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.     

Clinical efficacy of an endodontic antiseptic in a controlled release delivery system

Abstract The purpose of this clinical study was to assess the bacteriological status of the root canal after disinfection with a quaternary ammonium compound in a controlled release delivery system. Fifty-three teeth with apical periodontitis as evidenced by periapical radiolucencies were used. Under aseptic conditions the root canals were completely instrumented and irrigated with sodium hypochlorite. After the instrumentation, 38 teeth were treated with the quaternary ammonium compound in the controlled release dispenser; 15 teeth were treated with formocresol. Bacteriological samples from the root canals were taken after 7 days using an anaerobic technique. The results indicated that the quaternary ammonium compound in controlled release was as effective as formocresol in obtaining bacteria-free root canals. The advantages of an antiseptic with a long lasting effect for the elimination of bacteria from the root canal and for the prevention of reinfection were emphasized.     

三种冲洗液用于超声根管预备抗菌效果的对比研究

目的 探讨生理盐水、次氯酸钠、口泰与超声波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颗患牙随机分为3组，每组各20颗患牙，三组均用超声法进行根管预备并分别以生理盐水、次氯酸钠、口泰作为超声冲洗液，根管预备前后分别取样进行厌氧培养。结果 次氯酸钠组和口泰组其厌氧菌减少程度均明显大于生理盐水组（P〈0．01）；次氯酸钠组和口泰组之间其厌氧菌减少程度无显著性差异（P〉0．05）。结论 口泰与超声波联合应用可有效杀灭感染根管内厌氧菌，其抗菌效果与次氯酸纳相近似，是一种较理想的根管超声冲洗液。     

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.     

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.     

Suitability of controlled release delivery system for root canal disinfection

Abstract The purpose of the present study was to assess the bacteriologic status of the root canal after disinfection with a quaternary ammonium compound in a controlled release system. Root canal infection was induced in 57 single root teeth in dogs. The canals were then instrumented under aseptic conditions and irrigated with sodium hypochlorite and sterile saline. After the instrumentation, 10 canals were treated with the quaternary ammonium compound in the controlled release system, 9 canals with the quaternary ammonium compound on a cotton pellet, 10 canals with formocresol, 10 canals with a paste of calcium hydroxide. In 18 canals, no intracanal medicament was used. Bacteriologic samples were taken after 14 days using an anaerobic technique. The results indicated that the quaternary ammonium compound in the controlled release system was as effective as formocresol and calcium hydroxide in rendering the root canal free of bacteria. The advantages of an antiseptic with a long-lasting effect for the elimination of bacteria from the root canal and for the prevention of culture reversals were stressed.     

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.     

Debris Remaining in the Apical Third of Root Canals after Chemomechanical Preparation by Using Sodium Hypochlorite and Glyde: An In Vivo Study

Introduction

During chemomechanical instrumentation, several liquid or paste substances are used to ease the action of the files and to eliminate debris and the smear layer. The aim of this study was to evaluate whether the use of a paste containing EDTA during cleaning and shaping of the root canal helps to eliminate debris.

Methods

Twenty root canals in dog teeth were instrumented by a crown-down technique by using nickel-titanium rotary files. In 10 root canals (group A), sodium hypochlorite was used during instrumentation, followed by a final irrigation with 17% liquid EDTA. In another 10 canals (group B), sodium hypochlorite was again used as the irrigating solution, but Glyde File Prep paste was used with every instrument, and a final irrigation with EDTA was also carried out. Two additional teeth were used as positive and 2 as negative controls. The jaws were prepared for histologic evaluation.

Results

In group A where Glyde was not used during cleaning and shaping, little or no debris was found in the apical third of the instrumented root canals; however; in group B in which Glyde File Prep paste was used during chemomechanical instrumentation, moderate to high accumulation of debris was observed in the apical third.

Conclusions

The use of Glyde File Prep paste during rotary mechanical instrumentation favors the accumulation of debris in the apical third of the root canals. Irrigation with NaOCl and a final flush with EDTA by means of a small-gauge needle with simultaneous aspiration led to less accumulation of debris than in the Glyde File Prep group (P < .05).     

Canal markings produced by endosonic instruments

Abstract It has been recognised that ultrasonic files leave a diagonal pattern within the canal following endosonic instrumentation. There is confusion on the causative factor on the production of these marks. Furthermore there is little information about the marks produced by sonic files. An in vitro system consisting of highly polished dentin discs demonstrated that the ultrasonic K-file made a diagonal pattern that was an imprint of the cutting edges of the file. The sonic files produced different markings which were the result of their longitudinal and transverse motion. Root canals of extracted teeth were prepared with these instruments and similar grooves were observed. The ultrasonic K-file had diagonal grooves in the coronal and middle third of the root canal but longitudinal marks in the apical third. The rispisonic and shaper files produced debris even in the presence of NaOCl. This debris was formed into discrete parallel bands. Both longitudinal and transverse grooves were present and the canal had many other scratches similar to those seen with the dentin discs. There were differences between the marks produced by either ultrasonic or sonic endosonic instruments but it is unknown whether this influences the long term prognosis of the root canal therapy.     

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。     

Lubrication during root canal treatment

Lubrication is involved in all root canal treatment phases, from dental dam placement to canal obturation. Most often associated with instrumentation, lubrication is required to facilitate the mechanical action of hand/rotary files and to help emulsify and suspend the debris produced. Aqueous irrigation solutions such as sodium hypochlorite and ethylenediaminetetraacetic acid (EDTA) should be regarded as lubricants, but paste‐type substances are marketed specifically for this purpose. As more patients demand the retention of challenging teeth with narrow and curved root canals, the importance of lubrication in all aspects of root canal treatment must be acknowledged.     

Evaluation of the effectiveness of sodium hypochlorite used with three irrigation methods in the elimination of Enterococcus faecalis from the root canal, in vitro

The effectiveness of 4.0% sodium hypochlorite (NaOCl) used with three irrigation methods in the elimination of Enterococcus faecalis from the root canal was tested in vitro . Root canals contaminated with E. faecalis were treated as follows: (i) irrigation with 2 mL of NaOCl solution and agitation with hand files; (ii) irrigation with 2 mL of NaOCl solution and ultrasonic agitation; (iii) irrigation with NaOCl alternated with hydrogen peroxide. Contaminated canals irrigated with sterile saline solution served as the control. Paper points used to sample bacteria from the root canals were transferred to tubes containing 5 mL of brain heart infusion (BHI) broth. Tubes were incubated and the appearance of broth turbidity was indicative of bacteria remaining in the root canal. There were no statistically significant differences between the experimental groups. However, NaOCl applied by the three methods tested, was significantly more effective than the saline solution (control group) in disinfecting the root canal.     

Morphometrical analysis of cleaning capacity using nickel-titanium rotary instrumentation associated with irrigating solutions in mesio-distal flattened root canals

Variations in the internal anatomy of root canals may interfere with the success of root canal because tissue remnants may remain in the isthmus, re-entrances and ramifications of flattened root canals making instrumentation more difficult. Successful root canal treatment depends fundamentally on shaping, cleaning, disinfection and obturation. This study verified the quality of cleaning of ProFile .04 rotary technique associated with different irrigating solutions: 0.5% sodium hypochlorite, calcium hydroxide + Tergentol and 2% chlorhexidine in canals with mesio-distal flattening. Twelve human mandibular central incisors were randomly divided into 3 groups and instrumented up to ProFile 0.4 #35 file after cervical preparation, and processed histologically. After optical microscopic evaluation, statistical analysis showed that the percentage of cleaning of the three irrigating solutions was statistically different. Two-by-two comparisons classified the irrigating solutions in increasing order of cleaning: calcium hydroxide + Tergentol < chlorhexidine < 0.5% sodium hypochlorite.     

The effects of hand, sonic and ultrasonic instrumentation on the shape of curved root canals

This study compared the effects of hand, sonic and ultrasonic instrumentation on the shape of curved root canals in 60 extracted human lateral incisors and premolars. Each root of moderate or severe canal curvature was mounted onto a simulated crown and filled with a radiocontrast medium. Enlarged photographic prints obtained from radiographs taken before and after root canal preparation were measured. The results indicated a lower incidence of apical zip and elbow formation in the ultrasonic preparations when compared with those prepared by hand and sonic, irrespective of the canal curvature. A more prominent hour-glass shape was prepared by hand and sonic instruments particularly in severely curved root canals. A distinctive taper was produced by each method of preparation. All three instrumentation techniques showed preferential dentine removal from the convex aspect of the canal in the apical portion and the concave aspect in the middle portion of the root canal.     

下颌第二磨牙C形根管的特点和临床治疗

目的探讨下颌第二磨牙C形根管的发生率、临床诊断和治疗方法。方法通过对152例下颌第二磨牙拍摄术前X线片和术中根管探查,按照Melton标准诊断C形根管;采用机用镍钛器械Hero642进行根管预备,次氯酸钠超声冲洗,热牙胶垂直加压技术充填根管。记录C形根管的发生率及临床特点,根据治疗前、中、后的X线片评价根管预备和充填的效果。结果下颌第二磨牙C形根管的发生率为32.2%,79.6%的C形根管患牙X线片表现为锥形融合牙根,20.4%表现为近、远中独立牙根;所有患牙均无根管内并发症发生,治疗效果好。结论下颌第二磨牙C形根管主要存在于融合牙根,根管探查结合X线片可诊断C形根管;机用镍钛器械预备根管、次氯酸钠超声冲洗和垂直加压技术充填根管可获得良好的治疗效果。     

Bacteriologic evaluation of ultrasonic root canal instrumentation

The antibacterial effect of ultrasonic instrumentation in the treatment of infected root canals was clinically evaluated. Sodium hypochlorite solution (0.5%) was used as an irrigant, but no antibacterial intracanal dressing was used between the appointments. The ultrasonic technique eliminated the bacteria from the canals more efficiently than hand instrumentation alone. Even though ultrasonication definitely improves the procedure of root canal disinfection, the use of an antibacterial dressing between appointments is necessary to achieve as complete a reduction in bacterial levels as possible.     

Stereomicroscopic evaluation of canal shape following hand, sonic, and ultrasonic instrumentation

This study evaluated the root canal shape after using sonic, ultrasonic, and hand instrumentation on the mesial canals of extracted human mandibular first and second molars. One-hundred and five mesial roots were randomly divided into six experimental groups and one untreated control group of 15 roots each. The following instrumentation techniques were evaluated in the experimental groups: hand instrumentation with K-Flex files, sonic instrumentation with the Endostar 5, sonic instrumentation with the Sonic Air MM 3000, and ultrasonic instrumentation with the Cavi-Endo unit. Each technique was directly compared with each other. The mesial roots were instrumented alternating the techniques between the buccal and lingual canals in each group so that a direct comparison could be made. All canals were instrumented to a size corresponding to a #30 K-Flex file 1 mm from the anatomical apex. The roots were then sectioned perpendicular to the long axis so the apical and middle thirds could be evaluated with the stereomicroscope for canal shape. The control group was sectioned and examined without instrumentation. A significantly more regular shape was obtained at both levels with hand instrumentation than was obtained with either sonic or ultrasonic techniques. The comparisons between the sonic and ultrasonic techniques showed significantly better shapes were obtained with the Sonic Air MM 3000 instrument.     

钙化根管的根管显微镜治疗

目的:探讨应用根管显微镜治疗钙化根管的方法,并对其疗效进行评价.方法:因根管钙化进行根管治疗的患牙33个,在根管显微镜引导下,将超声预备、手动NiTi器械预备以及EDTA化学预备相结合进行治疗,记录预备时间,术后1周进行根管充填,半年后复查并进行疗效评价.结果:根管显微镜下钙化根管的治疗成功率为88.9%,平均每根根管耗时25.8 min.结论:在根管显微镜引导下,将超声预备、手动NiTi器械预备以及EDTA化学预备相结合可提高钙化根管治疗的成功率.     

Clinical Study of Antimicrobial Efficacy of Laser Ablation Therapy with Indocyanine Green in Root Canal Treatment

IntroductionLaser ablation (LA) therapy is used as an adjunct to endodontic treatment to improve microbial reduction. However, studies evaluating the impact of LA with indocyanine green (ICG) are scarce. This study aimed to evaluate the antimicrobial efficacy of LA therapy with ICG in root canal treatment.MethodsSixty patients with periapical lesions in teeth with a single canal and absence of pain, edema, and previous treatment were selected. Patients were randomly allocated into 3 groups according to the apical sizes used (n = 20); 25/04, 30/04, and 35/04 were the final sizes used. In half the patients of each group, 2.5% sodium hypochlorite was used as an irrigating solution, and in the other half, saline solution was used. After instrumentation, all patients received LA therapy with ICG. Root canal sampling was performed before (S1) and after (S2) root canal instrumentation and immediately after LA therapy with ICG (S3). Colony-forming units were counted, and statistical tests were applied (P < .05).ResultsThere was a significant reduction in colony-forming units from S1 to S2 in all treatment protocols (P < .05); 2.5% sodium hypochlorite as an irrigating solution showed a greater microbial reduction compared with saline solution (P < .05). LA therapy with ICG further reduced the microbial counts significantly (S2 to S3 and S1 to S3) whether sodium hypochlorite or saline was used (P < .05).ConclusionsLA therapy with ICG significantly increased microbial reduction in root canals regardless of instrumentation sizes or the irrigation solution used.     

Variations in stroke rate and loading using hand sonic or ultrasonic instrumentation

Abstract An in vitro model system was developed to investigate the stroke rate and loading during hand, sonic, or ultrasonic instrumentation. The model system consisted of a mandibular molar tooth attached to a strain gauge and interface to a computer. Ten clinicians instrumented the distal canal of lower molar teeth. Stroke rates used and loads applied were measured using different sized files with the three different preparation techniques. There was no significant difference in stroke rates between different file sizes (p>0.05) within the same generator, however, stroke rate for hand was significantly slower than for sonic or ultrasonic (p<0.01). Loading of the canal wall rose with increase in file size which was significant for hand (p<0.01) and sonic (p<0.05) but not ultrasonic (p>0.05). There was a tendency for loading to be higher with hand instrumentation, this however was not significant (p>0.05).