Noncontact 3D evaluation of surface topography of reciprocating instruments after retreatment procedures

Abstract This study evaluated the Reciproc R25 and Pro-R 25 instruments in unused condition, after one and a second use in endodontic retreatment employing a noncontact 3D light interferometer profiler, scanning electron microscopy (SEM) and cyclic fatigue tests. Twenty single-root teeth were instrumented with Reciproc R25 and filled with gutta-percha and sealer. A 3D profiler with a 20x objective using the Mx™ software was used to evaluate the cutting blade surfaces of Reciproc R25 and Pro-R 25 (n=5 per group) in unused condition, after the first and second uses in retreatment procedures. After retreatment, SEM was used to evaluate the topographic features of the used instruments. Cyclic fatigue tests were performed to compare new to used instruments. One-way ANOVA followed by Tukey test was used to compare the tested instruments before and after the first and second uses. Student t-test was used to compare the different instruments and for cyclic fatigue evaluation. No significant differences were observed in the cutting blade surfaces of Reciproc and Pro-R before and after one and two uses (p>0.05). Reciproc without use showed higher Sa and Sq when compared to Pro-R without use (p<0.05). No differences were observed between Reciproc and Pro-R after one and two uses (p>0.05). New and unused Reciproc showed longer time to fracture than Pro-R instruments (p<0.05), and only Pro-R showed differences between new and used instruments (p<0.05). Retreatment procedures with Reciproc and Pro-R did not change the surface topography of instruments. Reciproc had greater resistance to cyclic fatigue compared with Pro-R.

Resumo Este estudo avaliou os instrumentos Reciproc R25 e Pro-R 25 sem uso, após um primeiro e um segundo uso em retratamento endodôntico com perfilômetro 3D por interferometria de luz sem contato, microscópio eletrônico de varredura (MEV) e testes de fadiga cíclica. Vinte dentes unirradiculares foram instrumentados com Reciproc R25 e obturados com guta-percha e cimento endodôntico. Um perfilômetro 3D com uma objetiva 20x usando o software Mx ™ foi usado para avaliar as superfícies da lâmina de corte do Reciproc e Pro-R (n = 5 por grupo) na condição sem uso, após o primeiro e após um segundo uso em procedimentos de retratamento. Após retratamento, o MEV foi usado para avaliar as características topográficas dos instrumentos utilizados. Testes de fadiga cíclica foram realizados para comparar instrumentos novos com instrumentos usados. O teste One-way ANOVA seguido pelo teste de Tukey foi usado para comparar os instrumentos testados nos diferentes estágios. Para comparar os diferentes instrumentos e para avaliação de fadiga cílcica, foi utilizado o Student t-test. Não foram observadas diferenças estatisticamente significantes nas superfícies das lâminas de corte dos instrumentos Reciproc e Pro-R antes e após um e dois usos (p> 0,05). O Reciproc na condição sem uso apresentou maior Sa e Sq quando comparado ao Pro-R (p <0,05). Não foram observadas diferenças entre Reciproc e Pro-R após um e dois usos (p> 0,05). O Reciproc sem uso apresentou maior tempo de fratura do que os instrumentos Pro-R (p<0,05), e apenas o Pro-R apresentou diferenças entre instrumentos novos e usados (p<0,05). Os procedimentos de retratamento com Reciproc e Pro-R não alteraram a topografia da superfície dos instrumentos. Reciproc apresentou maior resistência à fadiga cíclica em comparação com o Pro-R.

Shaping Ability of Reciprocating and Rotary Systems After Root Canal Retreatment: a CBCT Study

Abstract The purpose of this in vitro study was to evaluate the shaping ability of reciprocating and continuous rotary systems after root canal retreatment. After preparation and root canal filling, mesial canals of 54 mandibular molars were distributed into 3 groups (n=18), according to the filling material removal and re-instrumentation protocols: WOG group - WaveOne Gold system; PTN group - ProTaper Next system; and PTU group - ProTaper Universal system. Cone-beam computed tomographic (CBCT) images acquisition of the mesial root canals was performed at different moments: (1) before instrumentation (unprepared root canals), (2) after preparation and filling, (3) after filling material removal and (4) re-instrumentation. The apical transportation (AT), centering ability (CA) and change in root canal diameter were assessed by CBCT analysis. The remaining filling material quantification was performed by radiographic examination. The statistical analyses were performed using the 3-way ANOVA, Tukey-Kramer, Kruskal-Wallis and Dunn multiple Comparison tests (p<0.05). The tested instruments did not show full CA (=1.0). PTN group had greater AT at the 5th mm in comparison with the WOG group (p<0.05). After re-instrumentation, WOG group had greater root canal diameter change at the 1st and 5th mm than PTN and PTU groups (p<0.05). There was no significant difference among groups when comparing the amount of remaining filling material after re-instrumentation (p>0.05). The tested systems provided minimal alteration in root canal morphology at the apical portion after root canal retreatment. However, WOG promoted greater change in root canal diameter.

Resumo O objetivo deste estudo in vitro foi avaliar a capacidade de modelagem de sistemas rotatórios e reciprocantes após o retratamento do canal radicular. Após o preparo e obturação do canal radicular, os canais mesiais de 54 molares inferiores foram distribuídos em 3 grupos, de acordo com os protocolos de remoção do material obturador e re-instrumentação: (n=18): grupo WOG - sistema WaveOne Gold; Grupo PTN - sistema ProTaper Next; e grupo PTU - sistema ProTaper Universal. A análise das imagens de tomografia computadorizada de feixe cônico foi realizada em diferentes momentos: (1) antes da instrumentação (canais radiculares não preparados), (2) após o preparo e obturação, (3) após a remoção do material obturador e (4) re-instrumentação. O transporte apical (TA), a capacidade de centralização (CC) e a mudança no diâmetro do canal radicular foram avaliados por análise tomográfica. A quantificação do restante do material obturador foi realizada por exame radiográfico. As análises estatísticas foram realizadas utilizando os testes de ANOVA de 3 fatores, Tukey-Kramer, Kruskal-Wallis e Comparações Múltiplas de Dunn (p<0,05). Os instrumentos não apresentaram CC perfeita (=1,0). PTN apresentou maior TA no 5º mm em comparação ao grupo WOG (p<0,05). Após a re-instrumentação, o grupo WOG apresentou maior aumento no diâmetro do canal radicular no 1° e 5° mm do que os grupos PTN e PTU. Não houve diferença significativa entre os grupos em relação à remoção do material obturador (p>0,05). Os sistemas testados proporcionaram alteração mínima na morfologia do canal radicular na porção apical após o retratamento do canal radicular. No entanto, WOG promoveu maior alteração no diâmetro do canal radicular.

Conventional endodontic retreatment of persistent pain on previously treated tooth in an elderly patient: A case report

@#Clinical evaluation for a successful root canal treatment is assessed by various criteria, which are clinical, histopathological, and radiographical criteria. Therefore, failure of endodontic treatment can be described as a recurrence of clinical symptoms, with the presence of a periapical radiolucency or both. Failure factors in the treatment are frequently related to persistent infection. Conventional endodontic retreatment is indicated for symptomatic previously treated teeth or asymptomatic teeth with inadequately done initial endodontic treatment to avoid potential recurrence. Endodontic retreatment in elderly patients is a great challenge because the clinician has to reassure both the physical and psychological factors of the patient to determine whether to save a tooth or perform an extraction. Some difficulties may also be found in root canal retreatment, including finding the root canal hole or root canal blockage found in parts of the root canal that have not been repaired in the previous treatment. A 60-year-old female patient came with the chief complaint of recurrent pain, and subjective discomfort in the maxillary left central incisor. The patient had anxiety about the dental treatment. The tooth had a history of root canal treatment four months ago. The clinical examination showed a positive response to the percussion test. The radiographical analysis showed a root canal underfilling, 2-3 mm short of length from the apex. The tooth was diagnosed as a previously treated tooth with symptomatic apical periodontitis. Endodontic retreatment was performed based on the patient’s clinical condition and consent, followed by composite restoration. The clinical and radiographic re-evaluation after four weeks of follow-up revealed an excellent condition. This favorable result showed that a conventional retreatment plan of persistent pain on the previously treated tooth in an elderly patient led to progressive healing, and a longer follow-up was advised.

Intentional reimplantation of left lower second molar as an alternative to extraction: a case report / Reimplante intencional del segundo molar inferior como alternativa a la extracción: reporte de caso

In patients who need endodontic re-treatment, and where the prognosis for surgical or non-surgical re-treatment is poor or treatment may be risky, one alternative is to opt for extraction of the affected tooth and replacement by an implant. However treatment by intentional reimplantation (IR) is also a possibility. The object of the present study was to present a case of a patient aged 71 years who needed endodontic re-treatment, where IR treatment was selected. The patient reported spontaneous pain which disappeared completely with the use of analgesics. This tooth had previously been treated endodontically around 1 year earlier, and no pain was reported in the first two months after treatment.Nonetheless, about 3 months before the present consultation, intensity of the symptoms had increased with a sensation of pressure in the apical-coronal direction. Cone-beam computerised tomography (CBCT) showed a periapical lesion in tooth 3.7. Based on the clinical and imaging examinations, acute apical periodontitis was diagnosed in tooth 3.7.The tooth was treated by IR. It was carefully extracted and inspected for cracks or perforations. It was treated under the microscope with root resection, and then retrograde obturation was carried out with bioceramic material. The tooth was then repositioned in its alveolus. It was immobilised for 15 days, after which the patient could return gradually to normal masticatory function. In the 6 months check-up the patient presented no pain or sensitivity to percussion. No root resorption or periapical radiolucency was observed in the periapical X-ray. We conclude that IR is an alternative to extraction followed or not by prosthetic treatment, for patients who need endodontic re-treatment. The treatment presents good levels of success, and of acceptance by the patient.

En pacientes que necesitan de retratamiento endodóntico y el retratamiento quirúrgico o no quirúrgico tiene un pronóstico desfavorable o puede ser riesgoso, se puede optar por la extracción del diente afectado y su reemplazo por implante o se puede elegir el tratamiento mediante la técnica de reimplante intencional (RI). El objetivo del presente estudio fue presentar un caso de paciente de 71 años con necesidad de retratamiento endodóntico, donde se optó por la realización del RI. Paciente relatava dolor espontáneo que desaparecia completamente con el uso de analgésicos. Este diente ya había sido tratado endodónticamente hace alrededor de 1 año, y el paciente noreportó dolor en los primeros dos meses después del tratamiento.No obstante, hace aproximadamente 3 meses la intensidad de los síntomas aumentó, junto con la sensación de presión en el sentido ápice-corona. La tomografía computarizada cone-beam (TCCB) mostró lesión periapical en el diente 3.7. Basado en el examen clínico e imagenológico se diagnosticó periodontitis apical aguda en el diente 3.7.Para el tratamiento se realizó la técnica de RI, siendo extraído el diente cuidadosamente, e inspeccionado a fin de localizar fisuras o perforaciones. El diente fue tratado bajo microscopio y se realizó la resección de la raíz. Se realizó la obturación retrógrada con material biocerámico. Enseguida el diente fue reposicionado en su alveolo, la inmovilización fue realizada durante 15 días y la paciente logró retornar gradualmente a su función masticatoria. En el seguimiento de 6 meses la paciente no presentó dolor o sensibilidad a la percusión. En la radiografía periapical no se observó resorción radicular o radiolucencia periapical. Concluimos que el RI en pacientes que necesitan retratamiento endodóntico es una alternativa a la realización de la exodoncia seguida o no, de tratamiento protético, donde existe una buena aceptación por parte del paciente y éxito en el tratamiento.

Non-surgical endodontic retreatment in periapical abscess: A case report

@#Endodontic failure affects the teeth and surrounding tissues. This is a case of a 62-year-old female with a chief complaint of pain and swelling occurring frequently in the upper left teeth for 6 months. The tooth was treated a year ago. Nonsurgical endodontic retreatment was carried out and observed for 4 months. The size of the lesion reduced significantly during the healing evaluation. This case report aimed to show the management of a non-surgery endodontic retreatment in periapical abscess using a rotary instrument.

Avaliação radiográfica e em microscopica eletrônica de varredura de remanescentes de obturação após a re-instrumentação endodôntica / Radiographic and scanning electron microscopic assessment of root canal filling remnants after endodontic re-instrumentation

Objetivo: Falhas no tratamento endodôntico podem ocorrer por várias razões. O retratamento endodôntico é uma alternativa interessante para tratar esse problema clínico. No entanto, não é possível remover completamente o material obturador do canal radicular por qualquer das técnicas atuais de retratamento. O objetivo deste estudo foi avaliar a presença de resíduos de material obturador após a re-instrumentação endodôntica. Material e Métodos: Sessenta dentes anteriores humanos foram preparados pela técnica escalonada com Flexofiles, limas K e brocas GatesGlidden (GG). Entre o uso de cada instrumento ou broca, os canais radiculares foram irrigados com hipoclorito de sódio (NaOCl). A lama dentinária foi removida por irrigação com ácido etilenodiaminotetraacético e NaOCl. Após secagem com pontas de papel, os canais radiculares foram divididos aleatoriamente em 5 grupos (n = 12), de acordo com o material obturador: cones Resilon/cimento Real Seal ou cones de guta-percha e cimento Endofill, Sealapex, AH Plus ou MTA Fillapex. Após uma semana, o material obturador foi removido usando Eucaliptol e K-files. Os canais radiculares foram re-instrumentados com limas K e brocas GG de tamanhos maiores do que as anteriormente usadas. A presença de remanescente de material obturador no canal radicular foi analisada por radiografia e microscopia eletrônica de varredura (MEV). A análise estatística foi realizada pelo teste de Regressão Logística Binária (P < 0,05). Resultados: As análises radiográfica e por MEV mostraram que o material do grupo MTA Fillapex foi melhor removido do que o dos grupos Endofill, Sealapex, AH Plus e Real Seal. Conclusão: Após a re-instrumentação, o grupo MTA Fillapex apresentou menos remanescentes nos canais radiculares que os grupos Endofill, Sealapex, AH Plus e Real Seal. O material residual foi encontrado mais frequentemente no terço apical. (AU)

Objective: Failures in endodontic treatment may occur by several reasons. Endodontic retreatment is an interesting alternative to manage this clinical problem. However, it is not possible to completely remove the root canal filling by any current retreatment technique. The aim of this study was to evaluate the presence of residual root canal filling materials after endodontic reinstrumentation. Material and Methods: Sixty extracted anterior human teeth were prepared by step-back technique with Flexofiles, K-files and Gates-Glidden (GG) burs. Between the use of each file or bur, root canals were irrigated with sodium hypochlorite (NaOCl). Smear layer was removed by irrigation with ethylenediaminetetraacetic acid and NaOCl. After drying with paper points the root canals were randomly divided into 5 groups (n = 12), according to filling material: Resilon cones/Real Seal sealer or gutta-percha cones and Endofill, Sealapex, AH Plus or MTA Fillapex sealers. After one week, root canal fillings were removed using Eucaliptol and K-files. Root canals were reinstrumented with K-files and GG burs sized larger than the first ones. The removal of root canal filling material was analyzed by radiography and scanning electron microscopy (SEM). Statistical analysis was performed using Binary Logistic Regression test (P < 0.05). Results: Radiographic and SEM analysis showed that material from the MTA Fillapex group was better removed than that from Endofill, Sealapex, AH Plus and Real Seal groups. Conclusion: After re-instrumentation, MTA Fillapex group showed less remnants into the root canals than Endofill, Sealapex, AH Plus and Real Seal groups. Residual material was most often found in the apical third(AU)

Eficiencia de tres técnicas en la remoción de gutapercha / Efficiency of three different techniques in the removal of gutta-percha

Cuando la terapia endodóntica fracasa, las opciones para solucionar este problema incluyen preservar el diente a través del retratamiento ortógrado o cirugía apical. Siempre que sea posible, el retratamiento endodóntico no quirúrgico debe ser la opción elegida. Diferentes sistemas rotatorios han sido propuestos como una alternativa a la instrumentación manual para la remoción de la gutapercha.El objetivo de este trabajo fue comparar la eficacia y la eficiencia en la desobturación total del canal radicular, utilizando dos tipos de instrumentos rotatorios: limas Protaper Universal® y limas Protaper Retratamiento® con limas manuales tipo K. Se instrumentaron 45 canales radiculares, con limas mecanizadas del sistema Mtwo®, hasta la 25/06 y terminados de conformar con lima K #40 e irrigados con hipoclorito de sodio al 2,5 % entre cada instrumento. Los dientes fueron obturados con técnica de condensación lateral, utilizando conos de gutapercha y cemento Tubliseal®.La muestra se dividió al azar en tres grupos A, B y C, de 15 canales cada uno, el grupo A se desobturó con limas Protaper Universal. El grupo B se desobturó con limas Protaper retratamiento y el grupo C se desobturó totalmente con limas K. Se cronometró cada procedimiento de desobturación y al término de esta, se tomó una radiografía en sentido buco-lingual y otra en sentido mesio-distal para cuantificar la remoción de gutapercha en cada grupo. Los resultados muestran que no existe diferencia significativa en la eliminación total del relleno endodóntico entre los tres grupos (p= 0,271) pero que los tiempos empleados en la desobturación total de los canales entre los grupos, muestra diferencias significativas entre Protaper Retratamiento y limas K, y entre Protaper Universal y limas K (p <0,05). Bajo las condiciones de este estudio, ningún sistema fue capaz de remover toda la gutapercha del interior del canal radicular.

When primary endodontic treatment fails, the treatment alternatives for root preservation are orthograde retreatment or apical surgery. Whenever possible, orthograde retreatment must be the first option. Different rotary systems have been proposed as an alternative to manual instrumentation for the removal of gutta-percha. The aim of this study was to compare the efficacy and efficiency of the total removal of gutta-percha from root canals, using two types of rotary instruments: Protaper Universal Files® and Protaper Retreatment Files®, compared to manual K type Files. A total of forty-five canals were instrumented with Mtwo files® up to a 25.06 file and the shaping was completed with a 40 K-type File and irrigated with 2.5 % Sodium Hypochlorite between each instrument. The teeth were obturated with Lateral Condensation Technique, using gutta-percha and Tubliseal® sealer. Samples were divided in groups A, B and C, 15 canals each, and gutta-percha was removed using the following protocols: group A with Protaper Universal; Group B using Protaper Retreatment and Group C using K type Files. Each procedure was timed and at the end of it, two periapical radiographs were taken: one buccolingual and one mesiodistal, in order to quantify the amount of gutta-percha removed. The results analysis show that there is no significant difference in the amount of gutta-percha removed between the three groups (p= 0.271) but that the time invested to perform the removal of the gutta-percha was significantly less between for the rotary systems, when compared to manual instrumentation (p <0.05). Under the conditions of this study, no system was able to remove all gutta percha inside the root canal.

Sistema rotatório Mtwo para retratamento endodôntico: revisão de literatura / Rotary system Mtwo for endodontic retreatment: literature review

O retratamento endodôntico é sempre a primeira opção indicada para solucionar o fracasso do tratamento. Atualmente, o retratamento vem sofrendo grandes avanços, buscando técnicas e instrumentos que provoquem o mínimo de danos possíveis, com uma maior eficiência e em menor tempo. Dentre esses instrumentos, encontra-se o sistema Mtwo para retratamento (Mtwo-R), que é um sistema rotatório de níquel-titânio da nova geração o qual tem sido alvo de muitas pesquisas nos últimos anos. O objetivo deste trabalho foi realizar um levantamento da literatura com o intuito de ressaltar as vantagens e desvantagens do sistema rotatório Mtwo-R, quando comparado com outros tipos de sistemas rotatórios e com técnicas manuais.

Endodontic retreatment is always the first option to solve the failure of the previous root canal treatment. Currently, the retreatment has undergone great advances, developing techniques and instruments that cause the least possible damage, with greater efficiency and dispending less time. Among these instruments is the Mtwo system for retreatment (Mtwo-R), which is a new generation of nickel-titanium rotary system which has been extensively studied in recent years. The objective of this study was to survey the literature in order to highlight the advantages and disadvantages of rotary system Mtwo-R compared with other types of rotary systems and manual techniques.

Regenerative Endodontic Treatment as a Retreatment Option for a Tooth with Open Apex - A Case Report

Abstract: Treatment of non-vital immature teeth with apical periodontitis has always been a challenge in Endodontics. Regenerative endodontic treatment (RET) has been successfully used for the management of these cases. The aim of this study is to present a case of RET used for the retreatment of a previously endodontically treated permanent tooth with an open apex. A 14-year-old boy with a poor endodontic treatment done on his maxillary right central incisor developed symptomatic apical periodontitis. Radiographically, incomplete root development with thin dentinal walls and an open apex were evident. After accessing and removing previous filling materials, the canal was copiously irrigated with 2.5% sodium hypochlorite. A triple antibiotic paste was placed inside the canal and left for 15 days. After removal of the antibiotic mixture, bleeding was induced into the canal by passing a hand file out of the apex. A collagen membrane barrier was placed over the blood clot, followed by sealing with mineral trioxide aggregate. Access was sealed with permanent filling materials. Clinical examination at 12, 24 and 36 months revealed no symptoms. Radiographic examination showed resolution of the periapical lesion and apical closure. Sensitivity tests with cold and an electric pulp test elicited a negative response at all recall periods. On the basis of long-term results, RET may be an effective option for the retreatment of an immature permanent tooth with a failed previous treatment and periapical periodontitis.

Endodontic Retreatment by Removal of Metallic Post: A Case Report.

Endodontic retreatment is a considered as a comprehensive field, divided into various categories such as coronal disassembly, removing obturation materials, locating previously missed canals, etc. This field of endodontics has its own technologies and techniques that are required to achieve clinical success. Because the field of non-surgical retreatment is comprehensive, this case report will limit its focus to the removal of the post. Removal of posts from endodontically treated teeth is a major obstacle in the retreatment of teeth having recurrent pathology, which often leads to the extraction of a tooth that might have been saved with endodontic retreatment. This case report shows the non-surgical endodontic retreatment of incompletely obturated maxillary central incisors by removal of metallic posts.

Influence of Apical Patency and Cleaning of the Apical Foramen on Periapical Extrusion in Retreatment

This study evaluated the influence of apical patency, root filling removal technique and cleaning of the apical foramen, concerning the amount of debris extruded during root canal retreatment. Forty mandibular incisors were randomly assigned to 4 groups - GIM (n=10), GIIM (n=10), GIPT (n=10) and GIIPT (n=10), which were named according to leaving (I) or not (II) apical patency during canal preparation and filling removal technique (manual - M or ProTaper system - PT). After filling material removal, each specimen of each group had the apical foramen cleaned by sizes 15, 20 and 25 instruments, generating 12 subgroups: GIM15, GIM20, GIM25, GIIM15, GIIM20, GIIM25, GIPT15, GIPT20, GIPT25, GIIPT15, GIIPT20 and GIIPT25. Extruded filling debris was collected by a Milipore filtration system, an HV-durapore, 0.45 µm pore filter with a 25 mm diameter. The filters were weighed before and after the collection on an analytical scale (10–5 g), and the difference was calculated. The mean weight of extruded filling debris was analyzed statistically by Kruskal-Wallis and Friedman ANOVA tests (α=0.05). The mean values found in the groups (in mg) were: GIM (0.95±0.94), GIIM (0.47±0.62), GIPT (0.30±0.31) and GIIPT (0.32±0.44). There was no statistically significant difference among any of the groups or subgroups (p>0.05). ProTaper provided the smallest amount of extruded filling material, regardless of presence or absence of apical patency, followed by manual technique, without and with apical patency. Additional amounts of debris were collected during cleaning of the apical foramen, regardless of the instrument, presence/absence of patency or root filling removal technique.

Este estudo verificou a influência da patência apical, técnica de desobturação e limpeza foraminal na quantidade de material sólido extruído, durante retratamento endodôntico. Quarenta incisivos inferiores foram divididos aleatoriamente em quatro grupos - GIM (n=10), GIIM (n=10), GIPT (n=10) e GIIPT (n=10) - nomeados de acordo com a realização (I) ou não (II) de patência apical durante o preparo de canais e a técnica de desobturação - manual (M) ou sistema ProTaper (PT). Após a desobturação, realizou-se a limpeza foraminal em cada espécime de todos os grupos com instrumentos #15, #20 e #25, gerando 12 subgrupos: GIM15, GIM20, GIM25, GIIM15, GIIM20, GIIM25, GIPT15, GIPT20, GIPT25, GIIPT15, GIIPT20 e GIIPT25. O material sólido extruído foi coletado pelo sistema de filtração Millipore®, com filtros de 0,45 µm de poro e 25 mm de diâmetro. Os filtros foram pesados antes e após a coleta, em balança analítica de precisão (10–5g), e as diferenças foram calculadas. Os valores médios encontrados (em mg) foram: GIM (0,95±0,94), GIIM (0,47±0,62), GIPT (0,30±0,31) e GIIPT (0,32±0,44), sem diferença estatística entre quaisquer dos grupos ou subgrupos (p>0,05). O sistema Protaper proporcionou a menor quantidade de material sólido extruído, independente da presença ou não de patência apical seguidos da técnica manual sem e com patência apical. Quantidades adicionais foram coletadas durante a limpeza foraminal, independente do instrumento utilizado, da presença ou não da patência apical ou da técnica de desobturação.

Location of three canals in the mesiobuccal root of the maxillary first molar

Introduction:The knowledge on the complex anatomy of the maxillary first molar and location of extra canals are essential for diagnosis and endodontic treatment success. Objective:The purpose of this study was to report a clinical case showing a varied number of root canals in maxillary molars with the aid of the operating microscope (OM). Case report: The endodontic retreatment of the right maxillary first molar with unusual anatomical variation was performed, displaying three canals in the mesiobuccal root (MB), a root canal in the distobuccal root (DV) and a root canal in the palatal root (P). To remove the resin core inside pulp chamber with and without the aid of dental operating microscope, a high-speed drill and ultrasonic tip (diamond round) was used, respectively, for the refinement of the pulp chamber walls. The dental operating microscopewas used during the access surgery, location, negotiation of canals and checking of the completion of all stages of the retreatment. Subsequently, the cleaning, shaping and filling of the root canal system was completed. The presence of three canals in the mesiobuccal root, one in the distobuccal root and one in the palatal root was found. Conclusion: Variations in the number of canals could be confirmed during the surgery access in endodontic retreatment cases with the aid of dental operating microscope.

The importance of microsonics concept for optimization of endodontic retreatment outcome: a case report

Introduction: During the past few decades, the endodontic treatment has benefited from the development of new techniques and devices, which have improved the outcome and predictability. Important attributes such as the operating microscope and ultrasonics have found indispensable applications in a number of dental procedures in endodontics. Objective and case report: This study describes a case of endodontic retreatment of a maxillary first molar in which the second mesiobuccal canal could be located by extending the access to the mesial direction further than usual and by a closer inspection of the pulp chamber floor. Conclusion: The "microsonics concept" has enhanced the quality of endodontic treatment and retreatment, becoming increasingly more useful in applications such as localization of root canal orifices.

Retratamento endodôntico de dentes com contenção intrarradicular:orientação clínica / Endodontic retreatment of teeth restored with intraradicular posts: clinical orientation

Objetivo: Tendo em vista orientar os profissionais da odontologia na conduta clínica, o presente trabalho propôs-se a criação de uma tabela com situações clínicas contendo sugestões de tratamento em relação às possíveis falhas ocorridas tanto na adaptação da contenção intrarradicular quanto no tratamento endodôntico. Material e método: Foram avaliadas as condições de tratamento no âmbito clínico e radiográfico e discutidas as possíveis soluções de tratamento mais viáveis para os respectivos problemas. A tabela foi construída levando-se em consideração a experiência profissional dos alunos de oito edições do curso de especialização em endodontia da Faculdade de Odontologia da Universidade Federal de Uberlândia, no período de 1995 a 2010. Resultados: Na condição satisfatória do pino, sua remoção só foi indicada onde se observa tratamento endodôntico insatisfatório e lesão periapical presente. Na condição insatisfatória do pino, sua remoção foi indicada independente da qualidade do tratamento endodôntico, e após a remoção o retratamento endodôntico foi também indicado, independente da presença ou não de lesão periapical. O fator determinante na indicação da cirurgia parendodôntica foi a presença da lesão periapical e mesmo assim foi indicada a proservação clínica e radiográfica antes da cirurgia. Conclusões: Caso ocorra o insucesso do tratamento de um dente com canal tratado e restauração coronária com pino intracanal, a conduta clínica a ser tomada dependerá de vários fatores, dentre eles a presença de lesão periapical, a extensão da obturação e a qualidade da restauração coronária, principalmente com relação ao comprimento e diâmetro do pino intrarradicular.

Aim: To guide dentists in their clinical practice, the present study presents a table list of clinical situations and treatment suggestions related to possible failures in both post adaptation and endodontic treatment. Methodology: Work conditions were evaluated in both clinical and radiographic aspects and the most viable treatment solutions were discussed. The table was built considering the professional experience of the students throughout eight editions of the endodontics specialization course in the Federal University of Uberlandia, from 1995 to 2010. Results: When the post?s condition was considered acceptable, its removal was only indicated when the endodontic treatment was considered inacceptable and there was a presence of periapical lesion. If the post?s situation was considered inacceptable, its removal was indicated regardless of the endodontic treatment?s quality, and after post?s removal, endodontic retreatment was also indicated in the presence or absence of periapical lesions. The determinant factor to indicate periapical surgery was the presence of periapical lesion and, even so, its indication was considered a secondary procedure. Conclusions: If a treatment failure of an endodontic treated tooth with an intracanal retained coronal restoration occurs, the clinical conduct will depend on several factors such as: presence of perapical lesion, extend of the root canal filling and quality of coronal restauration, mainly with relation to the length and diameter of the intracanal post.

Re-Treatment of A Mandibular First Molar With An Independent Middle Mesial Canal- A Case Report.

With increasing reports of aberrant canal morphology, the clinician needs to be aware of varied anatomy in teeth. The purpose of this article is to report the successful non surgical endodontic re-treatment of one such clinical case of mandibular first molar with three mesial canals in which the middle mesial canal had an independent foramen.

Prevalência e etiologia do retratamento endodôntico: estudo retrospectivo em clínica de graduação / Prevalence and etiology of the endodontic retreatment: a retrospective study in an undergraduate dental clinic

O objetivo deste trabalho foi avaliar a prevalência e a etiologia de retratamentos endodônticos realizados por estudantes de graduação. Foram analisados retrospectivamente casos de retratamentos endodônticos feitos na Clínica de Endodontia do curso de Odontologia da Universidade Estadual de Montes Claros - Unimontes- MG, Brasil, no período de 2000 a 2004. As análises foram realizadas por meio de avaliação das radiografias e dos dados presentes nos prontuários dos pacientes. Dados pessoais do paciente e história clínica do dente foram anotados, incluindo o tipo do dente envolvido, o gênero e a idade do paciente. Dos 673 casos avaliados, 52 (7,7%) eram de retratamento endodôntico, predominante em pacientes do gênero feminino (57,6%). O dente mais acometido foi o incisivo central superior (34,6%) e a faixa etária prevalente, de 15 a 35 anos (48,1%). A principal causa relacionada com o insucesso do tratamento endodôntico foi a presença de obturações deficientes (94,2%). A maior parte dos dentes envolvidos estava assintomática (67,3%). Conclui-se que a prevalência de dentes com necessidade de retratamento endodôntico na população estudada foi baixa. A etiologia predominante para os retratamentos foi a obturação deficiente dos canais radiculares em dentes assintomáticos.

The aim of this study was to evaluate the prevalence and the etiology of endodontic re-treatments performed by undergraduate students. Endodontic retreatments accomplished in the Dental School of the State University of Montes Claros – Unimontes - MG, Brazil, between the period of 2000-2004 were retrospectively evaluated.The analyses were made using the radiographies and the information present in the patient’s records.Detailed personal and dental history was obtained from the patient’s records, including the tooth type and patient’s gender and age. From a total of 673 cases requiring endodontic treatment, 52 (7.7%) were submitted to endodontic retreatment, predominantly in female patients (57.6%). The more affected tooth was the uppercentral incisor (34.6%) and the prevalent age group was from 15 to 35 years (48.1%). The main reason for the endodontic failure was the presence of poor coronal restoration (94.2%). The majority of the teeth which needed retreatment was asymptomatic (67.3%). In conclusion, the prevalence of endodontic retreatments in the studied population was low. The predominant etiology was the deficient sealing of root canals in the asymptomatic teeth.

Comparative sem evaluation by of three solvents used in endodontic retreatment: an ex vivo study

This study compared, by scanning electron microscopy (SEM), the efficacy of three solvents on the removal of filling materials from dentinal tubules during endodontic retreatment. Forty human maxillary canines with straight canals were prepared according to a crown-down technique and enlarged to a#30 apical file size, before obturation with gutta-percha and a zinc-oxide-eugenol based sealer. The samples were stored for 3 months before being randomly assigned to four groups: chloroform (n=10), orange oil (n=10), eucalyptol (n=10) and control (n=10). Solvents were applied to a reservoir created on the coronal root third using Gates Glidden drills. The total time for retreatment using the solvents was 5 minutes per tooth. Following retreatment the roots were split longitudinally for SEM evaluation. SEM images were digitized, analyzed using Image ProPlus 4.5 software, and the number of dentinal tubules free of filling material from the middle and apical thirds was recorded. No significant difference was found among the solvent groups regarding the number of dentinal tubules free of root filling remnants in the middle and apical root thirds (p>0.05). However, the control group had fewer dentinal tubules free of filling material (p<0.05). Under the tested conditions, it may be concluded that there was no significant difference among the solvents used to obtain dentinal tubules free of filling material remnants.

A performance do Sistema ProTaper no retratamento endodôntico / The performance of ProTaper system during the endodontic retreatment

O desenvolvimento de novos instrumentos rotatórios para o tratamento endodôntico gera a necessidade de novos estudos para avaliar a eficiência desses instrumentos no retratamento dos canais radiculares. Este trabalho buscou avaliar se a remoção do material obturador é total ou parcial, bem como o tempo gasto para atingir o comprimento de trabalho utilizando-se o sistema ProTaper. Trinta e seis caninos humanos foram preparados e obturados formando três grupos experimentais (n=12): GI=sistema Thermafill; GII=McSpadden; GIII=condensação lateral. Os três grupos foram então submetidos ao retratamento utilizando-se o sistema ProTaper (sem o uso de solvente) e os tempos foram aferidos. Após a remoção do material obturador, os espécimes foram seccionados longitudinalmente e avaliados por meio de uma câmera acoplada a uma impressor, para determinação da presença ou não de remanescente obturador. Como resultado, obteve-se uma remoção incompleta do material obturador de todos os espécimes, e com relação ao tempo houve diferença estatisticamente significante entre o grupo obturado com McSpadden e os demais grupos. Conclui-se que os instrumentos ProTaper testados mostraram-se rápidos para atingir o comprimento de trabalho durante o retratamento, entretanto devem ser complementados por outra técnica de retratamento

The development of new rotary instruments for endodontic treatmentdemands new studies to evaluate their efficacy on the retreatment of root canals. The scope of this study was to analyze the partial or total removal of the filling material by the ProTaper system in the retreatment of gutta-percha-filled root canals, as well as the time required to reach the previous working length. Thirty-six human canines were equally divided in three groups (n=12) and had their root canals prepared by the following methods: GI=Thermafill system; GII=McSpadden; GIII-lateral condensation. After that, all specimens were retreated without solvent and using the ProTaper system. The time necessary to remove the filling material was registered. After the removal of the filling material,the specimens were sectioned longitudinally and magnified images of the sections were recorded and printed. The presence or absence of remaining filling material was registered. The results showed a significant statistical difference between the McSpadden group and the others with relation to the time required for filling removal. All groups exhibited an incomplete removal of the filling material. It can be concluded thatalthough the rapidity that the ProTaper instruments reached the workinglength, the system has to be associated to another retreatment

The performance of ProTaper system during the endodontic retreatment

The development of new rotary instruments for endodontic treatment demands new studies to evaluate their efficacy on the retreatment of root canals. The scope of this study was to analyze the partial or total removal of the filling material by the ProTaper system in the retreatment of gutta-percha-filled root canals, as well as the time required to reach the previous working length. Thirty-six human canines were equally divided in three groups (n=12) and had their root canals prepared bythe following methods: GI=Thermafill system; GII=McSpadden; GII Ilateral condensation. After that, all specimens were retreated without solvent and using the ProTaper system. The time necessary to remove the filling material was registered. After the removal of the filling material,the specimens were sectioned longitudinally and magnified images ofthe sections were recorded and printed. The presence or absence of remaining filling material was registered. The results showed a significant statistical difference between the McSpadden group and the others with relation to the time required for filling removal. All groups exhibited an incomplete removal of the filling material. It can be concluded that although the rapidity that the ProTaper instruments reached the working length, the system has to be associated to another retreatment.

O desenvolvimento de novos instrumentos rotatórios para o tratamento endodôntico gera a necessidade de novos estudos para avaliar a eficiência desses instrumentos no retratamento dos canais radiculares. Este trabalho buscou avaliar se a remoção do material obturador é total ou parcial, bem como o tempo gasto para atingir o comprimento de trabalho utilizando-se o sistema ProTaper. Trinta e seis caninos humanos foram preparados e obturados formando três grupos experimentais (n=12):GI = sistema Thermafill; GII = McSpadden; GIII = condensação lateral.Os três grupos foram então submetidos ao retratamento utilizando-se o sistema ProTaper (sem o uso de solvente) e os tempos foram aferidos.Após a remoção do material obturador, os espécimes foram seccionados longitudinalmente e avaliados por meio de uma câmera acoplada a uma impressora, para determinação da presença ou não de remanescente obturador. Como resultado, obteve-se uma remoção incompleta do material obturador de todos os espécimes, e com relação ao tempo houve diferença estatisticamente significante entre o grupo obturado com McSpadden e os demais grupos. Conclui-se que os instrumentos ProTaper testados mostraram-se rápidos para atingir o comprimentode trabalho durante o retratamento, entretanto devem ser complementados por outra técnica de retratamento.

The effect of gutta-percha removal using nickel-titanium rotary instruments / 대한치과보존학회지

The purpose of this study was to quantify the amount of remaining gutta-percha/sealer on the walls of root canals when three types of nickel-titanium rotary instruments(Profile, ProTaper and K3) and a hand instrument(Hedstrom file) used to remove these materials. The results of this study were as follows: 1. In the total time for gutta-percha removal, Profile group was the fastest and followed by K3, Protaper, Hedstrom file group. 2. In case of the evaluation of the volume of remained gutta-percha from radiograph, K3 group got the highest score and followed by Protaper, Hedstrom file, Profile group in the apical 1/3. 3. In case of the evaluation of the volume of gutta-percha remained from stereomicroscope, K3 group got the highest score and followed by Protaper, Hedstrom file, Profile group in the apical 1/3. These results showed that instrumentation using nickel-titanium rotary instrument groups was faster than that using hand instrument group. The effect of gutta-percha removal using Profile group was better than that using Protaper and K3 group in the nickel-titanium rotary instrument groups.