Effect of apical constriction diameter, irrigant flow rate, and needle tip design on apical pressure / 대한치과재료학회지

The purpose of this study was to evaluate the effects of apical constriction (AC) diameter, irrigant flow rate, and needle tip design on apical pressure (AP) during the root canal irrigation. Five extracted human mandibular premolars were instrumented up to #35 (0.06 taper) using nickel-titanium rotary instruments. AC was determined at 1 mm from the apical foramen. Three needles with different tip designs (notched, side-vented, and flat) were placed 3 mm from AC. APs were measured with varying flow rates of 0.05, 0.1, 0.2, and 0.3 mL/s. The AC diameter of the teeth was enlarged to #40 and #45 (0.06 taper) successively, and the aforementioned measurement procedure was repeated (n=5). When the other conditions were controlled, AP increased with decreasing AC diameter or increasing irrigant flow rate, and the AP of flat needle was the highest, followed by notched, and side-vented needle (p0.35 mm, open-end (notched or flat) needles can be used to improve irrigant replacement in the apical portion using a flow rate of 0.05 mL/s.

Morphology of the physiological apical foramen of maxillary premolars / Morfología del foramen apical de premolares maxilares

SUMMARY: The purpose of this study was to determine the shape and diameter of the physiological foramen in maxillary premolars of a Chilean population. The sample consisted of 125 extracted maxillary premolars, in which the apical three to five millimeters were cut and observed under magnification of 40x, photographed (Motic Cam), and analyzed using Motic Images Plus 2.0 ML in order to obtain measurements of the minor and major diameter of each physiological foramen. The average minor and major diameter in maxillary premolars was 0.270 and 0.413 mm, respectively. In terms of shape, 72.19 % had oval shaped physiological foramen; 18.93 % were irregularly shaped and 8.88 % were round. Oval and irregular canals are significantly more difficult to shape and require special attention in order to obtain a thoroughly disinfected root canal system.

RESUMEN: El objetivo del estudio fue determinar la forma y el diámetro del foramen fisiológico de premolares maxilares en una población Chilena. La muestra consistió en 125 premolares maxilares extraídos, a los que se cortó de 3 a 5 milímetros apicales, fueron observados bajo magnificación de 40x, fotografiado (Motic Cam) y analizados utilizando Motic Images Plus 2.0 ML para obtener las mediciones de el diámetro menor y mayor de cada foramen fisiológico. El promedio del diámetro menor y mayor en premolares maxilares fue de 0,270 y 0,413 mm respectivamente. En cuanto a la forma 72,19 % tenía el foramen fisiológico de forma oval; 18,93 % tenía forma irregular y 8,88 % fue redondo. Canales ovales e irregulares son significativamente más difíciles de conformar y requieren especial atención para obtener una adecuada desinfección del sistema de canales radiculares.

Morphology of the physiological apical foramen in maxillary and mandibular first molars / Morfología del foramen fisiológico apical en primeros molares maxilares y mandibulares

Information regarding the anatomy of the physiological apical foramen is limited. Knowing its diameter and shapes contributes to clinical work, specifically to the cleaning and shaping of the apical third. The aim of this ex vivo study was to determine the minimum and maximum diameters and shape of the physiological apical foramen in the roots of maxillary and mandibular first molars. A descriptive study was conducted on 89 recently extracted first molars. Roots 3-5 mm from the apex were sectioned and prepared for analysis at 40x magnification. The minimum and maximum diameters of each physiological foramen were measured using the program Motic Images plus 2.0 ML. The shape of the foramina, classified as round, oval or irregular, was determined by the difference between the maximum and minimum diameters. A total of 174 physiological foramina were analyzed. The average of the minimum and maximum diameters was between 0.24-0.33 mm in maxillary first molars and between 0.25-0.33 mm in mandibular first molars. In maxillary molars, the most common shape of the foramen was oval (50%), then irregular (32%), then round (18%). In mandibular molars, the oval shape was also the most frequent (59%), followed by irregular (23%) and round (18%). The findings of this study regarding the morphology of physiological apical foramina in first molars make it easier for the operator to choose the appropriately-sized instruments to perform endodontic therapy successfully.

La información relacionada a la anatomía del foramen fisiológico apical es limitada. Conocer su diámetro y forma contribuye al trabajo clínico, específicamente en los procedimientos de limpieza y conformación del tercio apical. El objetivo de este estudio ex vivo fue determinar los diámetros menor, mayor y la forma del foramen fisiológico apical en las raíces de primeros molares maxilares y mandibulares. Se realizó un estudio descriptivo sobre 89 primeros molares recientemente extraídos. Se seccionaron las raíces a 3­5 mm del ápice y fueron preparadas para su análisis bajo magnificación de 40X. Se midieron los diámetros mayor y menor de cada foramen fisiológico mediante el programa Motic Images plus 2.0 ML. La forma de los forámenes fue determinada de acuerdo a la diferencia entre diámetro mayor y menor, clasificándose como redondo, oval o irregular. Un total de 174 forámenes fisiológicos fueron analizados. El promedio del diámetro menor y mayor fue entre 0,24­0,33 mm en primeros molares maxilares y entre 0,25­0,33 mm en primeros molares mandibulares. En molares maxilares, la forma del foramen más común fue la oval (50%), luego irregular (32%) y redonda (18%). En molares mandibulares, la forma oval también fue la más frecuente (59%), seguida por la irregular (23%) y redonda (18%). Los hallazgos de este estudio en relación a morfología de los forámenes fisiológicos apicales en primeros molares, permite al operador facilitar la elección de instrumentos del calibre adecuado para realizar con éxito la terapia endodóntica.

Influência da espessura de dentina, da constrição apical e do diâmetro do forame apical na precisão de leitura com localizadores foraminais eletrônicos / Influence of dentin thickness, apical constriction and diameter of the apical foramen in the accuracy of readings with electronic apex locators

Este trabalho teve como objetivo avaliar a influência da espessura de dentina radicular apical, da constrição apical e do diâmetro do forame apical na precisão de leituras realizadas com os localizadores foraminais eletrônicos Mini Apex Locator e Root ZX II®. Foram utilizados 30 incisivos inferiores permanentes unirradiculados de humanos, extraídos, com raízes íntegras e ápices completamente formados e portadores de um único canal. Por meio de um paquímetro, as espessuras radiculares dos dentes foram medidas, no sentido mésio-distal a 1,0 e a 4,0mm aquém do forame apical. Após a abertura coronária, uma lima tipo K no 10, munida de limitador de penetração, foi introduzida no canal radicular até que sua extremidade pudesse ser visualizada na altura do forame, com o auxílio de um microscópio óptico com aumento de 7,8X. Dessa medida, subtraiu-se 1,0mm, estabelecendo-se o comprimento de trabalho. A dilatação do canal radicular foi feita, inicialmente, com brocas de Gates Glidden, em ordem numérica decrescente, da número 5 até a número1, até 4,0mm aquém do forame apical. Os dentes foram fixados em um modelo experimental especialmente desenvolvido para permitir a medição com os localizadores foraminais eletrônicos. Tal modelo era constituído por dois segmentos de PVC: um de menor calibre, com diâmetro correspondente a meia polegada por 2,0cm de comprimento, com as duas extremidades abertas e outro, de maior calibre, com uma das extremidades fechada e com diâmetro interno equivalente ao diâmetro externo do primeiro segmento (3/4 de polegada). No segmento de maior diâmetro, foi feito um orifício lateral que permitiu o posicionamento do eletrodo labial do localizador foraminal eletrônico e, para a medição, no seu interior, foi colocado alginato e, então, encaixado o componente de menor diâmetro, fazendo com que o ápice radicular ficasse imerso no alginato. Foram realizadas as leituras com os localizadores, iniciando-se com a lima tipo K no 10 e seguindo-se...

This study evaluated the influence of the apical root dentin thickness, apical constriction and diameter of the apical foramen in the accuracy of readings obtained using the electronic apex locators Mini Apex Locator and Root ZX II ®. The study was conducted on 30 extracted human single-rooted permanent mandibular incisors, with intact and completely formed roots and presenting a single canal. The root thickness of the teeth was measured with a pachymeter in mesiodistal direction, at 1.0 and 4.0mm from the apical foramen. After coronal opening, a 10 K file with a stop was introduced in the root canal until its end could be observed at the level of the apical foramen, with aid of a light microscope with 7.8X magnification. One millimeter was subtracted from this measurement for establishment of the working length. Enlargement of the root canal was initially performed using Gates Glidden burs, in decreasing order, from number 5 to number 1, up to 4.0mm beyond the apical foramen. The teeth were fixated in an experimental model especially designed to allow the measurement with the electronic apex locators. This model was composed of two PVC segments: one smaller, with diameter corresponding to half inch with 2.0cm length, with both ends open; and the other, with larger diameter, with one end closed and internal diameter similar to the external diameter of the first segment (3/4 inch). In the segment with greater diameter, a lateral orifice was made to allow positioning of the lip electrode of the electronic apex locator. For the measurement, alginate was poured and the component with smaller diameter was fitted, so as the root apex was immersed in alginate. Readings were performed using the electronic apex locators, initiating with a 10 K file and following the sequence of instrumentation and measurement up to 130 K file. The 10 K file was used in all diameters. After this stage, the root canals were overinstrumented, i.e. the file tip was introduced until 1.0mm...

Influência da espessura de dentina, da constrição apical e do diâmetro do forame apical na precisão de leitura com localizadores foraminais eletrônicos / Influence of dentin thickness, apical constriction and diameter of the apical foramen in the accuracy of readings with electronic apex locators

Este trabalho teve como objetivo avaliar a influência da espessura de dentina radicular apical, da constrição apical e do diâmetro do forame apical na precisão de leituras realizadas com os localizadores foraminais eletrônicos Mini Apex Locator e Root ZX II®. Foram utilizados 30 incisivos inferiores permanentes unirradiculados de humanos, extraídos, com raízes íntegras e ápices completamente formados e portadores de um único canal. Por meio de um paquímetro, as espessuras radiculares dos dentes foram medidas, no sentido mésio-distal a 1,0 e a 4,0mm aquém do forame apical. Após a abertura coronária, uma lima tipo K no 10, munida de limitador de penetração, foi introduzida no canal radicular até que sua extremidade pudesse ser visualizada na altura do forame, com o auxílio de um microscópio óptico com aumento de 7,8X. Dessa medida, subtraiu-se 1,0mm, estabelecendo-se o comprimento de trabalho. A dilatação do canal radicular foi feita, inicialmente, com brocas de Gates Glidden, em ordem numérica decrescente, da número 5 até a número1, até 4,0mm aquém do forame apical. Os dentes foram fixados em um modelo experimental especialmente desenvolvido para permitir a medição com os localizadores foraminais eletrônicos. Tal modelo era constituído por dois segmentos de PVC: um de menor calibre, com diâmetro correspondente a meia polegada por 2,0cm de comprimento, com as duas extremidades abertas e outro, de maior calibre, com uma das extremidades fechada e com diâmetro interno equivalente ao diâmetro externo do primeiro segmento (3/4 de polegada). No segmento de maior diâmetro, foi feito um orifício lateral que permitiu o posicionamento do eletrodo labial do localizador foraminal eletrônico e, para a medição, no seu interior, foi colocado alginato e, então, encaixado o componente de menor diâmetro, fazendo com que o ápice radicular ficasse imerso no alginato. Foram realizadas as leituras com os localizadores, iniciando-se com a lima tipo K no 10 e seguindo-se...

This study evaluated the influence of the apical root dentin thickness, apical constriction and diameter of the apical foramen in the accuracy of readings obtained using the electronic apex locators Mini Apex Locator and Root ZX II ®. The study was conducted on 30 extracted human single-rooted permanent mandibular incisors, with intact and completely formed roots and presenting a single canal. The root thickness of the teeth was measured with a pachymeter in mesiodistal direction, at 1.0 and 4.0mm from the apical foramen. After coronal opening, a 10 K file with a stop was introduced in the root canal until its end could be observed at the level of the apical foramen, with aid of a light microscope with 7.8X magnification. One millimeter was subtracted from this measurement for establishment of the working length. Enlargement of the root canal was initially performed using Gates Glidden burs, in decreasing order, from number 5 to number 1, up to 4.0mm beyond the apical foramen. The teeth were fixated in an experimental model especially designed to allow the measurement with the electronic apex locators. This model was composed of two PVC segments: one smaller, with diameter corresponding to half inch with 2.0cm length, with both ends open; and the other, with larger diameter, with one end closed and internal diameter similar to the external diameter of the first segment (3/4 inch). In the segment with greater diameter, a lateral orifice was made to allow positioning of the lip electrode of the electronic apex locator. For the measurement, alginate was poured and the component with smaller diameter was fitted, so as the root apex was immersed in alginate. Readings were performed using the electronic apex locators, initiating with a 10 K file and following the sequence of instrumentation and measurement up to 130 K file. The 10 K file was used in all diameters. After this stage, the root canals were overinstrumented, i.e. the file tip was introduced until 1.0mm...

In vitro evaluation of the consistency of two electronic apex locators / 대한치과보존학회지

The purpose of this study was to evaluate the consistency of two electronic apex locators in vitro model. Materials consisted of fifty two extracted premolars and two electronic apex locators; Root ZX (J. Morita, Osaka, Japan) and E-Magic Finder Deluxe (S-Denti, Cheonan, Korea). After access preparation, the teeth were embedded in a saline-mixed alginate model. Canal lengths of each tooth were measured at "0.5" and "Apex" mark of the apex locators, respectively so that each tooth had two measurements from 0.5 and Apex points. The file was fixed at final measurement using a glass ionomer cement. The apical 4 mm from the apex was exposed to measure the distance from the file tip to the major apical foramen of each tooth. Average distances and standard deviations were used to evaluate the consistency. Results showed that all measurements of both Root ZX and E-Magic Finder located the major foramen the range of +/- 0.5 mm level. Both apex locators showed better consistency at Apex mark than at 0.5 mark. The average distance of file tip-major foramen was - 0.18 mm at 0.5 mark and - 0.07 mm at Apex mark in Root ZX, - 0.25 mm at 0.5 mark and - 0.02 mm at Apex mark in E-Magic Finder. Standard deviation was 0.21 at 0.5 mark and 0.12 at Apex mark in Root ZX, 0.12 at 0.5 mark and 0.09 at Apex mark in E-Magic Finder.

In vitro evaluation of accuracy and consistency of four different electronic apex locators / 대한치과보존학회지

The purpose of this study was to evaluate the accuracy and the consistency of four different electronic apex locators in an in vitro model. Fourty extracted premolars were used for the study. Four electronic apex locators (EAL) were Root ZX, SmarPex, Elements Diagnostic Unit (EDU), and E-Magic Finder Deluxe (EMF). After access preparation, the teeth were embedded in an alginate model and the length measurements were carried out at "0.5"and "Apex"mark using four EALs. The file was cemented at the location of the manufacturers'instruction (Root ZX, EDU, EMF: 0.5 mark, SmarPex: Apex mark). The apical 4mm of the apex was exposed and the distance from the file tip to the major foramen was measured by Image ProPlus (x 100). The distance from the file tip to the major foramen was calculated at 0.5 and Apex mark and the consistency of 0.5 and Apex mark was compared by SD and Quartile of Box plots. In this study, Root ZX and EMF located the apical constriction accurately within +/- 0.5 mm in 100%, whereas SmarPex and EDU located in 90% and in 70% respectively. For Root ZX and EMF, there was no significant difference between the consistency of 0.5 and Apex mark. However, for the EDU and SmarPex, Apex mark was more consistent than 0.5 mark. From the evaluation of the consistency in this study, for Root ZX and EMF, both 0.5 and Apex mark can be used as a standard mark. And for EDU and SmarPex, the Apex mark can be recommended to be used as a standard mark.

Physical morphology of the root canal taper in the apical region of human permanent first morlars / 北京大学学报(医学版)

Objective:To investigate the physical morphology of the root canal taper in human maxillary and mandibular permanent first molars.Methods: Forty maxillary and 44 mandibular extracted human permanent first molars were investigated.The roots were dissected transversely from their apical foramen vertical to the long axis of the root,and 1-mm-thick serial sections were made.The root apex side of each section was observed with a stereomicroscope at 30? magnification.The maximum and minimum canal diameters were measured at 0,1,2,and 3 mm from the apical foramen.The physical canal taper in the apical section was calculated.Results: 47.5%-60.0% of the narrowest diameter of root canals were present at the foramen,and 25.0%~42.5% located at the level of 1 mm from apical foramen.Almost all physical configurations of root canals in 3 mm apical region showed a bottleneck-like taper.Canal dia-meters increased rapidly at 1-2 mm with the biggest taper,and the taper had a bigger variance(0.07-0.35).The ring of shrunken bottleneck was formed at the level of 1 mm from apical foramen.The taper of canal in maximal diameter was larger than the one in minimal diameter.Conclusion: The physical morphology of bottleneck-like taper in apical canal was helpful to locate the canal apical stop in root canal treatment.

In vitro measurement accuracy of RootZX electronic apex locator in teeth with apical root resorption / 实用口腔医学杂志

0.05). Conclusion:Accurate working length may be obtained with RootZX electronic apex locator.