Endodontic guide for the conservative removal of a fiber-reinforced composite resin post.

Prosthetic dentistry involves functional and esthetic restoration. Some situations require the use of fiber-reinforced composite resin posts that help preserve restorations. However, if the initial treatment fails, a new endodontic intervention may be required for fiber-reinforced composite resin post removal. This procedure can be complex and challenging but can be facilitated with guided endodontics. This clinical report describes the use of a prototyped guide created with virtual planning for fiber-reinforced composite resin post removal. The guide improved patient safety, shortened the treatment time, and eliminated the need for a new restoration.

Guided Endodontics in Nonsurgical Retreatment of a Mandibular First Molar: A New Approach and Case Report.

This case report describes the use of the guided endodontics for a non-surgical endodontic retreatment of the mandibular molar. A 38-year-old female reported apical swelling and localized pain on the tooth #30, exacerbated when chewing hard food. Periapical radiographic examination showed pulp canal obliteration in the apical third associated with extensive radiolucent area. Cone-beam computed tomography (CBCT) images were requested to support the diagnosis and enable preparation of a surgical guide, used to direct access to the canals that were obliterated and incompletely filled. The follow-up at 24 months radiographically showed completely healed apical area in the involved tooth. This non-surgical technique demonstrated efficacy in case resolution.

Case Reports in Maxillary Posterior Teeth by Guided Endodontic Access.

The localization of partial or completed root canal obliteration is a challenging task in endodontic practice. Recently, guided endodontics has become an alternative solution for those cases. Although this technique has already been used clinically in managing anterior teeth, in this report, we describe 3 complex clinical scenarios of calcified root canals of 1 molar and 2 premolars using guided endodontics. The clinical cases reported here show that technological evolutions should make guided endodontic procedures more widespread because their execution is relatively fast and safe even in the case of the upper molar. Additionally, 12-month clinical follow-up visits showed the effectiveness of the guided endodontic procedures.

In vitro evaluation of apical microleakage in retrofillings with different resection angles.

Paraendodontic surgery is a procedure that aims to solve problems that could not be solved by, or when it is not possible to perform conventional endodontic treatment. The aim of this experimental study was to compare the apical microleakage of teeth sectioned at 45° or 90° to the long axis of the tooth and rootend filled with mineral trioxide aggregate (MTA) using stereomicroscopy. In this study, 26 maxillary central incisors were used. Cleaning and shaping were performed with use of the Oregon technique and the samples were randomly divided into two groups. In Group A (n=10) apical section was performed at an angle of 90°, making a retrocavity with an ultrasonic tip and retrofilling with MTA. In group B (n=10) the same procedures were performed, but the apical section was at a 45° angle. Then the samples were immersed in a dye (India ink), placed in an oven at 37° for 48 h before applying the clearing technique. Afterwards the teeth were assessed by stereomicroscope at 20x magnification to analyze dye leakage. Data were submitted to the Student'st test with significance level p<0.05. There was statistically significant difference between groups. Group B showed higher apical microleakage values compared with group A (P=0.004), but both groups showed dye leakage. The results showed that the 90° apical section promoted lower dye microleakage values at the dentinretrofilling material interface than the 45°section and could be considered the most effective technique for apical preparation in paraendodontic surgery.

A cirurgia paraendodôntica é um procedimento que visa resolver problemas que não poderiam ser resolvidos, ou quando não é possível realizar o tratamento endodôntico convencional. O objetivo deste estudo experimental foi comparar a microinfiltração apical de dentes seccionados a 45° ou 90° em relação ao longo eixo do dente e extremidade radicular preenchida com agregado de trióxido mineral (MTA) utilizando estereomicroscopia. Neste estudo, 26 incisivos centrais superiores foram utilizados. Limpeza e modelagem foram realizadas com o uso da técnica de Oregon e as amostras foram divididas aleatoriamente em dois grupos. No Grupo A (n = 10) foi realizada seção apical em ângulo de 90°, reali zando retrocavidade com ponta ultrassônica e retrobturação com MTA. No grupo B (n = 10), os mesmos procedimentos foram realizados, mas a seção apical estava em um ângulo de 45°. Em seguida, as amostras foram imersas em um corante (nanquim), colocadas em estufa a 37°C por 48 h, antes da aplicação da técnica de clareamento. Posteriormente, os dentes foram avaliados por estereomicroscópio, com aumento de 20x, para análise do vazamento de corante. Os dados foram submetidos ao teste t de Student, com nível de significância p <0,05. Houve diferença estatisticamente significante entre os grupos. O grupo B apresentou maiores valores de microinfil tração apical em comparação ao grupo A (P = 0,004), mas ambos os grupos apresentaram vazamento de corante. Os resultados mostraram que a seção apical de 90° promoveu menores valores de microinfiltração de corante na interface do material retrobturador dentinário do que a seção 45° e pode ser considerada a técnica mais efetiva para preparo apical em cirurgia paraendodôntica.

Three-dimensional endodontic guide for adhesive fiber post removal: A dental technique.

This dental technique describes a protocol for adhesive fiber post removal using a prototyped endodontic guide. The removal of an adhesive fiber post is an important step for endodontic retreatment and the resolution of prosthetic problems. Computer-aided design and computer-aided manufacturing (CAD-CAM) technology was used to generate guides with prototyping and is a useful tool for fiber post removal.

Midbuccal Canals of Maxillary Molars Evaluated by Cone-Beam Computed Tomography: Endodontic Management of Two Cases

Maxillary molars present variable root canal and root morphologies. This report describes the endodontic management of two cases of midbuccal canals found in maxillary molars. Midbuccal canals were present in a maxillary first molar with a single buccal root (Case 1), and in a maxillary second molar with three buccal roots (Case 2). An assessment of the internal configuration of these teeth was performed using cone-beam computed tomography (CBCT). Magnification with a dental operating microscope, surgical loupes, and the use of an endodontic explorer enabled the identification of the midbuccal canal orifices. The root canals in both cases were chemomechanically prepared and filled. Postobturation radiographic images revealed four (one midbuccal, two mesiobuccal and one palatal) and five (one midbuccal, two mesiobuccal, one distobuccal and one palatal) root canals, which were filled in Cases 1 and 2, respectively. Complex canal configurations of maxillary molars including the presence of midbuccal canals were presented. CBCT was a valuable tool in this diagnosis, as it provided a precise description of these unusual anatomical variations.

Molares superiores apresentam morfologias radiculares e canais radiculares variáveis. Este relato de caso descreve o manejo endodôntico de dois casos de canais mésio-centrais (MC) encontrados em molares superiores. Canais MC estavam presente em um primeiro molar superior com uma única raiz vestibular (Caso 1), e em um segundo molar com três raízes vestibulares (Caso 2). Uma avaliação da configuração interna destes dentes foi realizada usando tomografia computadorizada de feixe cônico (TCFC). Ampliação com microscópio operatório odontológico, lupas cirúrgicas e o uso de um explorador endodôntico possibilitaram a identificação dos orifícios dos canais MC. Os canais radiculares dos dois casos foram preparados e obturados. Imagens radiográficas pós-obturação revelaram quatro (um MC, dois mésio-vestibulares e um palatino) e cinco (um MC, dois mésio-vestibulares, um disto-palatino e um palatino) canais radiculares, que foram obturados nos Casos 1 e 2, respectivamente. Configurações complexas de canais em molares superiores, incluindo a presença de canais MC foram apresentadas. TCFC foi uma ferramenta útil no diagnóstico e propiciou uma descrição precisa destas variações anatômicas incomuns.

Effect of pre-flaring and file size on the accuracy of two electronic apex locators.

OBJECTIVE: This ex vivo study evaluated the effect of pre-flaring and file size on the accuracy of the Root ZX and Novapex electronic apex locators (EALs). MATERIAL AND METHODS: The actual working length (WL) was set 1 mm short of the apical foramen in the palatal root canals of 24 extracted maxillary molars. The teeth were embedded in an alginate mold, and two examiners performed the electronic measurements using #10, #15, and #20 K-files. The files were inserted into the root canals until the "0.0" or "APEX" signals were observed on the LED or display screens for the Novapex and Root ZX, respectively, retracting to the 1.0 mark. The measurements were repeated after the preflaring using the S1 and SX Pro-Taper instruments. Two measurements were performed for each condition and the means were used. Intra-class correlation coefficients (ICCs) were calculated to verify the intra- and inter-examiner agreement. The mean differences between the WL and electronic length values were analyzed by the three-way ANOVA test (p<0.05). RESULTS: ICCs were high (>0.8) and the results demonstrated a similar accuracy for both EALs (p>0.05). Statistically significant accurate measurements were verified in the pre-flared canals, except for the Novapex using a #20 K-file. CONCLUSIONS: The tested EALs showed acceptable accuracy, whereas the pre-flaring procedure revealed a more significant effect than the used file size.

Effect of pre-flaring and file size on the accuracy of two electronic apex locators

OBJECTIVE: This ex vivo study evaluated the effect of pre-flaring and file size on the accuracy of the Root ZX and Novapex electronic apex locators (EALs). MATERIAL AND METHODS: The actual working length (WL) was set 1 mm short of the apical foramen in the palatal root canals of 24 extracted maxillary molars. The teeth were embedded in an alginate mold, and two examiners performed the electronic measurements using #10, #15, and #20 K-files. The files were inserted into the root canals until the "0.0" or "APEX" signals were observed on the LED or display screens for the Novapex and Root ZX, respectively, retracting to the 1.0 mark. The measurements were repeated after the preflaring using the S1 and SX Pro-Taper instruments. Two measurements were performed for each condition and the means were used. Intra-class correlation coefficients (ICCs) were calculated to verify the intra- and inter-examiner agreement. The mean differences between the WL and electronic length values were analyzed by the three-way ANOVA test (p<0.05). RESULTS: ICCs were high (>0.8) and the results demonstrated a similar accuracy for both EALs (p>0.05). Statistically significant accurate measurements were verified in the pre-flared canals, except for the Novapex using a #20 K-file. CONCLUSIONS: The tested EALs showed acceptable accuracy, whereas the pre-flaring procedure revealed a more significant effect than the used file size.

Endodontic management of a long-standing horizontal mid-root fracture: case report in a young patient.

The purpose of this case report was to present the successful endodontic management of a long-standing horizontal mid-root fracture in a permanent maxillary central incisor. A 12-year-old boy with a history of traumatic injury sustained 15 months previously to the maxillary central incisor presented for treatment. Clinical examination revealed physiological mobility, pulp chamber exposed to the oral environment, and the buccal mucosa with a sinus tract in the area of the traumatized tooth. A radiolucent lesion at the fracture line and apical fragment with obliteration of the root canal space were observed radiographically. Conservative root canal treatment of the coronal segment was performed using calcium hydroxide as an intracanal dressing. The calcium hydroxide was replaced every 8 weeks for 10 months. A hard tissue barrier was observed after this period, and the coronal fragment of the root canal was filled. After 4 years, the tooth was asymptomatic and functional and no periapical lesion was observed.

Orthograde retreatment failure with extruded MTA apical plug in a large periradicular lesion followed by surgical intervention: case report.

Absence of periapical healing after orthograde retreatment using an apical plug with mineral trioxide aggregate (MTA) can require surgical intervention. A patient with a root-filled maxillary central incisor with chronic apical periodontitis and sinus tract was referred for endodontic retreatment. Excessive apical enlargement was verified, indicating an MTA apical plug placement; however, an unintentional extrusion of MTA occurred during this step. The root canal was filled with gutta-percha and sealer, and periodic recalls were scheduled. The sinus tract was observed after six months and the lesion remained unaltered, although the extruded MTA had resorbed; therefore, an apicoectomy and retrograde root-end filling with MTA were performed. Absence of sinus tract, normal clinical aspect, and complete repair of the lesion were observed at the two-year follow-up.

Synergistic growth effect among bacteria recovered from root canal infections

The objective of this study was to determine the ecological relationships between bacterial species that colonize infected root canals. Root canal bacteria recovered from one patient with pulp canal necrosis were evaluated in vitro for synergistic and antagonistic activities determined by mono and co-culture growth kinetics and the production of bacteriocin-like substances using the double layer diffusion method. Peptostreptococcus prevotii triggered a significant increase of Fusobacterium nucleatum growth, while the former bacteria did not affect the growth of P. prevotii. The bacterial species did not produce antagonism activity against itself or against any of the other two species. Despite many studies have demonstrated the capability of root canal microorganisms to produce antagonistic substances, these in vitro experimental tests show the synergistic effect of P. prevotii on the growth of F. nucleatum.

Synergistic growth effect among bacteria recovered from root canal infections.

The objective of this study was to determine the ecological relationships between bacterial species that colonize infected root canals. Root canal bacteria recovered from one patient with pulp canal necrosis were evaluated in vitro for synergistic and antagonistic activities determined by mono and co-culture growth kinetics and the production of bacteriocin-like substances using the double layer diffusion method. Peptostreptococcus prevotii triggered a significant increase of Fusobacterium nucleatum growth, while the former bacteria did not affect the growth of P. prevotii. The bacterial species did not produce antagonism activity against itself or against any of the other two species. Despite many studies have demonstrated the capability of root canal microorganisms to produce antagonistic substances, these in vitro experimental tests show the synergistic effect of P. prevotii on the growth of F. nucleatum.

Comparison of the time required for removal of intraradicular cast posts using two Brazilian ultrasound devices

The aim of this in vitro study was to compare the time required for removal of intraradicular cast posts cemented with zinc phosphate (ZF) or glass ionomer cement (GIC), using two Brazilian ultrasound devices (BUD). Seventy two human inferior premolars with single root canals were sectioned transversally at the cementoenamel junction. In each specimen, the root canal was endodontically treated, the post space was prepared to a depth of 9 mm and the canal was molded to obtain a post impression. After the casting procedures, the posts were randomly distributed into 2 groups (n = 36) according to the luting material used: G1 - ZF and G2 - GIC. The tooth and luted post set was then embedded in an acrylic resin block. The groups were then divided into 3 subgroups (n = 12) according to the ultrasound device used: A - Enac (Osada Electric, Japan), used as a control group; B - Profi II Ceramic (Dabi Atlante, Brazil) and C - Jet Sonic Satelec (Gnatus, Brazil). The posts were submitted to the vibration process with maximum power set on all surrounding surfaces. Time of application was recorded with a chronometer until complete post dislodgment, and the data were analyzed by the ANOVA test (p < 0.05). The averages required for post removal in G1 and G2 were respectively 41.42 and 92.03 seconds, with significant statistical difference (p = 0.001). No statistical difference was observed among the three ultrasound devices (p = 0.088), and the BUD presented a performance similar to that of the international gold standard device (Enac). Moreover, the type of luting agent had a greater influence on the time required for post removal than the origin of the ultrasonic unit.

Hipersensibilidade dentinária pós-operatória: uma revisão / Postoperative dentinary sensitivity: a review

Este artigo é uma revisão bibliográfica sobre a sensibilidade pós-operatória, devido ao uso de adesivos dentinários em procedimentos restauradores. A ocorrência desta sensibilidade vem sendo observada, com freqüência crescente, na clínica diária. Para evitar esta sensibilidade indesejável, torna-se de fundamental importância o conhecimento do tecido dentinário, a composição do material restaurador e sua utilização