Cellular and Molecular Tissue Response to Triple Antibiotic Intracanal Dressing

Introduction

The aim of this study was to characterize the response of mouse subcutaneous tissue to triple antibiotic paste (TAP) using conventional light microscopy and real-time PCR (qRT-PCR).

Methods

Polyethylene tubes containing TAP or calcium hydroxide (CH) (ie, the control group) were implanted in mouse subcutaneous tissue. Animals that received empty tubes or no tubes were used as additional controls. After periods of 7, 21, and 63 days postimplantation, the specimens were removed and subjected to histologic processing. The number of inflammatory cells and vessels, vessel areas, vascular density, and relative percentage of collagen were evaluated. Gene expression of proinflammatory (interleukin-1 beta, tumor necrosis factor alpha, and interleukin 17) and anti-inflammatory (transforming growth factor beta) cytokines and angiogenic factors (vascular endothelial growth factor and hypoxia-inducible factor-1 alpha) was quantified by 7 and 21 days postimplantation. Results were analyzed using the Student t test, analysis of variance, and the Tukey test (α = 0.05).

Results

TAP induced an exuberant inflammatory and angiogenic response, with higher numbers of inflammatory cells, higher vascular area and density, and lower relative percentage of collagen compared with CH. In general, the expression of genes involved in inflammation and angiogenesis was higher in the TAP group compared with animals that received CH or empty tubes.

Conclusions

The response of mouse subcutaneous tissue to TAP was characterized by exuberant and persistent inflammatory and angiogenic responses with no repair and high gene expression of biomarkers associated with inflammation and angiogenesis.     

Osmolarity and root canal antiseptics

Antiseptics used in endodontics for disinfection purposes include root canal dressings and irrigants. Osmotic shock is known to cause the alteration of microbial cell viability and might have a role in the mechanism of action of root canal antiseptics. The aim of this review was to determine the role of osmolarity on the performance of antiseptics in root canal treatment. A literature search using the Medline electronic database was conducted up to 30 May 2013 using the following search terms and combinations: ‘osmolarity AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; osmolality AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; osmotic AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; osmosis AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm; sodium chloride AND root canal or endodontic or antiseptic or irrigation or irrigant or medication or dressing or biofilm’. Publications were included if the effects of osmolarity on the clinical performance of antiseptics in root canal treatment were stated, if preparations with different osmolarities values were compared and if they were published in English. A hand search of articles published online, ‘in press’ and ‘early view’, and in the reference list of the included papers was carried out following the same criteria. A total of 3274 publications were identified using the database, and three were included in the review. The evidence available in endodontics suggests a possible role for hyperosmotic root canal medicaments as disinfectants, and that there is no influence of osmolarity on the tissue dissolution capacity of sodium hypochlorite. There are insufficient data to obtain a sound conclusion regarding the role of hypo‐osmosis in root canal disinfection, or osmosis in any further desirable ability.     

微波辐射加氢氧化钙根管封药治疗瘘管型慢性根尖周炎的疗效观察

目的 观察微波辐射加氢氧化钙根管封药治疗瘘管型慢性根尖周炎的临床疗效。方法 选择148例150个患牙，随机分成两组。实验组78颗患牙，采用微波辐射加氢氧化钙甘油糊剂治疗；对照组72颗患牙，采用传统的甲醛甲酚根管封药；1周后复诊行根管充填，1a后作疗效对比观察。结果 微波辐射加氢氧化钙根管封药，显效率84．6％，总有效率98．5％；甲醛甲酚一次封药，显效率41．70％，总有效率86．1％。两组疗效有显著性差异（P〈0．05）。结论 微波辐射加氢氧化钙根管封药是一种治疗瘘管型慢性根尖周炎的高效、安全的方法。     

氢氧化钙和洗必泰抑制粪肠球菌的抗菌性检测

目的:检测氢氧化钙和洗必泰凝胶根管封药对粪肠球菌的抑制作用。方法:将成功建立粪肠球菌感染的60个根管模型,随机分成4组,每组15个样本,分别用氢氧化钙、20 g/L洗必泰凝胶、氢氧化钙和20 g/L洗必泰凝胶联合、生理盐水(空白对照组)进行根管内封药处理,14 d后,分别用5号和6号GG钻钻取根管内壁层深0～100μm和100～200μm的牙本质,收集碎屑,用BHI梯度稀释后进行细菌培养和计数。结果:无论在根管壁深0～100μm处,还是100～200μm处,空白组均有大量的细菌生长,而3个实验组根管内粪肠球菌明显减少,分别与空白对照组相比,差异均具有统计学意义(P<0.05);各实验组之间相比,氢氧化钙组活菌数最高,与其他两组相比,差异均有统计学意义(P<0.05),其次为20 g/L洗必泰凝胶组,氢氧化钙联合洗必泰组最低,但与单独使用洗必泰组相比,差异无统计学意义(P>0.05)。结论:在根管封药中,氢氧化钙和洗必泰均对粪肠球菌有较好的抗菌性,其中洗必泰凝胶的抑菌作用更强。     

浅谈中药不良反应的原因

目的：研究各类中药的不良反应所造成的原因;方法：分别从中药的毒性、药量、辩证、配伍、炮制、剂型等九个方面,分别讨论会引起使用中药的不良反应;讨论：医、药、护人员都要严格按要求合理使用中药,患者也应接受正确的药物治疗教育,杜绝因服用中药不当而引起的不良反应.     

Susceptibility of Candida albicans and Enterococcus faecalis to Chitosan,Chlorhexidine gluconate and their combination in vitro

The aim of the present study was to analyse the sustain release of Chlorhexidine with Chitosan and to investigate the antimicrobial activity of 2% Chlorhexidine gel, 2% Chitosan gel and their combination against Candida albicans and Enterococcus faecalis. Sustain release of Chlorhexidine with Chitosan was determined using UV spectrophotometer. Then the inoculae of these organisms were used to make the lawn culture on sabouraud's dextrose agar and blood agar plates. Wells were prepared in these lawn cultures and filled with 2% Chlorhexidine gel, 2% Chitosan gel and their combination. The agar plates were incubated overnight at 37°C and the zone of inhibition was examined after 48 h. Release of Chlorhexidine with Chitosan was better than plain Chlorhexidine release. Combination of Chlorhexidine and Chitosan showed maximum inhibitory zone for C. albicans (25.2 mm) and E. faecalis (26.0 mm). Plain Chlorhexidine gel showed intermediate inhibitory zone for C. albicans (20.6 mm) and E. faecalis (21.4 mm) and plain Chitosan gel showed minimum inhibitory zone for C. albicans (16.6 mm) and E. faecalis (11.0 mm). Carbopol which served as control did not have any antimicrobial effect. The present study suggests that 2% Chlorhexidine gel in combination with 2% Chitosan gel has the highest antimicrobial effect against C. albicans and E. faecalis compared with 2% Chlorhexidine gel or 2% Chitosan gel alone.     

Effect of calcium hydroxide treatment on periodontal repair and root resorption

Abstract Pulpal application of calcium hydroxide is a common treatment for external root resorption. Several mechanisms of action have been suggested. In the present investigation, the effect of pulpal calcium hydroxide on cells at the root surface and in the periodontal ligament was studied by means of scanning-electron microscopy and light microscopy. Lateral incisors in monkeys were extracted, a groove was made- in the root surface and the teeth were then immediately replanted. The pulps of some teeth were infected by bacteria from the saliva. Application of calcium hydroxide in the root canal caused a limited necrosis of the cells resorbing dentin as well as the cells forming reparative cementum in the experimental groove. In the non-infected teeth, a temporary ankylosis developed. The high pH having a bactericidal and necrotizing effect seemed to be sufficient to explain the therapeutic effect of calcium hydroxide on root resorption.     

Contact allergy to furazolidone

A case of occupational contact allergy to furazolidone, used as an animal feed additive and as an antimicrobial drug in veterinary medicine, is described. The patient did not react to furazolidone 2% pet. Using PEG-400 and alcohol as patch test vehicles resulted in positive patch test reactions. No cross-reactions were observed to other nitrofuran derivatives (nitrofurazone, nitrofurantoin) or to furfural. The literature on contact allergy to nitrofurans is reviewed.     

自制氢氧化钙糊剂与临床常用根管消毒剂抗菌效果及细胞毒性的实验室性能比较

目的：依据ISO7406技术报告和中国医药行业标准YY0268-1995,前期实验室研制一种便于临床使用的氢氧化钙糊剂,与目前临床使用的根管消毒剂的抗菌效果及细胞毒性进行性能比较。方法：通过琼脂扩散法、培养基稀释法和四唑盐比色法（MTT）比较所研制的氢氧化钙糊剂（CHCM）与氢氧化钙/生理盐水、氢氧化钙牙胶尖（Roeko,Calcium Hydroxide Plus）、45%苯甲酚溶液（Ⅰ）和45%甲醛甲酚溶液（Ⅱ）的抗菌性和细胞毒性。结果：45%甲醛甲酚溶液（Ⅱ）的抗菌效果最好,氢氧化钙糊剂（CHCM）次之,氢氧化钙牙胶尖和氢氧化钙/生理盐水糊剂抗菌效果不如其他实验组。45%甲醛甲酚溶液（Ⅱ）在2、3、4d的细胞毒性程度为2级,在5 d为3级。氢氧化钙/生理盐水的细胞毒性程度为0级。氢氧化钙糊剂（CHCM）、氢氧化钙牙胶尖和45%苯甲酚溶液（Ⅰ）的细胞毒性程度为1级。结论：研制的氢氧化钙糊剂其生物安全性符合ISO7406技术报告和中国医药行业标准YY0268-1995中的有关要求,与氢氧化钙/生理盐水、氢氧化钙牙胶尖、45%苯甲酚溶液（Ⅰ）和45%甲醛甲酚溶液（Ⅱ）相比具有良好的抗菌效果和生物安全性。