3D Apicoectomy Guidance: Optimizing Access for Apicoectomies.

When conventional endodontic treatment resources are depleted, endodontic surgery becomes an alternative treatment for apical periodontitis to remove unreachable infected areas and seal the root canal. Digital workflows have been used more frequently in many dental applications in recent years. In endodontics, virtual 3-dimensional (3D) planning and endodontic guidance are new aspects important for the treatment of complex cases. This report aimed to present 3D Apicoectomy Guidance, a novel method of performing guided ultraconservative endodontic surgery with conventional implant-guided drills, and to describe its application in a case with a complex anatomic scenario and intimate contact with the maxillary sinus. Implantology computer software, as well as cone-beam computed tomography images and a digital scanning 3D impression, enabled virtual planning of the surgical procedure. Subsequently, a 3D template was produced to guide the instruments used in the osteotomy and root resection. The patient was completely asymptomatic at the 1-week follow-up visit. Cone-beam computed tomography scans were performed at 1 and 6 months after surgery and showed that resection of the apex of the root was performed accurately and that a thin dentin slice remained distally, preventing the rupture of the sinus membrane. The patient remained asymptomatic, and the tissue healed normally. The method used was shown to be very straightforward and reliable. This method allowed the patient to be treated expeditiously with very precise tissue removal.

In vitro evaluation of apical microleakage in retrofillings with different resection angles / Avaliaçâo in vitro da microinfiltraçâo apical de retrobturaçoes com diferentes ángulos de ressecçâo

ABSTRACT 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 root-end 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's-t 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 dentin-retrofilling material interface than the 45°-section and could be considered the most effective technique for apical preparation in paraendodontic surgery.

RESUMO A cirurgia paraendodontica é um procedimento que visa resolver problemas que nao poderiam ser resolvidos, ou quando nao é possível realizar o tratamento endodontico convencional. O objetivo deste estudo experimental foi comparar a microinfiltragao apical de dentes seccionados a 45° ou 90° em relagao ao longo eixo do dente e extremidade radicularpreenchida 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 segao apical em ángulo de 90°, realizando retrocavidade com ponta ultrassonica e retrobturagao com MTA. No grupo B (n = 10), os mesmos procedimentos foram realizados, mas a segao apical estava em um ángulo de 45°. Em seguida, as amostras foram imersas em um corante (nanquim), colocadas em estufa a 37°Cpor 48 h, antes da aplicagao 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 nivel de significáncia p <0,05. Houve diferenga estatisticamente significante entre os grupos. O grupo B apresentou maiores valores de microinfil-tragao apical em comparagao ao grupo A (P = 0,004), mas ambos os grupos apresentaram vazamento de corante. Os resultados mostraram que a segao apical de 90° promoveu menores valores de microinfiltragao de corante na interface do material retrobturador dentinário do que a segao 45° e pode ser considerada a técnica mais efetiva para preparo apical em cirurgia paraendodontica.