Journal of Dental Specialities
  • Year: 2016
  • Volume: 4
  • Issue: 1

Accuracy of different methods to determine working length in teeth with open apex-an ex-vivo comparative study

1Senior Resident, Centre for Dental Education and Research, All India Institute of Medical Sciences, New Delhi, India

2Assistant Professor, Department of Conservative Dentistry and Endodontics, Sinhgad Dental College & Hospital, Pune, Maharashta, India

3Associate Professor, Centre for Dental Education and Research, All India Institute of Medical Sciences, New Delhi, India

*Address for Correspondence: Ajay Logani, Associate Professor, Department of Conservative Dentistry and Endodontics, Centre for Dental Education and Research, All India Institute of Medical Sciences, New Delhi, INDIA. E-mail: apexlogani@yahoo.co.in

Online published on 20 September, 2016.

Abstract

Teeth with open apices present difficulty in estimation of working length because of extensive apical resorption and thin dentinal walls coupled with long-standing infection.

To comparatively evaluate the accuracy of a 6th generation apex locator, digital radiograph, paper point and tactile technique for their ability to determine the working length in teeth with open apices.

Forty single-rooted maxillary anterior teeth were selected after excluding the teeth with curved roots. To simulate immature open apices, the apical 3–5 mm of the roots were removed such that ISO #80 file passed through the canal without any hindrance. The differences between dentinal-wall lengths in the same root was created using fine diamond round burs. Based on the method used to determine the working length, teeth were divided into five study groups and one control group as follows-Group I-radiographic measurement using paralleling technique, Group II-electronic working length measurement using Raypex 6 apex locator, Group III-tactile working length, Group IV-paper point working length and Group V-combination of apex locator, tactile and paper point techniques. In control group, actual working length was determined using direct observation of apical exit of file at shortest distance under dental operating microscope. Accuracy of all the methods to determine the working length was compared with the control group. The data was compiled and subjected to statistical tests and results were compiled.

Within ±0.5 mm, combined electronic, tactile and paper point working length (CETPPWL) method showed 99.5% of accuracy. Radiographic working length (RWL) using paralleling technique gave the least accurate result (around 78%) (n=40 for all groups).

In teeth with open apices working length determination is a challenge. No single method is accurate. Combination of use of apex locator, tactile and paper point method is recommended.

Keywords

Open Apex, Working Length, Electronic Working Length, Tactile Working Length, Paper Point Technique