根管残余细菌对根管治疗预后的影响

目的　探讨根管预备后残留细菌对根管治疗预后的影响。方法　选取50颗患慢性根尖周炎的单根管牙,分为实验组和对照组。实验组21颗患牙采用逐步后退法及超声冲洗预备根管,根管预备后取样做细菌培养, 立即充填根管,一次性完成根管治疗。对照组采用常规根管治疗方法治疗。根管治疗后6个月、1年及2年复查。结果　①两组患牙根管治疗预后无明显差异。②实验组患牙根管预备后残余细菌与根管治疗预后无明显关系。 ③患牙术后疼痛与根充情况和术前症状无明显关系。结论　近期观察见经过彻底的根管预备,根管内微量残余细菌对根管治疗预后无明显影响。     

Thermafil根管充填技术的临床评价

目的 :研究Thermafil根管充填技术的效果。方法 :选择牙髓病或根尖周病患者 60例 ,按就诊顺序随机分为 2组。即Thermafil根管充填组 (TC组 )和冷牙胶侧方加压充填组 (LC组 )。对 2组的根管充填时间、术中疼痛情况和根管充填效果进行比较。术后 3个月和 6个月进行复查 ,并拍摄X线片。结果 :以牙为单位 ,TC组适充 18颗 ,超充 11颗 ,欠充 1颗 ;在LC组中 ,适充 2 7颗 ,超充 3颗 ,无欠充 (P <0 .0 5)。TC组术中不适 4颗 ,LC组 2颗 (P >0 .0 5)。以根管为单位 ,根管充填时间Thermafil充填技术组平均 3 6.6s/根管 ,LC组平均 2 47.4s/根管 (P <0 .0 1)。结论 :Thermafil充填技术临床操作简便省时 ,但容易造成超充     

The long-term sealing ability of an epoxy resin root canal sealer used with five gutta percha obturation techniques

AIM: The aim of the present study was to evaluate the long-term sealing ability (both apical and coronal) of an epoxy resin root canal sealer (AH26) when used with different gutta-percha obturation techniques. METHODOLOGY: Straight single-rooted teeth with mature apices were divided into 10 groups of 75 teeth and one group of 40 control teeth. Root canals were prepared according to the crown-down/step-back technique and using both 2.5% sodium hypochlorite and an EDTA paste. Root canals were obturated using cold lateral condensation, warm vertical condensation and hybrid condensation of gutta-percha; and with Thermafil and Soft-Core obturators. AH26 was used as the sealer in all cases. After root canal filling, each group was divided into five individual groups of 15 teeth. The first group of 15 teeth was kept for 1 day, the second for 1 week, the third for 4 months, the fourth for 6 months and the fifth for 12 months at 37 degrees C in vacutainers in 80% relative humidity. The teeth were immersed in India ink for 90 h, each root was split and sectioned longitudinally, and the maximum extent of leakage was measured using a stereomicroscope at x6 magnification. RESULTS: Leakage occurred whatever filling technique was combined with AH26. The number of teeth with gross leakage increased with time up to 4 months, but did not appear to increase between 6 and 12 months storage. The degree of apical leakage and the number of leaking teeth in the Soft-Core obturator groups was significantly higher than all four other gutta-percha obturation techniques. Up to 4 months the degree of coronal leakage and the number of leaking teeth in the Thermafil groups was significantly higher than the other gutta-percha obturation techniques, except for Soft-Core. In the Soft-Core obturator groups the degree of coronal leakage and the number of leaking teeth was significantly higher than the other gutta-percha obturation techniques, except for Thermafil at all evaluation times. CONCLUSION: The hybrid gutta-percha condensation technique was superior to the other four obturation techniques in respect of apical leakage. Coronal leakage was significantly greater during the first 4 months for the Thermafil system as compared to the three condensation techniques; coronal leakage was significantly greater at all time periods for the Soft-Core system. There were no significant differences between the Thermafil and the Soft-core system.     

慢性根尖周炎一次性根管治疗的临床疗效观察

目的：评价慢性根尖周炎一次性根管治疗的临床效果和可靠性。方法：选择患有慢性根尖周炎的直根管患牙200例,采用改良双敞技术和平衡力法预备根管,0．5％次氯酸钠及17％EDTA冲洗,随机均分为两组：一次性根管治疗组在上述操作完成后立即行牙胶尖加树脂类封闭剂AHplus侧方加压术充填根管;多次性根管治疗组根管内封入氢氧化钙糊剂复诊,待无症状后再行根充。治疗结束后1d、7d、30d随访记录患者的疼痛反应。1年后进行临床及X线复查,计算每组根管治疗的成功及失败率,并进行统计学检验。结果：有94例患者回访,一次性根管治疗组43例,多次根管治疗51例。根管治疗术后1d疼痛发生率一次性治疗组高于多次性组,且有统计学差异,7d、30d的疼痛发生率两组间无明显差异。1年后复查两组的成功率无统计学差异。一次性根管治疗组的前牙与后牙治疗成功率间无统计学差异。结论：慢性根尖周炎一次性根管治疗术后疼痛发生率较多次法高,但远期疗效等同于多次法者。     

An in vitro study of the quality of root fillings in teeth obturated by lateral condensation of gutta-percha or Thermafil obturators

The aim of this in vitro study was to assess the quality of root canal obturation and degree of linear apical dye penetration in teeth root filled with either laterally condensed gutta-percha or Thermafil obturators, A total of 150 teeth with single roots were included in the study. All canals were prepared using a standard step-back technique with anticurvature filing. Radiographs taken of the teeth to show the maximum degree of canal curvature were then exposed and the angle, radius and position of curvature determined. This information about the canals, together with their working length and diameter at end-point, was used to divide the teeth into two experimental and two control groups. A total of eight teeth were excluded because of technical difficulties, 65 were filled with Thermafil obturators, 63 were filled with laterally condensed gutta-percha whilst 14 teeth remained unfilled and acted as controls. Following obturation, the teeth were radiographed in two planes and the technical quality of fill assessed on a four-point scale. All access cavities were then sealed and the teeth immersed in dye for 48 h before being split longitudinally. Linear dye penetration via the apical foramen was then assessed. Canal obturation with Thermafil obturators (0.7 min) was significantly quicker (P > 0.001) than lateral condensation (6.4 min). Apical extrusion of sealer and gutta-percha occurred significantly more often with Thermafil obturators but there was little difference in the technical quality of the fillings and no significant difference in dye penetration. Under the conditions of this study, Thermafil obturators proved a satisfactory alternative to lateral condensation of gutta-percha.     

The sealing ability of the Thermafil obturation technique

Forty straight canals of maxillary canines and 40 curved canals in 20 mesial roots of mandibular molars were instrumented and randomly assigned to two groups of 40 canals each. For the experimental group, the canals were obturated using the Thermafil obturation technique. Lateral condensation was used for the obturation of the control group. Kerr pulp canal sealer was used in both group. The specimens were stored in 100% humidity for 1 wk. All teeth were suspended in black India ink for 14 days and decalcified in 5% nitric acid over a 2-day period. The teeth were then dehydrated in a graded series of alcohol to 100%. Methyl salycilate was used to clear and store the teeth for 48 h. Linear dye leakage measurements showed that canines obturated with the lateral condensation technique leaked significantly less than those obturated using the Thermafil technique (p = 0.02). The difference was not statistically significant in the molar roots.     

Evaluation of intracanal sealer distribution with 5 different obturation techniques.

OBJECTIVE: The aim of this study was to determine the distribution patterns of sealer relative to the gutta-percha and the canal wall following the use of different obturation techniques: vertical condensation, Obtura II, System B, SimpliFill, and Thermafil Plus; lateral condensation was used as a comparison. METHODS AND MATERIALS: One hundred five extracted single-rooted teeth were divided into 5 groups of 20 according to obturation technique, with 5 in the lateral condensation group. Instrumentation technique and sealer selection were based on the manufacturer's recommendations. Following obturation, teeth were stored for 4 months at 37 degrees C in 100% humidity. Roots were split longitudinally and halves were examined under a stereomicroscope (x 10) to determine the amount of sealer coverage between the gutta-percha and canal wall. Coverage was categorized as slight (0 to 1/3), low partial (1/3 to 2/3), high partial (2/3 to 9/10), and complete (9/10 to 10/10). RESULTS: Different techniques showed different patterns, but no obturation technique had sealer forming a continuous layer between the gutta-percha and canal wall. The vertical condensation group generally had low partial coverage. Obtura II was the only group to have slight coverage, which occurred in the coronal half. Coronal and apical halves in both the System B and Thermafil Plus groups had the most samples with high partial coverage. SimpliFill had the most samples with complete coverage in both the coronal and the apical portions. All lateral condensation samples showed low partial coverage. CONCLUSION: Sealer distribution patterns were incomplete and inconsistent, regardless of the obturation technique. No technique had sealer forming a continuous layer between the gutta-percha and canal wall.     

A laboratory study of root fillings in teeth obturated by lateral condensation of gutta-percha or Thermafil obturators

The aim of this in vitro study was to assess the quality of root canal obturation and degree of apical dye penetration in teeth root-filled with either laterally condensed cold gutta-percha or Thermafil obturators. A total of 144 extracted teeth with single roots were included in the study. All canals were prepared with a standard technique using a sonic handpiece with copious irrigation. Radiographs taken of the teeth to show the maximum degree of canal curvature were then exposed and the angle, radius and position of curvature determined. This information about the canals, together with their working length and diameter at end-point was used to divide the teeth into two experimental and two control groups. A total of 71 teeth were filled with Thermafil obturators, 69 with lateral condensation while four teeth remained unfilled and acted as controls. Following obturation, the teeth were radiographed in two planes and the technical quality of fill assessed on a four-point scale. All access cavities were then sealed and the teeth immersed in dye for 48 h before being split longitudinally. Linear dye penetration via the apical foramen was then assessed. In both straight and curved canals obturation with Thermafil obturators was significantly quicker (P< 0.001) than lateral condensation. Apical extrusion of gutta-percha occurred significantly more often in straight canals obturated with lateral condensation (P< 0.005) but there was no difference in curved canals. There was little difference in the radiographic quality of fill in the apical halves of the root fillings but Thermafil obturators were significantly better in the coronal halves when viewed from the proximal. Apical leakage of dye was significantly worse (P< 0.05) in curved canals filled with lateral condensation with a similar, but not significant, trend in straight canals. Under the conditions of this study, Thermafil obturators proved a satisfactor alternatie to lateral condensation of gutta-perch.     

The sealing ability of an epoxy resin root canal sealer used with five gutta-percha obturation techniques

Abstract – The purpose of the present study was to evaluate the apical sealing ability of an epoxy resin root canal sealer (AH-26) when used with different gutta-percha obturation techniques (i.e. cold lateral condensation, warm vertical condensation, hybrid condensation) and with Thermafil and Soft-Core obturators. Straight single-rooted teeth with mature apices were prepared according to the crown-down/step-back technique and divided in five groups of 45 teeth and one group of 12 control teeth. After root canal filling 15 teeth of each group were kept for 1 day, another 15 teeth for 1 week, and another 15 teeth for 4 months at 37 °C in vacutainers in 80% relative humidity. The 237 teeth were immersed in india ink for 90 hours, each root was split and sectioned longitudinally, and the maximum extent of leakage was measured using a stereomicroscope at ×6 magnification. It became clear that leakage occurred whatever technique was combined with AH26 and that leakage increased with time. The amount of apical leakage and the number of leaking teeth in the Soft-Core obturator groups was significantly higher than all other 4 gutta-percha obturation techniques combined with AH26. In this respect, the hybrid gutta-percha condensation technique turned out to be superior to the four other condensation techniques.     

根管充填质量对根管治疗术远期疗效的影响

目的：从X线影像角度分析根管充填质量对根管治疗远期疗效的影响。方法：选择已行根管治疗2a或2a以上的牙,运用平行投照法对根管治疗牙进行摄片;询问、查阅病史,了解患者年龄、性别、牙病病因及治疗时间;检查目前该牙根尖周状况;用SPSS13．0软件进行χ^2检验。结果：共调查病例215例,根管治疗牙376颗．成功率为54．79％。若以根管计算,共有513个根管,成功率为61．4％。根管充填质量（根充位置和密合度）对根管治疗疗效有显著的影响（P〈0．01）,根充距离X线片根尖0．5．2mm时最理想;根充密合者成功率高,尤其是根尖部。性别、年龄和根管充填时间对根管治疗疗效无影响。结论：根管充填质量对根管治疗远期疗效有显著影响。     

Comparative study of two canal obturation techniques by image analysis and EDS microanalysis

AIM: The aim of this in vitro study was to compare the marginal adaptation achieved by two obturation techniques (lateral condensation and Thermafil) using human teeth prepared by continuous rotation with the HERO 642(R) system. METHOD: The percentages of gaps and sealer on the root canal surface were determined by analysing the images of 12 sections per tooth. Tubule sealer penetration was assessed by backscattered scanning electron microscopy and energy dispersive spectrometry microanalysis. RESULTS: The Thermafil obturation technique resulted in virtually no gaps and very low amounts of sealer on the root surface, unlike the lateral condensation technique. Tubule sealer penetration occurred with both techniques, but was deeper, especially in the mid and apical zones, with the lateral condensation technique.     

Quality of different gutta‐percha techniques when filling experimental internal resorptive cavities: A micro‐computed tomography study

The purpose of this ex vivo study was to determine the quality of root fillings in experimental internal resorptive cavities filled using cold lateral condensation (CLC), vertical condensation and Thermafil techniques. Forty‐five extracted maxillary canine teeth were selected. After root canal instrumentation, the roots were sectioned horizontally and experimental internal resorption cavities were prepared. The root sections were re‐approximated with a luting agent and randomly assigned to three groups (n = 15) to be filled using CLC, vertical condensation and Thermafil, respectively. Assessment of obturation quality in the internal resorptive cavity was performed using a desktop X‐ray micro focus computed tomography scanner, and the percentage of gutta‐percha (GP), sealer and voiding was calculated for each specimen. Data were statistically analysed using non‐parametric tests, with P < 0.05 denoting a statistically significant difference. Vertical condensation filled 96.25 ± 8.31% of the total artificial cavity, and was superior to CLC (63.20 ± 16.87%) and Thermafil (59.26 ± 18.47%). The mean percentage of voids was 3.75 ± 8.31% in the vertical condensation group, 37.09 ± 17.13% in the CLC group and 41.06 ± 18.60% in the Thermafil group. We conclude that obturation of experimental resorption cavities is significantly better when using vertical condensation than when using other GP‐based techniques.     

Root surface temperature rises in vitro during root canal obturation with thermoplasticized gutta-percha on a carrier or by injection

The aim of this in vitro study was to measure the temperature rise on the outer root surfaces of teeth during four different root canal obturation techniques. Sixty extracted human maxillary and mandibular premolars with a single canal were used. After root canal cleaning and shaping, the teeth were randomly divided into four groups of 15 teeth each and obturated with Thermafil obturators or Soft-Core obturators using Ultrafil or Trifecta low-temperature thermoplasticized gutta-percha techniques. Temperature changes on the external mesial root surfaces were measured using a thermal imaging camera. Lower temperature rises were found for Ultrafil and Trifecta techniques (2.14 degrees C and 2.03 degrees C, respectively) than for Thermafil and Soft-Core techniques (3.87 degrees C and 3.67 degrees C, respectively). These findings suggest that solid core gutta-percha combined with low-temperature injectable gutta-percha obturation techniques may impose less risk for thermal damage to the surrounding periradicular tissues.     

The sealing ability of an epoxy resin root canal sealer used with five gutta-percha obturation techniques

The purpose of the present study was to evaluate the apical sealing ability of an epoxy resin root canal sealer (AH-26) when used with different gutta-percha obturation techniques (i.e. cold lateral condensation, warm vertical condensation, hybrid condensation) and with Thermafil and Soft-Core obturators. Straight single-rooted teeth with mature apices were prepared according to the crown-down/step-back technique and divided in five groups of 45 teeth and one group of 12 control teeth. After root canal filling 15 teeth of each group were kept for 1 day, another 15 teeth for 1 week, and another 15 teeth for 4 months at 37 degrees C in vacutainers in 80% relative humidity. The 237 teeth were immersed in india ink for 90 hours, each root was split and sectioned longitudinally, and the maximum extent of leakage was measured using a stereomicroscope at x6 magnification. It became clear that leakage occurred whatever technique was combined with AH26 and that leakage increased with time. The amount of apical leakage and the number of leaking teeth in the Soft-Core obturator groups was significantly higher than all other 4 gutta-percha obturation techniques combined with AH26. In this respect, the hybrid gutta-percha condensation technique turned out to be superior to the four other condensation techniques.     

热软化牙胶插入充填法磨牙多根管充填的临床研究

目的　分析热软化牙胶插入法充填磨牙多根管的方法和其特点。方法　选择门诊磨牙尖周炎和牙髓炎患者 5 8例 ,随机分成 2组 :对照组采用牙胶侧方加压法充填 ,实验组采用热软化牙胶插入法充填。摄X线牙片比较两组根管充填效果及充填操作时间。结果　经秩和检验 ,侧方加压法组和热软化牙胶插入法组在充填弯曲根管时 ,两者充填效果总体分布有差异 ,热软化牙胶插入法充填弯曲根管效果优于侧方加压法 (U =4 4 0 1,P <0 0 1) ;而两组在较直根管充填效果差异无统计学意义 (P >0 5 ) ,两组的充填时间经t检验统计差异有显著性。结论　热软化牙胶插入法较传统牙胶侧方加压法对根管三维具有更好的适应性 ,尤其适合于弯曲根管的充填 ,操作简捷、省时。     

Sealing ability of Thermafil with and without sealer.

The purpose of this study was to evaluate the apical sealing ability of root canals filled using three obturating techniques. Sixteen maxillary first molars were obturated with Thermafil, 16 with Thermafil and a ZOE sealer, and 16 with laterally condensed gutta-percha. Two canal instrumentation methods were used, conventional step-back preparation with K-Flex files and traditional instrumentation combining reaming with reamers and filing with K-Flex files. Following obturation, the teeth were prepared for evaluation of the seal using India ink and a Profile Projector. The depth of penetration of the dye was statistically evaluated for each of the three roots with an analysis of variance. For sealing ability, there was no significant difference at the p < 0.05 level between the conventional step-back preparation and the traditional instrumentation technique. However, a significant difference was present at the p < 0.05 level for the obturation techniques. The mean linear dye penetration for the Thermafil technique was greater than that for lateral condensation.     

A Comparative in Vitro Study of Apical Microleakage with Five Obturation Techniques: Lateral Condensation,Soft-Core?, Obtura II?, Guttaflow? and Resilon?

Aim

A comparison was made between the root canal lateral condensation technique and other condensation techniques in which physical (temperature: Soft-Core®, Obtura II®) or chemical changes (condensation: Guttaflow®, Resilon®) may affect the dimensional stability of obturation and thus favor apical microleakage.

Materials and methods

A total of 212 single-root teeth removed for orthodontic or periodontal reasons were randomized to 5 groups of 40 teeth each. Six samples were used as positive controls, and another 6 as negative controls. The teeth were worked with the Hero 642 system, and each group was obturated using a different technique: lateral condensation, Obtura II®, Soft-Core®, Guttaflow® or Resilon®. The samples were immersed in black ink, and after 72 hours the teeth were transparentized using the technique described by Robertson. Filtration of the ink was measured under the stereoscopic microscope. Analysis of variance and post-hoc testing were used for the statistical analysis.

Results

The Soft-Core® obturated group showed significantly greater microleakage than the other groups, with no differences among the rest of the groups.

Conclusions

Under the conditions of this study, the teeth obturated with the Soft-Core® technique showed greater apical microleakage than the other systems.Key words: Apical microleakage, root canal obturation, sealing ability, transparentization     

Technical quality of root canal treatment in Taiwan

AIM: To evaluate the current technical quality of root canal treatment (RCT) in Taiwan. METHODOLOGY: A total of 1085 RCT cases, randomly selected from a large sample and representative of the Taiwanese population from April to September 2000, were evaluated by eight endodontic specialists. The qualitative evaluation of RCT cases was based on two variables: length of the root filling and density of the obturation. A root canal with both adequate filling length (the apical termination of the root filling within 2 mm of the radiographic apex) and complete obturation (no lateral or apical canal lumen visible in the apical one-third of the root canal) was defined as having good-quality endodontic work (GQEW). A tooth was defined as having a GQEW when all its canals were categorized as GQEW. RESULTS: From a total of 1867 root canals, overfilling occurred in 235 (12.6%), adequate filling length in 1152 (61.7%), underfilling in 466 (25.0%) and no filling in 12 (0.6%). Of the 1867 root canals, 710 (38.0%) demonstrated complete obturation and 1157 (62%) demonstrated incomplete obturation. GQEW was found in 650 (34.8%) root canals and 329 (30.3%) teeth. The percentage of teeth with GQEW in hospital cases (38.1%) was significantly greater (P < 0.001) than that in private clinic cases (24.3%). In addition, the frequency of teeth with GQEW in the anterior teeth (40.4%) or in the premolars (33%) was significantly greater (P < 0.001) than that in the molars (18.4%). CONCLUSIONS: Approximately 70% of the teeth receiving RCT in Taiwan were either of inadequate filling length or sealing density.