Bacteriologic status of the root canal after sonic, ultrasonic and hand instrumentation

Abstract The purpose of this study was to assess the bacteriologic status of the root canal after sonic, ultrasonic and hand instrumentation. Root canal infection was induced in 50 single-rooted teeth in young dogs by removing the pulp and filling the canals with dental plaque. After 7 clays the root canals were instrumented under aseptic conditions with conventional hand instruments, a sonic vibratory device or an ultrasonic device. Sterile saline or 2.5% sodium hypochlorite was used as irrigating solution. Following instrumentation a sterile paper point was sealed into the root canals. After 7 d the root canals were reopened under aseptic conditions and the paper points were incubated for the demonstration of bacteria, using pre-reduced thioglycolate culture medium and anaerobic chambers. The results obtained with the different instrumentation techniques and irrigating solutions were compared by means of the Chi-square test. The results indicated that the sonic and ultrasonic devices were not more effective in the elimination of bacteria from the root canal than conventional hand instrumentation. Irrigation with sodium hypochlorite appeared to be more effective than saline in producing bacteria-free root canals; however, this difference was not statistically significant. Thus, it appeared that more than one appointment and the supporting action of an antibacterial medicament between appointments would be necessary to achieve bacteria-free root canals in infected teeth in a predictable manner.     

Comparative debridement study between hand and sonic instrumentation of the root canal

Abstract The cleaning efficiency of hand and sonic instrumentation with MM Sonic 3000 in 60 single-rooted human straight teeth was evaluated using light and scanning electron microscopy. The root canals were instrumented with K-type files and Shaper Sonic files, respectively, and manually irrigated with 1 % sodium hypochlorite. The results showed no statistically significant difference between hand and sonic instrumentation. In both groups a smear layer, untouched predentin and pulp tissue debris were generally observed.     

Shape of the root canal after ultrasonic instrumentation with K-Flex files

Abstract This study investigated the feasibility of using K-Flex files with the Cavi-Endo ultrasonic unit. The effectiveness of the K-Flex files in shaping canals was compared with the ultrasonic Cavi-Endo K-files. Simulated curved canals in clear resin blocks were instrumented ultrasonically using the 2 file types. Pre- and postinstrumentation photographs were taken and the following were evaluated: apical and coronal areas, the incidence of the narrowing of the canals coronal to the apical transport (elbows). Displacement amplitude measurements were carried out in order to see any relationship between the incidence of elbows and displacement amplitudes of the files. The results indicated that the K-Flex files were more efficient than the ultrasonic K-files and resulted in less elbow formation. No direct relationship was observed between displacement amplitudes and the incidence of elbow formation. It is suggested that the manufacturers of ultrasonic units consider different file designs.     

A histobacteriological assessment of nonvital teeth after ultrasonic root canal instrumentation

Abstract The purpose of this study was to evaluate and discuss the bactericidal effect of ultrasound when applied in the root canal of teeth with necrotic pulp and periapical lesions. Twenty newly extracted teeth were instrumented with an ultrasonic unit and K-files using 0.5% sodium hypochlorite as irrigating solution. Compacted debris and micro-organisms were frequently observed in the apical region and in dentinal tubules of the root canal wall. Overinstrumentation that sometimes occurred led to contamination of the periapical lesions with micro-organisms and debris from the root canal.     

声波器械在根管治疗术中的应用

声波根管预备作为一种治疗手段用于牙髓病、根尖周病的治疗取得了一定的疗效。本文对声波器械的技术特点作一综述，包括声波器械的工作原理、切削能力、根管成形能力、去除玷污层的能力和杀菌能力等方面。     

Measurements of temperature generated by ultrasonic file in vitro

Abstract The temperature rise of the irrigant in the root canal during free vibration of the ultrasonic file was studied in vitro in 10 human teeth. The mean temperature rise was found to be 0.6°C. The minimal temperature increase may not significantly contribute to the effectiveness of ultrasonic root canal instrumentation.     

声波、超声波、手用根管器械预备弯曲根管的效果比较

目的：比较声波、超声波和手用根管器械预备弯曲根管的效果。方法：采用3种根管器械预备树脂块模拟根管并进行比较。结果：30个树脂块模拟根管预备效果显示：声波、超声波和手用器械根管预备效果无显著性差异。结论：声波根管器械具有临床应用价值。     

An in vitro comparison of root canal content extrusion using ultrasonic and hand instrumentation

Abstract The purpose of this study was to evaluate apical extrusion of root canal content using ultrasonic and hand instrumentation. Forty-nine tooth models were fabricated with clear resin. Each model contained a canal in the center. Each tooth model was mounted in a plastic cube (1 × 1 × 2 cm) with white dental plaster so that the coronal 2–3 mm of the model was exposed for instrumentation. Methylene blue dye with glycerin was used as a marker for root canal content. The study consisted of three groups. In group I, Enac ultrasonic instrumentation was used 1 mm from the apex; in group II, Enac ultrasonic instrumentation was used 3 mm from the apex; in group III, K Files were used with a push-pull instrumentation technique, 1 mm from the apex. After instrumentation the resin models were extracted and the plaster blocks were sectioned through the long axis of the models. Photographs were made of the area of apical leakage and the amount of dye penetration was measured using a planimeter. There were no differences between hand instrumentation and both ultrasonic groups. At p<0.05, ultrasonic instrumentation 3 mm from the apex leaked significantly more than the ultrasonic instrumentation 1 mm from the apex.     

Effect of ultrasonic instrumentation on Bacteroides intermedius

Abstract Two physical mechanisms of ultrasound, cavitation and acoustic streaming, were investigated in an ultrasonic endodontic unit. In addition, the potential of ultrasonic instrumentation for disruption of Bacteroides intermedius was examined at various time intervals. The ultrasonic file could not generate cavitation within the recommended power settings indicated for endodontic purposes. However, there was evidence of acoustic streaming. The latter phenomenon resulted in destruction of 21.6%, 30.4% and 92.9% of test bacteria after 1, 5 and 15 min sonication respectively. It appears that ultrasonic instrumentation of root canals has little bactericidal effect.     

声波器械去除根管玷污层能力的比较研究

目的:比较声波、超声波和手用器械去除根管玷污层能力。方法:收集离体单根管的前磨牙40个,随机分为4组,分别由声波器械、超声波器械、手用器械以及声波和手用器械联合行根管预备,应用扫描电镜进行观察,采用Wilcoxon秩和检验进行统计学分析,根据根管表面的玷污层的量和牙本质碎屑比较声波器械去除根管玷污层的能力。结果:根尖1/3部分,在去除玷污层方面,声波器械组、超声波器械组以及声波器械和手用器械联合组,与手用器械组之间有显著性差异(P<0.05);在去除牙本质碎屑方面,超声波器械组与手用器械组之间亦有显著性差异(P<0.05),声波器械组以及声波器械和手用器械联合组与手用器械组之间有非常显著性差异(P<0.01)。声波器械组以及声波器械和手用器械联合组,与超声波器械组在去除玷污层和牙本质碎屑方面无显著性差异(P>0.05)。根中1/3和根上1/3部分,各组间比较均无显著性差异(P>0.05)。结论:根尖1/3根管预备,声波器械去除玷污层和牙本质碎屑的能力优于手用器械,尤其是去除牙本质碎屑的能力更强;与超声波器械近似。     

����������е����ProTaper����Ʋ������ٴ���Ч����

目的：评价声波根管器械联合ProTaper锉治疗残髓炎的临床疗效。方法选择2011年2月至2012年2月在南平市妇幼保健院牙体牙髓科门诊就诊的残髓炎患者78例（共78颗患牙）,随机分为试验组（41例）和对照组37例。试验组采用声波根管器械联合ProTaper锉进行根管预备,对照组采用单纯的ProTaper锉进行根管预备。两组患者根管预备完成后均用氢氧化钙封药1周,然后行根管充填。比较两组患者根管预备后24 h、根管充填1周后的术后反应及1年后的疗效。结果试验组患者根管预备后24 h、根管充填1周后的疼痛反应均较对照组轻;试验组1年后的疗效亦优于对照组。结论声波根管器械联合ProTaper锉治疗残髓炎,可减少预备后的疼痛反应,同时提高根管充填的质量,保证根管治疗的成功率,值得临床推广应用。     

Efficiency of subgingival calculus removal with the Vector-system compared to ultrasonic scaling and hand instrumentation in vitro

OBJECTIVE: The recently introduced Vector-system (Duerr Dental, Bietigheim-Bissingen, Germany) is recommended to be used in conjunction with different insert tips and irrigation fluids. The aim of the study was to assess subgingival calculus removal depending on the mode of operation and to compare the results to conventional methods for root debridement. METHODS: Sixty extracted human teeth with calculus on the root surface were treated in an artificial periodontal pocket model using six methods: Vector-system with metal probe insert (VPP) or metal curette insert (VPC), both used with polishing fluid, Vector-system with metal probe insert (VAP) or metal curette insert (VAC), both used with abrasive fluid, EMS-ultrasonic system (U) and hand instrument (Gracey curette). Photographs of the root surface were taken at intervals of 10 s and calculus removal was assessed using a surface analysis software until the root surfaces were cleaned completely. Analysis of variances (ANOVA) of the ranks with subsequent comparison of mean ranks and calculation of homogeneous groups (Scheffe) were used for statistical analysis. RESULTS: Employing the hand instrument, highest efficiency could be observed (0.340 mm2/s). Calculus removal with the Vector-system and metal probe insert (VPP: 0.036 mm2/s; VAP: 0.067 mm2/s) was less effective (p < 0.05) than using the system with metal curette inserts (VPC: 0.122 mm2/s; VAC: 0.209 mm2/s). Employing the abrasive fluid, removal of deposits with the metal curette insert was as efficient as with the conventional ultrasonic system (U: 0.199 mm2/s, p > 0.05). CONCLUSION: The present in vitro study indicates that the efficiency of calculus removal with the Vector-system is significantly dependent on the selection of inserts and irrigation fluids.     

Effectiveness and safety of a sonic vibratory endodontic instrument

Abstract An air-driven sonic vibratory handpiece to which specially designed K-type files are attached has been developed. When activated, the root canal instruments will vibrate in a whirling motion, and when moved up and down, will abrade the root canal wall. The sonic system was tested in simulated root canals in plastic blocks and in usage tests in dogs' teeth. Forty-nine roots in 3 dogs were divided into 3 groups. Two of the groups were instrumented with the sonic device under continuous irrigation with 2.5% NaOCl or 15% EDTA. The 3rd group was treated with conventional chemomechanical instrumentation and 2.5% NaOGl. The teeth were then extracted, fixed and split in a longitudinal direction and the root canals examined in the scanning electron microscope. After hand instrumentation and sonic instrumentation using NaOCl for irrigation, the canal wall was covered by a smear layer and dentin chips and occasional tissue remnants were seen. An extraoral fine mist of NaOCl was seen during continuous irrigation with this medicament, causing eye soreness in the operator. Continuous irrigation with EDTA during sonic instrumentation removed the smear layer and gave clean canal walls. The vibratory files appeared safe and size 20 followed curved canals well. The effectiveness of the sonic device was similar to hand instrumentation. It considerably improved the ease and, to some extent, the speed of root canal instrumentation.     

口康含漱液用于超声根管预备抗菌效果的研究

目的探讨口康与超声联合应用杀灭感染根管内厌氧菌的效果。方法将60例慢性根尖周炎患者共60个患牙随机分为3组,每组各20个患牙,A组常规法手持器械根管预备和常规针筒式根管冲洗,B、C组均用超声法进行根管预备并分别以生理盐水、口康作为超声冲洗液,根管预备前后分别取样进行厌氧培养。结果B组厌氧菌减少程度明显大于A组(P<0.05);C组厌氧菌减少程度明显大于B组(P<0.01),显著大于A组(P<0.001)。结论超声在根管杀菌方面有独特的优势,口康可有效杀灭感染根管内厌氧菌,是一种较理想的根管超声冲洗液。     

An evaluation of basic periodontal therapy using sonic and ultrasonic sealers

10 adult patients with periodontitis were treated with oral hygiene instruction and a single episode of supra- and subgingival debridement using either a sonic or an ultrasonic instrument in a split-mouth design. The clinical response was evaluated by measurements of dental plaque, bleeding on probing, probing depths, and probing attachment levels taken at baseline and every 3rd month for 12 months. An improvement of periodontal conditions was observed during the initial 3-6 month period followed by a stabilization of parameters. No difference in clinical response could be observed between sites treated with the sonic or ultrasonic instruments.     

Clinical suitability of a sonic vibratory endodontic instrument

Abstract A sonic vibratory device with the shape, size and weight of a dental handpiece has been developed for the instrumentation of root canals. Specially designed K-type files are used with the handpiece, which is air-driven and may be attached to the high-speed air line of a dental unit. A clinical study was performed using conventional hand instruments and the sonic system in the instrumentation of root canals. Also studied was the use of continuous irrigation of the root canal with EDTA and filtered tap water with the sonic device. Instrumentation time, procedural and clinical complications, as well as overall suitability of the new device were evaluated. The results indicated that the sonic vibratory system was well-suited for root canal instrumentation. The vibratory files appeared safe and complications were well within acceptable limits. Irrigation with a continuous flow of EDTA was not acceptable, mainly because of crystallization and clogging of tubes and handpieces. Filtered tap water was well-tolerated and its cleaning effect was good. The sonic device could be used with ease and resulted in decreased operator fatigue when compared with hand instrumentation.     

Efficacy of automated versus hand instrumentation during root canal retreatment: an ex vivo study

Aim To compare automated and manual instrumentation techniques for removing filling material from root canal walls during root canal retreatment. Methodology One hundred extracted human single‐rooted teeth were root filled and stored. Specimens were divided into two groups: group A, Endofill plus gutta‐percha; group B, Sealer 26 plus gutta‐percha. The filling material was removed using the following techniques: group I – Gates–Glidden and K‐type files; group II – ProFile; group III – ProTaper; group IV – K3; group V– Micro Mega Hero 642. The remaining filling debris on the root canal walls were assessed radiographically, images were digitized and analysed using Image ProPlus software. The roots were split for evaluation in a stereomicroscope by epiluminescence and photomicrographs were taken for further analysis. The area covered with filling debris was analysed by means of Student's t‐test to compare the evaluation methods. The student's t‐test was also used to compare the removal of filling materials. An anova test was applied to compare the different techniques (P < 0.05). Results A significant difference occurred between radiographic and photomicrographic evaluation methods (P < 0.05). No significant difference was observed between the filling materials on terms of their removal (P > 0.05). Manual instrumentation left more filling debris on the root canal walls when compared to K3 (P < 0.05) and ProTaper (P < 0.01). Conclusions A photomicrographic method by epiluminescence was more effective than the radiographic method to evaluate filling debris. There was no significant difference between the filling materials in terms of their removal. K3 and ProTaper were more efficient than manual instrumentation.     

声波与超声波器械配合不同冲洗液对根管清理效果的扫描电镜研究

目的：比较声波与超声波根管器械配合不同冲洗液预备根管的清理效果。方法：制作根管扫描电镜标本，观察根管玷污层分布和牙本质小管暴露情况，各标本的冠1／3、中1／3、根尖1／3区域各取10个500倍视野照相，分级评分(玷污层分数，SL)。统计学分析比较三种冲洗液条件下声波和超声波器械根管清理的差异。结果：仅以蒸馏水作冲洗液，声波不能有效清理碎屑与玷污层；25g／L NaClO冲洗，根尖1／3玷污层的去除超声组优于声波组，但未清除玷污层栓层；25g／L NaClO结合170g／L EDTA作冲洗液，玷污层去除显著且两组无显著差异，但根尖1／3差于根管中上段，超声组部分区域牙本质小管蚀刻与融合。结论：声波结合25g／L NaClO和170g／L EDTA可有效去除玷污层并达到与超声器械近似的根管清理效果，根管内荡洗去除玷污层栓层效果显著，且未对根管壁产生破坏，但有必要加强根尖部荡洗。     

Inability of laser and rotary instrumentation to eliminate root canal infection

BACKGROUND: The authors evaluated the antibacterial effectiveness of laser instrumentation and rotary instrumentation of anterior, single-rooted teeth infected with Enterococcus faecalis. METHODS: The authors divided 35 infected samples into five groups: Group A: inoculation, laser, 17 percent ethylene-diamine-tetra-acetate (EDTA), 2.5 percent sodium hypochlorite (NaOCl) (n=10); Group B: inoculation, laser, 17 percent EDTA, sterile saline (n = 10); Group C: inoculation, rotary, 17 percent EDTA, 2.5 percent NaOCl (n=10); Group D: inoculation, no instrumentation (positive control) (n=5); Group E: no inoculation, no instrumentation (negative control) (n=5). They sampled and incubated dentin shavings from each canal for bacterial growth. RESULTS: In Group A, eight tubes were positive for bacterial growth. In Group B, 10 tubes were positive for bacterial growth. In Group C, six tube were positive for bacterial growth. In Group D, all of the tubes were positive for bacterial growth. In Group E, no tubes showed bacterial growth. The Fisher exact test showed no significant differences among groups A, E and C. CONCLUSION: Neither the laser nor the rotary instrumentation was able to eliminate endodontic infection. CLINICAL IMPLICATIONS: Although lasers have been presented as high-tech tools for disinfecting root canals, the laser was ineffective in this study.