The effects of file size, sodium hypochlorite and blood on the accuracy of Root ZX apex locator in enlarged root canals: an in vitro study

Abstract

Background:The initial electronic apex locator (EAL) length measurement is generally established with a small-sized file. It is not known whether file size would be interfering with the reading accuracy of the EAL. This study aimed to evaluate the effect of file size on the accuracy of Root ZX apex locator using an agar model when sodium hypochlorite solution or blood was present during electronic measurements in enlarged root canals. Methods: A total of 36 extracted lower premolars were used. In stage 1, the canals were instrumented using size 10-40 K-files with a size 40 K-file as the master apical file (MAF). The teeth were then divided randomly into two groups of 18 teeth each. In group A, the teeth were mounted in one per cent agar and irrigated with six per cent sodium hypochlorite solution (NaOCl), while in group B the teeth were mounted in agar and irrigated with human blood. In stage 2, the canals were enlarged using a size 60 K-file as the MAF. In stages 1 and 2, the apical portions of the canals were instrumented using the step-back sequence (up to a size 80 K-file). In stage 3, the canals were enlarged using a size 80 K-file as the MAF. In each stage, the length was measured with a Root ZX until the meter value reached 'APEX' using small and large size files. Results: Three-way ANOVA and Bonferroni test showed that file size, stage of preparation and type of irrigant all had a significant influence on the measurement error (P<0.0001), with all the interactions between these three factors being significant (P<0.0001). Conclusions:As the diameter of the root canal increased, the measured length with the smaller size files became shorter. A file of a size close to the prepared canal diameter should be used for root length measurement in the presence of blood. In the presence of NaOCl, the Root ZX was highly accurate even when the file was much smaller than the diameter of the canal. The agar model was effective and suitable for testing EALs in vitro.Key words: Agar, blood, electronic apex locator, file size, root length determination, root canal preparation, sodium hypochlorite.Abbreviations and acronyms: EAL = electronic apex locator; MAF = master apical file; NaOCl = sodium hypochlorite solution.

Farklı preparasyon genişliklerinde iki elektronik apeks bulucu cihazın doğruluğunun değerlendirilmesi

“…14,15 Diğer çalışmalarda ise klinik olarak kabul edilebilir olan ±1.0 mm tolerans aralığı kullanıl-mıştır. 4 Biz de çalışmamızda apikalde preparasyon yapıldığından ve dişlerin farklı apikal daralım şekillerine sahip olabileceğinden ±1.0 mm hata payını kabul ettik.…”

“…Ebrahim ve ark. 4 sırasıyla 40, 60 ve 80 numaraya kadar genişletilmiş kök kanallarında Root ZX EAB cihazın doğruluğunu incelemişlerdir. Kök kanal çapının arttığında küçük eğe kullanımının daha kısa ölçümlere yol açabildiğini bildirmişlerdir.…”

“…Bu cihazlar kanal eğesine bağlanarak eğenin ucunun kök kanalını terk edip periodonsiyuma giriş yaptığı noktayı belirlemek amacı ile kullanılmakta-dır. 4 EAB'ler insan dokusundaki karakteristik elektriksel özellikleri kullanarak apikal daralımı tespit eder. 5 Ça-lışma boyutu tespitinde EAB cihazların kullanımı radyografik yöntem gibi diğer yöntemlere göre daha güvenilir sonuçlar verebilmektedir.…”

“…6,7 EAB cihazlar, ölçümleri apikal uç yerine apikal foramene göre gerçekleştirdiğinden bu problem ortadan kalkmıştır. 4 EAB cihazlar minör çap bölgesini bulabilmek için kullanılır. 1 Mikroskopik çalış-malar apikal daralım bölgesinin major foramenden 0.5-1 mm mesafede yer aldığını göstermiştir.…”

Influence of Blood on the Accuracy of Raypex 5 and Root ZX Electronic Foramen Locators: An In Vivo Study

“…The presence of blood within the root canal as an electrolyte material may also influence the accuracy of EFLs. To date, there have been few and controversial in vitro studies on the effect of the presence or absence of blood within the root canal on the accuracy of EFLs (15)(16)(17). However, there are no in vivo studies on this issue.…”