Dentis种植系统的临床效果观察

目的：探讨Dentis种植系统的临床应用效果。方法：对132例牙列缺损患者行Dentis种植体植入,3-6个月后行上部义齿修复,并进行临床和放射学的随访观察。结果：206枚种植体中有2枚在修复后6个月内脱落,其余未见松动、脱落和植入体根周X射线透射区,留存率99.0%,成功率99.0%。结论：选择合适的病例,配合应用相应术式,Dentis种植系统的临床应用效果良好。     

Numerical assessment of the performance of a scalp‐implantable antenna: Effects of head anatomy and dielectric parameters

We numerically assess the effects of head properties (anatomy and dielectric parameters) on the performance of a scalp‐implantable antenna for telemetry in the Medical Implant Communications Service band (402.0–405.0 MHz). Safety issues and performance (resonance, radiation) are analyzed for an experimentally validated implantable antenna (volume of 203.6 mm³), considering five head models (3‐ and 5‐layer spherical, 6‐, 10‐, and 13‐tissue anatomical) and seven scenarios (variations ± 20% in the reference permittivity and conductivity values). Simulations are carried out at 403.5 MHz using the finite‐difference time‐domain method. Anatomy of the head model around the implantation site is found to mainly affect antenna performance, whereas overall tissue anatomy and dielectric parameters are less significant. Compared to the reference dielectric parameter scenario within the 3‐layer spherical head, maximum variations of ?19.9%, +3.7%, ?55.1%, and ?39.2% are computed in the maximum allowable net input power imposed by the IEEE Std C95.1‐1999 and Std C95.1‐2005 safety guidelines, return loss, and maximum far‐field gain, respectively. Compliance with the recent IEEE Std C95.1‐2005 is found to be almost insensitive to head properties, in contrast with IEEE Std C95.1‐1999. Taking tissue property uncertainties into account is highlighted as crucial for implantable antenna design and performance assessment. Bioelectromagnetics 34:167–179, 2013. © 2012 Wiley Periodicals, Inc.     

The Most Appropriate Position and Number for Absolute Anchorages for Orthodontic Tooth Movements

Absolute anchorages proved to be very effective for orthodontic tooth movements. We used a 3D digitizer to record each tooth on pre-treatment diagnostic and post-treatment predictive setup models and then 3D coordinate system conversion was performed to make the coordinate values comparable. An arithmetic calculation of vector and moment based on the orthodontic forces and the tooth displacement under preliminary premises undertaken to decide the most favorable pOsition and number for absolute anchorages. Position-For two-dimensional and three-dimensional calculations, the most appropriate positions for absolute anchorages should theoretically be on the line of resultant force (2D) and the plane (3D) where the total moment effect tends to be zero. Number-As for the number of the absolute anchorages needed, it depends on the number of target teeth. Different combinations of target teeth provide different sets of results.     

Schistosoma japonicum: treatment of different developmental stages in mice with long-acting praziquantel implants

This paper reports the effective treatment of Schistosoma japonicum in a mouse model with long-acting praziquantel (PZQ)-loaded poly(ε-caprolactone) implants. The implants yielded stable, high plasma PZQ concentrations ranging 100–1600 ng/mL during the 40-day investigation period. For assessment of efficacy, the implants were implanted into mice immediately after infection and at 1, 2, 3 and 4 weeks after infection to treat the schistosomes at different developmental stages. All the mice were sacrificed at 6 weeks after infection for worm and egg recovery, worm morphology examination, and histopathological analysis of implantation site tissues. The worm burdens, egg burdens, and numbers of miracidia hatched from the retrieved eggs for all the implant-treated groups (except groups T2-A, T4 and T5) were reduced by 100% when compared with the control group. From groups T2-A, T4 and T5, some schistosome debris was recovered. Eggs were found in only group T5 for which the time between infection and implantation was 4 weeks, which enabled the maturation of juvenile female schistosomes into adult ones that lay eggs. Histopathological observations of implantation tissue showed no evidence of granulomatous foreign-body or lymphoid cell aggregation, demonstrating good biocompatibility of the PZQ implants. These results demonstrate that the long-acting PZQ implants can kill schistosomes at any developmental stages and attenuate/avoid the associated liver damage.     

Modification of the Micro Arc-oxidized Ti Surface for Implant Applications

Surface treatments applied to titanium and its alloys for implant applications are important for the development of bio properties.In this study,first an oxide layer was formed on the surface of the titanium plate by micro arc oxidation,and then both calcium phosphate and calcium phosphate/chitosan accumulation were performed for different samples by the sol-gel method.FE-SEM/EDS examinations,XRD,FTIR and thermal analysis were performed for these micro arc-oxidized,cal-cium phosphate-coated and calcium phosphate/chitosan-coated surfaces.The surface roughnesses for these surfaces were measured between 10 μm and 100 μm,suitable for bone development on the surface.The effect of chitosan addition on the calcium phosphate-coated surface on apatite formation ability and antibacterial properties was investigated.Although the addition of chitosan slows down the formation of apatite,it ensured that the coating had antibacterial properties.The calcium phosphate/chitosan biocomposite obtained can be recommended for dental and orthopedic implants.     

老年糖尿病患者牙周重度破坏后种植研究

目的:研究2型糖尿病老年患者牙周重度破坏后不同血糖水平对于牙齿种植术后炎症指标、种植体稳定性及菌斑指数的影响,探讨患者血糖控制情况和种植牙术后效果的关系。方法:选取我院2011年1月至2013年1月40例在牙周重度破坏后行种植体置入的2型糖尿病老年患者,按照术后8周糖化血红蛋白水平是否≥7.5%分为实验组和对照组,分别测定两组患者术后24小时血常规,对比其白细胞、中性粒细胞及淋巴细胞水平;同时于术后第4、8、12周检测其种植体稳定参数(ISQ);术后3个月、6个月检测其菌斑指数(PLI)。结果:术后24小时,实验组的白细胞、中性粒细胞及淋巴细胞水平显著高于对照组,P0.01;术后第4、8、12周的ISQ值,实验组显著低于对照组,P0.01;术后3个月、6个月的菌斑指数,实验组显著高于对照组,P0.01。结论:2型糖尿病老年患者牙周重度破坏后不同血糖水平与其炎症反应、种植体稳定性及细菌繁殖情况密切相关,控制术前及术后血糖,有利于提高种植体稳定性并降低术后炎症反应,减少细菌繁殖,促进尽早愈合。     

Acetabular morphology and resurfacing design

The bony surfaces of 18 archaeological hemipelves were scanned using a 3D laser surface scanner and CyDir™ software on a Silicon Graphics workstation. The acetabular area was selected and point data from the approximately spherical bone surface saved. These data were input to a MATLAB routine that calculated the radius and centre of the best-fit sphere. The goodness of fit was estimated using the mean and standard deviation of the distance of the bone surface points from the sphere surface. Eight points, at approximately equal distances around the acetabular rim, were selected with reference to bony landmarks. A plane containing three of these points served as an orientation reference plane. The vectors joining the eight rim points to the centre of the best-fit sphere were found. The angles between these vectors and the normal to the reference plane were calculated. Paired angles were summed to give the angle subtended by the acetabular rim in four directions. The overall mean angle was 158° (range of mean angles 145°–173°). The largest individual angles, some exceeding 180°, were in the superior–inferior direction, while the mean angle in the anterior–posterior direction, i.e. that controlling flexion-extension, was 152°. Males had larger subtended angles than females, although the difference was not statistically significant. Simulated reaming increased all angles by approximately 10°. The subtended angles are important parameters in the design of the acetabular component of a hip replacement and particularly important in resurfacing hip replacement when the volume available is tightly constrained.     

Techniques for Processing Eyes Implanted with a Retinal Prosthesis for Localized Histopathological Analysis: Part 2 Epiretinal Implants with Retinal Tacks

Retinal prostheses for the treatment of certain forms of blindness are gaining traction in clinical trials around the world with commercial devices currently entering the market. In order to evaluate the safety of these devices, in preclinical studies, reliable techniques are needed. However, the hard metal components utilised in some retinal implants are not compatible with traditional histological processes, particularly in consideration for the delicate nature of the surrounding tissue. Here we describe techniques for assessing the health of the eye directly adjacent to a retinal implant secured epiretinally with a metal tack.Retinal prostheses feature electrode arrays in contact with eye tissue. The most commonly used location for implantation is the epiretinal location (posterior chamber of the eye), where the implant is secured to the retina with a metal tack that penetrates all the layers of the eye. Previous methods have not been able to assess the proximal ocular tissue with the tack in situ, due to the inability of traditional histological techniques to cut metal objects. Consequently, it has been difficult to assess localized damage, if present, caused by tack insertion.Therefore, we developed a technique for visualizing the tissue around a retinal tack and implant. We have modified an established technique, used for processing and visualizing hard bony tissue around a cochlear implant, for the soft delicate tissues of the eye. We orientated and embedded the fixed eye tissue, including the implant and retinal tack, in epoxy resin, to stabilise and protect the structure of the sample. Embedded samples were then ground, polished, stained, and imaged under various magnifications at incremental depths through the sample. This technique allowed the reliable assessment of eye tissue integrity and cytoarchitecture adjacent to the metal tack.     

The effects of extracellular slime from Staphylococcus epidermidis on phagocytic ingestion and killing

Abstract Extracellular slime (Ecs) from three strains of Staphylococcus epidermidis was prepared and added to fresh suspensions of polymorphonuclear neutrophils. Phagocytic ingestion and killing of opsonised and unopsonised S. epidermidis strains was assessed over time using slide preparations stained by the Gram's method and microbiological culture. Both phagocytic ingestion and killing were inhibited. Investigation as to one possible mechanism of action of Ecs on phagocytes was performed using 1 μ polystyrene spheres which were incubated overnight with Ecs. It was found that the surface tension was altered with Ecs making the beads more hydrophilic, a factor which may interfere with the phagocytic response to infection.     

Prediction of the intramembranous tissue formation during perisprosthetic healing with uncertainties. Part 1. Effect of the variability of each biochemical factor

A stochastic model is proposed to predict the intramembranous process in periprosthetic healing in the early post-operative period. The methodology was validated by a canine experimental model. In this first part, the effects of each individual uncertain biochemical factor on the bone-implant healing are examined, including the coefficient of osteoid synthesis, the coefficients of haptotactic and chemotactic migration of osteoblastic population and the radius of the drill hole. A multi-phase reactive model solved by an explicit finite difference scheme is combined with the polynomial chaos expansion to solve the stochastic system. In the second part, combined biochemical factors are considered to study a real configuration of clinical acts.