Thursday, June 1, 2023

If the initial working length film shows the tip of a file to be greater than 1 mm from the ideal location, the clinician should.. Correct the length and begin instrumentation



the ideal location

If the initial working length film shows the tip of a file to be greater than 1 mm from the ideal location, the clinician should:


  • a. Correct the length and begin instrumentation.
  • b. Move the file to 1 mm short of the ideal length and expose a film.
  • c. Interpolate the variance, correct the position of the stop to this distance, and expose the film.
  • d. Confirm the working length with an apex locator.
  • e. Position the file at the root apex and expose a film.

What tool is used to electronically measure the length of the canal of a tooth?

An electronic apex locator is an electronic device used in endodontics to determine the position of the apical constriction and thus determine the length of the root canal space.

What is working length in root resorption?

According to Weine's recommendations, the working length should be 1, 1.5 or 2 mm short of the radiographic terminus depending upon the periapical status and alveolar bone surrounding the tooth.

What is the working length of apical resorption?

This position is used as the new radiograph apex, and the working length is established 1 to 2 mm coronal to that point. In cases of extensive irregular apical resorption, the new working length can conceivably be 5 mm or more coronal from the original root apex.

Why is it important for the dentist to accurately measure the length of each root canal?

Inaccurate determination of working length may lead to short or overextended obturation. Short working length may result in retained necrotic tissues in apical area and overextended working length may result in over-instrumentation and over-obturation.


How is the length of the root canals measured describe the process?

tooth: (1) an X-ray is taken with a measuring wire inserted into the canal, and then the length of the root canal is estimated by establishing a ratio between the length of the tooth over the length of wire inserted with the lengths found on the film.

How does the dentist confirm that the measurements for canal length are correct?

The odontometer helps in accurately determining the root canal length through perception of an auditory tone thus eliminating the drawbacks of the earlier methods used for measuring the length of the involved root canal.

Which instrument is used to estimate the working length in a root canal therapy?

The use of apex locator has gained a lot of attention while determining working length of canals during endodontic treatment. [18] In the present study, Propex (Dentsply Maillefer, Switzerland) apex locator was used, which is a multi-frequency based apex locator to determine root canal length.

Where should the working length end?

The working length (WL) is the length from a coronal reference point to the apical limit of the preparation. The optimal end point for root canal preparation and obturation is to the apical constriction.

Why is working length important?

Accurate determination of working length prevents UNDER INSTRUMENTATION that could leave tissues and debris in the apical segment, or OVER INSTRUMENTATION which could cause patient discomfort, damage periapical tissue, or potentially cause an infection or cyst development from the placement of irritating materials

What is the purpose of the working length radiograph?

The desired "working length" for the biomechanical preparation and resultant obturation of the root canal system is one of the most important phases of endodontics. Traditionally, radiographs are used to confirm working length of the root length and to evaluate the subsequent obturation of the root canal system.

What causes loss of working length?

Loss of working length has several causes. These include failure to have an adequate reference point from which the corrected working length is determined, packing tissue and debris in the apical portion of the canal, ledge formation, and inaccurate measurements.

What is the accuracy of working length measured by apex locator and digital radiography?

Pearson chisquare test was applied to compare the apex locator and digital radiographic measurement with actual working length. RESULTS: The Root ZX® apex locator was 95% accurate to identify the apical constriction as compared 70% accuracy given by radiographs within 0.5 mm of the apex.

What is the working length of lower 1st molar?

Study revealed that average length of upper 1st molar is 20.62mm and for lower 1st molar is 20.28mm; the range of length for upper 1st molar is 17.16mm - 25.33mm and for lower 16mm - 24mm. The study also revealed that the tooth length has no significance on the sex of the people of same race.

What file is used to determine working length?

Working length was determined by tactile method, by using Ingle's radiographic method and by using a Foramatron-IV digital apex locator. The teeth were then extracted and the actual working length was determined by placing an endodontic file in the root canal 0.5 mm short of the apex.

What is the clinical significance of working length determination?

Working length determination is the second step in Root canal Treatment procedure after Access Cavity preparation. It is very important because the objective of Root Canal Treatment cannot be achieved with the working length being determined.

What is the best way to determine working length?

Radiographic technique:

The traditional way of determining working length is by taking radiographs with files in the canals. Where canals overlap, as in the mesial canals of lower molars, the radiograph can be taken with an increased horizontal angulation to separate the canals.

What is initial working length?

Working length is defined in the endodontic glossary as the distance from a coronal reference point to the point at which canal preparation and obturation should terminate.