Retrospective clinical evaluation of root canal treatment with or without photodynamic therapy for necrotic teeth and teeth subjected to retreatment.

PURPOSE: To compare the effect of photodynamic therapy (PDT) as a procedure to complement root canal treatment (RCT), for both primary treatment and retreatment. METHODS: This was a retrospective study based on analysis of clinical records. A total of 214 teeth that had undergone RCT on either a primary or retreatment basis, with or without complementary PDT, were evaluated. For 118 teeth that met the previously established inclusion criteria, the time until healing was evaluated. Complementarily, the need for application of calcium hydroxide (CaHy) between visits and the number of visits necessary for completing the treatment were assessed. Data were analyzed using the Mann-Whitney and χ2 tests with a significance level of P < 0.05. RESULTS: Periapical radiolucency resolution was achieved at 15 ± 9.33 months in the RCT + PDT group and 20.35 ± 22.1 months in the RCT group (P = 0.07). For primary treatment, CaHy was necessary in 72.4% of the RCT cases and 16.4% of the RCT + PDT cases (P < 0.01). For retreatment cases, CaHy was used in 82.7% of the RCT cases and 17% of the RCT + PDT cases (P < 0.01). In the RCT group, more than two visits were necessary for primary treatment in 18.6% of the cases, compared with 13.10% in the RCT + PDT group (P = 0.31), whereas for retreatment, more than two visits were necessary for 64.9% and 49.1% of cases, respectively (P = 0.05). CONCLUSION: In comparison with RCT alone, teeth receiving RCT + PDT showed less variation in the time needed for periapical lesion healing, fewer cases required CaHy, and fewer cases required more than two visits to complete the treatment.

Influencia de la presencia de barrillo en la profundidad de penetración dentinaria del agente fotosensible empleado en la terapia fotodinámica / Influence of the presence of semar layer in the depth of dentinal penetration of the phosotensitizing agent used in photodynamic therapy

La efectividad antimicrobiana de la terapia fotodinámica (TFD), como complemento a la preparación biomecánica, depende del íntimo contacto entre un agente fotosensible, una fuente de energía (LED) y los microorganismos presentes en el conducto. Objetivo. Evaluar si la eliminación del barrillo dentinario influye en la penetración del agente fotosensibilizante dentro de los túbulos dentinarios en la TFD. Metodología. 20 premolares con conductos tipo I fueron decoronados a 12 mm del ápicy preparados biomecánicamente con MTwo y NaOCL al 5,25%. La muestra se dividió aleatoriamente en dos grupos (ni = 10): I, se irrigó con EDTA 17% seguido de suero fisiológico; II, se irrigó sólo con suero fisiológico. Tras la aplicación de la TFD, los especímenes fueron seccionados, obteniéndose discos correspondientes a los tercios coronal, medio y apical. Las muestras fueron visualizadas con un microscopio óptico de reflexión y el software Canvas X16. Se evaluaron el porcentaje de área teñida (PAT) y la penetración intratubular media (PIM). Análisis estadístico: Tests U de Mann-Whitney y Wilcoxon con un nivel de significación de p<0,05. Resultados. Los resultados de PAT y PIM fueron mayores en el grupo I (11,1 ± 5,1/0,45 ± 0,18) que en el II (4,93 ± 4,1/0,26 ± 0,16). No hubo diferencias significativas de PIM en los tercios coronales de I vs. II. Ambos grupos presentaron diferencias de PAT y PIM entre sus tercios. Conclusión. La remoción del barrillo dentinario previa a la aplicación de la TFD mejora significativamente la penetración del agente fotosensible en los tres tercios de la raíz

Antimicrobial efectiveness of the photodynamic therapy (PDT), in addition to chemicomechanical preparation, depends on the contact between a photosensitizer, a light source (LED) and root canal microorganisms. Aim. To evaluate if the removal of smear layer influences the penetration of the photosensitizer into dentinal tubules in the PDT. Methodology. 20 premolars with Type I canals were sectioned at 12 mm from apex and conformed with MTwo and 5.25% NaOCl. Were randomized divided in two groups (ni = 10): group I was irrigated with 17% EDTA and 0.9% NaCl; group II was irrigated with 0.9% NaOCl. For the PDT 0.01% of TBO (Fotosan® ,CMS) as photosensitizer was applied into the canal and activated for 30 sec with a LED red light source (Foto-san630®, CMS). After this, all specimens were sectioned in order to obtain dentin discs of coronal, medium and apical third. Samples were evaluated with an optical microscope at 20x and the software Canvas X16, measuring the percentage of stained area (PAT) and Intratubular media penetration (PIM). Statistical analysis: Test U de Mann-Whitney y Wilcoxon with a significance level of p < 0.05. Results. The results of PAT and PIM were higher in Group I (11,1 ± 5,1/0,45 ± 0,18) than Group II (4,93 ± 4,1/0,26 ± 0,16). No significant differences of PIM were founded between coronal thirds of I vs II. Both groups presented differences of PAT and PIM between their thirds. Conclusion. The removal of smear layer before the TFD application improves the penetration of the photosensitizer in the three root thirds

Conformación de conductos de doble curvatura con sistemas rotatorios de lima única / S-shape root canal shaping with one-file rotary systems

Objetivo. Comparar la modificación de conductos simulados con doble curvatura después de su preparación con 4 sistemas de lima única. Material y métodos. Se usaron 40 bloques de resina con conductos simulados de doble curvatura y divididos en 4 grupos (ni=10). Los bloques fueron preparados hasta una lima 25 usando los sistemas Reciproc (R25), Wave One Gold (Primary), One Shape y F360 (25). Se obtuvieron imágenes pre- y post-instrumentación y se superpusieron para su análisis. Se dividió la doble curvatura en 11 niveles. Se calculó la distancia desde la pared no instrumentada hasta la instrumentada. Para comparar el ensanchamiento del conducto en cada nivel se utilizó el test ANOVA, las comparaciones dos a dos se hicieron mediante el test de Tukey. El nivel de significación se estableció en p<0,05. Resultados. Todos los sistemas de lima única estudiados modifican de manera importante la curvatura apical. Wave One Gold ensanchó más en la pared interna de la curvatura apical, manteniendo un ensanchamiento más proporcional en la curvatura coronal; mientras que F360 removió más material desviando el conducto hacia la parte interna en ambas curvaturas, siendo estas diferencias estadísticamente significativas. Conclusiones. La morfología del conducto, tras instrumentación, se mantiene más fiel a la forma inicial en los sistemas Wave One Gold y One Shape

Objective. To compare the modification of simulated double curvature root canals after preparation with four single file systems. Material and methods. Forty resin blocks with simulated double curvature canals were divided into four groups (n=10), respectively instrumented to file size 25 using the Reciproc (R25), Wave One Gold (Primary), One Shape and F360 systems (25). Pre- and post-instrumentation images were obtained and overlapped for analysis. The double curvature was divided into 11 levels. The distance from the non-instrumented to the instrumented wall was calculated. Comparison of canal widening at each level was made using analysis of variance, with the Tukey test for two-by-two comparisons. Statistical significance was considered for p<0.05. Results. All the studied single file systems produced important modifications of the apical curvature. Wave One Gold resulted in greater internal wall widening in the apical curvature, with more proportional widening in the coronal curvature. In comparison, the F360 system removed more material, deviating the canal towards the internal portion in both curvatures - the differences being statistically significant. Conclusions. Canal morphology after instrumentation was seen to more closely reproduce the initial morphology when using the Wave One Gold and One Shape systems

Eliminación del barrillo dentinario en los conductos radiculares mediante irrigación con nuevas puntas de poliamida de activación sónica / Elimination of the root canal dentin smear layer by irrigation with new polyamide sonic-activated tips

Material y métodos: Estudio in vitro con dientes humanos monorradiculares (N = 40). La muestra se dividió en 4 grupos experimentales (ni = 10). Grupo I: irrigación con jeringa y punta de salida lateral sin activación. Grupo II: irrigación sónica con puntas de poliamida Eddy (TM). Grupo III: Irrigación con el sistema Endoactivator (R). Grupo IV: Irrigación con el sistema de activación ultrasónica pasiva (IRRI S (R)). La capacidad de eliminación de barrillo dentinario de cada uno de los sistemas fue evaluado mediante microscopía electrónica de barrido y con los índices de Torabinejad y de Serafino, en los tercios coronal, medio y apical de cada conducto. Los datos obtenidos fueron analizados con los test de Kruskal Wallis, Mann-Whitney y Wilcoxon (p ≤ 0,05). Resultados: No hubieron diferencias significativas en la capacidad de eliminación de barrillo dentinario en función del tercio radicular (p > 0,05). El grupo I mostró menor eficacia respecto a los otros grupos estudiados. El grupo IV obtuvo resultados levemente superiores que los otros grupos. Conclusiones: Ningún sistema de los estudiados elimina la totalidad del barrillo

Objective: To compare the efficacy of polyamide sonic activation tips in eliminating the dentin smear layer from root canals versus other activation systems used during irrigation. Material and methods: An in vitro study was made using single-root human teeth (N = 40). The sample was divided into four experimental groups (ni = 10). Group I: irrigation using a side port syringe without activation; Group II: sonic irrigation with Eddy (TM) polyamide tips; Group III: irrigation with the Endoactivator(R); Group IV: irrigation using the IRRI S (R) passive ultrasonic activation system. The dentin smear eliminating capacity of each system was evaluated by scanning electron microscopy and using the indices of Torabinejad and Serafino, in the coronal, middle and apical thirds of each canal. The data obtained were analyzed with the Kruskal-Wallis test, Mann-Whitney U-test and the Wilcoxon test. Statistical significance was considered for p ≤ 0.05. Results: There were no significant differences in smear la-yer eliminating capacity (p > 0.05) among the different root thirds. Group I showed less efficacy than the other groups. Group IV yielded slightly better results than the other groups. Conclusions: None of the studied systems were able to fully eliminate the smear layer

Condensación lateral modificada con gutapercha inyectada. Procedimiento y casos clínicos / Modified lateral condensation with injected gutta-percha. Technique and clinical cases

La condensación lateral en frío es una técnica de obturación radicular muy difundida. Permite controlar la adaptación apical del material de obturación, pero presenta una escasa deformación plástica de la gutapercha en frío lo que no permite su adaptación a las irregularidades del conducto. Por ello, proponemos una modificación de la condensación lateral en frío: la inyección de gutapercha termoplastificada en las primeras fases de la condensación lateral clásica, la posterior condensación con espaciadores digitales y la inserción de conos accesorios sobre una masa de gutapercha en estado plástico, lo cual permite, según los resultados clínicos y radiográficos que presentamos, una buena opción de obturación. Esta técnica denominada Condensación Lateral Modificada con Gutapercha Inyectada (CLMI) es simple, de fácil aprendizaje y efectiva. El control apical y la adaptación de la obturación a la morfología del conducto permite su empleo en prácticamente todas las variantes morfológicas de los conductos radiculares

Cold lateral condensation is a widely used root canal filling technique. It allows the control of the apical adaptation. However, it shows scant plastic deformation of the cold gutta-percha, which complicates adaptation to the irregularities of the root canal. In order to avoid this problem, we propose a modification of the cold lateral condensation technique in which thermosplasticized gutta-percha is injected in the first phases of the classical lateral condensation procedure, followed by condensation with digital spacers and the insertion of accessory cones over the gutta-percha mass in plastic state. As evidenced by the clinical and radiographic results obtained in the present study, this modified lateral condensation with injected gutta-percha (MLCI) technique constitutes a good option, being simple, easy to learn, and effective. The good apical control and adaptation of the filler material to the canal makes the procedure applicable to all morphological variants of the root canals

Terapia fotodinámica en un primer molar mandibular con periodontitis apical crónica e istmo intermesial permeable / Photodynamic therapy of a first mandibular molar with chronic apical periodontitis and a permeable inter-mesial isthmus

La terapia fotodinámica (TFD) es un procedimiento terapéutico con capacidad antimicrobiana demostrada en la literatura científica. Esta constatado que su empleo, después de la preparación químico-mecánica convencional, reduce la carga microbiana en el diente necrótico. Esto supone una ventaja en los casos de necrosis en dientes con anatomías complejas, como cuando existe un istmo. Por otro lado, la TFD podría ser una alternativa al empleo de medicaciones intraconducto en los dientes con patología periapical. El propósito de este articulo es describir la técnica de uso de la TDF, empleando una lámpara de diodos LED de baja potencia (FotoSan®) como fuente lumínica y azul de toluidina como fotosensibilizador, y mostrar los resultados de su asociación con el tratamiento endodóncico convencional, en un caso de un primer molar mandibular con istmo permeable, necrosis pulpar y periodontitis apical crónica

Photodynamic therapy (PDT) has been shown to exert antimicrobial action. Following conventional chemical-mechanical preparation, PDT reduces the microbial burden in the necrotic tooth. This implies an advantage in cases of necrosis in teeth with complex anatomical features, such as the presence of an isthmus. On the other hand, PDT could constitute an alternative to the use of drugs within the canal of teeth with periapical disease. This study describes the PDT technique using a low-power LED lamp (FotoSan®) as light source and toluidine blue as photosensitizer. A description is provided of the results obtained on combining the technique with conventional endodontic treatment of a first mandibular molar with a permeable isthmus, pulp necrosis and chronic apical periodontitis

Consideraciones metodológicas sobre el estudio de la adaptación del cemento sellador a las paredes del conducto: comparación entre el microscopio electrónico de barrido y el confocal láser / Methodological considerations on the study of endodontic sealer adaptation to root canal walls: comparison between scanning electronic and laser confocal microscopes

Objetivo: Evaluar la correlación entre las observaciones con el microscopio electrónico de barrido (MEB) y con el microscopio confocal láser (MCL) para el estudio de la adaptación a las paredes del conducto de TopSeal. Material y métodos: Diez dientes unirradiculares fueron instrumentados con el sistema de limas rotatorias MTwo hasta el 35/.04. Se irrigó con 5 ml de NaOCl (5,25%) entre limas y con 5 ml de EDTA (17%) como irrigante final. La obturación se realizó con condensación lateral utilizando conos de gutapercha y cemento TopSeal marcado con un fluorocromo. Se obtuvieron secciones transversales a 3, 5 y 8 milímetros del ápice, que fueron analizadas con MCL y luego metalizadas y observadas con MEB. Se estableció el grado de adaptación al perímetro del conducto en cada sección con ambos procedimientos. En el análisis estadístico se utilizaron el coeficiente de correlación de Pearson para la evaluación de la interfase cemento-dentina entre ambos métodos y el ANOVA para el análisis de la penetración intratubular del cemento evaluada con MCL. Resultados: El coeficiente de correlación de Pearson fue de 0,75 (p = 0,001) para los porcentajes medios de adaptación. Medias: MCL 71,40 y MEB 83,67. Los coeficientes para los tercios apical, medio y coronal fueron 0,940, 0,772 y 0,877 respectivamente, en todos los casos significativos. Respecto a la penetración del cemento sellador, no se encontraron diferencias significativas en los niveles estudiados. Conclusiones: Ambas técnicas microscópicas son complementarias, mientras que el MEB proporciona mayor seguridad en el estudio de la interfase, el MCL permite analizar la penetración intratubular del material

Aim: To compare two different microscopic techniques (SEM and CLSM) in studying filling materials adaptation to canal walls. Material and Methods: Ten sound extracted single-rooted teeth were selected, instrumented and filled with gutta-percha and TopSeal using lateral condensation technique. Following root filling, teeth were sectioned transversally at 3, 5 and 8 mm from the apex and analyzed using Confocal Laser Scanning Microscope and Scanning Electronic Microscope. Percentage of root canal perimeter with sealer penetration to the dentinal tubules and depth of penetration were compared between groups and statistically analyzed using a Pearson correlation analysis (p=0.001) and ANOVA test for intratubular penetration. Pearson’s correlation coefficient for the whole sample was 0.75 (p=0.001). Results: When comparing sealer adaptation to dentinal walls between thirds, apical medium and coronal, mean values were statistically significant: 0.940, 0.772 and 0.877 respectively. For intratubular penetration no significant difference between root canal thirds was found. Conclusions: Both techniques are complementary in the study of endodontic filling materials performance inside root Canals

Fibre post behaviour prediction factors. A review of the literature.

INTRODUCTION: The advantages of fibre posts over stainless steel posts have been demonstrated in numerous studies. For clinical success, various factors need to be taken into account in post-retained restorations. MATERIAL AND METHODS: A review was made of literature on fibre posts published from 2000 to February 2011, identified through searches of the PubMed/Medline databases. RESULTS: The position of the tooth in the arch, ferrule size, proximal contact, periodontal support and restoration type are survival prediction factors that should be considered when performing post-endodontic restoration. Since fibre posts present good biomechanical behaviour as a result of their elastic modulus, which is similar to that of dentine, treatment failure occurs through decementation rather than because of root fracture, as occurs with metal posts. The shape of the post and, consequently, the thickness of the luting, can modify the retention capacity. Consequently, more anatomically-shaped posts have been developed, as have new techniques to reduce the volume of the dentine/cement interface: lateral condensation, surface remodelling or custom designs. CONCLUSIONS: Different aspects of the preparation process can be modified to assist in improving fibre post retention, but further investigation, mainly clinical, is needed to acquire a better understanding of how different factors influence the long-term clinical behaviour of the posts. Key words:Fiber post, post shape, post adaptation, post retention, endodontics.

Microestructure alterations of rotary files aftermultiple simulated operative procedures

Aim: To assess morphological alterations of ProTaper rotary NiTi files before and after continuous use by scanning electron microscopy (SEM). Study Design: 30 root canals were chosen with an angle between 15 and 30º. Before starting to prepare the canals the files were observed microscopically using a scanning electronic microscope. The ProTaper sequence recommended by the manufacturer was used, with NaOCl as irrigant. The instruments were sterilised after every three canals were shaped. The instruments were observed with the same microscope after shaping each canal, until 30 root canals were shaped. The criteria used for checking the instruments were: blunt cutting edges, disruption of cutting edge, microfractures, fatigue cracks, metal flash, dentine remains.Results: Many microscopic defects were found such as: cutting edge breaks (up to 70%); fatigue cracks, between 33 and 100%. No microfractures were found. An S1 and an SX file were fractured. Conclusion: ProTaper instruments are quite reliable if used following usual requirements (AU)

Microstructure alterations of rotary files after multiple simulated operative procedures.

AIM: to assess morphological alterations of ProTaper rotary NiTi files before and after continuous use by scanning electron microscopy (SEM). STUDY DESIGN: 30 root canals were chosen with an angle between 15 and 30 degrees . Before starting to prepare the canals the files were observed microscopically using a scanning electronic microscope. The ProTaper sequence recommended by the manufacturer was used, with NaOCl as irrigant. The instruments were sterilised after every three canals were shaped. The instruments were observed with the same microscope after shaping each canal, until 30 root canals were shaped. The criteria used for checking the instruments were: blunt cutting edges, disruption of cutting edge, microfractures, fatigue cracks, metal flash, dentine remains. RESULTS: Many microscopic defects were found such as: cutting edge breaks (up to 70%); fatigue cracks, between 33 and 100%. No microfractures were found. An S1 and an SX file were fractured. CONCLUSION: ProTaper instruments are quite reliable if used following usual requirements.