桩道预备后剩余根管充填物的根尖封闭作用评价

目的:比较不同根管充填方法及桩道预备后不同长度的充填材料对根尖的封闭作用,寻找根管充填方法和剩余充填材料的最佳搭配选择,为临床应用提供理论依据.方法:132颗单根管牙随机分为6个实验组(每组各20颗)和2个对照组(每组各6颗).根管预备后A、B、C3组行冷牙胶侧方加压充填,桩道预备后分别剩余4、6、8 mm根管充填物;D、E、F3组行连续波热牙胶充填,桩道预备后分别剩余4、6、8 mm根管充填物;G组(阴性对照组)随机选择不同充填方法及不同长度剩余根管充填物:H组不进行根管充填.利用葡萄糖定量检测微渗漏模型,检测各组从冠方向根方渗漏的葡萄糖浓度(体积).采用SPSS 19.0软件包对数据进行统计学分析.结果:A和D、B和E、C和F比较,冷牙胶侧方加压充填组微渗漏显著大于热牙胶充填组.A和B、A和C、D和E、D和F相比,差异均具有显著性;B和C、E和F相比,无显著差异,说明根尖剩余4 mm和6 mm组间具有显著差异,而剩余6 mm和8 mm组间无显著差异.结论:连续波热牙胶充填技术的根尖封闭性能显著优于冷牙胶侧方加压法.桩道预备后剩余6 mm微渗漏较少.是较合适的剩余充填材料长度.     

比较2种根管充填糊剂对根尖封闭性的作用

目的用染料渗透法测量根管微渗漏的程度,比较2种根管充填糊剂在根管充填后不同时间进行桩腔预备后对根尖部的封闭能力。方法选取90颗成人的上颌中切牙,逐步后退法预备根管,侧向加压技术充填根管,充填剂分别用Cortisomol糊剂（A组）和氧化锌丁香油糊剂（B组）,每组45颗上颌中切牙。根据根管充填后桩腔预备时间将A组上颌中切牙随机分为A1组、A2组和A3组,每组15颗,A1组为根管充填后即刻进行桩腔预备,A2组为根管充填后2周进行桩腔预备,A3组为根管充填后4周进行桩腔预备。根据根管充填后桩腔预备时问将B组上颌中切牙随机分为B1组、B2组和B3组,每组15颗,B1组为即刻进行桩腔预备,B2组为根管充填后2周进行桩腔预备,B3组为根管充填后4周进行桩腔预备。进行桩腔预备后用染料渗透法评价各组根尖渗透能力。结果Cortisomot组（A组）与氧化锌丁香油组（B组）在根管充填后相同时间进行桩腔预备后,根尖微渗漏的差异具有统计学意义（P〈0．01）。A组在根管充填后即刻、2周、4周时进行桩腔预备,其根尖微渗漏的差异具有统计学意义（P〈0．01）。B组在根管充填后即刻、2周、4周时进行桩腔预备,其根尖微渗漏的差异无统计学意义（P〉0．05）。结论Cortisomol根管充填糊剂的封闭作用效果比氧化锌丁香油糊剂好。     

玻璃离子减少桩道预备后根管微渗漏的实验研究

目的 研究桩道预备后用玻璃离子封闭根充物冠方对减少根管微渗漏的效果.方法 选取70颗离体单根管下颌前磨牙,阳性对照组5颗,阴性对照组5颗,A、B、C、D 4组各15颗.常规根管充填后,A、B、C、D 4组进行桩道预备,A组保留根尖4 mm根充物;B组保留根尖5 mm根充物;C组保留根尖3 mm根充物 1 mm Vitrebond玻璃离子;D组保留根尖4 mm根充物 1 mm Vitrebond玻璃离子.用葡萄糖微渗漏模型检测6组第1、2、 4、 7、 10、 15、 20、 25、 30天根管冠根向渗漏出的葡萄糖量.结果 A、B、C、D 4组第 1、 2、 4、 7 天微渗漏值差异无统计学意义(P>0.05);从第10天开始, A、B组微渗漏值均明显高于C、D组(P<0.05),而C、D组之间差异无统计学意义(P>0.05);A、B组微渗漏值在第20、 25、30天差异有统计学意义(P<0.05).结论 玻璃离子可以成功减少桩道预备后根管的微渗漏.     

桩道预备对不同根管糊剂充填后根尖封闭性的影响

目的 液体转移法评价根管桩道预备对三种根管糊剂充填后根尖封闭性的影响。方法24颗人上颌前牙截冠后统一工作长度为16 mm,进行根管预备及根管充填。样本随机分组为Endométhasone组、AH-P lus组和GuttaF low组,每组8个样本。1周后液体转移法测量桩道预备前根管微渗漏。随后1~6#G钻逐步桩道预备,保留根尖4 mm充填物。再测量桩道预备后的根管微渗漏。实验数值采用SPSS 13.0统计学软件进行霍特林T2检验,取α=0.05。结果 桩道预备对各实验组的影响无统计学意义(P>0.05)。GuttaF low组桩道预备后的微渗漏值最小为(4.393±2.052)×10-3μl/(kPa.m in)。结论 桩道预备不影响根管糊剂充填后的根尖封闭性。GuttaF low是值得推广的新型根管充填剂。     

连续波热牙胶充填后不同时机桩腔预备对根尖封闭性的影响

目的 评价连续波热牙胶充填后不同时机桩腔预备对根尖封闭性的影响。方法 50颗单根管牙,采用冠向下法,使用ProTaper机用镍钛系统预备根管。随机选择5颗牙为阴性对照组,5颗牙为阳性对照组。另40颗牙随机分为A、B、C、D4组,每组10颗,所有根管均使用连续波热牙胶充填术充填根管,阳性对照组不使用根管封闭剂,然后A、B、C、D组分别于根充后即刻、3d、7d、30d四个不同时间点进行桩腔预备。采用葡萄糖定量法测定第2、7、14、21、28d从冠方向根方渗漏的葡萄糖量。结果 从第14d起即刻桩腔预备组与延迟桩腔预备三组相比,葡萄糖渗漏量均有显著性差异(P<0.05),而实验期间延迟桩腔预备三组之间相比没有统计学差异(P>0.05)。结论 延迟桩腔预备会削弱充填材料和封闭剂封闭根管的能力。     

桩腔预备对冷热牙胶充填根管根尖封闭性的影响

目的:通过葡萄糖定量检测法检测根管桩腔预备后微渗漏的大小,比较连续波热牙胶充填和冷牙胶侧压充填后桩腔预备对根尖封闭性的影响。方法:50颗单根管牙,采用冠向下法,使用ProTaper机用镍钛系统预备根管。随机选择5颗牙为阴性对照组,5颗牙为阳性对照组。另40颗牙随机分为A、B、C、D 4组,每组10颗,A组、B组、阴性、阳性对照组使用连续波热牙胶充填术充填根管,阳性对照组不使用根管封闭剂,C组、D组使用冷牙胶侧压充填术充填根管,然后A组:即刻、B组:第7天、C组:即刻、D组:第7天进行桩腔预备。采用葡萄糖定量法测定第2、7、14、21、28天从冠方向根方渗漏的葡萄糖量。结果:第14天起A、B 2组之间,C、D 2组之间,A、C 2组之间,B、D 2组之间,葡萄糖渗漏量差异均有显著性(P<0.05)。结论:延迟桩腔预备会削弱充填材料和封闭剂封闭根管的能力,连续波热牙胶充填的根尖封闭能力优于冷牙胶侧压充填。     

桩腔预备对根尖封闭性的影响及检测方法的研究进展

桩核冠修复是临床大面积牙体缺损的主要修复方法,桩腔预备是修复的第一步,预备过程中保持剩余根管充填物的完整性对于根尖封闭有重要意义.目前的研究表明:桩腔预备对根尖封闭性的影响与桩腔预备时机、剩余根管充填物长度和桩腔预备技术等有关.微渗漏量作为评价根尖封闭效果的重要指标,检测方法种类繁多,包括染色法、流体滤过(传输)系统、...     

桩道预备对两种新型根管充填剂封闭性的影响

目的液体转移法评价根管桩道预备对两种新型根管糊剂充填后根尖封闭性的影响。方法 24颗人上颌前牙截冠后统一工作长度为16mm,进行根管预备。样本随机分组为Endofill组、Acroseal组和AH Plus组(对照组),每组8个样本。根管充填1周后液体转移法测量桩道预备前根管微渗漏。随后1-6号G钻逐步桩道预备,保留根尖4mm充填物。再次测量桩道预备后的根管微渗漏。实验数值采用SPSS 13.0统计学软件进行霍特林T2检验,取α=0.05。结果桩道预备增加Endofill组的根尖微渗漏,差别有统计学意义(P<0.05)。桩道预备不影响Acroseal组和AH Plus组的根尖微渗漏(P>0.05)。结论桩道预备降低了Endofill的根尖封闭性。建议Endofill慎用于需桩核冠修复的根管充填。     

Obtura Ⅱ热塑牙胶改良充填法的实验研究

目的探讨将常温流动牙胶充填术融入高温注射式热牙胶充填技术的可行性。方法 70颗单根管离体牙根管预备后随机分组,分别采用ObturaⅡ充填(A组)、Touch-heat+ObturaⅡ充填(B组)、GuttaFlow+ObturaⅡ充填(C组)、冷牙胶侧压充填(D组)、不做充填(E组),根充完成后修整所用充填根管内牙胶长度为10 mm,建立葡萄糖微渗漏模型,通过对葡萄糖定量分析检测根管充填后根尖部微渗漏,观察比较根尖封闭效果。结果各组葡萄糖微渗漏随观察时间延长持续增加,3组实验组微渗漏差异无统计学意义(P>0.05)。结论 GuttaFlow+ObturaⅡ充填法封闭效果可靠且操作易行,有一定的可行性。     

采用葡萄糖定量分析法评价连续波热牙胶充填技术的根管封闭性能的研究

目的采用葡萄糖定量法检测根管微渗漏模型评价连续波热牙胶充填技术的根管封闭性。方法选取30颗离体单直根管下颌前磨牙,机用镍钛ProTaper根管预备后随机分成连续波热牙胶充填组和冷牙胶侧方加压充填组(每组10例)和2个对照组(阳性对照和阴性对照各5例),根充后建立微渗漏葡萄糖定量分析法模型,通过在第1、4、7、20天用葡萄糖氧化酶法检测从冠方向根方渗出的葡萄糖的量,观察其微渗漏情况。结果第1天2组微渗漏值无显著性差异(P>0.05),第4、7天,连续波充填组的微渗漏小于冷侧压充填组(P<0.05),第20天时,2组无显著性差异(P>0.05)。结论尽管冷侧压充填发生微渗漏快于连续波充填,但是两者的根管封闭性无显著差异。     

Leakage along apical root fillings with and without smear layer using two different leakage models: a two-month longitudinal ex vivo study

AIM: To compare two different experimental models when measuring leakage along root fillings with or without smear layer. METHODOLOGY: One hundred and twenty single-rooted teeth were prepared to size 50 and allocated to two groups: fluid transport model (n = 60) and glucose penetration model (n = 60). The roots in each group were divided into three subgroups of 20 teeth each. Smear layer was left in place in group 1 but removed in groups 2 and 3. In groups 1 and 2 canals were filled with laterally compacted gutta-percha cones and AH 26. Group 3 was laterally compacted with Resilon cones and Epiphany sealer. The coronal portion of the filling was removed to assure only 4 mm of filling remained in the canal. Leakage of glucose was evaluated by measuring its concentration once a week for a total period of 56 days using a glucose penetration model. Fluid transport was evaluated by measuring the movement of an air-bubble using a fluid transport model, 1 and 8 weeks after canal filling. Differences between the groups in glucose concentrations and fluid transport were statistically analysed with the Kruskal-Wallis and the Mann-Whitney tests. The level of significance was set at alpha = 0.05. RESULTS: Glucose penetration was significantly different between the three groups after the first 8 days (P < 0.05). Resilon leaked the most throughout the experiment period. No significant difference (P > 0.05) existed between the two gutta-percha groups at all time intervals (Mann-Whitney test). In the fluid transportation model, no statistically significant differences were observed between all three experimental groups (P > 0.05) at either 1 or 8 weeks after filling (Kruskal-Wallis test). CONCLUSIONS: Under the conditions of this study, the glucose penetration model was more sensitive in detecting leakage along root fillings. Removing the smear layer before filling did not improve the sealing of the apical 4 mm of filling. Resilon allowed more glucose penetration but the same amount of fluid transport as the gutta-percha root fillings.     

Glucose penetration and fluid transport through coronal root structure and filled root canals

AIM: To measure glucose penetration and fluid transport through coronal root structure and compare it with leakage along the coronal region of root fillings. METHODOLOGY: A total of 50 single-rooted teeth were selected and divided into three groups. Ten roots were sectioned longitudinally and the apical portion was removed leaving a total length of 9 mm. These 20 half-roots served as group 1: root structure (n = 20). The canals of the remaining 40 roots were prepared to size 50 and filled with vertically compacted injectable filling material and sealer. Group 2: Resilon + Epiphany (n = 20) and group 3: gutta-percha + AH26 (n = 20). The apical portion of the root was removed. Glucose penetration through the coronal root structure and coronal root fillings was checked over a period of 4 weeks and fluid transport was measured after completion of the glucose penetration test. Differences between the groups were statistically analysed with the Kruskal-Wallis test and the Mann-Whitney test. RESULTS: The three groups presented significantly different glucose penetration (P < 0.05). The two groups of filled canals showed significant glucose leakage whilst the root structure group did not show any leakage. In the fluid transport model, the root structure group also did not show any leakage. No significant difference in leakage existed between the two vertically compacted filling materials, Resilon with Epiphany sealer and gutta-percha with AH26 in both models (P > 0.05). CONCLUSION: Under the conditions of this study, in both models used, no leakage was observed through root structure. Filled canals were associated with penetration of glucose regardless of the material used.     

An evaluation of the influence of passive ultrasonic irrigation on the seal of root canal fillings

AIM: To evaluate the influence of passive ultrasonic irrigation (PUI) on the seal of root canal fillings. METHODOLOGY: A total of 40 mandibular premolars were distributed equally into two groups and the root canals were cleaned and shaped; they were then filled with gutta-percha and AH26 (sealer) using the warm vertical compaction technique with the System B (Analytic Technology, Redmond, WA, USA) device. In one group PUI was applied, after completion of instrumentation and hand-irrigation. In the other group, PUI was not applied. Thereafter, leakage of glucose was evaluated by measuring its concentration once a week for a total period of 56 days using a glucose penetration model. Differences between the groups in terms of glucose concentrations were statistically analysed with the Mann-Whitney test; the level of significance was set at P=0.05. RESULTS: After the first month the root fillings in teeth where PUI had been used, sealed the root canal significantly better than in teeth where no PUI had been used (P=0.017). CONCLUSION: Root fillings sealed the root canal better when PUI had been used.     

The unpredictability of seal after post space preparation: a fluid transport study

A root canal filling remaining after post space preparation is commonly expected to provide adequate seal. Coronal leakage of 30 endodontically treated teeth was measured before post space preparation using a fluid transport assay. In 10 of these teeth post space was prepared, using a two-step procedure, first to a remaining filling of 6 mm and then to 3 mm, with the leakage studied after each step. In 10 teeth the removal was done in one step to a remaining length of 3 mm. The other 10 teeth, with intact root canal fillings, served as controls and were tested twice for leakage. A significant difference was found between the sealing ability of intact fillings and that of partially removed ones (p < 0.05). The difference between the sealing ability of 3 and 6 mm remaining length group was not statistically significant. The lack of statistical differences between the 6 mm and 3 mm fillings was due to a great variability which existed among the 3 mm remaining fillings. These results suggest that 3 to 6 mm fillings provided a seal inferior to that of intact root canal fillings. Reduction of the fillings to 3 mm resulted in an unpredictable seal.     

Quality of cold and warm gutta-percha fillings in oval canals in mandibular premolars

AIM: The aim of this study was to determine the quality of cold and warm gutta-percha fillings in oval canals. METHODOLOGY: Two groups of mandibular premolars with oval canals were selected after bucco-lingual and mesio-distal radiographs indicated an internal long: short diameter of > or =1.6 at a level 5 mm from the apex. After instrumentation they were obturated, respectively, by cold lateral compaction of gutta-percha cones (cold GP) and vertical compaction of warm gutta-percha (warm GP). Leakage along apical root fillings was measured using a fluid transport model. After the leakage test, horizontal sections were cut 2 and 4 mm from the apex. The area of the canal and gutta-percha in cross-sections was measured using an image analysis program. The quality of root fillings was evaluated by calculating the percentage of gutta-percha-filled canal area (PGP). RESULTS: No significant difference in leakage was found between the two groups (P = 0.570). The warm GP group produced significantly higher PGPs than the cold GP group 4 mm from the apex only (P = 0.522 at 2 mm: P = 0.000 at 4 mm). CONCLUSIONS: The percentage of gutta-percha-filled canal area using warm GP was greater than that of the cold GP in oval canals.     

The influence of root-end resection and root-end cavity preparation on microleakage of root filled teeth in vitro

AIM: To investigate in vitro the influence of root-end resection and root-end cavity preparation on leakage of root filled teeth. METHODOLOGY: The root canals of 48 roots, 16 mandibular premolars (G1), 16 mandibular incisors (G2) and 16 maxillary incisors (G3), 12 mm in length, were enlarged using a modified 'balanced force' technique and filled with gutta-percha and sealer using lateral compaction. After setting, leakage along the canal was measured using a fluid transport model. Root-end resection and root-end cavity preparation were then performed, leaving roots 10 mm in length with root fillings of 7 mm (groups R1, R2 and R3, respectively). Fluid transport was measured again along the remaining root fillings of all groups using the same experimental conditions. Results of leakage before and after root-end resection were analysed statistically using the Kruskal-Wallis and Wilcoxon tests. RESULTS: A total of 31% of the roots leaked before and 54% after root-end preparation; the difference was significantly different (P < 0.001). No significant differences were found either among groups G1, G2, G3 (P = 0.565) or among groups R1, R2, R3 (P =0.2628). Significant differences, however, were shown between groups G1-R1 (P = 0.0053), G2-R2 (P =0.0089) and G3-R3 (P = 0.0461). CONCLUSIONS: Root-end resection and root-end cavity preparation compromised the seal of 7 mm root fillings in all tooth groups. Increased leakage was recorded in the following order: mandibular incisors > mandibular premolars > maxillary incisors.     

A quantitative microleakage study on a new retrograde filling technique

An in vitro endodontic leakage model was used to compare the sealing ability of conventional retrograde amalgam fillings with a new retrograde filling technique by measuring dye leakage quantitatively. The new technique consisted of retrograde preparation of the root canal using the Endocursor, an endodontic handpiece. The canal was then filled with sealer and injection-moulded gutta-percha, using either the Hygenic Ultrafil system or the Unitek Obtura method. In both cases the gutta-percha was vertically condensed and subsequently cold-burnished. The two experimental groups and the amalgam group each consisted of 20 extracted human canine teeth and lower premolars. The results were analysed statistically by ANOVA and a Student-Newman-Keuls multiple comparison test. After 1 week at 37 degrees C, very little leakage was observed in the amalgam and gutta-percha groups. After a second week, during which leakage was enhanced by gas pressure, leakage in the amalgam group was significantly greater than that in the gutta-percha groups (P less than 0.01). There were no significant differences between the two experimental gutta-percha groups. It is concluded that the new retrograde filling technique causes less leakage than the conventional amalgam retrograde filling technique in an in vitro model.     

A comparison of techniques for assessment of coronal dye leakage.

This study was designed to compare different techniques for coronal dye leakage testing. One hundred and fifty extracted human anterior teeth were fully instrumented and randomly divided into two experimental groups of 60 teeth each, plus two groups of 15 teeth each for positive and negative controls. One group was rinsed with 5.25% NaOCl (smear layer intact), whereas the other group was flushed with 17% EDTA and 5.25% NaOCl (smear layer removed). Roots were obturated with gutta-percha using lateral condensation and AH Plus as root canal sealer. Each experimental group was divided into three subgroups of 20 teeth each for three methods of testing coronal dye leakage: passive dye penetration, penetration with vacuum applied, and fluid filtration methods. The teeth were left in 100% humidity at 37 degrees C for 5 days before being immersed in Indian ink for 2 days and cleared. The linear extent of dye penetration was measured. Mean depth of leakage for the groups with the smear layer intact was 2.5 +/- 1.0 mm for passive dye penetration, 6.7 +/- 2.8 mm for vacuum dye penetration, and 3.0 +/- 1.1 mm for fluid filtration dye penetration. In the group in which the smear layer was removed, the mean depths of leakage were: 3.2 +/- 2.1 mm for passive dye penetration, 5.8 +/- 2.8 mm for vacuum dye penetration, and 3.4 +/- 2.1 mm for fluid filtration. The vacuum method resulted in significantly (p < 0.05) more dye penetration than fluid filtration and passive dye penetration. The presence or absence of smear layer had no statistically significant effect (p > 0.05) on any of the leakage testing techniques.     

The quality of root fillings remaining in mandibular incisors after root-end cavity preparation

AIM: The aim of this study was to determine the quality of root fillings remaining in mandibular incisors after root-end resection and root-end cavity preparation. METHODOLOGY: Roots of 40 mandibular incisors,12 mm in length, were divided into two groups and instrumented using a balanced force technique and obturated by vertically compacted warm gutta-percha. In one group sealer was used when back-filling the root canal with the Obtura System. The other group was also back-filled with the Obtura System but without sealer. The apical 4 mm of each root filling was removed by root-end resection and root-end cavity preparation. Fluid transport along the 7 mm of remaining root filling was measured. After the leakage test, horizontal sections were cut at a level 3 mm from the apical end of the remaining root filling. The cross sectional area of the canal and gutta-percha was measured using an image analysis program. The quality of the remaining root fillings was also evaluated by calculating the percentage of gutta-percha filled canal area. RESULTS: In total, 27 (67%) out of the 40 roots demonstrated leakage. No significant difference was found between the two groups (P = 0.265). In the cross-sections the bucco-lingual canal diameter was up to 2.6 mm long (mean 1.6 mm). The average percentage of gutta-percha filled canal area was 85.6%. Warm gutta-percha could not obturate areas where debris remained after instrumentation. CONCLUSIONS: The quality of the root fillings in mandibular incisors was poor, probably because the unprepared recesses of oval canals were not clean.     

Leakage of five root canal sealers

AIM: The aim of this study was to examine the apical sealing ability of five root canal sealers using a fluid transport model. METHODOLOGY: A comparison of root canal scalers AH26, AH Plus, Diaket, Apexit, and Ketac-Endo were tested on 60 single-rooted teeth. The coronal part of each tooth was removed at the amelo-cemento junction, and also 3 mm of the root tip. Root canals were instrumented using the 'step-back' technique with Gates Glidden drills and irrigated with 2.5% NaOCl. The specimens were divided into five groups of 10 samples each and filled with test materials and gutta-percha points by the cold lateral condensation technique. Ten teeth were used as a control group, out of which five served as negative and five as positive controls. The leakage was measured by the movement of an air bubble in a capillary glass tube connected to the experimental root section. RESULTS: The differences in leakage amongst Ketac-Endo (0.318 microL: SD 0.084), AH26 (0.319 microL; SD 0.075), AH Plus (0.330L; SD 0.085) Apexit (0.360 microL; SD 0.127) and Diaket (0.387 microL; SD 0.140) were not statistically significant (P > 0.05). CONCLUSIONS: Under the conditions of this study, all five sealers produced a satisfactory seal.