应用套筒冠义齿对牙列缺损伴余留牙重度磨耗进行重建

目的对牙齿重度磨耗的老年人牙列缺损患者,用套筒冠义齿修复缺损并重建咬合,观察其临床效果。方法对11例患者先用临时性（牙合）垫义齿恢复其垂直距离,试戴3-6个月合适后改用圆锥型套筒冠义齿修复。结果31例患者100%感觉适应,固位力好,稳定舒适,咀嚼有力。结论对（牙合）重度磨耗的老年牙列缺损患者,套筒冠义齿可有效重建咬合,恢复咀嚼功能,改善面容。

安氏Ⅲ类错中常见矢状向评价指标的可靠性分析

目的:探讨ANB角、Wits值,W角、YEN值和r角对安氏Ⅲ类错畸形患者颌骨矢状关系评价的可靠性。方法:选取80例恒牙列期安氏Ⅲ类错畸形患者的X线头颅定位侧位片,计算其ANB值、Wits值,W角,YEN角、r角及其变异系数,并对测量结果进行相关性分析。结果:5项测量指标变异程度不同,ANB值、Wits值,W角,YEN角、r角的变异系数分别为0.67、0.45、0.04、0.03、0.10,且5项指标间均存在相关性。结论:ANB值、Wits值、W角、YEN角和r角均可作为评价安氏Ⅲ类患者颌骨矢状向关系的指标,但YEN角可能更具有可靠性。

Key technologies of frequency-hopping frequency synthesizer for Bluetooth RF front-end

A scheme of a frequency-hopping frequency-synthesizer applied to a Bluetooth ratio frequency （RF） front-end is presented,and design of a voltage controlled oscillator （VCO） and dual-modulus prescaler are focused on.It is fabricated in a 0.18 μm mixed-signal CMOS （complementary metal-oxide-semiconductor transistor） process.The power dissipation of VCO is low and a stable performance is gained.The measured phase noise of VCO at 2.4 GHz is less than -114.32 dBc/Hz.The structure of the DMP is optimized and a novel D-latch integrated with ＂OR＂ logic gate is used.The measured results show that the chip can work well under a 1.8 V power supply.The power dissipation of the core part in a dual modulus prescaler is only 5.76 mW.An RMS jitter of 2 ps is measured on the output signal at 118.3 MHz.It is less than 0.02% of the clock period.

Clinical Application of TESCERA^TM ATL Indirect Composite Inlay and Onlay

Objective: A new indirect composite restorative system with water combingpressure, light, and heat was introduced for the fabrication of inlays and onlays. Methods: Fifteendefected teeth were selected for composite resin inlay and onlay fabrication with Tescera ATL unitequipment. The clinical trial was carried out for 3 months. Results: After 3 months test, 7parameters were checked, 15 Tescera inlays and onlays were demonstrated that exceptional esthetics,all 7 parameters were good and the patients were very satisfied. Conclusion: inlays , which weremade with Tescera ATL restorative system, are esthetics; physical properties of materials areimproved highly, and have a long-lasting durability. This restorative system is worthy to be usedand further studied in dental practice.

Distalization of maxillary molars for Class Ⅱ malocclusion with Chinese Ni-Ti coil-springs appliance

Objective: To evaluate the effects of the Chinese Ni-Ti coil-springs appliance on distalization of maxillary molars and the reciprocal effects on the anchorage teeth. Methods:Twenty-four adolescent patients(12 boys,12 girls) with Class Ⅱ malocclusion were selected and the coil-springs appliance was used during the treatment. Pre- and postdistalization lateral cephalometric radiographs were analyzed and compared. Results: The average time for the correction of Class Ⅱ molar relationship was 4.6 months. And the mean distance of molar distalization was 4.4 mm. The Chinese Ni-Ti coil-springs also demostrated less tipping and better bodily movement of maxillary molars. Conclusion: This study suggests that the Chinese Ni-Ti coil-springs appliance distalizes the upper molar significantly, while there is no remarkable loss of anchorage because of patients’ wearing headgear with J hooks at night and Class Ⅱ elastics in the day time.

Solidification of Be-free Ni-based dental alloy

A novel, Nb- and Si-rich and Be-free Ni-based alloy was cast by two methods of investment casting and continuouscasting to study the microstructure evolution during solidification and its mechanical properties. The solidification of the alloy startedwith the primary crystallization of FCC-γ, followed by a binary eutectic reaction, with the formation of a heterogeneous constituent：FCC-γ＋G-phase, which replaced the low-melting eutectic （FCC-γ＋NiBe） in the Be-bearing alloys. AlNi6Si3 and γ′ formed during theterminal stages of solidification by investment casting, while the formation of AlNi6Si3 was suppressed by continuous casting. TheScheil solidification model agreed very well with the experimental results.

Infection frequency of Epstein-Barr virus in subgingival samples from patients with different periodontal status and its correlation with clinical parameters

Objective: To detect the infection frequencies of different genotypes of Epstein-Barr virus (EBV) in subgingival samples from chronic periodontitis (CP) patients, and to discuss the correlation between infection with EBV and clinical pa-rameters. Methods: Nested-PCR assay was used to detect EBV-1 and EBV-2 in subgingival samples from 65 CP patients, 65 gingivitis patients and 24 periodontally healthy individuals. The amplicons were further identified by restriction fragment length polymorphism analysis (RFLP) with endonucleases Afa I and Stu I. Clinical parameters mainly included bleeding on probing (BOP), probing depth (PD), attachment loss (AL) in six sites of the dentition. Results: In CP patients, gingivitis and periodontally healthy individuals, the infection frequencies were 47.7%, 24.6% and 16.7% for EBV-1, and 15.4%, 7.7% and 0% for EBV-2, respectively. In 2 out of the 65 CP patients co-infection of EBV-1 and EBV-2 was found. The positive rate of EBV-1 in chronic periodontitis patients was higher than that in gingivitis patients (P=0.01) and periodontally healthy individuals (P=0.01). But no significant difference was shown in EBV-1 frequency between gingivitis patients and healthy individuals (P>0.05) or in EBV-2 frequency among the three groups (P>0.05). In CP patients, higher mean BOP value was found in EBV-1 or EBV-2 positive patients than that in EBV negative ones (P<0.01), but with no statistical difference in the mean PD or AL value between EBV positive and negative patients (P>0.05). After initial periodontal treatment, 12 out of the 21 EBV-1 positive CP patients did not show detectable EBV-1 in subgingival samples. Conclusion: nPCR plus RFLP analysis is a sensitive, specific and stable method to detect EBV-1 and EBV-2 in subgingival samples. Subgingival infection with EBV-1 is closely associated with chronic perio-dontitis. Infection of EBV in subgingival samples was correlated with BOP.

Comparison of Clinical Effects of Au-Pt Based and Ni-Cr Based Porcelain Crowns

Objective To compare the long-term clinical effects of two kinds of crowns and bridges made of porcelain fused to Au-Pt alloy and Ni-Cr alloy. Methods A total of 131 teeth (64 patients) were rehabilitated using porcelain-fused-to-metal crowns, among which 59 were rehabilitated with Au-Pt alloy metal ceramic crown and 72 with Ni-Cr alloy metal ceramic crown. The porcelain fracture, shade, marginal adaptation, gingival discoloration, and gingival status after finishing restoration and 36 months of follow-up were evaluated. Results After 36 months of restoration, porcelain fused to Au-Pt alloy crown showed better clinical effects than porcelain fused to Ni-Cr alloy crown in shade, marginal adaptation, gingival discoloration, as well as gingival status (all P<0.05). Conclusion The Au-Pt alloy ceramic crown is superior to Ni-Cr alloy ceramic crown in long-term clinical effects.

Interspecific Hybridization Between Crassostrea angulata and C. ariakensis

lnterspecific hybridization can generate heterosis, which is proven to be a useful tool in selective breeding programs for oyster culture. Crassostrea angulata and C. ariakensis are two important economic shellfish species in China. We conducted 2 × 2 reciprocal crosses to determine whether these two species can cross-fertilize and their hybrids can hatch, survive and perform hetero- sis. Fertilization was found symmetrical without delay. The rate of fertilization success of C. angulata ♀× C. ariakensis ♂ was lower than that of C. ariakensis ♀ x C. angulata ♂, and the success rate of both hybridizations was lower than that of two intraspecific crosses each. During the planktonic period, survival rate of the progeny was lower in the hybrid crosses than in the intraspecific crosses. On day 360, mean shell height of the progeny of C. angulata ♀ x C. angulata ♂ was highest, which was followed by that of C. angulata ♀ × C. ariakensis ♂, C. ariakensis ♀x C. ariakensis ♂ and C. ariakensis ♀× C. angulata ♂ in a descending order. Mor- phology of adults produced by the hybrid crosses was similar to that of C. angulata. Both hybrids underwent normal gonad devel- opment and produced mature gametes in the mating season. This study provided new insights into the quantitative traits in interspeci- fic crosses of Crassostrea species, thus being of guidance value for selective breeding of oyster.

The bonding bite plate combined with the face mask protracting maxilla to treat skeletal crossbite in the early mixed dentition

Objective： To evaluate the orthopedic effects of a new method to treat skeletal crossbite in the early mixed dentition. Methods ：Twenty cases （5.8-7. 5 years old ） with skeletal crossbite were treated by bonding the bite plate combined with the face mask protracting the upper jaw. Cephalometric radiographs were taken and analyzed before and after treatments. Results： On average, in all 20 cases the maxilla was moved by 2.06 mm forwards the mandible was turned 2.45° downward and backwards the skeletal crossbites were corrected and the facial profiles were improved satisfactorily. The period of treatment was conducted for 1.7 months on average. Conclusion： A good effect can be achieved by bonding bite plate combined with the face mask protracting the upper jaw to treat skeletal crossbite in the early mixed dentition, which will benefit the craniofacial growth and the development of young children.

Impact and Benefits of Micro-Databases＇ Integration on the Statistics of the Banco de Portugal

Data are critically important to good decision-making. In an increasingly complex economy, conventional data collecting schemes are no longer sufficient. To deal with the challenge of maintaining its statistics relevant to the users in an ever-shifting environment, the Banco de Portugal decided to explore the largely unused statistical potential of the available micro-databases and to integrate the existing administrative and survey data, thus enhancing the basic information infrastructure while protecting confidentiality. This presentation will address the benefits and problems to be dealt with when two or more data-sources are to be integrated.

Critical Factors in Financing and Management of Light Rail Transit Systems： Delphi Methodology Approach

In recent years, a large number of LRT （light rail transit） networks and tramways have been built in Spain using the tender system. The rhythm of construction has been such that very few analyses have been carried out and those that have were only partially done because the main participants involved had ulterior motives which impeded their having a critical and independent opinion of the projects carried out. Within this framework, the Delphi methodology presents itself as a very useful instrument, as the intrinsic advantages that it has added to the characteristic that the experts who participate in the project can remain anonymous without detracting value from the conclusions obtained as these are grouped together according to their worth.

The application of nanotechnology in the improvement of dental composite resins

In this paper, nanotechnology for the improvement of dental composite resins has been reviewed in the background of the existing shortcomings, focusing on the improvement for polymerization shrinkage, anti-bacterial properties and mechanical properties of composite resins. The results show that the use of nanotechnology and nano materials can be an effective method to improve the performance of dental composite resins in a various ways. At last, the paper also discusses the perspective about the dental composite resins.

A comparative study of SPECT/CT fusion imaging and CT in infiltrated mandible by gingival carcinoma

Objective： The aim of the study was to evaluate the clinical value of ^99mTc-methylene diphosphonic acid （MDP） SPECT/CT fusion imaging and CT scanning in diagnosis of infiltrated mandible by gingival carcinoma. Methods： 18 cases of gingival carcinoma were processed infiltrated mandible by ^99mTc-MDP SPECT/CT fusion image and CT, and their scanning results compared with pathology findings. Results： Eleven of 13 cases with well-differentiated squamous cell carcinoma showed positive images, one of 11 cases was false positive images by pathology findings, and 10 cases were exhibited infiltrated mandibles; 5 cases with moderately differentiated and poorly differentiated squamous call carcinoma showed positive images, pathology showed carcinoma call had infiltrated cavum ossis of mandible. Five of 18 cases were positive images by CT. Conclusion： ^99mTc-MDP SPECT/CT fusion imaging is a useful method in diagnosis of infiltrated mandible by gingival carcinoma.

Design principle for parameters and interferences of tungsten carbide insert interface on roller bits

The lifetime of roll-bits with inserted tooth will be obviously decreased while drilling in strata and the tungsten carbide can be integrally separated from the roll-cone,which will need more trip out time to replace the roller bit.This study provides an entire analysis on stress as well as strength for teeth and tooth holes in loaded conditions.Qualities of tooth drop from matrix within roller bit.The optimized interferences of teeth inserted into the bit can be reasonably obtained by the critical interference derived from some relevant influence factors on the tooth-fixing quality of roller bits.

The Portuguese Newspapers Market Between Consolidation and Concentration Strategies

The main objective of this research is to assess the existence （or lack） of media concentration in the Portuguese dailies newspaper sector, and to evaluate the extension to which this situation may be compromising fundamental society values： freedom of speech and right of access to information. Authors resorted to market indicators, namely total average circulation,number of copies per issue, business volume and advertising investments. These indicators are found to be complementary： some indicators evaluate group position in the readers＇ market, whereas other evaluates group position in the general market and the advertising market in particular. Based in this market information, we used quantitative models （HII, CR4 and Noan） to measure de concentration in the newspaper segment. Additionally we tried to demonstrate that to analyze the dailies newspaper concentration situation in Portugal a holist perspective of the media market is needed, using a country context to understand some local characteristics and market structure and political, economic, social and technological dynamics. Additionally, there are evidences that existing concentration indexes are not conclusive because of potential replacement effects in the Portuguese media sector.

THERAPEUTIC EFFECT OF NON-SURGICAL TREATMENT OF CHRONIC PERIODONTITIS IN DIABETIC CHINESE

Objective To observe the therapeutic effect of non-surgical treatment on diabetic Chinese withchronic periodontitis. Methods Moderate to advanced chronic periodontitis ( CP) was studied in 36 diabetes mellitus (DM) patients classified as 20 with high and fluctuating blood glucose level (DM-H) and 16 with relatively low and stable blood glucose level (DM-L). 28 non-DM CP patients acted as controls (Non-DM). Plaque index (PlI) , gingival index (GI) , bleeding on probing (BOP) , probing depth (PD) and clinical attachment loss (AL) of all patients were recorded at 6 sites on each tooth at the baseline and 1, 3 and 6 months after oral hygiene instruction (OHI), scaling and root planing. Results It was found that the short-term effect of non-surgical periodon-tal procedure had resulted in significant resolution of gingival inflammation and pronounced reduction in pocket depth and gain of attachment loss in both DM and Non-DM CP patients. Conclusion The pilot study suggested that non-surgical periodontal treatment allowed for favorable treatment responses in a group of Chinese diabetic subjects with chronic periodontitis and that their various profiles of blood glucose did not influence the short-term healing response to OHI, scaling and root planning.

Treatment of Toothache by Puncturing Hegu （LI 4）

To observe the clinical effect in the treatment of toothache by puncturing Hegu（LI 4）. Methods： Two hundred and seventy-eight cases of the patients were randomly divided into the treatment group （139 cases） and the control group （139 cases）. The treatment group was treated by puncturing Hegu （LI 4） with electric stimulation and the control group, by puncturing Chenshan （BL 57） with electric stimulation, for 3 days as one course of the treatment, to grade pain and observe the anesthetic effect respectively. Results： There was no significant difference in the remarkable effective rate between the two groups before withdrawal of the needle in the treatment for one day （P〉0.05）. In the other times, the remarkable effective rate was obviously higher in the treatment group than in the control group （P〈0.05）, Conclusion： Acupuncture on Hegu （LI 4） is effective in treating toothache.

Effects on cytotoxicity and antibacterial properties of the incorporations of silver nanoparticles into the surface coating of dental alloys

The aim of this study was to research the changes in cytotoxicity and antibacterial properties after silver nanoparticles （AgNPs） were incorporated into the surface coating of dental alloys. AgNPs were attached to cobalt chromium alloys and pure titanium using a hydrothermal method, according to the reaction： AgNO3＋NaBH4-, Ag＋1/2H2＋1/2B2H6＋NaNO3. A 3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyl tetrazolium bromide （MTT） assay was used to evaluate the cytotoxicity of the alloys when in contact with osteogenic precursor cells （MC3T3-E1） from mice and mesenchymal stem cells （BMSC） from rats. The antibacterial properties of dental alloys incorporating three different concentrations （10, 4, and 2 μmol/L）of AgNPs were tested on Staphylococcus aureus （SA）and Streptococcus mutans （MS）. High cytotoxicity values were observed for all dental alloys that contained 0% of AgNPs （the control groups）. The incorporation of AgNPs reduced cytotoxicity values. No significant difference was observed for antibacterial performance when comparing dental alloys containing AgNPs to the respective control groups. The results demonstrated that the cobalt chromium alloys and pure titanium all had cytotoxicity to MC3T3-E1 and BMSC and that the incorpo- ration of AgNPs could reduce this cytotoxicity. The concentrations of AgNPs adopted in this study were found to have no antibacterial action against SA or MS.

Toxicity testing of four silver nanoparticle-coated dental castings in 3-D LO2 cell cultures

To address the controversial issue of the toxicity of dental alloys and silver nanoparticles in medical ap- plications, an in vivo-like LO2 3-D model was constructed within polyvinylidene fluoride hollow fiber materials to mimic the microenvironment of liver tissue. The use of microscopy methods and the measurement of liver-specific functions optimized the model for best cell performances and also proved the superiority of the 3-D LO2 model when compared with the traditional monolayer model. Toxicity tests were conducted using the newly constructed model, finding that four dental castings coated with silver nanoparticles were toxic to human hepatocytes after cell viability assays. In general, the toxicity of both the castings and the coated silver nanoparticles aggravated as time increased, yet the nanoparticles attenuated the general toxicity by preventing metal ion release, especially at high concentrations.