An in vitro biological and anti-bacterial study on a sol–gel derived silver-incorporated bioglass system

OBJECTIVES: The purpose of this study was to evaluate the in vitro antibacterial and biological activity of silver-incorporated bioactive glass system SiO(2)-CaO-P(2)O(5)-Ag(2)O (AgBG). The bacteriostatic and bactericidal properties of this new quaternary glass system along with the ternary sol-gel glass system SiO(2)-CaO-P(2)O(5) (BG) have been studied using Escherichia coli as a test micro-organism. The AGBG system thus appears to be a promising material for dental applications, since similar effects might be produced on a film of bacteria and mucous that grows on the teeth. METHODS: The SiO(2)-CaO-P(2)O(5)-Ag(2)O and SiO(2)-CaO-P(2)O(5) glass systems were synthesized by the sol-gel technique and characterized for their physicho-chemical properties. The antibacterial activity and biological properties were evaluated by determining the minimum inhibitory concentrations (MICs). Release of Ag(+) into the culture medium was measured by inductively coupled plasma (ICP) analysis. RESULTS: The in vitro antibacterial action of the SiO(2)-CaO-P(2)O(5)-Ag(2)O was compared with that of its ternary counterpart glass system. The concentrations of Ag-bioglass, in the range of 0.02-0.20mg of Ag-bioglass per millilitre of culture medium, were found to inhibit the growth of these bacteria. The Ag-bioglass not only acts bacteriostatically but it also elicited a rapid bactericidal action. A complete bactericidal effect was elicited in the early stages of the incubation at Ag-bioglass concentration of 20mg/ml and the ternary glass system had no effect on bacterial growth or viability. The antibacterial action of Ag-bioglass was exclusively attributed to the leaching of Ag(+) ions from the glass matrix. SIGNIFICANCE: One of the major advantages of incorporating silver ions into a gel glass system is that the porous glass matrix can allow for controlled sustained delivery of the antibacterial agent to dental material, used even under anaerobic conditions such as deep in the periodontal pocket. This glass system also provides long-term action required for systems which are constantly at risk of microbial contamination.     

芦荟凝胶用于治疗儿童口腔复发性溃疡的临床观察

目的:检验芦荟凝胶治疗儿童复发性口腔溃疡的疗效。方法:自行研制芦荟凝胶,以中药开喉剑喷雾剂作为对照,检验其治疗儿童复发性口腔溃疡的临床效果。结果:芦荟凝胶与开喉剑喷雾剂的效果相当,在缩小溃疡面积、改善充血情况、减轻疼痛、减少溃疡数目方面均没有显著差异。结论:芦荟凝胶对于儿童复发性口腔溃疡具有较好的临床治疗效果,是较理想的儿童口腔辅助药物。     

Effects of different fluoride recharging protocols on fluoride ion release from various orthodontic adhesives

Objective

The purpose of this study was to find the most effective fluoride recharging protocol for orthodontic adhesives.

Methods

Five orthodontic adhesives were used: a non-fluoride-releasing composite, a fluoride-releasing composite, a polyacid-modified composite (compomer), and two resin-modified glass-ionomer cements (RMGICs). Each specimen was placed into deionized water (DW) and the initial fluoride ion release was measured for 2 months. Each specimen was then subjected to four different treatments to simulate a fluoride recharge: 1000 ppm NaF solution, acidulated phosphate fluoride gel (APF), fluoride-containing dentifrice and DW (control). After topical fluoride treatment, each specimen was submitted to fluoride re-release tests.

Results

Fluoride-containing adhesives initially showed higher rates of fluoride ion release, but significantly declined to lower levels. The overall cumulative fluoride ion release during the initial period was RMGICs > compomer > fluoride-containing composite > non-fluoride-releasing composite. After topical fluoride treatment, the amount of fluoride ion re-released was proportional to the amount of fluoride ion previously released from the adhesives. However, the amount of fluoride ions released only lasted for 2 days and then returned to the levels before fluoride application. The overall cumulative fluoride ion re-release according to the fluoride treatments was APF and NaF solution > dentifrice.

Conclusion

This study suggests that using the combination of RMGICs and a fluoride-containing mouth rinse solution is the most effective protocol for long-term fluoride re-release from orthodontic adhesives, given the difficulty of routine use of APF at home, although all topical fluoride treatments can recharge fluoride ion in adhesives.     

Fluoride profiles in different sites of approximal surfaces of second primary molars after topical application of acidulated phosphate fluoride gel in vivo

Thirty-four (17 paired) extracted second primary molars were obtained from 17 individuals (9 boys and 8 girls) aged from 9 yr 2 months to 12 yr 7 months. A tooth on one side was extracted as a control, and an acidulated phosphate fluoride (APF) gel was then applied to the paired contralateral second primary molar. Three months later, the experimental tooth was extracted. Nine sites were assayed by a microsarapling technique from small areas of the approximal enamel surface. The fluoride and phosphorus concentrations were determined by a fluoride electrode and by colorimetric procedure, respectively. Fluoride concentrations were higher in the teeth treated with the APF gel than in the control teeth. The highest fluoride uptake was observed in the central area of the approximal surfaces. Deeper areas (>10 μm) had a marked uptake of fluoride as compared with surface areas (< 3 μm). It was concluded that the APF gel application increased the fluoride levels of approximal tooth surfaces, particularly the mid-central site, of second primary molars, even at 3 months after application.     

三色散凝胶贴膏剂的HPLC指纹图谱研究和多元成分含量测定

目的  建立三色散凝胶贴膏剂的HPLC指纹图谱,同时对其多种成分进行含量测定,为其质量控制提供依据。方法  采用Hypersil Gold C₁₈色谱柱(250 mm×4.6 mm,5 μm),流动相为乙腈-0.1%磷酸水溶液,梯度洗脱,流速为1.0 mL/min,柱温为30 ℃,检测波长为240 nm,进样量为20 μL,建立三色散凝胶贴膏剂的HPLC指纹图谱,运用《中药色谱指纹图谱相似度评价系统》2012A版对其进行相似度评价;采用外标法,利用混合对照品测定12个成分的含量。结果  在选定的色谱条件下建立了三色散凝胶贴膏剂的HPLC指纹图谱,共标定16个共有峰,与对照品比对出12个成分,10批三色散凝胶贴膏剂的相似度在0.943~0.994之间;12个成分在一定浓度范围内均成良好的线性,相关系数均大于0.999 1,平均加样回收率在95.35%~99.43%之间,RSD均小于3.0%,12个成分在10个批次中的含量基本一致。结论  建立的三色散凝胶贴膏剂指纹图谱及含量测定方法,准确可靠,重复性好,可为进一步完善三色散凝胶贴膏剂的质量控制提供参考。      

广东省东莞市2012—2018年黄金海岸沙门菌临床分离株的病原学特征

目的 通过分析2012—2018年东莞市黄金海岸沙门菌临床分离株的病原学特征,为早期发现该罕见血清型沙门菌引起的聚集病例的及时干预和控制提供病原学依据。方法 对东莞市2012—2018年食源性疾病监测中分离的30株黄金海岸沙门菌临床分离株进行复核鉴定、血清分型、抗生素敏感性试验和脉冲场凝胶电泳（PFGE）的分子分型。结果 30株黄金海岸沙门菌抗原式均为6,8∶r∶l,w,每年菌株数量的构成比有随年度增加而增高的趋势,且差异有统计学意义（χ²=19.67,P<0.05）。东莞市黄金海岸沙门菌对磺胺异噁唑、四环素、复方新诺明、氯霉素、链霉素的耐药率较高,分别为90.0%、90.0%、80.0%、80.0%和76.7%;对头孢他啶、头孢噻肟、头孢吡肟、亚胺培南的敏感率达到100%;对3类及3类以上抗生素耐药的菌株数达到25株,占比为83.33%。30株黄金海岸沙门菌共分为12个PFGE 型,其中2种PFGE型包含条带的相似率为100%的谱型分别为DG-GC06型15株和DG-GC12型3株。结论 东莞市黄金海岸沙门菌的构成比在2012—2018年间呈逐年上升趋势,多重耐药现象严重,且存在潜在暴发现象,应加强暴发发现、流行病学调查及耐药监测。     

硅胶胃管留置时间的研究

报道９０例重型颅脑损伤病人胃管留置时间的研究。随机将病人分为３组，置管时间甲组１１～２０天；乙组２１～３０天；丙组３１～４０天。结果：甲组与乙组对鼻、咽粘膜影响差异无显著性；乙组与丙组差异有显著性。结论：硅胶胃管留置适宜时间是２１～３０天。     

异维A酸红霉素凝胶联合胶原蛋白敷料治疗中度寻常性痤疮疗效观察

目的:观察异维A酸红霉素凝胶联合胶原蛋白敷料治疗中度寻常性痤疮的临床疗效及安全性。方法:96例中度寻常性痤疮患者,随机分为治疗组和对照组各48例。对照组外用异维A酸红霉素凝胶,1次/天,治疗6周;治疗组在对照组基础上联合使用胶原蛋白敷料,1次/天,每次30min,连续使用4周,第5~6周隔日使用1次。疗程均为6周。结果:治疗组愈显率和有效率分别为89.58%和100.00%,对照组为66.67%和91.67%,两组疗效比较差异均有统计学意义(P0.05)。治疗组发生轻度局部刺激反应率为12.50%,对照组为10.42%,均未发现任何全身不良反应,两组用药不良反应比较差异无统计学意义(P0.05)。结论:异维A酸红霉素凝胶联合胶原蛋白敷料贴敷治疗痤疮安全、有效,可临床推广应用。     

自体脂肪游离移植在矫正面部局部凹陷性畸形中的临床应用

目的:探究自体颗粒脂肪游离移植在面部美容中的临床应用疗效,为临床上提供更为合理的治疗方案。方法:回顾性研究我院2010年2月~2012年4月,81例面部局部凹陷性畸形患者,其中观察组采用自体颗粒脂肪游离移植的方法,对照组采用硅胶进行治疗,比较两组患者的治疗效果。结果:观察组患者治疗的总有效率为90.74%,对照组患者治疗的有效率为85.52%,两组患者的治疗效率之间没有显著差异,P0.05,观察组患者不良反应的发生率为移位(0%)、排斥反应(0%)、局部红肿5.56%、局部硬结3.70%明显低于对照组14.81%、18.52%、29.63%和22.22%,P0.05。结论:自体颗粒脂肪游离移植在面部美容中具有较好的临床效果以及较少的副作用,值得推广使用。     

膨体聚四氟乙烯与固体硅胶隆鼻术后肿胀的临床分析比较

目的:临床分析比较膨体聚四氟乙烯和固体硅胶两种假体隆鼻术后的肿胀厚度消退速度,为医生与就医者选择膨体聚四氟乙烯或者固体硅胶假体提供临床资料依据。方法:将就医者分为膨体聚四氟乙烯假体组和固体硅胶假体组,运用面部三维重建技术,观察比较两组就医者在隆鼻术前、术后1天、术后3天、术后5天和术后7天肿胀厚度的变化。结果:隆鼻术后1~7天,无论是膨体聚四氟乙烯组还是固体硅胶组肿胀厚度都降低。术后1、3、5、7天比较膨体聚四氟乙烯组与固体硅胶组肿胀厚度,差异无统计学意义(P0.05)。结论:膨体聚四氟乙烯组与固体硅胶组隆鼻术后肿胀厚度消退速度趋于一致,无显著差异。从术后肿胀的角度告知医生和就医者,在隆鼻术时选择膨体聚四氟乙烯或者固体硅胶假体均可,在肿胀厚度消退速度方面的区别不大。