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.

The application of casein phosphopeptide and amorphous calcium phosphate with fluoride (CPP-ACPF) for restoring mineral loss after dental bleaching with hydrogen or carbamide peroxide: An in vitro study.

OBJECTIVE: To conduct an in vitro evaluation of the effect of casein-phosphopeptide and amorphous calcium phosphate with fluoride [CPP-ACPF] upon the calcium [Ca] and phosphorus [P] composition and morphology of dental enamel and dentin after the application of two bleaching agents: 37.5% hydrogen peroxide [HP]) and 35% carbamide peroxide [CP]. MATERIALS AND METHODS: The crowns of 40 extracted human teeth were divided into four groups (n=10 each). The crowns were sectioned along the cervical-incisal axis, and each half was embedded in acrylic resin, leaving a window 3mm in diameter to explore the enamel or dentin (according to the study group involved). Groups 1a and 1b corresponded to the two halves belonging to the same tooth and were treated with HP applied to enamel three times for 10min. Afterwards, CPP-ACPF was applied in group 1b for five minutes. The same procedure was carried out in groups 2a and 2b, but application was done on dentin. Groups 3a and 3b were treated with CP applied to enamel once for 30min. Posteriorly, CPP-ACPF was applied in group 3b for five minutes. Groups 4a and 4b were treated in the same way as groups 3a and 3b, but application was done on dentin. The morphological changes were evaluated using confocal laser scanning microscopy (CLSM), and the changes in Ca and P composition were assessed by environmental scanning electron microscopy coupled to a microanalytical system (ESEM+EDX). Comparisons between groups were made using the Kruskal-Wallis test, and Duncan test was applied for two-by-two comparisons, with a significance level of p<0.05. RESULTS: Both HP and CP produced similar changes in enamel morphology and produced no changes in dentin. Groups treated with CPP-ACPF after bleaching improved the percentage of Ca and P. Statistical significance was reached only in the case of the percentage of Ca in enamel (group 1b versus group 1a, p=0.01) (group 3b versus group 3a, p=0.03). CONCLUSIONS: The application of CCP-ACPF for five minutes on the enamel surface after tooth bleaching is effective in restoring the Ca lost as a result of the bleaching process, while their effect in dentin could not be demonstrated.

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

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