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Table of Content
20 February 2002, Volume 20 Issue 01
  • Development of GI- Ⅱ Tinted Inf iltration Glass and Determination of Its Properties
    West China Journal of Stomatology. 2002, 20(01):  7-9. 
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    Glass is the weak phase in the glass-alumina composite , and it plays a key role in determining the physical , me2 chanical and optical properties. The purpose of this study was to explore the fabrication arts of GI- Ⅱtinted infiltration glass and de2 termine its properties.Methods : The thermal properties of the glass were tested on a TMA2940 thermal analyzer with heating rate of 5 ℃Pmin and temperature range of 25~750 ℃. The bar- shaped specimens were prepared with the size of 25 mm×5 mm ×2 mm and their flexural strengths and elastic modulus with 3-point bending test were measured. The Vicker’s hardness and indenta2 tion fracture toughness were also determined. The refractive index and changes of chemical constituents were tested by means of V prismatic refractometer and 2910 DTA analyzer. Results : The results showed that the thermal expansion coefficient , Tg and Tf , refractive index , 3-point bending flexural strength , bending elastic modulus , Vicker’s hardness , indentation fracture toughness and density were 61997 ×10 - 6 ℃- 1 (25~500 ℃) , 635 ℃and 650 ℃, 1164 MPa , 96127 MPa , 31116 GPa , 51534 GPa , 1105 MN·m1P2 , and 31214 gPcm3 respectively. Though certain heat processing conditions did result in micro-crystalline in the glass , it remained stable under routine glass infiltration firing cycles.Conclusion :GI- Ⅱtinted infiltration glass had favorable physical , me2 chanical properties and good thermal stability.

    The Biological Effects of Recombinant Human Bone Morphogenetic Protein 2 on Human Periodontal Ligament Fibroblasts
    Si Xiaohui,Liu Zheng
    West China Journal of Stomatology. 2002, 20(01):  10-12. 
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    The purpose of this study is to study the biological effects of recombinant human bone morphogenetic protein 2 (rhBMP2) on human periodontal ligament fibroblasts (HPDLFs) . Methods : Human periodontal ligament fibroblasts were primary cultured and detected the different doses of rhBMP2 on their proliferation , alkaline phosphatase (ALP) activity , osteocalcin (OC) synthesis and formation of the mineralized nodules. Results : rhBMP2 (0125~2 mgPml) had no remarkable effect on the prolifera2 tion of HPDLFs. The ALP activity , OC synthesis and formation of the mineralized nodules of HPDLFs were significantly stimulated by 015~2 mgPml rhBMP2. Conclusion : The effects of rhBMP2 on HPDLFs are dose- dependent. Not only can rhBMP2 stimulate the expression but also promote the maturation of osteoblastic phenotype of HPDLFs.

    A Study of Tarnish Induced by Streptococcus sobrinus Serotype g on Co-Cr , Ni-Cr and Casting Titanium Alloys
    Song Yingliang,Xu Junwu,Ma Xuanxiang,et al
    West China Journal of Stomatology. 2002, 20(01):  14-17. 
    Abstract ( 942 )   HTML ( 1 )   PDF(pc) (94KB) ( 342 )   Save
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    The objective of this study was to investigate the tarnish induced by Streptococcus sobrinus serotype g on Co-Cr , Ni-Cr and casting titanium alloys.Methods :Co-Cr , Ni-Co and casting titanium alloys were respectively machined into a size of 10 mm ×10 mm×1 mm in tablets , and totally 90 specimens with 30 of each were prepared for the test. The 30 specimens of each al2 loy were randomly and equally divided into three subgroups , including the blank control group , the media control group and the in2 oculated media group. Under the aerobic condition , the surfaces of the sucrose agar media were inoculated with Streptococcus sob2 rinus serotype g. The labeled sterile specimens were placed on the surface of the media for 10 weeks. The specimens were changed to a new sucrose media with bacteria each week. The specimens were removed after 10 weeks of incubation , immersed in 0105 % glutaraldehyde solution to eliminate AaY4 , rinsed with distilled water. After 2 weeks , the specimens were removed and observed visually or examined by MINOLTA CR-100 color apparatus. Results :Compared with the blank control , the control media without bacteria did not influence the alloy specimens ( P > 0105) . Streptococcus sobrinus serotype g caused tarnish on specimens. There was significant difference between the control media group and the blank control group with inoculated media group on all the spec2  imens ( P < 0105) . Conclusion : Streptococcus sobrinus serotype g affects the color of Co-Cr , Ni-Cr and casting titanium alloys ,but the color does not change from yellow-green range to red-yellow range.

    Effects of the Mechanical Stress on the Proliferation and Function of Osteoblast-like Cells in vitro
    Zheng Yi,Chen Guoping,Zhou Zheng,et al
    West China Journal of Stomatology. 2002, 20(01):  18-20. 
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    The aim of this study was to investigate the effects of the mechanical stress on the proliferation and function of os2 teoblast-like cells (UMR106) of rats , and further to explore the mechanism of remodeling of periodontium from an angle of me2 chanics. Methods :The flow cytometry and MTTmethod was used to examine the number of osteoblasts-like cells and their prolifer2 ation and metabolic enzymic activity 6 h , 12 h , 18 h , 24 h , 30 h , and 36 h after the top- bottom axial stress (225 ×g) was exert2  ed on the UMR106 in vitro. Results :The difference of cell phase fraction and function between the experimental group and the con2 trol group were of great significance ( P < 0101) . The maximum SPF increasing and functional decreasing appeared 12 h after the appliance of the stress , and all indexes were no significantly different between the two groups 24 h after the stress was supplied. Forward light scatter had no remarkable alteration.Conclusion :The top- bottom axial stress (225 ×g) could inevitably influence the proliferation and function of osteoblast-like cells without pathological damage occurred.

    A Study of Rebuild of A Three- dimensional Anatomic Model of Mandibles
    Zhao Baodong,Li Ningyi
    West China Journal of Stomatology. 2002, 20(01):  21-23. 
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    The aim of this study was to rebuild the anatomic structures of the mandibular bone and the canal , and to testify the reliability of the rebuilt model.Methods :15 mandibular bones with teeth are chosen , and a three- dimensional model was built with the method of CT. The slices vertical to the compensating curve were made in every dental position. Then the authors collect2 ed the data of alveoli and mandibular canal in every slice. The same work was done to the bone specimen , and then comparative analysis was done. Results :The wideness of the alveoli and 10 mm bellow increased from mesial to distal position. It was the same of the alveoli from the top to the bottom. The mandibular canal lied in the inner and inferior side of the mandibular body. There was no significant difference in data collected with these two methods.Conclusion :Different types of dental implants should be cho2 sen according to the anatomic characteristic of the mandibular bone in every dental position before the operation to avoid complica2 tions. And a reliable , accurate and direct method of planning an implant operation is to rebuild a three- dimensional model.

    Application of Carotid Artery Reconstruction in Head Neck Malignancy
    Sun Jian,Zhang Zhiyuan,Ye Weimin,et al
    West China Journal of Stomatology. 2002, 20(01):  24-26. 
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    The purpose of this study was to establish an ideal operation method to deal with head and neck carcinomas of late stage and involving the carotid.Methods : A total of four metastasized head neck carcinomas involving the carotid arteries were in2 cluded in this clinical trail. The primary tumors of the four cases tumors were carcinomas of tongue , esophagus , laryngeal and pa2 rotid glands. All four cases were examined by means of TCD , DSA , SPECT to confirm good compatibility of brain blood circulation before operations. The bony petrous sections of carotid arteries were drawn off after the exposure of the bone tissue for exterior skull . A by-pass was set up by inserting a shunt tube between the common carotid and the infernal carotid artery. The extended tu2 mor resection was carried out involving the resection of the carotid artery. The artery was reconstructed with saphena magna vein transplantation in one case , and replaced by artificial vessels in two cases. Tissue defects were repaired by pedicle PMMF.Re2 sults : The B-typed ultrasound and TCD examination two weeks to six months post-operatively showed the four cases revealed good condition of transplanted carotid arteries , except one case occurred Honer’s syndrome , but there was no central nerve’s symptom or complication in the other three cases.Conclusion :This operation method could provide a good chance of survival by curettage of later staged head neck tumors. The authors recommend reconstruction of carotid artery in the operation treatment of malignant head neck carcinomas during late stages.

    A Retrospective Study of Clinical Manifestation and Human Papilloma Virus Detection of Oral Condyloma Acuminate in Children
    He Zhixiu,Liu Laikui,Chen Yan
    West China Journal of Stomatology. 2002, 20(01):  27-29. 
    Abstract ( 1415 )   HTML ( 2 )   PDF(pc) (155KB) ( 950 )   Save
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    The aim of this study is to study genotype , transmission , clinical and pathological characteristics , and prognosis of oral condyloma acuminate (CA) in children. Methods : The authors retrospected the clinical characteristics and slices of HE staining of six cases which have been diagnosed as oral CA and , performed immunohistochemistry ( IHC) and in situ hybridization ( ISH) analysis to detect the DNA of human papilloma virus in 5 cases. Results : Oral CA often happened in the hard or soft plates of children of two-year-old. Most of them came from the families had been infected by human papilloma virus (HPV) . Histological examination demonstrated that koilocytes were common in the upper spinous and corneal layers. HPV was detected in all cases. HPV16P18- E6 antigen was positive in 4 of 5 cases examined. The result of ISH only show one case was HPV6- and HPV11- posi2 tive , and the other case was HPV-positive , but HPV could not be detected when recurring.Conclusion : The pathogen leading to oral condyloma acuminate (CA) and the transmission way of children may be different from that of adults.

    The Effectiveness and Reliability of Skin Paddles of Free Fibula Flaps in Reconstruction of Maxillofacial Defects
    Mao Chi,Peng Xin,Yu Guangyan,et al
    West China Journal of Stomatology. 2002, 20(01):  30-32. 
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    The paper reviewed the effectiveness and reliability of skin paddles of free fibula flaps in the reconstruction of maxillofacial defects.Methods :Fifty-five consecutive free fibula osteocutaneous flap transfers performed fromJune 21 , 1999 to Oc2 tober 31 , 2000 were reviewed. The skin paddles of each flap were analyzed in terms of surgical design , blood supply , size , recon2 struction location , and survival. Results :Fifty- seven skin paddles were used for the 55 free fibula flaps (double skin paddles for 2 flaps) , 37 were nurtured by one perforator , 18 by two and two by 3 perforators. Twenty-eight skin paddles were used for intraoral reconstruction , 7 for extraoral reconstruction , 1 for both intraoral and extraoral reconstruction , 2 for soft tissue augmentation , and the remaining 19 were simply used as windowfor monitoring the blood flow of fibula flap. One free fibula flap with one skin paddle was lost because of venous thrombosis , and the other 54 flaps survived completely , with 100 % survival of 56 skin paddles.Con2 clusion :The skin paddle of free fibula flap is safe and reliable. It can be used for all kinds of soft tissue reconstruction , as well as window for monitoring the blood flow of fibula flap after operation.

    Observation of Vasoactive Intestinal Polypeptide in Patients with Trigeminal Neuralgia : A 16-cases Report
    Zhao Yunfu,Jiang Xiaozhong,Liu Yuan,et al
    West China Journal of Stomatology. 2002, 20(01):  33-34. 
    Abstract ( 861 )   HTML ( 0 )   PDF(pc) (147KB) ( 444 )   Save
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    The aim of this study was to observe whether vasoactive intestinal polypeptide (VIP) participated in the attack of trigeminal neuralgia , and to understand further its pathogenetic mechanism.Methods :Sixteen patients were studied. During the at2 tacks the venous blood was sampled from both the external jugular vein and cubital fossa vein ipsilateral to the pain , and after op2 erations the venous blood from the external jugular vein was sampled again , the external jugular vein blood of eleven normal volun2 teers was collected as the control. Plasma levels of VIP were determined using sensitive radioimmunoassays.Results :During the at2 tacks of trigeminal neuralgia the levels of VIP in the external jugular vein blood were significantly higher than that in the cubital fossa vein blood , postoperative external jugular vein blood and the external jugular vein blood of normal volunteers.Conclusion : VIP indeed participates in the attack of trigeminal neuralgia in the local region , the role of VIP may be relating to enhancing the effects of substance P in local neurogenic inflammation.

    Soft Tissue Changes of Patients with Skeletal Class ⅡMalocclusion after Orthodontic and Surgical Treatments
    Chen Kaiyun,Zheng Yi,Wang Xin,et al
    West China Journal of Stomatology. 2002, 20(01):  35-38. 
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    One of the prime concerns of both the orthodontist and the oral surgeon must be the final soft tissue profile and the esthetic appearance of the patient. The purpose of this study was to evaluate the amount , direction , and predictability of the soft tissue changes associated with simultaneous skeletal changes.Methods :The authors analyzed the recent 22 cases with skeletal class II malocclusion in Orthodontic Department , College of Stomatology , West China University of Medical Sciences with 7 male and 15 female from 20 to 30 years old. Each patient was taken standardized lateral cephalograms before the treatment and 6~12 months after the treatment. A total of 16 hard and soft tissue landmarks were evaluated in both horizontal and vertical directions.Results : In the horizontal directions , the soft tissue maxillary landmarks (superior labial sulcus , labrale superius , and upper lip stomion) moved posterior with a range of 2. 17 to 2. 33 mm. The strongest correlations were found between the posterior movement of the up2 per incisal edge and the three soft tissue parameters : superior labial sulcus r = 0. 78 , labrale superius r = 0. 81 , upper lip stomion r = 0. 75. The softPhard tissue ratios of the mandible anterior movement is 0. 83∶1 between inferior labial sulcus and B point , and 0. 95∶1 for Pog′to Pog. In the vertical directions , all the soft tissue mandible landmarks (Pog′, inferior labial sulcus , labrale in2 ferius , lower lip stomion) moved upward more than 2 mm. And the softPhard tissue ratio is from 1. 07∶1 to 1. 34∶1. Conclusion : The combined orthodontic and surgical treatment is an efficient way to cure skeletal class II malocclusion. All the patients regained satisfactory face appearance and profile. Although the soft tissue movement is less than the hard tissue in both jaws in the horizontal direction , the vertical movement of the mandibular soft tissue is greater than that of the underlying hard tissue.

    Fracture Strength of Custom-fabricated Celay All-ceramic Post and Core
    Zhang Yuxing,Lu Zhiyue,Wang Keli,et al
    West China Journal of Stomatology. 2002, 20(01):  39-41. 
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    The purpose of this study is to compare the fracture strengths of custom-fabricated Celay all-ceramic post-core , custom cast metal post-core , and prefabricated stainless steel post (Parapost) plus composite resin core with or without a 2. 0 mm dentine ferrule.Methods :A total of 60 recently extracted human maxillary central incisors were endodontically treated and divided into five groups of 12. They were given the following treatments : Group A: Celay ceramic post-core with 2. 0 mm dentine ferrule , Group B : Celay ceramic post-core with no dentine ferrule , Group C: cast metal post-core with 2. 0 mm dentine ferrule , Group D: cast metal post-core with no dentine ferrule , and Group E: prefabricated post and composite core with 2. 0 mm dentine ferrule. All specimens were stored at 100 % humidity at room temperature for 30 days before testing. Each specimen was in a special jig at a 45°angle to the long axis and subjected to a load on MTS 810 universal material testing machine until failure , with crosshead speed of 0. 02 cmPmin. Analysis of variance followed by the Newman- Keuls pairwise multiple comparison test was used to compare the results of the groups tested. Results :There was a statistically significant difference between five groups ( P < 0. 01) . Celay ceramic post-core with 2. 0 mm dentine ferrule ( 758. 35 N ±119. 26 N) and cast metal post-core with 2. 0 mm dentine ferrule (756. 63 N ±166. 22 N) had a significantly larger mean failure threshold for fracture than the other three groups which had no sig2  nificant difference between each other. There was a statistically significant difference between the fracture resistance of Celay postcore restored teeth with and without 2. 0 mm dentine ferrule.Conclusion :The custom-fabricated Celay post-core could be a choice for clinical use in endodontically treated tooth when the final restoration is an all-ceramic crown and the preparation has a 2. 0 mm dentine ferrule.

    A Clinical Study on Immediate Implantation of Particulate Hydroxylapatite Artif icial Bone after Teeth Extraction
    Liu Lei,Li Shengwei,Tian Weidong
    West China Journal of Stomatology. 2002, 20(01):  42-44. 
    Abstract ( 842 )   HTML ( 0 )   PDF(pc) (155KB) ( 442 )   Save
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    The aimof this study is to investigate the effect and complication of immediate implantation of particulate hydroxy2 lapatite artificial bone after teeth extraction.Methods : Particulate hydroxylapatite artificial bone was implanted into 65 extraction sockets after teeth extraction. All patients were followed up until 3 months after the operation. They are examined with clinical ex2 amination and X- ray examination to observe the effect and complication of the implantation operation.Results :The wound healed well in all cases without any complication. Compared to the alveolar ridge before teeth extraction , and the height of the alveolar ridge after teeth extraction didn’t decrease. Conclusion : Implantation of particulate hydroxylapatite artificial bone after teeth extrac2 tion could maintain the height of the alveolar ridge and reduce the complication of teeth extraction. It would be helpful for the fol2 lowing prosthetic restoration. The immediate implantation of artificial bone is therefore needed further study.

    McNamara Cephalmetric Analysis of the 67 Chengdu Adolescents with Normal Occlusions
    Wang Yanmin,Zhou Li,Gao Hui
    West China Journal of Stomatology. 2002, 20(01):  45-47. 
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    The purpose of this study was to obtain the normal value of McNamara analysis for Chengdu adolescents with nor2 mal occlusion of early permanent dentition.Methods : McNamara analysis was conducted on the basis of the lateral cephalograms of 67 Chengdu adolescents with normal occlusions , and the obtained data was compared with that of Shanghai adolescents and Mc2 Namara. Results : There was no difference in the normal values of McNamara analysis between male and female Chengdu adoles2 cents. The Comparative results between Chengdu and Shanghai adolescents indicated significantly larger values of Shanghai adoles2 cents in effective middle facial lengths , mandibular lengths and lower anterior facial heights. The vertical distances from the upper incisor to point A and , from the lower incisor to A- Po line of Chengdu adolescents were larger than those of white adolescents. Conclusion : There is significantly difference in values of normal occlusions of McNamara analysis among different regions and dif2 ferent races.

    The Association between IL-1 Gene Polymorphisms and Susceptibility to Severe Periodontitis
    Duan Haiyan,Zhang Jincai,Zhang Yunhui
    West China Journal of Stomatology. 2002, 20(01):  48-51. 
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    The purpose of this study was to investigate the relationship between IL-1 gene polymorphisms and susceptibility to severe periodontitis in Chinese of the Han Nationality.Methods : DNA samples with buccal swabs were collected from 30 pa2 tients with severe adult periodontitis (AP) , 20 patients with rapid progressive periodontitis (RPP) and 94 healthy control (HC) in2 dividuals. Polymorphisms in the IL-1 gene cluster were analyzed with PCR-RFLP. Results : It was found that the frequency of IL-1B + 3953PTaq I allele 2 was significantly higher in severe AP patients ( OR = 6. 8 , P < 0. 05) and RPP patients ( OR = 9. 6 , P < 0. 05) than in healthy controls , and the frequency of IL-1RN intron IIPVNTR allele 2 was significantly higher in the group of severe AP patients ( OR = 6. 3 , P < 0. 05) than in the group of healthy controls. Conclusion : IL-1B + 3953PTaq I allele 2 and IL-1RN intron IIPVNTR allele 2 are genetic indicators of susceptibility to severe AP and RPP , and both AP and RPP are genetic heterogeneous.

    Suppression Effect of Human Tumor Necrosis Factor-α Gene Transfection on Tongue Carcinoma Cells
    Gao Zhennan,Li Shengwei,Gao Jiarang,et al
    West China Journal of Stomatology. 2002, 20(01):  52-54.  doi:人肿瘤坏死因子-α|舌癌|基因转染|阳离子脂质体
    Abstract ( 800 )   HTML ( 0 )   PDF(pc) (155KB) ( 469 )   Save
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    The aim of this study was to investigate suppression effects of the transfection of human tumor necrosis factor- α (hTNF-α) gene on tongue carcinoma cells.Methods : The shuttle plasmid containing hTNF-α gene was extracted and purified, then it was transferred into Tca8113 tongue carcinoma cells with cationic liposome DOSPER. The control group was only given equivalent liposomes , except the plasmid. After culturing for 24 , 48 , 72 and 96 hours , the expression of hTNF- αgene in Tca8113 cells was analyzed by ELISA and , the survival rate of transferred cells was assayed byMTT enzymatic labeling technique.Results : The transferred Tca8113 cells displayed significantly overexpression of hTNF-α ( P < 0. 05) . The survival rate of the transferred Tca8113 cells was decreased significantly ( P < 0. 05) . Conclusion : Transfection of hTNF-αgene in vitro mediated by cationic li2 posomes can induce the overexpression of hTNF-αand inhibit the growth of tongue carcinoma cells.

    Synergistic Effects of Human Tumor Necrosis Factor-α Gene Transfection and Interferon-γ on the Growth of Tongue Carcinoma Cells
    Gao Zhennan,Li Shengwei,Gao Jiarang,et al
    West China Journal of Stomatology. 2002, 20(01):  55-57. 
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    The purpose of this study is to investigate the synergistic effects of human tumor necrosis factor-α (hTNF-α) trans2 fection and interferon-γ ( IFN-γ) on the growth of tongue carcinoma cells.Methods : The cultured Tca8113 tongue carcinoma cells was divided into 2 groups , one group was transferred with hTNF-αgene. Each of the 2 groups was then divided into 5 subgroups , and the subgroups were added IFN-γuntil the final IFN-γconcentrations respectively were 0 , 10 , 100 , and 1000 UPml. After cul2 turing for 48 hours , the survival rates of the all groups of cells were assayed byMTT enzymatic labeling technique , and the expres2 sion of hTNF-αin Tca8113 cells was observed with immunocytochemistry. Results : IFN-γdid not affect the growth of Tca8113 cells without hTNF-α, however , the transfection of hTNF-αwith the above different concentrations of IFN-γ synergistically inhibited the growth of Tca8113 cells , the concentrations of IFN-γwere positively correlated with the inhibition effects ( r = 0. 733 , P < 0. 01) , the transferred Tca8113 cells displayed remarkable overexpression of hTNF-α, compared with the non-transferred. Conclusion : IFN-γcan enhance the inhibition effects of hTNF-αtransfection on the tongue carcinoma cells.

    Preparation of Nanometer Powders of Dental Alumina Ceramics
    Zhao Ke,Chao Yonglie,Yang Shiyuan,Wang Junxia
    West China Journal of Stomatology. 2002, 20(01):  58-61. 
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    The purpose of this study was to explore the preparation method of nanometer powders of dental alumina ceram2 ics. Methods : The effects of concentration of inorganic precursors , pH value , calcination temperature and ageing time on the syn2 thesizing process , phase composition and microstructure of the materials were studied. Aluminium nitrate with concentrations of 0103 molPL , 0105 molPL , 011 molPL and 012 molPL were used as inorganic precursors to prepare alumina powders via sol-gel method. Ammonia water was added into the solutions to adjust the pH values to 5 , 9 and 11. The dried gel was then calcined un2 der different temperatures , from 950 ℃to 1200 ℃. The prepared alumina powders were studied by using X- ray diffraction (XRD) , and scanning electron microscope (SEM) . Results : The alumina powder which was prepared with 0. 1 molPL aluminium nitrate , pH 9 , and calcined at 1200 ℃for 10 min showed good physical characteristics. The diameter of final powder was about 70 nm. Conclusion : With the proper preparation condition , weakly agglomerated powders of alumina in nanometer particle size could be obtained.

    Construction of the Pyruvate Oxidase Gene Def iciency Variant Strain of Streptococcus oralis
    Pang Ruoyu,Zhang Rong,Zhang Yunhui,et al
    West China Journal of Stomatology. 2002, 20(01):  62-65. 
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    The purpose of this study is to construct a pyruvate oxidase gene deficiency variant strain of Streptococcus oralis ( S . oralis) . Methods : The sopox gene , which was got using polymerase chain reaction (PCR) , and the 130- basepair segment of which was cut down with endonuclease BamHI , and transferred into S . oralis (ATCC10557) by using electrotransformation. The authors obtained a variant strain of S . oralis , and then the catalase activity of the first culture and 3-4 subcultures was examined. Results : The authors obtained a pyruvate oxidase gene deficiency variant strain of S . orlis. The catalase activity examination showed that the ability of producing H2O2 of the variant strain of S . orlis declined , whose catalase activity was between those of the positive control (ATCC10557) and the negative control ( Escherichia coli , JM109) . But the produced H2O2 quantity of their subcultures was less than that of the negative control.Conclusion :The construction of the pyruvate oxidase gene deficiency variant strain of Streptococcus oralis is successful.

    The Prevalence of Permanent Caries in Adolescent in Sichuan Province
    Wan Huchun,Hu Deyu,Li Xue,et al
    West China Journal of Stomatology. 2002, 20(01):  66-68. 
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    The aim of this survey was to obtain some information of the prevalence of dental caries in the youth aged 12 , 15 and 18 years of Sichuan province.Methods : Based on WHO and national oral health survey standards , dental caries prevalence and treatment needs were investigated randomly in selected young individuals of Sichuan province in 1995.Results : The prevalent rates of caries of 12- , 15- , and 18-year-old adolescents were 28. 47 % and 36. 40 % and 39. 54 % respectively. The mean DMFT of 12- , 15- and 18-year-old were 0. 52 , 0. 81 , and 0. 99. There are more pit and fissure caries than smooth caries in the young of 12-year-old than those of 15- and 18-year-old. Conclusion : Despite improvement can be seen in adolescents’oral health in Si2 chuan , there remains a proportion of active untreated decays. Some simple prevention programs are needed to stabilize the caries.