一次性注射器填充级HDPE专用料的研制

通过对母料载体树脂的筛选,无机填料的选择,添加性能优良的耐辐射助剂,制成了具有耐辐射性能、加工性能良好的母料,该母料的制备工艺简单。本文所述的填充级HDPE专用料是将HDPE与填充母料经过简单掺混制成的。经测试专用料满足国家医药标准YY 0114—93《医用输液、输血、注射器聚乙烯专用料》的要求。制品厂试验表明:该填充级的HDPE专用料加工性能良好,用该填充级HDPE专用料注射成型的注射器芯杆装配成一次性注射器满足国家专业标准ZBC 31009—87《一次性无菌注射器》的要求。该填充母料的加入可大大降低材料的成本,100份HDPE 7006A可添加67份填充母料,该填充级专用料的价格比HDPE树脂降低约1500元/吨,因此该填充级HDPE专用料的推广和使用具有良好的经济效益。     

Chipping fracture resistance of dental CAD/CAM restorative materials: Part I – Procedures and results

Objective

The edge chipping test was used to measure the fracture resistance of CAD/CAM dental restoration ceramics and resin composites.

Methods

An edge chipping machine was used to evaluate six materials including one feldspathic porcelain, two glass ceramics, a filled resin-composite, a yttria-stabilized zirconia, and a new ceramic-resin composite material. Force versus edge distance data were collected over a broad range of forces and distances. Data were analyzed by several approaches and several chipping resistance parameters were evaluated. The effects of using different indenter types were explored.

Results

The force versus distance trends were usually nonlinear with good fits to a power law equation with exponents usually ranging from 1.2 to 1.9. The order of chipping resistance (from least to greatest) was: feldspathic porcelain and a leucite glass ceramic (which were similar), followed by the lithium disilicate glass ceramic and the two resin composites (which were similar), and finally the zirconia which had the greatest resistance to chipping. Chipping with a Vickers indenter required 28–45% more force than with the sharp conical 120° indenter. The two indenters rank materials approximately the same way. The power law exponents were very similar for the two indenters for a particular material, but the exponents varied with material. The Rockwell C indenter gives different power law trends and rankings.

Significance

Despite the variations in the trends and indenters, simple comparisons between materials can be made by chipping with sharp conical 120° or Vickers indenters at 0.50 mm. Broad distance ranges are recommended for trend evaluation.     

Cariogenicity of soft drinks, milk and fruit juice in low-income african-american children: a longitudinal study

BACKGROUND: The authors conducted a study to test the hypothesis that high consumption of soft drinks, relative to milk and 100 percent fruit juice, is a risk factor for dental caries in low-income African-American children in Detroit. METHODS: Trained dentists and interviewers examined a representative sample of 369 children, aged 3 to 5 years, in 2002-2003 and again two years later. The authors used the 2000 Block Kids Food Frequency Questionnaire (NutritionQuest, Berkeley, Calif.) to collect dietary information. They assessed caries by using the International Caries Detection and Assessment System. RESULTS: Soft drinks, 100 percent fruit juice and milk represented the sugared beverages consumed by the cohort. A cluster analysis of the relative proportion of each drink at baseline and follow-up revealed four consumption patterns. Using zero-inflated negative binomial models, the authors found that children who changed from being low consumers of soft drinks at baseline to high consumers after two years had a 1.75 times higher mean number of new decayed, missing and filled tooth surfaces compared with low consumers of soft drinks at both time points. CONCLUSION: Children who consumed more soft drinks, relative to milk and 100 percent fruit juice, as they grew older were at a greater risk of developing dental caries. CLINICAL IMPLICATIONS: Health promotion programs and health care providers should emphasize to patients and caregivers the caries risk associated with consumption of soft drinks.     

疝环填充式和平片式无张力疝修补术治疗腹股沟疝的手术疗效研究

目的：对比分析疝环填充式和平片式无张力疝修补术治疗腹股沟疝的手术疗效及并发症情况。方法：回顾性分析80例腹股沟疝患者的临床资料,其中行疝环填充式无张力疝修补术患者42例,行平片式无张力疝修补术患者38例,对比分析两组的手术效果。结果：两组在手术时间、术中出血量及术后下床活动时间、住院时间方面比较,差异不显著,但B组行平片式无张力疝修补术的平均费用明显低于A组,两组比较,差异有显著统计学意义,P〈0．01。各组80％以上患者体温均小于38．5℃,两组均无一例出现切口感染。但两组患者术后尿潴留的发生率均较高,术后随访1年,两组均在术后不同时间出现1例复发病例,其余并发症如术后阴囊水肿及局部异物感等各组比较,差异不显著,P〉0．05。结论：疝环填充式和平片式无张力疝修补术治疗腹股沟疝手术效果相似,但平片式无张力疝修补术费用略低一些,更适合基层医院推广和应用。     

几种常用及新型充填材料密合度的实验研究

目的 :为前牙及后牙充填选择合适的材料提供依据。方法 :将 75颗离体牙分为五组 ,分别充填银汞合金 ,银汞合金 +粘接剂 ,复合树脂 ,玻璃离子 ,DyractAP。所有离体牙均进行染料渗透试验 ,观察染料渗漏深度。结果 :单纯银汞合金充填渗漏率最大 ,与银汞合金 +粘接剂组渗漏率具有显著性差异 (p <0 0 1) ;复合树脂、GC及DyractAP相比 ,DyractAP密合度最好 ,三者渗漏率具有显著性差异 (p<0 0 5 )。结论 :对于后牙面充填 ,银汞合金粘接修复是首选方法。对于楔状缺损及根颈部缺损 ,以Dyract较好。     

佛山市中小学生龋病流行病学调查

按世界卫生组织规定的标准和方法,对佛山市中小学生龋病的患病情况进行了抽样调查,并与1983年全国中小学生龋病牙周病调查中佛山市的结果进行比较,结果显示佛山市中小学生,无论乳恒牙的龋均和患龋率都无显著变化,但充填率却有大幅度提高。     

2010年广西灵山县高中生龋齿患病情况调查

目的了解广西灵山县高中生恒牙患龋情况,探索发生龋齿的原因及防治对策。方法对灵山县在校学生每年进行1次学生健康检查。检查结果经数据统计处理后,对学生患龋率、龋均、龋失补率进行流行病学分析。结果学生总患龋率为19.44%,男生为15.58%,女生为23.19%;学生总龋均为0.48,男生为0.36,女生为0.60,患龋率和龋均在男女生之间有统计学意义差异(P0.01)。学生总体充填比率为14.79%,男生为17.31%,女生为13.31%,差异有统计学意义(P0.01)。不同年级学生患龋情况比较,患龋率高二学生最高(22.04%),充填比率高三最高(17.66%),患龋率和充填比率在高二与高三之间差异有统计学意义(P0.01);城镇学生患龋率为22.16%,农村学生患龋率为16.52%;城镇学生龋均为0.51,农村学生龋均为0.45,患龋率和龋均在城镇学生和农村学生之间差异有统计学意义(P0.01)。充填比率在城镇学生和农村学生之间差异无统计学意义(P0.05)。结论灵山县高中生恒牙龋均较高,患龋率较低,充填比率也较低,应继续加强口腔健康教育,进行定期检查、窝沟封闭和充填治疗,以降低患龋率和龋均。     

Microtensile bond strength of a filled vs unfilled adhesive to dentin using self-etch and total-etch technique

OBJECTIVE: The purpose of this study was to evaluate the effect of a filled adhesive (One-Step Plus; Bisco) versus an unfilled adhesive (One-Step; Bisco) on the microtensile bond strength (muTBS) to dentin using total-etch (Uni-etch; Bisco) and self-etch (Tyrian SPE; Bisco) techniques. METHODS: Twenty extracted human third molars were ground flat to expose occlusal dentin. After the dentin surfaces were polished with 600-grit SiC paper, the teeth were randomly assigned to four groups according to the bonding agent and technique being used. Dentin surfaces were bonded with One-Step Plus+total-etch; One-Step Plus+self-etch; One-Step+total-etch and One-Step+self-etch. Composite buildups were performed with Clearfil AP-X (Kuraray Medical). Following storage in distilled water at 37 degrees C for 24 h, the bonded specimens were serially sectioned into 0.7 mm-thick slabs and then trimmed to hour-glass shapes with a 1 mm2 cross-sectional area (n=20). Microtensile bond strengths were determined using the EZ-test (Shimadzu) at a cross-head speed of 1 mm/min. Data were analyzed using two-way ANOVA and Tukey's post hoc test. RESULTS: There were no significant differences in the muTBS between One-Step Plus and One-Step adhesives when they were used with the total-etch and self-etch techniques (p>0.05). However with the total-etch technique both adhesives yielded significantly higher bond strength values than the self-etch technique (p<0.001). CONCLUSION: The filled adhesive One-Step Plus did not show any beneficial effect than the unfilled adhesive One-Step on the muTBS to dentin with total-etch and self-etch techniques. Irrespective from the adhesive type, self-etch technique revealed lower bond strengths than the total-etch technique.     

经皮激光椎间盘汽化减压术结合硬膜外填充术临床研究

目的观察并比较单纯行硬膜外填充术或单纯行经皮椎间盘汽化减压术（PLDD）与两法结合的治疗效果。方法选取腰椎间盘突出症患者384例,随机分为3组：单纯行硬膜外填充术治疗组90例,单纯行PLDD术治疗组89例,PLDD术结合硬膜外填充术治疗组205例。于治疗前和治疗后3、12个月采用VAS评估疼痛程度,并观察治疗前后临床体征变化。结果单纯行PLDD术治疗组显效、有效、好转、无效依次为89．8％（79／89例）、4．5％（4／89例）、4．5％（4／89例）、2．2％（2／89例）;单纯行硬膜外填充术治疗组显效、有效、好转、无效依次为75．6％（68／90例）、11．1％（10／90例）、o．0％（0／90例）、13．3％（12／90例）;PLDD术结合硬膜外填充术治疗组显效、有效、好转、无效依次为96．6％（198／205例）、3．4％（7／205例）、0．0％（0／205例）、0．0％（0／205例）。结论PLDD术结合硬膜外填充术治疗腰椎间盘突出症疗效优于单纯行硬膜外填充术或单纯行PLDD术。