Eucommia ulmoides Oliv.antagonizes H_2O_2-induced rat osteoblastic MC3T3-E1 apoptosis by inhibiting expressions of caspases 3,6,7,and 9

Eucommia ulmoides Oliv.(EuO),also known as Duzhong,native to China,has been reported to have antioxidative function,but its cellular mechanism is not fully examined yet.We investigated inhibitory effects of EuO leaf ethanol extracts on H2O2-induced apoptosis in rat osteoblastic MC3T3-E1 cells and underlying mechanisms.Locally-grown Duzhong leaves were extracted with ethanol.MC3T3-E1 cells were treated with EuO (6.25,12.5,25,50,and 100 μg/ml) for 24 h,and then H2O2 (800 μmol/L) for an additional 24 h.Cell survival rate,percentage of apoptosis,and expressions of caspases 3,6,7,and 9 were examined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay,microscopic analysis,Western blotting,and reverse transcription polymerase chain reaction (RT-PCR).The final EuO leaf ethanol extract powder was detected to contain caffeotannic acid at 58 mg/g and geniposide at 3.45 mg/g by high performance liquid chromatography (HPLC).EuO remarkably restrained cell oxidative damage and increased cell survival rate in a dose-dependent manner: 0 μg/ml,0.21;6.25 μg/ml,0.28;12.5 μg/ml,0.31;25 μg/ml,0.48;50 μg/ml,0.54;and 100 μg/ml,0.66 (P<0.05),with the half-effective concentration being around 25 μg/ml.MTT results were confirmed by microscopic analysis.Western blotting and RT-PCR analyses showed that the expressions of caspases 3,6,7,and 9 were significantly decreased in the EuO-treated cells compared with the control (EuOand H2O2-free) (P<0.05),with the half-effective concentration of EuO ranging from 12.5 to 25 μg/ml.We conclude that the ethanol-extracted EuO leaf extracts promoted the growth of MC3T3-E1 cells,and suppressed the H2O2-induced apoptosis in a rat MC3T3-E1 osteogenic cell model,likely due to the inhibition of caspases’ activities.The results indicate that EuO is a potent antioxidant,which may contribute to its many cellular protective functions,including the promotion of bone growth.

In vitro remineralization of hybrid layers using biomimetic analogs

Resin-dentin bond degradation is a major cause of restoration failures. The major aim of the current study was to evaluate the impact of a remineralization medium on collagen matrices of hybrid layers of three different ad- hesive resins using nanotechnology methods. Coronal dentin surfaces were prepared from freshly extracted premo- lars and bonded to composite resin using three adhesive resins （FluoroBond II, Xeno-III-Bond, and iBond）. From each tooth, two central slabs were selected for the study. The slabs used as controls were immersed in a simulated body fluid （SBF）. The experimental slabs were immersed in a Portland cement-based remineralization medium that con- tained two biomimetic analogs （biomineralization medium （BRM））. Eight slabs per group were retrieved after 1, 2, 3, and 4 months, respectively and immersed in Rhodamine B for 24 h. Confocal laser scanning microscopy was used to evaluate the permeability of hybrid layers to Rhodamine B. Data were analyzed by analysis of variance （ANOVA） and Tukey＇s honest significant difference （HSD） tests. After four months, all BRM specimens exhibited a significantly smaller fluorescent area than SBF specimens, indicating a remineralization of the hybrid layer （P≤0.05）. A clinically applicable biomimetic remineralization delivery system could potentially slow down bond degradation.

数字时代的口腔修复学：1例病例报告

在技术革命的时代潮流中，牙科技术的发展日新月异。整个工作流程已经数字化，修复设计和制作都是通过计算机辅助完成的。这个病例报告描述了使用数字技术进行24颗牙齿重建的过程。

病例报告：应用磁体进行正畸牵引

处理龈下冠根折裂时．若修复不符合生物学宽度的要求．常会引发一系列临床问题。目前已得到认可的修复方法包括用常规矫治器对残根进行正畸牵引，或进行临床冠延长术．再就是将残根拔出后进行修复。综合考虑美观和功能的因素．使用磁体进行正畸牵引也是一个可行措施。该病例即展示了简捷的磁体正畸牵引的方法。

Influence of casein phosphopeptide-amorphous calcium phosphate application,smear layer removal, and storage time on resin-dentin bonding

The aim of this study is to evaluate the influence of Tooth Mousse （TM） application, smear layer removal, and storage time on resin-dentin microtensile bond strength （pTBS）. Dentin specimens were divided into two groups： （1） smear layer covered; （2） smear layer removed using 15% EDTA for 90 s. In each group, half the specimens were treated once with TM for 60 min. After bonding procedures using a two-step self-etching adhesive （Clearfil SE Bond （CSE）; Kuraray Medical, Tokyo, Japan）, an all-in-one adhesive （G-Bond （GB）; GC Corp, Tokyo, Japan）, and a total-etch adhesive （Adper Single Bond 2 （SB）; 3M ESPE, St. Paul, MN, USA）, the specimens were stored for 3 d or 6 months in deionized water at 37 ℃, and pTBS was tested and analyzed. With the exception of SB （no TM application） and GB, the pTBS was significantly increased for CSE and SB using EDTA pre-conditioning and 3 d of storage （P≤0.001）. Bond strength of GB decreased significantly when using EDTA （3 d storage, P〈0.05）. TM application only increased the pTBS of GB （no EDTA） and SB （with EDTA） after 3 d （P≤0.02）. Comparing the adhesives after 3 d of storage, CSE exhibited the greatest pTBS values followed by GB and SB （P≤0.02）. The factors of adhesive, EDTA, and TM did not show any significant impact on pTBS when specimens were stored for 6 months （P〉0.05）. The additional application of TM and EDTA for cavity preparation seems only to have a short-term effect, and no influence on pTBS of dentin bonds after a period of 6 months.

Effect of ultraviolet photofunctionalization of dental titanium implants on osseointegration

Objective： The aim of the current study was to evaluate the effect of ultraviolet（UV） photofunctionalization of dental titanium implants with exposure to the oral cavity on osseointegration in an animal model. Methods： Forty-eight titanium implants（Camlog~？ Conelog~？ 4.3 mmx9.0 mm） were placed epicrestally into the edentulous jaws of three minipigs and implant stability was assessed by measuring the implant stability quotient（ISQ）. Prior to implantation half of the implants were photofunctionalized with intense UV-light. After three months, the implants were exposed and ISQ was measured again. After six months of implant exposure, the minipigs were sacrificed and the harvested specimens were analyzed using histomorphometric, light, and fluorescence microscopy. Main results： Forty-two of 48 implants osseointegrated. The overall mean bone-implant contact area（BIC） was（64±22）%. No significant differences were found in BIC or ISQ value（multivariate analysis of variance（MANOVA）, P〉0.05） between implants with and without exposure to UV photofunctionalization. Conclusions： No significant effects were observed on osseointegration of dental titanium implants nine months after exposure of UV photofunctionalization.