root canal therapy - Medical Dictionary

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root canal therapy		A treatment modality in endodontics concerned with the therapy of diseases of the dental pulp. For preparatory procedures, root canal preparation is available. [ Articles \| Books \| Images \| Discussion groups ]

Additional comments : Free Full Text Root canal therapy of a maxillary first molar with five root canals: case report This paper reports the case of a maxillary left first molar that presented three root canals in the mesiobuccal root. Root canal therapy and case management are described. Features like wide crown access, adequate illumination and use of exploring files where important for successful completion of the endodontic treatment. The importance of apical patency and cleaning of the apical foramen on root canal preparation The apical limit of root canal instrumentation has always been a matter of great controversy. Despite the large number of published studies on this subject, a consensus has not yet been reached. In fact, the recent discussion on apical patency and cleaning of the apical foramen, as well as the incorporation of these procedures to the endodontic treatment, seem to have raised even more polemics. It is likely that all this polemics has its roots in the lack of interrelation between the theoretical knowledge of pulp stump and periapical tissues and the real clinical practice. By addressing the most important aspects of this theme, this paper aims to present news concepts about the importance of apical patency and cleaning of the apical foramen during root canal preparation. Shock of paradigms on the instrumentation of curved root canals This paper makes a practical analysis about the paradigm on the instrumentation of curved root canals. In Endodontics, a paradigm has been created. Theories and techniques for instrumentation of curved root canals state that the use of a #25 file in the apical portion fulfills all the requirements for cleaning and shaping of the root canal system. Every scientific theory or paradigm should be continuously opened to modifications or refutation. The existence of extremely flexible instruments fabricated from metal alloys, methods for accurate determination of the real anatomic diameter and achievement of optimal shaping and cleaning of the apical portion created new theories and a new paradigm on the instrumentation of curved root canals. Therefore, this new insight will gradually modify the mentality of researchers and clinicians, but will still be open to further investigations and theories. 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. The clinical significance and management of apical accessory canals in maxillary central incisors BACKGROUND: The maxillary central incisor is considered to be the least difficult subject for a clinical endodontic experience. However, the internal anatomy of maxillary central incisors can present a number of variations, including multiple accessory canals. CASE DESCRIPTION: This article highlights the clinical significance and management of accessory canals located in the apical one-third of maxillary central incisors. The authors present two case reports in which failure to detect the accessory canals led to root canal failure and subsequent surgical intervention. Another two case reports present the serendipitous discovery and nonsurgical management of accessory canals during the initial treatment of maxillary incisors. CONCLUSIONS AND CLINICAL IMPLICATIONS: It is important for the clinician to be able to detect the signs suggesting the presence of accessory canals in maxillary central incisors. Failure to do so may lead to a less-than-optimal endodontic treatment outcome. Periapical surgery using the ultrasound technique and silver amalgam retrograde filling. A study of 71 teeth with 100 canals (pdf) INTRODUCTION: Periapical surgery using ultrasound allows the treatment of root canals of difficult access, with the sacrifice of little root tissue. As a result, periapical disorders which were condemned to treatment failure in the past can now be dealt with successfully. MATERIAL AND METHODS: In 71 teeth presenting 100 root canals treated with ultrasound and subjected to retrograde filling with silver amalgam, the course and short-term success of management was evaluated in relation to lesion size, the magnitude of apical resection, and the size of the retrograde filling cavity. The duration of follow-up was one year, with post-treatment controls after 6 and 12 months. RESULTS: After 6 months, the percentage clinical and radiological success was 92% and 58%, respectively. One year after periapical surgery the corresponding percentages were 95% and 80%. Global success after 6 months was 63%, versus 84.2% after 12 months. No statistically significant relation was observed between treatment success and the size of the periapical lesion, the amount of apex resected, or the size of retrograde filling. CONCLUSION: Periapical surgery using ultrasound and retrograde filling with silver amalgam affords a high success rate after 12 months. Do procedural errors cause endodontic treatment failure? Apical periodontitis is a sequel to endodontic infection and manifests itself as the host defense response to microbial challenge emanating from the root canal system. It is viewed as a dynamic encounter between microbial factors and host defenses at the interface between infected radicular pulp and periodontal ligament that results in local inflammation, resorption of hard tissues, destruction of other periapical tissues, and eventual formation of various histopathological categories of apical periodontitis, commonly referred to as periapical lesions. The treatment of apical periodontitis, as a disease of root canal infection, consists of eradicating microbes or substantially reducing the microbial load from the root canal and preventing re-infection by orthograde root filling. The treatment has a remarkably high degree of success. Nevertheless, endodontic treatment can fail. Most failures occur when treatment procedures, mostly of a technical nature, have not reached a satisfactory standard for the control and elimination of infection. Even when the highest standards and the most careful procedures are followed, failures still occur. This is because there are root canal regions that cannot be cleaned and obturated with existing equipments, materials, and techniques, and thus, infection can persist. In very rare cases, there are also factors located within the inflamed periapical tissue that can interfere with post-treatment healing of the lesion. The data on the biological causes of endodontic failures are recent and scattered in various journals. This communication is meant to provide a comprehensive overview of the etio-pathogenesis of apical periodontitis and the causes of failed endodontic treatments that can be visualized in radiographs as asymptomatic post-treatment periapical radiolucencies. Mandibular nerve paresthesia caused by endodontic treatment The paresthesias of the inferior dental nerve consists of a complication that can occur after performing various dental procedures such as cystectomies, extraction of impacted teeth, apicoectomies, endodontic treatments, local anesthetic deposition, preprosthetic or implantologic surgery. The possible mechanisms of nervous lesions are mechanical, chemical and thermal. Mechanical injury includes compression, stretching, partial or total resection and laceration. The lesion can cause a discontinuity to the nerve with Wallerian degeneration of the distal and integrated fibers of the covering (axonotmesis) or can cause the total sectioning of the nerve (neurotmesis). Chemical trauma can be due to certain toxic components of the endodontic filling materials (paraformaldehyde, corticoids or eugenol) and irrigating solutions (sodium hypochlorite) or local anesthetics. Thermal injury is a consequence of bone overheating during the execution of surgical techniques. We present a clinical case of paresthesia of the inferior dental nerve after the introduction of a gutta-percha point in the mandibular canal during the performance of a root canal therapy of the inferior first molar. The etiology and the treatment of this endodontic complication are described. Vertical root fractures: clinical and radiographic diagnosis BACKGROUND: Early detection and management of vertical root fractures, or VRFs, remain a vexing issue that has caused needless suffering for patients as well as for dentists. The authors present techniques to aid the dentist in recognizing VRFs. METHODS: During a five-year period, the authors examined 36 patients who had VRFs. Absent control subjects and a larger number of patients, the authors did not design this investigation for statistical analysis. They diagnosed VRFs through dental histories and clinical and radiographic examinations. RESULTS: The study revealed VRFs in 36 teeth, two of which were vital and 34 of which were nonvital (that is, endodontically treated). The 34 VRFs resulted from excessive operative procedures performed in the root canal after endodontic therapy. Thirty-one of these 34 VRFs were caused by poorly designed dowels (too long, too wide or both) or inappropriate selection of the tooth as a bridge abutment; two VRFs were caused by a restoration that exerted lateral pressure on the axial walls of the preparation; and one VRF was caused by overzealous endodontic forces. The VRFs in the two vital teeth were in men who had a history of bruxism or clenching. CONCLUSIONS AND CLINICAL IMPLICATIONS: VRFs can be detected early by listening to the patient's chief complaints, carefully examining periapical and bitewing radiographs and performing a thorough clinical examination.

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