Abstract: The aim of this study was to compare the efficacy of passive ultrasonic irrigation and EasyClean for removing residual filling material in retreatment. Twenty-two maxillary lateral incisors with apical curvature were instrumented with ProTaper files and filled with Endofill using the lateral compactation technique. Removal of filling material was performed with Reciproc, Mtwo and ProDesign Logic 50/.01 files. The teeth were inserted in a silicone mould, which was placed in a metal muffle, and split to visualize the residual filling material. The samples were divided into two groups (n = 11) according to the irrigation protocol: Passive ultrasonic irrigation (PUI group) with 3 activations of 20 seconds and EasyClean (Easy Equipamentos Odontológicos, Belo Horizonte, Brazil) (EC group) used in continuous rotation with 3 activations of 20 seconds, both using NaOCl and EDTA. Environmental scanning electron microscopic images of the apical, middle, and cervical thirds were taken before and after the irrigant activation. The Kappa test was used to determine interexaminer agreement. Statistical analysis was performed using Kruskal–Wallis, Mann–Whitney, and Wilcoxon tests (p < 0.05). PUI and EC improved the removal of remnant filling material in all root canal thirds (p < 0.05). PUI and EC presented similar performance in the final step of retreatment (p > 0.05). No significant difference was observed in the removal of filling material in the apical, middle, and cervical thirds in both groups (p > 0.05). EasyClean in continuous rotary motion is useful in retreatment and was shown to be as effective as ultrasonic activation in the removal of remnant filling material.

ABSTRACT The knowledge of the internal anatomy of three-rooted mandibular molars may help clinicians to diagnose and plan the root canal treatment in order to provide adequate therapy when this variation is present. Objectives: To determine the prevalence of three-rooted mandibular molars in a Brazilian population using cone beam computed tomography (CBCT) and to analyze the anatomy of mandibular first molars with three roots through micro-CT. Material and Methods: CBCT images of 116 patients were reviewed to determine the prevalence of three-rooted first mandibular molars in a Brazilian subpopulation. Furthermore, with the use of micro-CT, 55 extracted three-rooted mandibular first molars were scanned and reconstructed to assess root length, distance between canal orifices, apical diameter, Vertucci's classification, presence of apical delta, number of foramina and furcations, lateral and accessory canals. The distance between the orifice on the pulp chamber floor and the beginning of the curvature and the angle of canal curvature were analyzed in the distolingual root. Data were compared using the Kruskal-Wallis test (α=0.05). Results: The prevalence of three-rooted mandibular first molars was of 2.58%. Mesial roots showed complex distribution of the root canal system in comparison to the distal roots. The median of major diameters of mesiobuccal, mesiolingual and single mesial canals were: 0.34, 0.41 and 0.60 mm, respectively. The higher values of major diameters were found in the distobuccal canals (0.56 mm) and the lower diameters in the distolingual canals (0.29 mm). The lowest orifice distance was found between the mesial canals (MB-ML) and the highest distance between the distal root canals (DB-DL). Almost all distal roots had one root canal and one apical foramen with few accessory canals. Conclusions: Distolingual root generally has short length, severe curvature and a single root canal with low apical diameter.

ABSTRACT Objectives To evaluate the sealing ability of three root-end filling materials (white MTA, CPM, and MBPc) using an Enterococcus faecalis leakage model. Material and Methods Seventy single-root extracted human teeth were instrumented and root-ends were resected to prepare 3 mm depth cavities. Root-end preparations were filled with white MTA, CPM, and MBPc cements. Enterococcus faecalis was coronally introduced and the apical portion was immersed in BHI culture medium with phenol red indicator. The bacterial leakage was monitored every 24 h for 4 weeks. The statistical analysis was performed using the Wilcoxon-Gehan test (p<0.05). Results All cements showed bacterial leakage after 24 hours, except for the negative control group. The MBPc showed significantly less bacterial leakage compared with the MTA group (p<0.05). No significant differences were found between the CPM and the other groups. Conclusions The epoxy resin-based cement MBPc had lower bacterial leakage compared with the calcium silicate-based cements MTA and CPM.

Objective To evaluate the biocompatibility and the setting time of Portland cement clinker with or without 2% or 5% calcium sulfate and MTA-CPM. Material and Methods Twenty-four mice (Rattus norvegicus) received subcutaneously polyethylene tubes filled with Portland cement clinker with or without 2% or 5% calcium sulfate and MTA. After 15, 30 and 60 days of implantation, the animals were killed and specimens were prepared for microscopic analysis. For evaluation of the setting time, each material was analyzed using Gilmore needles weighing 113.5 g and 456.5 g, according to the ASTM specification Number C266-08 guideline. Data were analyzed by ANOVA and Tukey's test for setting time and Kruskal-Wallis and Dunn test for biocompatibility at 5% significance level. Results Histologic observation showed no statistically significant difference of biocompatibility (p>0.05) among the materials in the subcutaneous tissues. For the setting time, clinker without calcium sulfate showed the shortest initial and final setting times (6.18 s/21.48 s), followed by clinker with 2% calcium sulfate (9.22 s/25.33 s), clinker with 5% calcium sulfate (10.06 s/42.46 s) and MTA (15.01 s/42.46 s). Conclusions All the tested materials showed biocompatibility and the calcium sulfate absence shortened the initial and final setting times of the white Portland cement clinker.

OBJECTIVES: To compare, in vivo, the accuracy of conventional and digital radiographic methods in determining root canal working length. MATERIAL AND METHODS: Twenty-five maxillary incisor or canine teeth from 22 patients were used in this study. Considering the preoperative radiographs as the baseline, a 25 K file was inserted into the root canal to the point where the Root ZX electronic apex locator indicated the APEX measurement in the screen. From this measurement, 1 mm was subtracted for positioning the file. The radiographic measurements were made using a digital sensor (Digora 1.51) or conventional type-E films, size 2, following the paralleling technique, to determine the distance of the file tip and the radiographic apex. RESULTS: The Student "t" test indicated mean distances of 1.11 mm to conventional and 1.20 mm for the digital method and indicated a significant statistical difference (p<0.05). CONCLUSIONS: The conventional radiographic method was found to be superior to the digital one in determining the working length of the root canal.

OBJECTIVE: This study compared the influence of three epoxy resin-based sealers with distinct radiopacities on the observers' ability to detect root canal filling voids during radiographic analysis. MATERIAL AND METHODS: The root canals of 48 extracted maxillary canines were prepared and divided into three groups. Each group was laterally condensed with one sealer (AH Plus®, Acroseal® or a non-radiopaque sealer), and a longitudinal void was simulated in half of the specimens from each group (n=8). Buccolingual radiographs were obtained and randomly interpreted for voids by a radiologist and an endodontist in a blinded fashion. Teeth were cut and inspected under a microscope to confirm the position of void. Differences in sensitivity and specificity between groups and examiners were compared using the Fisher's Exact and McNemar tests, respectively (α=0.05). RESULTS: Significantly lower sensitivity levels (p<0.05) were observed in the coronal portion of fillings performed with both radiopaque sealers. Specificity values for Acroseal® were significantly higher (p<0.05) in the coronal and apical portions of fillings. CONCLUSIONS: The type of root canal sealer can affect the observers' ability to detect root canal filling voids during radiographic analysis of upper single-rooted teeth.

The aim of this study was to evaluate in vitro the effect of sputter- coating for SEM analysis on the formation of cracks on root-end surfaces after retrograde cavity preparation with ultrasonic tips. Root-end cavities were prepared with either Satelec S12/90oD diamond-coated or S12/90o non-coated stainless steel retrotips. Impressions were taken before and after retrograde cavity preparation. The resected root apices and their respective impressions were examined using a scanning electron microscope, and the presence, extension and numbers of cracks were recorded after each procedure. The number of cracks observed directly on the ultrasonically prepared root-end surfaces was larger than that observed in their respective impressions taken after root-end cavity preparation, which suggests that cracking was mostly produced by the sputtercoating process required for SEM analysis. Impressions of the root-end cavities prepared with non-coated ultrasonic stainless steel retrotips showed a greater incidence of cracks (3/10 impressions) than those that replicated cavities prepared with diamond-coated retrotips (1/10 impressions). No statistical difference was found between the diamond and stainless steel retrotips.

El objetivo del presente estudio fue evaluar in vitro el efecto del proceso de metalizacion de la dentina, necesaria para la observacion al microscopio electronico de barrido, sobre la formacion de fracturas dentinarias en retropreparaciones apicales realizadas con ultrasonido. Se realizaron retropreparaciones apicales en 20 piezas dentarias utilizando puntas ultrasonicas diamantadas Satelec S12/90° D (N=10) o puntas no diamantadas Satelec S12/90°. Se tomaron impresiones con silicona antes y despues de que fueran realizadas las retropreparaciones. Los apices radicu - lares y sus respectivas impresiones fueron metalizados y examinadas utilizando un microscopio electronico de barrido. La presencia, extension y numero de fracturas en la dentina fue registrada despues de cada procedimiento. El numero de fracturas observados en la dentina en las retropreparaciones fue mayor que el observado en las impresiones tomadas despues de realizado el procedimiento ultrasonico, lo cual indica que gran cantidad de fracturas en la dentina fueron producidas por el proceso de metalizacion requerido para el analisis al microscopio electronico de barrido y no por el procedimiento ultrasonico. El analisis de las impresiones mostro una mayor incidencia de fracturas cuando se utilizaron las puntas ultrasonicas no diamantadas (3/10) que cuando se utilizaron las puntas ultrasonicas diamantadas (1/10). Sin embargo, la diferencia no fue estadisticamente significativa (p>0.05).

OBJECTIVE: This study used dye leakage assay and scanning electron microscopy to evaluate, respectively, the sealing ability and marginal adaptation of three root-end filling materials used as apical plugs, as well as the possible correlation between these properties. MATERIAL AND METHODS: Ninety-eight single-rooted human teeth were prepared to simulate an open apex. The teeth were allocated to three experimental groups (n = 30), which received a 5-mm thick apical plug of (1) gray MTA AngelusTM, (2) CPM TM and (3) MBPc, and two controls groups (n = 4). After immersion in 0.2% Rhodamine B solution for 48 h, the teeth were sectioned longitudinally and analyzed by Image Tool 3.0 software. The marginal adaptation between apical plugs and the root canal walls were analyzed by SEM. RESULTS: MBPc had significantly less (p<0.05) apical leakage than the other materials. Regarding marginal adaptation, CPM TM showed the best numerical results, though without statistical significance from the other materials (p<0.05). There was no correlation between the two properties. CONCLUSIONS: When used as apical plugs, the tested root-end filling materials had similar marginal adaptation to the dentin walls, but MBPc had the best sealing ability, as demonstrated by the least apical leakage from all tested materials.

OBJETIVO: Avaliar a radiopacidade produzida por sete cimentos comercialmente disponíveis (AH Plus, Epiphany, Sealapex, Acroseal, Sealer 26, Endomethasone and Endofill) e um em estágio experimental (MBP). METODOLOGIA: Depois de homogeneizados os materiais, o teste de radiopacidade foi executado conforme a especificação nº 57 da ANSI/ADA. Radiografou-se os espécimes junto a uma escala de Alumínio e as imagens resultantes foram digitalizadas. As densidades radiográficas expressas em milímetros de Alumínio (mm Al) foram comparadas por meio da análise de variância e teste de Tukey (α=0.05). RESULTADOS: Os cimentos AH Plus (10 mm Al) e Epiphany (9 mm Al) apresentaram as maiores radiopacidades seguidos pelo Sealapex (8 mm Al), Endofill (7 mm Al), Endométhasone (7 mm Al), MBP (7 mm Al) e Sealer 26 (6 mm Al). Acroseal (5 mm Al) mostrou a menor radiopacidade entre os cimentos testados (P<0.05). CONCLUSÃO: Concluiu-se que as diferentes radiopacidades dos cimentos testados estão acima do nível mínimo recomendado pela especificação nº 57 da ANSI/ADA.

PURPOSE: To evaluate the radiopacity produced by seven commercially available (AH Plus, Epiphany, Sealapex, Acroseal, Sealer 26, Endomethasone and Endofill) and one experimental (MBP) root canal sealers. METHODS: Sealer radiopacity testing was performed according to ANSI/ADA Specification No. 57. Specimens were radiographed with an aluminum stepwedge, and the resulting images were digitalized. Radiographic densities expressed in Aluminum mm (mm Al) were compared using an ANOVA and Tukey's test (α=0.05). RESULTS: AH Plus (10 mm Al) and Epiphany (9.0 mm Al) were the most radiopaque root canal sealers, followed by Sealapex (8 mm Al), Endofill (7 mm Al), Endomethasone (7 mm Al), MBP (7 mm Al) and Sealer 26 (6 mm Al). Acroseal (5 mm Al) showed the smallest radiopacity among the tested sealers (P<0.05). CONCLUSION: The radiopacities of the tested sealers were above the minimum level recommended by ANSI/ADA Specification No. 57.

O propósito deste estudo ex vivo foi investigar se dois cimentos obturadores de fórmulas diferentes influenciariam a percepção radiográfica de obturações de canais radiculares. Os canais radiculares de 48 caninos superiores extraídos foram preparados e divididos em 3 grupos. Em cada grupo os canais foram preenchidos através da condensação lateral da guta-percha e de um dos cimentos testados (Endométhasone, Sealer 26 e cimento não-radiopaco), e um defeito de ponta a ponta foi simulado em metade dos espécimes de cada grupo (n=8). As imagens radiográficas vestíbulo-linguais obtidas foram aleatoriamente interpretadas quanto à existência de defeitos por um radiologista e um endodontista. As diferenças em sensibilidade e especificidade entre os grupos e examinadores foram comparadas respectivamente usando-se os testes Exato de Fisher e McNemar ajustados ao nível de significância de 5%. Ambos os cimentos radiopacos ocasionaram uma redução significativa da sensibilidade na parte cervical das obturações. O uso do Endométhasone aumentou os valores de especificidade para as porções cervical e apical das obturações dos canais radiculares. Concluiu-se que os cimentos testados influenciaram de maneira distinta a percepção radiográfica de obturações endodônticas executadas com condensação lateral.

The aim of this ex vivo was to investigate if two radiopaque root canal sealers with different formulations would influence the radiographic perception of root canal fillings. The root canals of 48 extracted maxillary canines were prepared and randomly assigned to 3 groups of 16 specimens each. In each group, the root canals were filled by lateral condensation of gutta-percha and one of the tested sealers: Endométhasone, Sealer 26, or a non-radiopaque sealer. A through-and-through void was simulated in half of the specimens from each group (n=8). The buccolingual radiographic images obtained were randomly interpreted for voids existence by a radiologist and an endodontist. The differences in sensitivity and specificity between groups and examiners were compared using, respectively, Fisher's Exact and McNemar tests at 5% significance level. Both radiopaque sealers caused a significant decrease in sensitivity at the coronal part of fillings. The use of Endométhasone increased specificity values for both coronal and apical portions of the root canal fillings. In conclusion, the tested sealers influenced the radiographic perceptions of laterally condensed root canal fillings in a different way.

This ex vivo study evaluated the quality of digital radiographic images obtained with the photostimulable phosphor plate system (Digora) according to the processing delay and maintenance of optical plates in either opaque (supplied with the system) or transparent protective plastic cases during this period. Five radiographs were obtained from the mandibular molar region of a dry human mandible using optical plates. These plates were placed in the protective plastic cases before obtaining the radiographs and were processed immediately or after processing delays of 5, 60 and 120 min, when the case was removed. The results revealed a reduction in image quality when processing was delay 120 min compared to the other times. The opaque case provided better protection to the sensor than the transparent case. In conclusion, a 120-min processing delay for the Digora system caused a reduction in image quality, yet without interfering with the quality of diagnosis. The opaque case supplied by the system's manufacturer provided better protection to the optical plate than the transparent case.

This study investigated the solubility of mineral trioxide aggregate (MTA) and Portland cement since its mixture until 672 hours, by means of two complimentary methods. Metal ring molds filled with the cements were covered with distilled water and, at each experimental time (3, 24, 72, 168, 336 and 672 hours), were weighed as soon as the plates in which the samples have been placed. Empty rings served as the control group (n=8). Mean weight gain and loss was determined and analyzed statistically by two-way ANOVA and Tukey's test for all pairwise comparisons. Only Portland cement showed less than 3% weight loss through 24 hours. Detached MTA residues were heavier than those of Portland cement over the 3 to 168 hours. The weight of MTA rings increased more than that of Portland rings within 672 hours (p=0.05). The findings of the present study indicate that, in an aqueous environment MTA is more soluble than Portland cement and exceeds the maximum weight loss considered acceptable by ISO 6876 standard (2001).

The aims of this study were to evaluate the quality of indirect digitized radiographic images taken during endodontic procedures and to compare the measurements recorded with this technique to those obtained from conventional radiographs. Two-hundred conventional periapical radiographs taken at the undergraduate Endodontics Clinic of the Dental School of Bauru were digitized. The conventional and indirect digitized images were compared by three examiners as to the quality and accuracy of the measurements recorded during endodontic treatment, in canal length determination, gutta-percha adaptation, lateral condensation and final obturation. The conventional radiographs were observed on a film viewer, surrounded by a dark card, and measured with magnifying glass and a millimeter ruler; the indirect digitized images were evaluated on the Digora® for Windows software, with free utilization of the bright/contrast tool. Unlike the conventional radiographic images, all indirect digitized images were considered as having a high quality. The distance between the filling material and the root apex was 0.117 mm larger, on average, for the Digora® system (p<0.01). The measurements achieved by the investigated radiographic methods were clinically similar and they are thus equivalent. Changes in brightness and contrast of the images using Digora®software improved the diagnosis.

This study aimed to compare the apical sealing of root-end fillings performed with Lysanda (zinc oxide-eugenol paste) with radiopacifiers (iodoform or zinc oxide) and calcium hydroxide. Root-end cavities were prepared and filled with different materials, as follows: Group I - Lysanda paste with iodoform; Group II - Lysanda paste with iodoform and calcium hydroxide; Group III - Lysanda paste with iodoform and zinc oxide; Group IV - Lysanda paste with zinc oxide; Group V - mineral trioxide aggregate (MTA). After filling, the teeth were immersed in 2% methylene blue for analysis of marginal leakage. It was observed that marginal leakage occurred in all groups. Lysanda paste with iodoform showed the lowest leakage, with no statistically significant difference compared to the other groups. All materials can be considered as good options for root-end filling.

This study evaluated the sealing ability of apical plugs made of white and gray MTA-Angelus® and white Portland cement placed via the root canal and having different thicknesses (2, 5 and 7 mm). Ninety extracted human single-rooted teeth were instrumented using a size 40 K-file to standardize the foraminal opening by the stepback technique. The teeth were assigned to 3 groups (n=30), according to the material used for fabrication of the apical plugs: A = gray MTA; B = white MTA; C = white Portland cement. The groups were subdivided into groups of 10 teeth each according to the apical plug thickness (2, 5 and 7 mm). Marginal apical dye leakage was assessed using 0.2% Rhodamine B solution in which the specimens were immersed for 72 hours at 37ºC. The roots were sectioned longitudinally in a buccolingual direction for apical plug exposure, and digital photographs were taken and analyzed by Image Tool image-analysis software. Data were analyzed statistically by Kruskal-Wallis and Dunn's tests. Significance level was set at 5%. The least percent leakage was observed for 5- and 7-mm-thick plugs (p<0.05). No significant difference (p>0.05) was found between gray MTA and white Portland cement. Among the three materials analyzed, white MTA presented the highest marginal leakage (p<0.05). The findings of the present study showed that gray MTA and Portland cement had better sealing ability than white MTA when used as apical plugs. Dye leakage was smaller for 5- and 7-mm-thick plugs compared to 2-mm-thick plugs.