Analysis of electronic apex locators in human teeth diagnosed with apical periodontitis

Abstract Electronic apex locators (EAL) have been used to establish the working length (WL) in root canal treatment. In teeth diagnosed with apical periodontitis, resorption of tooth apical structures can lead to difficulties to obtain an appropriate WL. The aim was to compare the capacity of three EAL's (Root ZX II, Raypex 6 and Endo-Eze Quill) to locate the tip of the K-file between 0 to -0.5 mm from the apical foramen (AF) on teeth diagnosed with asymptomatic apical periodontitis (AAP). Electronic working length was performed on 60 roots with AAP. A K-file #15 was inserted in the root canal until the apical foramen (AF) was located, and followed was re-adjusted to -0.5 mm through observation in EAL display. The K-file was fixed to the tooth with composite and teeth were extracted. The 4 apical millimeters were worn out until the K-file could be seen and were prepared and measured its distance to AF in a scanning electron microscope. Appropriate WL was when the tip of the K-file was located between 0 to -0.5 mm from AF. Results: Root ZX II showed significant difference (p<0.01) with the other two EALs. Root ZX II presented the better performance than Raypex 6 or Endo-Eze Quill in teeth with AAP.

Resumo Os localizadores eletrônicos apicais têm sido usados ​​para estabelecer o comprimento de trabalho no tratamento do canal radicular. Nos dentes diagnosticados com periodontite apical, a reabsorção das estruturas apicais dos dentes pode levar a dificuldades na obtenção de uma odontometria apropriada. Este estudo comparou três localizadores apicais (Root ZX II, Raypex 6 e Endo-Eze Quill) para localizar a ponta do instrumento K-file entre 0 a -0,5 mm do forame apical em dentes com diagnóstico de periodontite apical assintomática. O comprimento de trabalho eletrônico foi realizado em 60 dentes com periodontite apical assintomática. Uma lima K-file de número 15 foi inserida no canal radicular até a localização do forame apical, e seguida foi reajustada para -0,5 mm por meio de observação no visor do localizador eletrônico apical. A lima K-file foi fixada ao dente usando compósito, e a seguir os dentes foram extraídos. Os 4 milímetros apicais foram desgastados até que a lima K-file pudesse ser visualizada para as medidas de distância no forame apical por meio de microscópio eletrônico de varredura. O comprimento de trabalho apropriado foi determinado quando a ponta do instrumento estivesse localizada entre 0 a -0,5 mm do forame apical. O Root ZX II apresentou o melhor desempenho (p<0,01) que o Raypex 6 ou Endo-Eze Quill em dentes humanos com periodontite apical assintomática.

Longitud de trabajo electrónica con Raypex 6 en conductos de molares inferiores / Electronic work length with Raypex 6 in lower molars canals

Resumen: Objetivo: Evaluar la precisión de Raypex 6 para localizar el foramen y ubicarse en la zona cemento dentina conducto (CDC) en conductos de molares inferiores por medio de diafanización. Material y métodos: 52 conductos permeables de 20 molares inferiores extraídos inmersos en alginato fueron utilizados. Se realizó abertura coronaria, localización, permeabilización e irrigación con hipoclorito de sodio al 5.25%. Con el localizador electrónico Raypex 6 se obtuvo conductometría electrónica. Se introdujo lima tipo K #15 o 20 en cada muestra que tenía el clip labial inserto en alginato. La pantalla del dispositivo indicó la posición del foramen apical en la barra roja y se procedió a reajustar la posición de la lima K en las dos primeras barras amarillas y la lima se fijó con resina acrílica. Los dientes se diafanizaron por medio de la técnica de ácido nítrico y se mantuvieron en salicilato de metilo. Las muestras se analizaron con microscopio clínico a 16x y de manera subjetiva se asignó el valor de preciso, si la punta de la lima se ubicó entre 0 a -0.5 mm, fuera o positivo (+) si la lima estuvo +0.1 mm o más y corto o negativo (-) si fue de -0.51 mm o menos con respecto al foramen apical. Resultados: De las 52 muestras analizadas, se encontraron 40 precisas, siete largas y cinco cortas. La estadística descriptiva demostró 76.9% de precisión. Conclusión: La longitud de trabajo electrónica con Raypex 6 mostró una adecuada precisión en conductos mesiales de molares inferiores.

Abstract: Objective: To assess precision of Raypex 6 to locate foramen and establish placement in the canal -dentin-cement (CDC) area in lower molar canals by means of diaphanization. Material and methods: 52 permeable canals from 20 extracted lower molars immersed in alginate were used. Crown opening, location, permeabilization and irrigation with 5.25% sodium hypochlorite were performed. Electronic conductometry was obtained with Raypex 6 electronic locator. A K #15/20 file type was inserted in all samples which had labial clip inserted in alginate. The device's screen indicated position of the apical foramen in the red bar, K files position was readjusted in the first two yellow bars, the file was then fixated with acrylic resin. Teeth were diaphanized by means of the nitric acid technique; teeth were kept in methyl salicylate. Samples were analyzed with clinical microscope at 16x, they were subjectively assigned a value called precise when the tip of the file was located at 0-0.5 mm, external or positive (+), when the file was +0.1 mm or more, and short or negative (-) when it was -0.51 mm or less with respect to the apical foramen. Results: Of the 52 analyzed samples, 40 were found to be precise, seven long and five short. Descriptive statistics showed 76.9% precision. Conclusion: Electronic working length with Raypex 6 showed suitable precision in mesial canals of lower molars.

Respuesta inflamatoria de Bioceramic a la implantación de tubos de dentina en tejido subcutáneo de ratas / Inflammatory response of Bioceramic material to dentin tube implantation in rats' subcutaneous tissue

El propósito fue evaluar la respuesta inflamatoria a la implantación del material Bioceramic en tejido subcutáneo de ratas. Se utilizaron nueve ratas machos Wistar (Rattus norvegicus) a las que les implantaron cuatro tubos de dentina rellenos con cemento sellador Bioceramic y un tubo vacío como grupo control. Se analizaron en tres periodos de tiempo (96 horas, 10 y 21 días). Los animales fueron sacrificados por sobredosis y las muestras obtenidas se procesaron mediante tinción con hematoxilina y eosina para ser analizadas microscópicamente. Los resultados mostraron a las 96 horas inflamación moderada en 75% y severa en 25%. 10 días después disminuyó la inflamación de moderada (67%) a severa (25%). En el periodo final de 21 días se observó inflamación moderada a leve (50%). Se concluye que existió inflamación de moderada a severa en los periodos iniciales, disminuyó a leve en el último periodo. Bioceramic presenta una aceptable respuesta biológica en tejido subcutáneo de ratas.

The aim of the present article was to assess inflammatory response caused by implantation of Bioceramic material in rats' subcutaneous tissue. Nine male Wistar rats were used (Rattus Norvegicus) to which four dentin tubes filled with Bioceramic sealing cement material and one empty tube (control group) were implanted. Results were analyzed in three time periods (96 hours, 10 and 21 days). Animals were sacrificed by anesthetic overdose. Obtained samples were processed by hematoxylin and eosin staining in order to be analyzed with microscope. Results after 96 hours revealed moderate inflammation in 75% of all cases and severe inflammation in 25% of all cases. Ten days later, inflammation decreased from moderate (67%) to mild (25%). At the final period of 21 days, moderate to mild inflammation was observed (50%). It was concluded that there was presence of moderate to severe inflammation at initial periods which decreased to mild inflammation at the final period. «Bioceramic¼ brand material exhibits acceptable biological response in rats' subcutaneous tissues.

Accuracy of Root ZX mini and Raypex 6 in locating the apical foramen of molars: radiographic and microscopic evaluation

Introduction: The precise localization of the apical foramen and the odontometry determination is an important stage since it locates the apical limit for instrumentation and filling. Objective: To compare the accuracy of Root-ZX Mini and Raypex 6 in locating apical foramen in extracted molars. Material and methods: 80 mesial and buccal canals from 40 mandibular and maxillary human molars were used. A size #15 K-file was introduced to canal, until the locator indicated the apical foramen (red bar/line in both devices). With the file in position, it was re-adjusted for Root-ZX II Mini on the green bar and on the two yellow bars for Raypex 6. All the samples were measured from the tip of the file to the apical foramen with radiovisiograph and the Sidexis software. The apical third of the root was shaved until exposure of the file. The distance from the file tip to the most coronal border of the apical foramen was obtained and it was measured with a clinical microscope at 16-fold magnification. The measured lengths with the radiovisiograph and the clinical microscope were analyzed with the statistical Student's T-test. Results: The average length from the tip of the file to the apical foramen using Root-ZX Mini was 0.695 mm and 0.543 mm with Raypex 6. There was no significant difference. Conclusion: Two devices were accurate in locating apical foramen with an adequate level of reliability.

Tratamento do canal radicular por meio de condutimetria sem radiografia transoperatória: relato de cinco casos / Root canal treatment by means of electronic conductometry without radiographic trans-operative verification: a report of five cases

Introdução: estabelecer o comprimento de trabalho durante o tratamento do canal radicular e muito importante, uma vez que permite que os procedimentos clínicos sejam realizados respeitando os limites do canal. Objetivo: o objetivo deste artigo e relatar cinco casos nos quais o tratamento do canal radicular foi realizado por meio de um método eletrônico sem radiografia transoperatória. Métodos: trés molares superiores e dois molares inferiores foram diagnosticados com pulpite irreversível ou necrose pulpar. Os casos foram tratados na Clinica de Endodontia do Hospital Militar Regional de Guadalajara, México, mediante assinatura de consentimento livre e esclarecido, por parte dos pacientes. O comprimento de trabalho do canal radicular foi determinado com a ajuda de um localizador apical Raypex 6 sem tomada radiográfica. Todos os canais radiculares foram preparados por meio do sistema de instrumentação Reciproc e obturados por meio da técnica hibrida de Tagger. Resultados: no controle radiográfico pós-operatório, observou-se que o nível de preenchimento do canal radicular, em 12 dos 14 canais, foi de 0 a 2 mm do ápice apical. Conclusão: os resultados do presente estudo sugerem que condutimetria e um método confiável para determinar o comprimento de trabalho, alem de reduzir o numero de tomadas radiográficas durante o tratamento do canal radicular.