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BACKGROUND/PURPOSE: Chelating agents have been used for the removal of the smear layer on teeth. However, due to inadequate volume and/or penetration of the solutions during irrigation, smear layer removal is less effective in the apical third. The purpose of this study was to compare the efficacy of three chelating solutions with and without manual dynamic irrigation in smear layer removal. MATERIALS AND METHODS: Sixty-six single-root canal teeth were decoronated, instrumented, and divided into six experimental groups (n = 10) and two control groups (n = 3). The groups received a final rinse with 1 mL of 17% EDTA and 5% or 10% citric acid (CA) for 1 minute, with or without manual dynamic activation, followed by a final 3-mL rinse with 4.2% NaOCl (5 minutes). The teeth were then longitudinally split and prepared for environmental scanning electron microscopy analysis. Digital images (500×) were taken for smear layer removal evaluation at 2 mm, 6 mm, and 10 mm from the working length. RESULTS: The most effective smear layer removal occurred with 5% and 10% CA combined with manual dynamic activation (Groups 7 and 8), where significant differences were observed when compared with the EDTA groups (Groups 2 and 6; P < 0.05). We found no significant differences between manual dynamic activation with 5% and 10% CA (Groups 7 and 8) in smear layer or debris removal (P > 0.05). CONCLUSION: Manual dynamic activation of CA improves smear layer removal, and a reduction in CA concentration to 5% does not compromise smear layer removal in comparison with higher concentrations.
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INTRODUCTION: The aim of the study was to compare the K3 and K3XF systems (SybronEndo, Glendora, CA) after 1 and 2 uses by evaluating apical transportation, working length loss, and working time in a manikin model. METHODS: Mesial canals of 40 extracted first mandibular molars were instrumented. Radiographs taken after instrumentation with #25, #30, #35, and #40 files were superimposed on the preoperative image in both mesiodistal and buccolingual angulations. AutoCAD (Autodesk Inc, San Rafael, CA) was used to measure working length loss and apical transportation at 0, 0.5, and 1 mm from the working length (WL). The working time was measured. Group comparison was analyzed using post hoc Tukey honestly significant difference tests (P < .05). RESULTS: No significant differences were found in apical transportation, working length loss between K3 and K3XF systems, or between the number of uses. Significant differences were found when canal enlargement was performed to a #35-40 (P < .05). K3 instrumentation performed significantly faster (29.6 ± 15.4) than with the K3XF system (40.2 ± 17.7) (P < .05). No differences were observed in working time when comparing the number of uses. CONCLUSIONS: K3 and R-phase K3XF rotary systems shaped curved root canals safely with minimal apical transportation, even up to a 40/04 file.
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Cavidad Pulpar/anatomía & histología , Maniquíes , Preparación del Conducto Radicular/instrumentación , Ápice del Diente/anatomía & histología , Equipo Dental de Alta Velocidad , Cavidad Pulpar/diagnóstico por imagen , Diamante/química , Humanos , Procesamiento de Imagen Asistido por Computador/métodos , Ensayo de Materiales , Diente Molar/anatomía & histología , Diente Molar/diagnóstico por imagen , Odontometría/instrumentación , Radiografía , Rotación , Factores de Tiempo , Ápice del Diente/diagnóstico por imagen , TorqueRESUMEN
INTRODUCTION: The purpose of the study was to compare the accuracy of the Root ZX electronic apex locator (J Morita Corp, Tokyo, Japan) between an in vivo and an in vitro model. METHODS: The working length (WL) was determined electronically for 46 root canals of human teeth with a 15 K-file using both in vitro (n = 23) and in vivo (n = 23) models. The files were fixed at the WL. The apical 4 mm of each canal was trimmed to expose the file tip. The samples were observed under a scanning electron microscope, and the distance from the file tip to the point 0.5 mm coronal to the major foramen (the final WL) was measured. The data were analyzed using the Student t test, and significance was set at P ≤ .05. RESULTS: The statistical analysis revealed no significant differences between the in vivo group and in vitro group with respect to the accuracy of the Root ZX device in determining the final WL. The mean distance from the final WL to the file tip was 0.23 ± 0.39 mm for the in vivo group and 0.29 ± 0.32 mm for the in vitro group. In determining the final WL, the Root ZX was accurate 78.3% of the time to ±0.5 mm and 100% of the time to ±1 mm in the in vivo group, whereas it was accurate 74% of the time to ±0.5 mm and 100% of the time to ±1 mm in the in vitro group. CONCLUSIONS: No statistically significant differences were observed between the in vivo group and the in vitro group.
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Cavidad Pulpar/anatomía & histología , Odontometría/instrumentación , Preparación del Conducto Radicular/instrumentación , Ápice del Diente/anatomía & histología , Adulto , Diente Premolar/anatomía & histología , Diente Canino/anatomía & histología , Electrónica/instrumentación , Diseño de Equipo , Humanos , Incisivo/anatomía & histología , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Odontometría/normasRESUMEN
INTRODUCTION: The purpose of this study was to compare the accuracy in vivo of 2 electronic apex locators (EALs), the Raypex 5 and the Mini Apex Locator. METHODS: The working length (WL) was determined electronically for 40 human root canals by using a K-file and 1 of the 2 EALs. The files were fixed at the WL, and the teeth were extracted. The apical 4 mm of each canal was trimmed to expose the file tip. The samples were observed under a scanning electron microscope, and the distance from the file tip to the point 0.5 mm coronal to the major foramen (the final WL) was measured. The data were analyzed by using Student t test, and significance was set at P < .05. RESULTS: No statistically significant differences were found between the Raypex 5 and the Mini Apex Locator devices. The mean distance from the final WL to the file tip was 0.174 ± 0.38 mm for the Raypex 5 and 0.286 ± 0.30 mm for the Mini Apex Locator. In determining the final WL, the Raypex 5 was accurate 75% of the time to ± 0.5 mm and 100% of the time to ± 1 mm, whereas the Mini Apex Locator was accurate 77.8% of the time to ± 0.5 mm and 100% of the time to ± 1 mm. CONCLUSIONS: Under the in vivo conditions of this study, no statistically significant differences were observed between the Raypex 5 and the Mini Apex Locator EALs.
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Odontometría/instrumentación , Ápice del Diente/anatomía & histología , Adulto , Impedancia Eléctrica , Equipos y Suministros Eléctricos , Humanos , Procesamiento de Señales Asistido por ComputadorRESUMEN
INTRODUCTION: iPex is a fourth-generation apex locator (EAL) that has not yet been tested in vivo. The purpose of this study was to compare the accuracy of the Root ZX (J Morita Corp, Tokyo, Japan) and iPex (NSK, Tochigi, Japan) EALs. METHODS: The working length (WL) was determined electronically for 40 root canals of human teeth with a K-file and one of the two EALs. The files were fixed at the WL, and the teeth were extracted. The apical 4 mm of each canal was trimmed to expose the file tip. The samples were observed under a scanning electron microscope, and the distance from the file tip to the point 0.5 mm coronal to the major foramen (the actual WL) was measured. The data were analyzed using the Mann-Whitney U test, and significance was set at P < .05. RESULTS: No statistically significant differences were found between the Root ZX and iPex devices. The mean distance from the actual WL to the file tip was 0.146 ± 0.43 mm for the Root ZX and 0.128 ± 0.49 mm for the iPex. In determining the actual WL, the Root ZX was accurate 72% of the time to ± 0.5 mm and 100% of the time to ± 1 mm, whereas the iPex was accurate 57.8% of the time to ± 0.5 mm and 100% of the time to ± 1 mm. CONCLUSIONS: Under the in vivo clinical conditions of this study, no statistically significant differences were observed between the Root ZX and iPex EALs.