Studies on the effect of ultrasound on properties and bonding strength of dentin smear layer / 口腔医学

Objective@# To explore the effect of ultrasound on dentin smear layer's surface and bonding strength of the universal resin adhesive under self-etching mode. @*Methods@# Forty mandibular third molars without caries were randomly divided into two groups; one was polished with silicon carbide sandpaper; the other was polished with silicon carbide sandpaper followed by ultrasonic treatment. Scanning electron microscope (SEM) was used to observe surface of the dentin. Treated teeth were bonded with two universal resin adhesives, Clearfil Universal Bond (pH=2.3) and All-Bond Universal (pH=3.1), and the penetration of the bonding interface was observed with a confocal laser scanning microscope (CLSM) after Rhodamine B staining. Finally, the micro tensile bond strength test was conducted to test the adhesion. @*Results@# The SEM showed that after polishing with silicon carbide sandpaper, the smear layer of the dentin surface was scratched, and dentin tubules were almost completely blocked, with no obvious dentin tubules exposed. After ultrasonic treatment, the scratches were reduced, and a large number of dentin tubules were exposed. CLSM showed that both adhesives could penetrate the dentin along the dentin tubules more deeply after ultrasound treatment. Micro tensile bond strength tests showed that ultrasonic treatment could enhance the bonding strength of two universal resin adhesives. However, there was no statistical difference in bonding strength between these two universal resin adhesives under the same treatment. .@*Conclusion@# Ultrasound can partially remove the smear layer on dentin's surface, expose dentin tubules, and increase universal resin adhesives' penetration depth and bonding strength under self-etching mode

[Effect of hydrofluoric acid concentration on the surface morphology and bonding effectiveness of lithium disilicate glass ceramics to resin composites].

OBJECTIVE: This study aimed at determining the influence of hydrofluoric acid (HF) in varied concentrations on the surface morphology of lithium disilicate glass ceramics and bond durability between resin composites and post-treated lithium disilicate glass ceramics. METHODS: After being sintered, ground, and washed, 72 as-prepared specimens of lithium disilicate glass ceramics with dimensions of 11 mm×13 mm×2 mm were randomly divided into three groups. Each group was treated with acid solution [32% phosphoric acid (PA) or 4% or 9.5% HF] for 20 s. Then, four acidified specimens from each group were randomly selected. One of the specimens was used to observe the surface morphology using scanning electron microscopy, and the others were used to observe the surface roughness using a surface roughness meter (including Ra, Rz, and Rmax). After treatment with different acid solutions in each group, 20 samples were further treated with silane coupling agent/resin adhesive/resin cement (Monobond S/Multilink Primer A&B/Multilink N), followed by bonding to a composite resin column (Filtek™ Z350) with a diameter of 3 mm. A total of 20 specimens in each group were randomly divided into two subgroups, which were used for measuring the microshear bond strength, with one of them subjected to cool-thermal cycle for 20 000 times. RESULTS: The surface roughness (Ra, Rz, and Rmax) of lithium disilicate glass ceramics treated with 4% or 9.5% HF was significantly higher than that of the ceramic treated with PA (P<0.05). The lithium disilicate glass ceramics treated with 9.5% HF also demonstrated better surface roughness (Rz and Rmax) than that of the ceramics treated with 4% HF. Cool-thermal cycle treatment reduced the bond strength of lithium disilicate glass ceramics in all groups (P<0.05). After cool-thermal cycle, the lithium disilicate glass ceramics treated with HF had higher bond strength than that of the ceramics treated with PA. The lithium disilicate glass ceramics treated with 4% HF had higher bond strength than that of the ceramics treated with 9.5% HF (P<0.05). During cool-thermal cycle, the lithium disilicate glass ceramics treated with 4% HF demonstrated higher reduction in bond strength than that of the samples treated with 9.5% HF (P<0.05). CONCLUSIONS: The concentration of HF significantly affected the surface morphology of lithium disilicate glass ceramics and the bond durability between resin composites and post-treated lithium disilicate glass ceramics. The bond strength between resin composites and post-treated lithium disilicate glass ceramic was more efficiently maintained by treatment with 9.5% HF.

Intracanial thrombus suction combined with visible thrombectomy stent for the treatment of acute intracranial main artery infarction: preliminary results of 5 cases / 介入放射学杂志

Objective To discuss the clinical effect of Penumbra aspiration system combined with Trevo thrombectomy device in treating acute intracranial main artery infarction.Methods The clinical data of a total of 5 patients with acute intracranial main artery infarction,who were treated with ACETM thrombectomy device combined with Trevo visible thrombectomy stent,were retrospectively analyzed.The lesions included anterior circulation infarction (n=2) and posterior circulation infarction (n=3).The mean age of patients was (60.4±11.6) years old.The operation time spent for thrombectomy,the recanalization time of occluded vessels,and the recovery of neural function were assessed.Results The puncture-recanalization intervals in the 5 patients were 29 min,32 min,35 min,33 min and 30 min respectively,with a mean time of (31.8±2.4) min.After intraoperative cerebral infarction thrombolysis treatment,the cerebral blood flow grading reached level 3.NIHSS score was remarkably improved from preoperative (11.0±7.4) points to 24 hpostoperative(4.2±1.1) points,to 7 days-postoperative(1.8±1.3) points,and to 30 days-postoperative (0.9±0.6) points (P＜0.05).Modified Rankin scale (mRS) score was 0-2 points in all patients.No intracranial hemorrhage transformation occurred.Conclusion In treating acute intracranial main artery infarction,ACETM thrombectomy device combined with Trevo visible thrombectomy stent can achieve the best recanalization effect with less times of thrombectomy procedure and short operation time.The clinical prognosis is satisfactory.

Effect of a chemical primer on the bond strength of a zirconia ceramic with self-adhesive resin cement / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To evaluate the bond strength and durability of a self-adhesive resin cement with a zirconia ceramic pretreated by a zirconia primer.</p><p><b>METHODS</b>Zirconia ceramic (Vita Inceram YZ) plates with a thickness of 2.5 mm were fired, polished, and then cleaned. Half of the polished ceramic plates were sandblasted with 50 μm alumina particles at 0.3 MPa for 20 s. The surface compound weight ratios were measured via X-ray fluorescence microscopy. The polished and sandblasted ceramic plates were directly bonded with self-adhesive resin cement (Biscem) or were pretreated by a zirconia primer (Z Primer Plus) before bonding with Biscem. The specimens of each test group were divided into two subgroups (n=10) and subjected to the shear test after 0 and 10,000 thermal cycles. The data were analyzed via three-way ANOVA.</p><p><b>RESULTS</b>After air abrasion, 8.27% weight ratio of alumina attached to the zirconia surface. Compared with air abrasion, primer treatment more significantly improved the primary resin bond strength of the zirconia ceramic. The primary resin bond strength of the zirconia ceramic with no primer treatment was not affected by thermocycling (P>0.05). However, the primary resin bond strength of the zirconia ceramic with primer treatment was significantly decreased by thermocycling (P<0.05).</p><p><b>CONCLUSION</b>Primer treatment can improve the primary resin bond strengths of zirconia ceramics. However, the bond interface of the primer is not stable and rapidly degraded during thermocycling.</p>

Clinical Observation of Lumbar Intervertebral Disc Protrusion Patients Treated with Acupotomy Therapy Combined with Acupuncture Based on Distal Points Selection / 广州中医药大学学报

Objective To evaluate the clinical effect of acupotomy therapy combined with acupuncture based on distal points selection for lumbar intervertebral disc protrusion ( LIDP) . Methods Sixty-eight LIDP patients were randomly divided into treatment group (N=33) and control group(N=35). The treatment group were given acupotomy therapy on the proximal positive response points in the lumbosacral region for relaxing the tendons,and acupuncture therapy based on distal points selection of Shugu, the Shu-stream point of the foot Taiyang bladder meridian, Zulinqi and Weizhong, the shu-stream point and the blood xi-cleft point of the foot Shaoyang gallbladder meridian respectively, twice a week, 2 weeks constituting one course of treatment. The control group was given conventional electroacupuncture therapy on Huatuo clip points, Dachangshu point, bilateral Shenshu points, Yinmen point, bilateral Zibian points and bilateral Yanglingquan points, and together with TDP radiation therapy, 5 times a week, 2 weeks constituting one course of treatment. The two groups received follow-up for one month. The low back pain scores of Japanese orthopaedic society ( JOA) and visual analog scores ( VAS) of pain were used for the evaluation of therapeutic effect after the treatment. Results ( 1) After treatment, the JOA scores were increased and VAS scores were decreased in both groups compared with those before treatment ( P< 0.05) , and the increase of JOA scores and the decrease of VAS in the treatment group were superior to those in the control group ( P< 0.05) . There was statistically significant difference of VAS scores between the two groups ( P < 0.05) during the follow-up period. ( 2) The total effective rate was 87.9%in the treatment group, and was 77.1%in the control group, the difference being significant (P<0.05) . Conclusion The acupotomy therapy combined with acupuncture based on distal points selection is effective and safe for lumbar intervertebral disc protrusion, which has the advantages of reliable long-term effect and low recurrence rate, showing good prospects for extensive clinical application.

Alpinetin down-regulating Bcl-2 promotes apoptosis of human hepatic cancer Hep3B cells / 中华普通外科杂志

Objective To study the effects of alpinetin on apoptosis of Hep3B cells and explore the related mechanism.Methods Hep3B cells were cultured in vitro,treated with alpinetin; RT-PCR and Western blot was used to detect the mRNA and protein levels of Bcl-2; MTT assay was used to detect the cellular growth inhibitory rate; Annexin V-FITC/PI double staining was used to detect the apoptosis rate of cells; Mitochondrial membrane potential was analyzed by flow cytometry; Western blot was used to detect protein expression of Caspase-3,9 and Cytochrome C ; the experiment was carried out in four groups:control group,high dosage of alpinetin group,middle dosage of alpinetin group and low dosage of alpinetin group.Results The expression of Bcl-2 in Hep3B cells were decreased by alpinetin.After treated with different dosages of alpinetin (40,80,120 μmol/L),the apoptotic inhibitory rate detected by MTT were 6.38％ ± 1.32％,21.58％ ± 1.97％ and 43.18％ ± 3.89％,significantly higher than those in control group (tlowdose =13.01,tmiddle dose =15.12,thighdose =14.79,average P ＜ 0.01) ; the expression of mitochondrial membrane potential green fluorescence protein (GFP) were 18.93％ ± 2.3％,31.11％ ± 2.67％ and46.06％ ± 2.95％,significantly higher than those in control group (tlow dose =16.70,tmiddle dose =31.38,thigh dose =48.15,average P ＜ 0.01).Western blot analysis showed that the expression of Caspase-3,9 andCytochrome C in cytoplasm significantly was higher than those in control group(Caspase-3:llow dose =11.94,tmiddle dose =10.18,thigh dose =18.82,average P ＜0.01; Caspase-9:tlow dose =15.11,tmiddle dose =20.41,thish dose =21.25,average P ＜0.01; Cytochrome C:tlow dose =15.11,tmiddle dose =28.47,thigh dose =16.01,average P ＜ 0.01).while that Cytochrome C in mitochondria significantly lower than those in control group (tlow dose =16.70,tmiddle dose =12.00,thighdose =27.61,average P ＜ 0.01).Conclusions Alpinetin promotes apoptosis of human hepatic cancer cells Hep3B by down-regulating Bcl-2,probably through mitochondrial pathway.

Effects of film thickness on the phase composition and microstructure properties of micro-arc oxidation coating / 生物医学工程学杂志

In this study, we obtained the TiO2 films with different thickness by micro-are oxidation (MAO) on commercially available pure titanium. By altering the duration time, we got the films 5 microm, 10 microm, and 20 microm in thickness, respectively. XRD and SEM were employed to characterize the phase, composition and microstructure of the films. The MAO film, which was about 5 microm thick, was porous and even with the pore size about 1 microm. No other crystalline phase except anatase was detected by XRD. The film, which was 10 microm thick, was similar to the former. The pores were well separated and homogeneously distributed over the surface. The XRD pattern indicated that the film was composed of anatase and a minor amount of rutile, whereas the pore size of 20 microm film was about 4-6 microm and was bigger than the others. Furthermore, the small cracks were easy to observe. XRD pattern showed that the Ti peak was significantly reduced and new Ca, P, O containing compound was formed in addition to rutile and anatase with the film thickness increasing. There were significant differences in regard to surface roughness of the three groups. These findings suggest that the film thickness has an intense effect on the quality of the MAO coating. By changing the film thickness, we can extensively change the composition, structure and chemical properties of the surface layer on titanium.