Although the available scientific evidence base is short and at considerable risk of bias , it is still possible to conclude that the apical locator reduces the patient radiation exposure and also that the electronic method may perform better on the working length determination .
INTRODUCTION Apical constriction has been proposed as the most appropriate apical limit for the endodontic working length .
Despite being the most used , some limitations are attributed to the radiographic method of working length determination .
It lacks precision because it is based on the average position of the apical constriction .
The electronic apex locators have been presented as an alternative to the odontometry performed by radiography .
These devices detect the transition of the pulp to the periodontal tissue , which is anatomically very close to the apical constriction and may perform with improved accuracy .
Comparison between two methods of working length determination and its effect on radiographic extent of root canal filling: a clinical study [ISRCTN71486641]
Background Obtaining a correct working length is critical to the success of endodontic therapy . Different methods have been used to identify this crucial measurement . The Aim of this clinical study was to compare the effect of working length determination using apex locator alone or in combination with working length radiograph on the apical extent of root canal filling . Methods A total number of 66 patients , 151 canals were r and omized into two groups , In group ( I ) working length was determined by apex locator alone , while in group ( II ) working length was determined by apex locator confirmed by working length radiograph , length of obturation was assessed , and the total number of radiographs was recorded . The data were analyzed using SAS system and T. tests were carried out . Statistical significance was considered to be P ≤ 0.05 . Results Sixty seven canals in group I were treated with a mean distance from the tip of root canal filling to radiographic apex -0.5 mm ± 0.5 and a mean of a total number of radiographs of 2.0 , while in group II eighty four canals were treated with a mean distance from the tip of root canal filling to radiographic apex -0.4 mm ± 0.5 and a mean of a total number of radiographs of 3.2 . There was no statistically significant difference in the mean distance from the tip of root filling to radiographic apex between group I and group II ( P > 0.05 ) . Conclusion The practice of using electronic apex locator in the determination of working length is useful and reliable with no statistical difference of the radiographic extent of root canal filling when using apex locator alone or in combination with working length radiograph . Under the clinical conditions of this study , it is suggested that the correct use of an apex locator alone could prevent the need for further diagnostic radiographs for determination of working length . This method can be useful in patients who need not to be exposed to repeated radiation because of mental , medical or oral conditions
Although the available scientific evidence base is short and at considerable risk of bias , it is still possible to conclude that the apical locator reduces the patient radiation exposure and also that the electronic method may perform better on the working length determination .
INTRODUCTION Apical constriction has been proposed as the most appropriate apical limit for the endodontic working length .
Despite being the most used , some limitations are attributed to the radiographic method of working length determination .
It lacks precision because it is based on the average position of the apical constriction .
The electronic apex locators have been presented as an alternative to the odontometry performed by radiography .
These devices detect the transition of the pulp to the periodontal tissue , which is anatomically very close to the apical constriction and may perform with improved accuracy .