【作者】 陈敏慜；

【导师】 谢晓莉；

【作者基本信息】 中南大学 ， 口腔临床医学， 2008， 硕士

【摘要】 目的:以离体牙为研究对象,运用扫描电镜比较几种常用冲洗液组合清洁根管的效果,并采用葡萄糖定量法评价其对根尖封闭能力的影响,以期为临床使用提供实验依据。方法:1.扫描电镜观察:选择单直根管离体上前牙6颗进行根管预备,按不同分组采用不同冲洗液进行根管冲洗。A组:预备中依次用17%乙二胺四乙酸和1%次氯酸钠冲洗,预备后用17%乙二胺四乙酸冲洗;B组:预备中依次用3%过氧化氢溶液和1%次氯酸钠冲洗,预备后用3%过氧化氢冲洗;C组:预备中依次用10%枸橼酸和1%次氯酸钠冲洗,预备后用10%枸橼酸冲洗;D组:预备中依次用1%盐酸四环素溶液和1%次氯酸钠冲洗,预备后用1%盐酸四环素溶液冲洗;E组:预备中和预备后均用1%次氯酸钠冲洗;F组:预备中和预备后均用生理盐水冲洗。每颗牙冲洗量均为25ml,冲洗时间为8分钟。将牙根沿纵轴均匀劈开,在距根尖3mm、6mm、9mm处刻痕标记,常规方法制作电镜标本,扫描电镜下分别对根管冠1/3、根管中1/3和根尖1/3进行观察并照相。2.微渗漏实验:选择单直根管离体牙61颗,随机分为7组进行根管预备,按照上述分组采用不同冲洗方法进行根管冲洗(G组冲洗方法同F组)。干燥后用AH-PLUS糊剂和牙胶尖侧向加压法充填根管。置于微渗漏检测模型上,于第1,2,4,7,10,15,20,30天取样进行微渗漏检测,方法为葡萄糖氧化酶法。结果:1、D组根管清洁效果最好,根管壁上无残存碎屑和玷污层存在,牙本质小管口大量开放,且无脱矿现象存在;A组、C组有少量残屑存在,但无玷污层覆盖根管壁,牙本质小管口开放程度高,冠方牙本质有部分脱矿;B组中等量残屑覆盖根管壁,牙本质小管口开放数量少;E组、F组根管壁被大量残屑、玷污层和细菌覆盖,仅E组冠1/3可见少数牙本质小管口开放,余视野内无开放性牙本质小管口可见。2、微渗漏量从大到小依次为:F组＞E组＞B组＞D组＞A组＞C组。统计学分析结果表明:各观察时点A组、B组、C组、D组、E组与F组间有显著性差异(P＜0.001),第10、15、20、30天A组、C组与E组、F组之间有统计学差异(P＜0.001),第20、30天A组、C组、D组与B组和E组、F组间有显著性差异(P＜0.001),但A组、C组、D组之间葡萄糖微渗漏结果无显著差异(P＞0.05)。结论:1、两种冲洗液联合使用效果优于单一冲洗液。2、去除玷污层可有效减少根管微渗漏的发生。3、17%乙二胺四乙酸、10%枸橼酸与1%次氯酸钠配伍使用效果相当,但都容易造成管间牙本质过度脱矿,临床应用时应注意严格控制冲洗时间。4、1%盐酸四环素联合1%次氯酸钠清洁根管、去除玷污层效果好,可有效降低微渗漏的发生,是有一定临床应用前景的冲洗液。更多还原

【Abstract】 OBJECTIVES:Extracted teeth were chosen as the research subjects,to compare the cleaning efficiency of six different kinds of combined irrigants by SEM（scanning electron microscope）,value the apical sealing ability by using quantitative analysis of glucose,and provide lab evidence for clinic application.METHODS:1.SEM observation:6 extracted human maxillary anterior teeth,with a singe straight root,were instrumented and irrigated differently by groups.Group A:The root canals were irrigated with 17% Ethylenediaminetetraacetic acid（EDTA）and 1%sodium hypochlorite （NaClO）in sequence during the instrumentation,17%EDTA after the instrumentation;Group B:The root canals were irritated with 3%hydrogen peroxide （H₂O₂）and 1%NaClO during the instrumentation,3%H₂O₂ after the instrumentation;Group C:The root canals were irrigated with 10%citric acid and 1% NaClO during the instrumentation,10%citric acid after the instrumentation;Group D:The root canals were irrigated with 1%tetracycline hydrochloride and 1%NaClO during the instrumentation,1% tetracycline after the instrumentation;Group E:The root canals were irrigated with 1%NaClO during and after the instrumentation;Group F:The root canals were irrigated with normal saline（NS） during and after the instrumentation.The total amount of irrigant was 25ml and the irrigation time was 8 minutes in each canal.The roots were split longitudinally,scored at 3mm, 6mm and 9mm,normally made for scanning electron microscopy（SEM） specimens,and then photographed at different regions of every specimen: the upper 1/3 of canal,the intermediate 1/3 of canal and the root apex 1/3 of canal.2.The microleakage experimentation:61 extracted human maxillary anterior teeth,with a singe straight root were divided into 6 groups, instrumented and irrigated differently by groups above-mentioned（The irrigation method of group G was the same as group F）.After dried,the roots were filled with AH-PLUS and gutta-percha by cold lateral compaction.All the roots were fixed on the glucose penetration models. The root apical leakage was measured by the concentration of glucose in 1,2,4,7,10,15,20,30 days with glucose oxidase-peroxidase（GOD） method.RESULTS:1.Group D got the best cleaning effect,with no debris or smear layer observed on the root canal wall and a lot of open dentinal tubules observed without demineralization.A small amount of debris but no smear layer were observed in Group A and Group C,and the dentinal tubules were open mostly but erose partly in coronal third.Moderate amount of debris and only small quantity opening dentinal tubules were observed in Group B.The surface of root canal walls in Group E and Group F were covered a great quantity debris,smear layer and bacterium, and small amount of opening dentinal tubules were just present in coronal third of Group E.2.The sequence of microleakage was:Group F＞Group E＞Group B＞Group D＞Group A＞Group C.Using repeated measure ANOVA,the leakage was significantly different between Group A,Group B,Group C, Group D,Group E and Group F at above-mentioned days.Group A and Group C had statistic difference with Group E and Group F at days 10th, 15th,20th,30th.Group A,Group C,Group D and Group B,Group E, Group F had significantly difference at day 20th,30th,and Group B have significantly difference with Group E and Group F.But there was no difference among Group A,Group C,Group D. CONCLUTIONS:1.The combination of two kinds of irrigants made better effect than the single irrigant.2.Removal of smear layer could decrease the root apical microleakage.3.17%EDTA+1%NaClO made the same effect as 10%citric acid +1%NaClO,but it easily caused the erosion of peritubular dentinal.So it must pay attention to strictly control the washing time in clinical applications.4.1%tetracycline+1%NaClO had a better cleaning effect and could significantly decrease the apical microleakage,so it could be widely used in clinical.更多还原