells in the tumor center. Previous studies have shown that triterpenoid of Rhus chinensis (TER) is involved in the proliferation and apoptosis of colorectal cancer cells, and can regulate their immune activity, but its mechanism needs to be further elucidated. In this study, the antitumor effect and adaptive immune response of TER on tumor-bearing mice were evaluated and compared with 5-fluorouracil. The results showed that TER could significantly inhibit tumor growth and prolong the survival time of tumor-bearing mice. The In Vivo studies have shown that TER can not only enhance antitumor immunity and promote the accumulation of CD8 + T cells to tumor sites, but also inhibit tumor progression by regulating the expression of PD-1 and PD-L1 and significantly reducing the mortality of mice. Our study demonstrated for the first time that TER has oncolytic effect, and recruited adaptive immune cells to enhance the efficacy of anti-PD-1/PD-L1 in colorectal cancer, which provides a potential therapeutic target for combined immunotherapy of colorectal cancer.

Diagnostic Accuracy of Three-Dimensional Endoanal Ultrasound for Anal Fistula: A Systematic Review and Meta-analysis.

BACKGROUND: Anal fistula is a relatively common anorectal disease. An accurate assessment of the main anal fistula type and the anatomy of the internal opening before surgery is necessary to obtain the best surgical results. Whether three-dimensional endoanal ultrasound (3D-EAUS) should be used as the first-line diagnostic tool for anal fistula is still controversial. The purpose of this study is to conduct a meta-analysis of the published literature on 3D-EAUS and anal fistula, and compare the results of 3D-EAUS and surgery to evaluate the diagnostic value of 3D-EAUS for anal fistula. METHODS: An online search of databases in English included PubMed, Embase, and Cochrane Library. After the diagnostic accuracy of 3D-EAUS of all anal fistula types was integrated, a single-group rate meta-analysis was performed; we analyzed 3D-EAUS separately for the diagnosis of different anal fistula types, and conducted a meta-analysis of test accuracy. The analysis combined sensitivity, specificity, and the respective 95% CI, to draw a summary receiver operating characteristic curve (SROC), and estimate the area under curve (AUC). RESULTS: Based on the inclusion criteria, we selected 8 studies covering 1057 cases of anal fistula and 548 cases of internal opening. The meta-analysis data show that 3D-EAUS has a total accuracy rate of 91% (95% CI, 88-94%). It has high sensitivity and specificity for different anal fistula classifications. The SROC curves for anal fistula internal openings were plotted, and the AUC was calculated to be 0.86 (95% CI, 0.83-0.89). CONCLUSIONS: 3D-EAUS can be used as the first-line diagnostic tool for anal fistula, because it has a high diagnostic accuracy for most anal fistulas. However, due to the insufficient diagnostic accuracy of 3D-EAUS for complex fistulas, 3D-EAUS combined with MRI examination can be used to more accurately detect the secondary extension of complex fistulas, so as to describe the complete anatomy of the fistula in more detail.

Treatment effect and mechanism of Fu's subcutaneous needling among patients with shoulder pain: A retrospective pilot study.

Fu's subcutaneous needling (FSN) is a new acupuncture therapy developed from acupuncture and Traditional Chinese Medicine models. The aim of this study was to investigate the effect of FSN on shoulder pain. In this retrospective comparative study, patient case files with shoulder pain (Group A) treated with FSN were analyzed and compared with the same number of patients with shoulder pain (Group B) treated with conventional acupuncture and physical therapy. Motion-related pain (MRP), pain under pressure (PUP), and Range of motion (ROM) were collected before and after intervention. In the 68 patients, there were 39 males and 29 females, aged 21-53 years old (mean ± SD = 36.4 ± 8.15) with onset time ranging from 1 day to 7 days (mean ± SD = 3.15 ± 1.73). MRP, PUP, and ROM scores were improved after FSN intervention (p < .05). There were significant differences between group A and group B in MRP, PUP, and ROM scores after FSN intervention and 1 week follow-up (p < .05). No adverse events, such as fainting and sharp pain, occurred during the treatment process. FSN can be an effective rehabilitation intervention for improving shoulder pain and shoulder range of motion.

Effects and mechanisms of fatty acid metabolism­mediated glycolysis regulated by betulinic acid­loaded nanoliposomes in colorectal cancer.

Although previous studies have demonstrated that triterpenoids, such as betulinic acid (BA), can inhibit tumor cell growth, their potential targets in colorectal cancer (CRC) metabolism have not been systematically investigated. In the present study, BA­loaded nanoliposomes (BA­NLs) were prepared, and their effects on CRC cell lines were evaluated. The aim of the present study was to determine the anticancer mechanisms of action of BA­NLs in fatty acid metabolism­mediated glycolysis, and investigate the role of key targets, such as acyl­CoA synthetase (ACSL), carnitine palmitoyltransferase (CPT) and acetyl CoA, in promoting glycolysis, which is activated by inducing hexokinase (HK), phosphofructokinase­1 (PFK­1), phosphoenolpyruvate (PEP) and pyruvate kinase (PK) expression. The results demonstrated that BA­NLs significantly suppressed the proliferation and glucose uptake of CRC cells by regulating potential glycolysis and fatty acid metabolism targets and pathways, which forms the basis of the anti­CRC function of BA­NLs. Moreover, the effects of BA­NLs were further validated by demonstrating that the key targets of HK2, PFK­1, PEP and PK isoenzyme M2 (PKM2) in glycolysis, and of ACSL1, CPT1a and PEP in fatty acid metabolism, were blocked by BA­NLs, which play key roles in the inhibition of glycolysis and fatty acid­mediated production of pyruvate and lactate. The results of the present study may provide a deeper understanding supporting the hypothesis that liposomal BA may regulate alternative metabolic pathways implicated in CRC adjuvant therapy.

The effect of intermittent hypoxia training on migraine: a randomized controlled trial.

OBJECTIVE: To study the effect of intermittent hypoxia training (IHT) for migraine. DESIGN: A single-blind, randomized controlled trial. All participants were recruited from a rehabilitation department in an acute university-affiliated hospital. METHODS: Participants with migraines were randomly assigned to two groups (IHT group and control group). The Migraine Disability Assessment (MIDAS), Visual Analog Scale (VAS), Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), Vascular endothelial growth factor (VEGF), calcitonin gene related peptide (CGRP) and cerebrovascular hemodynamic parameters were collected at baseline and end of the 8th week. The attack frequencies of migraines were evaluated at 3 months. RESULTS: Among the 48 subjects, five males and forty-three females, the ages ranged from 19 to 53 years old (mean ± SD = 31.3±7.78). MIDAS, SF-36, VAS, BAI, BDI, VEGF, CGRP and cerebrovascular hemodynamic parameters were improved after IHT intervention. There were significant differences between IHT group and the control group in MIDAS, SF-36, VAS, BAI, BDI, VEGF, CGRP and cerebrovascular hemodynamic parameters at the end of the 8th weeks (P<0.05). Attack frequencies were improved within 3 months after IH training intervention (P<0.01), but not in the control group (P>0.05). No adverse events occurred during the study. CONCLUSION: IHT could improve migraines after intervention up to three months. IHT could be an effective method for relieving a migraine.

Randomized Trial on Comparison of the Efficacy of Extracorporeal Shock Wave Therapy and Dry Needling in Myofascial Trigger Points.

OBJECTIVE: The aim of the study was to compare the efficacy of radial extracorporeal shock wave therapy and dry needling in the treatment of myofascial trigger points in the upper trapezius muscle. DESIGN: A total of 65 patients with myofascial trigger points were randomly divided into extracorporeal shock wave therapy group (n = 32) and dry needling group (n = 33). Patients received 3 wks of treatment at 1-wk intervals (in both groups). Visual analog scale, pressure pain threshold, Neck Disability Index, and shear modulus were evaluated before treatment, immediately after the first therapy, 1 mo, and 3 mos after the completion of the third therapy. RESULTS: Significant improvements of visual analog scale, pressure pain threshold, and Neck Disability Index scores were observed at all time points after treatment (P < 0.01) in both treatment groups. The shear modulus of myofascial trigger points was reduced in both dry needling group (P < 0.05) and extracorporeal shock wave therapy group (P < 0.01) immediately after the first treatment. Significant reductions in shear modulus were maintained up to 3-mo posttreatment in both groups (P < 0.01). There were no significant differences between the radial extracorporeal shock wave therapy group and dry needling group. CONCLUSIONS: The extracorporeal shock wave therapy is as effective as dry needling for relieving pain, improving function, and reducing shear modulus for patients with myofascial trigger points after a series of three treatments.

[Minimal invasive microscopic tooth preparation based on endodontic, periodontal and functional health].

Tooth preparation is the primary and core operation technique for dental esthetic restoration treatment, due to its effect of providing restoration space, bonding interfaces and marginal lines for dental rehabilitation after tooth tissue reduction. The concept of microscopic minimal invasive dentistry put forward the issue of conducting high-quality tooth preparation, conserve tooth-structure, protect vital pulp and periodontal tissue simultaneously. This study reviewed the concepts, physiology background, design and minimal invasive microscopic tooth preparation, and in the meantime, individualized strategies and the two core elements of tooth preparation (quantity and shape) are listed.

[All-ceramic premolar guiding plate retains resin-bonded fixed partial dentures].

OBJECTIVE: This study aims to investigate the fracture resistance and short-term restorative effects of resin-bonded fixed partial dentures (RBFPDs) made from heat-pressed lithium-disilicate-based glass-ceramic (IPS e.max press) and zirconia ceramic (WIELAND) and retained by all-ceramic guiding plates when used to restore missing mandibular second premolars. METHODS: A total of 64 human mandibular first premolars and first molars were prepared as abutments, then were randomly divided into 4 groups (n=8): E0, heat-pressed ceramic RBFPDs, no cyclic loading; E1, heat-pressed ceramic RBFPDs exposed to 300 000 cycles of dynamic loading; W0, zirconia ceramic RBFPDs, no cyclic loading; and W1, zirconia ceramic RBFPDs exposed to 300 000 cycles of dynamic loading. Fracture strength was tested in a universal testing machine. RESULTS: The medians of fracture strength were 1 242.85 N±260.11 N (E0), 1 650.85 N±206.77 N (W0), 1 062.60 N±179.98 N (E1), and 1 167.61 N±265.50 N (W1). Statistical analysis showed that all the groups exhibited significantly higher fracture strength compared with the maximum bite force in the premolar region (360 N; P<0.001). The W0 group had significantly higher fracture strength than the E0 group (P<0.05). Meanwhile, no significant difference in fracture strength was observed between the E1 and W1 groups (P>0.05). Significant statistical differences were found between the zirconia ceramic groups (W0 and W1, P<0.05) but not between the glassceramic groups (E0 and E1, P>0.05) after dynamic loading. CONCLUSIONS: The RBFPDs retained by all-ceramic guiding plates exhibited promising fracture properties and optimal short-term restorative effects when used to restore missing mandibular second premolars.

[The acceleration of titanium implant osseointegration by low intensity pulsed ultrasound: an experimental study in rats].

OBJECTIVE: To establish an animal model of titanium implant and to investigate the effects of low intensity pulsed ultrasound (LIPUS) on the implant osseointegration. METHODS: Twenty-four female Sprague Dawley (SD) rats were used. Titanium implants were inserted into tibia metaphysis bilaterally in each SD rat. Since the second day following implant surgery, LIPUS stimulation were carried out around the implant on the right side for 20 minutes per day, and implants on the left side remain untouched as self-control. Eight rats were sacrificed and tibiae specimens were harvested on the end of the 4th, 8th, and 12th week respectively. X-ray picture, micro-CT analysis and histological sections were performed to evaluate the effects of LIPUS on the implant osseointegration. RESULTS: Osseointegration at the interface between the implant and bone tissue was observed bilaterally. In the micro-CT histomorphometry analysis, the percentage of osseointegration (%OI) of experiment side were (45.708 ± 3.316)%, (46.231 ± 1.954)%, and (46.807 ± 1.451)% on the end of the 4th, 8th, and 12th week. Meanwhile, the %OI of control side were (43.021 ± 3.558)%, (44.272 ± 3.023)%, and (44.894 ± 4.215)% respectively. The %OI on the 4th weekend, bone volume ratio (BV/TV) on the 4th and 8th weekend, trabecular thickness (Tb. Th) and degree of anisotropy (DA) on the 8th and 12th weekend of the experiment side tibia were significantly greater than those on the control side (P < 0.05). The histological examination showed that the thickness of new bone around the implant and the bone-implant contact area was obviously greater in the LIPUS treated side compared to the control side. CONCLUSIONS: The LIPUS therapy may accelerate the bone healing and osseointegration at the interface between titanium implant and bone, and promote remodeling of bone trabecula on the early stage.

[Study and preparation of a novel apatite-wollastonite bioactive glass-ceramic-calcium sulphate hemihydrate composite].

OBJECTIVE: To prepare a novel apatite-wollastonite bioactive glass-ceramic-calcium sulphate hemihydrate(AW-BGC-CSH) composite, to study its biocompatibility, and to provide experimental support for its further clinical application. METHODS: Samples of AW-BGC-CSH composite were prepared with different AW-BGC granules-CSH ratios (50%, 40%, 30%, 20%). Surface morphology, microstructure and mechanical features of the composite were measured. Osteoblasts were cultivated in vitro on the composite. Cell morphology, proliferation, and the alkaline phosphatase (ALP) activity of osteoblasts were examined to determine the biocompatibility of the composite. RESULTS: The composite showed a three-dimensional pored structure with communicated micropores under scanning electron microscopy (SEM). The plasticity of the composite could be maintained within 3 - 5 min. Its top solidification temperature was 36.4°C and the maximum compressive strength was 9.3 MPa. The osteoblasts adhered to the composite and grew well. At 1, 3, 5, 7 d after cultivated, the microprotein contents of the composite were (251 ± 12), (296 ± 31), (580 ± 13) and (571 ± 15) mg/L, and the ALP activity of the composite were (4.50 ± 0.68), (6.90 ± 0.27), (12.05 ± 0.28) and (11.86 ± 0.63) U/mg. The results of the ALP activity and microprotein contents in the experiment group were significantly higher than those in the control group (P < 0.05). CONCLUSIONS: The prepared AW-BGC-CSH composite has a three-dimensional pored structure, favourable plasticity, mechanical property and good biocompatibility.

[Effects of Sol-Gel coating on the corrosion resistance of nickel-chronium alloys].

OBJECTIVE: To investigate the effects of Sol-Gel coating on the corrosion resistance of nickel-chronium alloys in vitro. METHODS: The bond strength of coating-substrate interface sintered at different temperatures (300, 400, 500, 600 degrees C) was tested by scratching method. The Sol-Gel coating was analyzed by scanning electron microscope (SEM), and its corrosion resistance was assessed by a static immersion method. RESULTS: The bond strength of coating-substrate interface reaches the peak at 400 degrees C. The Sol -Gel coating can apparently inhibit the release of metal ions and improve the corrosion resistance of nickel-chromium alloy. CONCLUSION: Sol-Gel coating can evidently improve corrosion resistance of the nickel-chromium alloy, which has great potential in prospective clinical practice.

[Feasibility of permanent maxillary tooth removal using articaine anesthesia without palatal injection].

OBJECTIVE: This study was to test the feasibility of permanent maxillary tooth removal using articaine without a second palatal injection. METHODS: Of 104 patients, 38 patients had bilateral extraction and 66 patients had unilateral extraction of maxillary tooth. In the test group, 1.7 mL articaine with 1:100000 epinephrine was injected into the buccal vestibule of the tooth and the tooth were extracted after 5 minutes. In the control group, the patients were subjected to both palatal injection with 2% lidocaine hydrochloride and buccal injection with articaine. All patients completed visual analog scales (VAS) after extraction. RESULTS: The achievement ratio of permanent maxillary tooth anesthesia of test group was 96.2%. The achievement ratio of permanent maxillary tooth anesthesia of control group was 97.1%. There was no statistical significance between achievement ratio of test group and control group(P > 0.05). CONCLUSION: Permanent maxillary tooth removal without palatal injection is possible by articaine injection to the buccal vestibule of the tooth.

[Effects of hypotonic solution on the proliferation, alkaline phosphatase activity and [Ca2+]i concentration of osteoblast-like cells].

OBJECTIVE: To investigate the effects of static-stretch from the hypotonic solution on the proliferation, alkaline phosphatase activity and [Ca2+]i in the osteoblast-like cells. METHODS: Mechanical loading was introduced by swelling in the hypotonic solution. In vitro cultured MG63 were incubated under continuous swelling of 277, 240 and 163mOsm for 2h, 4h, 8h, 12h, 24h and 48h. The cell proliferation was detected by MTT assay. ALPase and [Ca2+]i were determined by modified enzyme dynamic method and OCPC respectively. RESULTS: The cell proliferation, ALP activity and [Ca2+]i increased slowly under continuous static-stretch of 277 and 240mOsm. The cell proliferation was inhibited under 163mOsm, with a sharp increase of [Ca2+]i at 8h (11.383 +/- 0.111) and an increase of ALPase activity (0.326 +/- 0.002). CONCLUSION: The static-stretch induced from the hypotonic solution has an impact on the proliferation, differentiation, ALPase and Ca2+-ATPase of the MG63. The [Ca2+]i is correlated with the ALPase.

[Influence of manufacture technique on translucency and color of dental porcelain].

OBJECTIVE: To study the influence of manufacture technique on the translucency and color of dental porcelain. METHODS: Specimens were made of VITA VMK 95 dentin porcelain and enamel porcelain and divided into 3 groups: Sintering times group (1, 2, 4, 6, 8 and 10 times), sintering temperature group (910, 920, 930, 940 and 950 degrees C), sintering vacuum group (95, 65, 35 and 0 kPa). Transmittance, Y, dominant wavelength and saturation were measured by PR-650 spectra scan spectrocolorimeter. RESULTS: Transmittance of dentin porcelain increased after 6 times repeated sintering. Transmittance of enamel porcelain increased first after the second sintering, and then became decreasing when sintering more than 2 times. Transmittance of enamel porcelain deceased when sintering temperature was lower than standard. Decrease of sintering vacuum caused the transmittance of dentin and enamel porcelain decreased. The changing of value was coordinated with transmittance. Dominant wavelength and saturation had negative correlation with sintering times and temperature, and positive correlation with vacuum. CONCLUSION: Sintering times, temperature and vacuum all had prominent effects on the translucency and color of dental porcelain. Comparing with dentin porcelain, enamel porcelain was more sensitive with the modification of manufacture technique.

[Comparison of translucency between enamel, dentin and Vita veneer porcelain].

PURPOSE: To compare the translucency between enamel, dentin and dental porcelain. METHODS: 32 newly extracted vital human central incisors were collected and cut into 0.8mm enamel slices and 1.0 mm dentin slices. 1.0 mm dental porcelain specimen were made with different Vita veneer porcelain, EN1, EN2, T4, Window, A1, A2, A3, A3.5, A4, B2, C2, D2, 3 samples for each kind. The transmittance and reflectance of tooth slices and porcelain specimen were measured by PR-650 spectra scan spectrocolorimeter. The transmittance coefficients were also calculated. The 95% confidence interval was obtained by SPSS 12.0 software package. SNK method was used to compare the transmittance coefficients of different dentin porcelains. RESULTS: The transmittance coefficient of tooth enamel ranged from 0.0817 mm(-1) to 0.1009 mm(-1), which was higher than that of two kinds of enamel porcelain (0.0507 mm(-1) for EN1 and 0.0408 mm(-1) for EN2). The transmittance coefficient of dentin (0.0418-0.0482 mm(-1)) was also higher than that of dentin porcelain (0.016-0.027 mm(-1)). The transmittance coefficient of dentin porcelain decreased with the increasing of chroma (P<0.05). CONCLUSIONS: Prominent difference exists between translucency of tooth tissue and dental porcelain, especially between enamel and enamel porcelain.

[The effect of cryotreat on tensile properties of medium melting-point and high melting-point castable alloy].

OBJECTIVE: To introduce cryotreat technique into prosthetic dentistry by testing the tensile properties of CW-H Co-Cr-Mo cast alloy before and after cryotreat and to observe the image changes by SEM to study the mechanism that changes the tensile properties of the alloy. METHODS: 15 CW-H cast alloy were divided into 3 groups, i.e. control group (G1), cryotreated group (G2) and cryotreated plus post-cryogenic treated group (G3). The gauge test technique was employed to test the modulus of elasticity. Then the strength and percentage elongation (PE) were tested. SEM images were used to analyze the mechanism that improved the tension properties of the alloy. RESULTS: For CW-H alloy the strength and the modulus of elasticity of both G2 and G3 were effectively increased but PE effectively decreased than G1. There was no effectively difference between G2 and G3, but G3 was larger than G2. SEM images of G2 and G3 showed that secondary-carbonide separated out all over the alloy. CONCLUSION: The results obtained above suggest that cryotreat is an effective method in enhancing tensile properties of CW-H Co-Cr-Mo cast alloy.