Igor Prokopowitsch

Comparison of different irrigants on calcium hydroxide medication removal: microscopic cleanliness evaluation

Calcium hydroxide dressing residuals can compromise endodontic sealing. This study evaluated the cleaning efficacy of different endodontic irrigants in removing calcium hydroxide by SEM image analysis. Fifty-four single-rooted mandibular premolars were instrumented to a master apical file #60 and dressed with calcium hydroxide. After 36 hours, the teeth were reopened and Ca(OH)(2) medication was removed by 5 different experimental groups: 0.5% NaOCl (G1), EDTA-C (G2), citric acid (G3), EDTA-T (G4), and re-instrumentation with MAF using NaOCl and lubrificant, followed by EDTA-T (G5). The roots were split in the buccal-lingual direction and prepared for SEM analysis in cervical, middle, and apical thirds (9, 6, and 3mm from the apex). Five blinded examiners evaluated the wall cleanliness using a scale from 1 to 5. Statistical analysis was performed using Kruskal-Wallis at 5% level of significance. Group G5 had the best results in all thirds, with significant statistical differences compared to all other groups in the middle and coronal third, and to G1 in the apical third. On the other hand, G1, only flushed with NaOCl, had the worst results, with statistical differences in all thirds compared to the other groups. The best cleanliness was achieved by G4 and G5 groups. The recapitulation of MAF in combination with irrigants improved the removal of calcium hydroxide medication better than an irrigant flush alone.

Topography of four different endodontic rotary systems, before and after being used for the 12th time

Root canal preparation may damage NiTi instruments resulting in wear and deformation. The aim of this study was to make a comparative evaluation of the surface topography of the cervical third of four different rotary systems, before and after being used twelve times, in 1.440 resin blocks with simulated root canals with standardized 45° curvatures, and analyzed by atomic force microscopy – AFM. The blocks were divided into four groups and prepared according to the manufacturers recommendations: Group 1 ‐ K3®; Group 2 ‐ Protaper Universal®; Group 3 ‐ Twisted Files® and Group 4 ‐ Biorace®. After each preparation, the instruments were washed and autoclaved. A total of 240 instruments were selected, being 30 new instruments and 30 after having been used for the 12th time, from each group. These instruments were analyzed by AFM and for quantitative evaluation, the mean RMS (Root mean square) values of the cervical third of the specimens from the four groups were used. The result showed that all the rotary files used for the 12th time suffered wear with change in the topography of the cervical region of the active portion of the file (ANOVA p < 0.01). Classifying the specimens in increasing order, from the least to the greatest wear suffered, Group 3 (2.8993 nm) presented the least wear, followed by Group 4 (12.2520 nm), Group 1 (36.0043 nm) and lastly, Group 2 (59.8750 nm) with the largest amount of cervical surface wear. Microsc. Res. Tech., 2012.

Ex vivo analysis of root canal cleaning using Endo-PTC associated to NaOCl and different irrigant solutions

The aim of this study was to assess qualitatively, by means of SEM images, the cleaning of the dentin walls of root canals after chemical-surgical preparation using Endo-PTC cream with 0.5% and 1% sodium hypochlorite and different final irrigating solutions. Seventy-two single-rooted human teeth were divided into eight groups and prepared using Endo-PTC cream with sodium hypochlorite (NaOCl) at different concentrations, and irrigated with NaOCl at different concentrations. Final irrigation was performed with either EDTA-T or EDTA-C. The best results were obtained with Group 1, followed by Groups 5, 2, 7, 8, 3, 6 and 4. We can conclude that the use of 0.5% NaOCl during instrumentation and final flush of the root canals was more efficient in cleaning than was 1% sodium hypochlorite. EDTA-T was more efficient in removing smear layer than EDTA-C, and the cervical third presented better cleaning of the root canal walls than did the middle third, which showed cleaner dentin walls than the apical third.

POSICIONADOR RADIOGRÁFICO PERSONALIZADO PARA CONTROLE DO TRATAMENTO ENDODÔNTICO

O estudo das imagens do dente em tratamento endodontico e das suas estruturas anexas favorece a identificacao precoce das alteracoes capazes de comprometer o prognostico de sucesso. A perfeita informacao radiografica e a correta interpretacao comprovadamente orientam a conduta terapeutica, estreitando a relacao entre a cura e a patologia. Assim sendo, e devido a importância da fidelidade desse procedimento, os autores apresentam um dispositivo que, acoplado a qualquer posicionador comercializado, possibilita a tomada de imagens semelhantes sob o aspecto das suas dimensoes. A importância desse fato surgiu da necessidade do confronto das imagens obtidas entre as sessoes do tratamento. Os estudos clinicos indicaram que o posicionador personalizado obtido atraves de moldagem com material pesado favoreceu sensivelmente as analises comparativas das areas da superficie radicular externa acometidas de reabsorcao cemento-dentinaria, como sequela de trauma dental, bem como as regioes portadoras de rarefacao ossea periapical no decorrer da avaliacao da neoformacao.

Adaptation and penetration of resin-based root canal sealers in root canals irradiated with high-intensity lasers.

Abstract. This research analyzed the quality of resin-based sealer adaptation after intracanal laser irradiation. Extracted teeth (n=168) were root canal treated and divided into four groups, according to dentin surface treatment: no laser; Nd:YAG laser (1.5 W, 100 mJ, 15 Hz); diode laser (2.5 W in CW), and Er:YAG laser (1 W, 100 mJ, 10 Hz). The teeth were divided into four subgroups according to the sealer used: AH Plus, EndoREZ, Epiphany, and EpiphanySE. For testing the sealing after root canal obturation, the penetration of silver nitrate solution was measured, whereas to evaluate the adaptation and penetration of the sealer into the dentin, environmental scanning electron microscopy (ESEM) was used. The ESEM images were analyzed using a four-grade criteria score by three evaluators. The inter-examiner agreement was confirmed by Kappa test and the scores statistically compared by the Kruskal-Wallis’ test (p<0.05). Both adaptation and sealer penetration in root canals were not affected by the laser irradiation. Nd:YAG and diode laser decreased the tracer penetration for AH Plus, whereas EndoREZ and EpiphanySE performances were affected by Nd:YAG irradiation (p<0.05). It can be concluded that intracanal laser irradiation can be used as an adjunct in endodontic treatment; however, the use of hydrophilic resin sealers should be avoided when root canals were irradiated with Nd:YAG laser.

Condição Odontológica em Pacientes Internados em Unidade de Terapia Intensiva

Resumen pt: Objetivo: Avaliar clinicamente a condicao odontologica de pacientes internados em Unidade de Terapia Intensiva (UTI). Metodo: Foi realizado estudo explor...

Estudio de la variación de la permeabilidad de la dentina radicular usando isótopos 99mTc, después de la aplicación de láser de alta intensidad

espanolObjetivo: Este estudio tuvo como objetivo evaluar las variaciones de la permeabilidad dentinaria radicular de dientes humanos despues del preparo quimico-quirurgico e irradiacion con laser de Er: YAG, Nd: YAG, a traves de la utilizacion del radioisotopo tecnecio-99m (99mTc) libre. Materiales y metodos: Canales de treinta raices palatinas de primeros premolares superiores humanos fueron preparados y divididos, aleatoriamente, en 3 grupos experimentales: G1 (control), G2 (irradiacion con laser de Er: YAG) y G3 (irradiacion con laser de Nd: YAG). Las muestras recibieron en el interior del canal radicular, 99mTc libre en cantidad suficiente para el llenado y colocados en tubos de ensayo contiendo 1 ml de solucion salina. Despues de 1 hora, la cuenta del isotopo radioactivo (99mTc) fue realizada. Resultados: Despues del analisis estadistico (ANOVA), fue verificado que los mejores resultados obtenidos en cuanto a la disminucion de la permeabilidad se encontraron en el Grupo 3, seguido del Grupo 2 y del Grupo 1. Conclusion: Concluimos que irradiacion con laser de Nd: YAG provoco una disminucion significativa de la permeabilidad dentinaria del canal radicular. El laser de Er: YAG y el control en relacion a la permeabilidad de la dentina de las paredes del canal radicular no presentaron diferencias estadisticamente significativas a nivel de 5%. EnglishObjective: The objective of this study was to evaluate changes in root dentin permeability of human teeth after chemical-surgical preparation, and laser irradiation with Er: YAG, Nd: YAG, through the use of the radioisotope technetium-99m (99mTc) free. Materials and methods: thirty Channels palatal roots of human maxillary first premolars were prepared and divided randomly into three experimental groups: G1 (control), G2 (laser irradiation with Er: YAG) and G3 (Nd laser irradiation : YAG). in the samples were deposited 99mTc free inside the root canal, enough to fill and placed in test tubes containing 1 ml of saline. After 1 hour, the account of the radioactive isotope (99mTc) was performed. Results: After statistical analysis (ANOVA) found that the best results in terms of decreased permeability were found in Group 3, followed by Group 2 and Group 1. Conclusion: We conclude that irradiation with Nd: YAG caused a significant decrease in the permeability of root canal dentin. Laser Er: YAG and control in relation to the dentin permeability of root canal walls showed no statistically significant differences at 5%.