RAJIVGADNDHIUNIVERSITY OF HEALTH SCIENCES,

BANGALORE, KARNATAKA.

ANNEXURE II

PROFORMA FOR REGISTRATION OF SUBJECTS FOR DISSERTATION

1. / NAME OF THE CANDIDATE
AND ADDRESS (IN BLOCK LETTERS) / DR. AKSHATA.KULKARNI
BANGALORE INSTITUTE OF DENTAL SCIECES AND HOSPITAL AND POST GRADUATE RESEARCH CENTRE,
5/3, HOSUR ROAD,
BANGALORE-560029
2. / NAME OF THE INSTITUTION / BANGALORE INSTITUTE OF DENTAL SCIECES AND HOSPITAL AND POST GRADUATE RESEARCH CENTRE,
5/3, HOSUR ROAD,
BANGALORE-560029
3. / COURSE OF STUDY AND SUBJECT / MASTER OF DENTAL SURGERY IN CONSERVATIVE DENTISTRY AND ENDODONTICS.
4. / DATE OF ADMISSION / 02/06/2008
5. / TITLE OF THE TOPIC / Comparative evaluation of the accuracy of three third generation electronic apex locators and conventional radiography to determine working length-an in vitrostudy.
6. / BRIEF RESUME OF THE WORK:
6.1 NEED FOR STUDY:
Correct working length determination is the main factor leading to success in root canal treatments. Studies have shown histological results after endodontic treatment to be superior when instrumentation and root canal filling are limited to apical narrowing.1
A variety of apex locator are now available in the market, working on different principles and classified as resistance based, impedance based and frequency based. These devices should be validated for accuracy and reliability in vitro before application in-vivo.2,5
Many studies report on the accuracy achieved by new generation of apex locators as well as their extended measurement capabilities, which include accurate measurements in presence of electrolytes and irrigants like saline, hydrogen peroxide and sodium hypochlorite as well as pus and necrotic tissue.3
Electronic apex locators using two frequencies, like the third generation which report accuracy rates of 85% to 95% are being used to greater extent nowadays. They rely on the ratio of two electrical impedances between an electrode in contact with oral mucosa and one passed through the root canal in contact with the periodontal ligament. As Propex 2, Sybron mini apex locator and I-Pex apex locators are based on this principle, this present study is designed to compare these three electronic apex locators with conventional radiography method.3,4
6.2 REVIEW OF LITERATURE:
1. This study was done to compare the accuracy of two apex locators,in locating the apical foramen and concluded that they were more accurate compared to conventional radiography.
2. This study was done to describe and evaluate a newly developed model for demonstrating and teaching the use of electronic apex locators to demonstrate electronic working length measurement.
3.This study was done to test in an in-vitro model the accuracy of two apex locators to compare the results to those of radiographic method of tooth length determination. Under experimental conditions, electronic measurements were more reliable than radiographs in the process of root length determination.
4. The purpose of this study was to investigate whether the use of electronic apex locator as an adjunct to the radiographic determination of working length could potentially result in reduction of x-ray exposure to patients during endodontic therapy.
The results suggested that electronic apex locators potentially decrease the radiation exposure to the patient by minimising the number of additional radiographs required during endodontic treatment. However they should only be used as adjuncts along with conventional radiographs.
5.The study was to describe and evaluate a newly developed model for its application in research and test for accuracy of two apex locators. Also, the effects of storage time of this model in 100% humidity on the apex locator readings werestudied. It was concluded that a simple inexpensive model can be manufactured using acrylic resin, natural teeth and alginate impression material.
6.3 OBJECTIVES OF THE STUDY:
The aim of the study is to compare third generation apex locators with conventional radiography.
7. / MATERIALS AND METHODS:
7.1 SOURCE OF DATA:
60 freshly extracted, straight, single rooted human maxillary anterior teeth with complete apex formation will be collected.
Inclusion criteria:
-straight canals
-teeth with closed apices
-single rooted teeth
Exclusion criteria:
-curved canals
-teeth with open apices
-carious teeth
-fractured teeth
-calcified teeth
7.2 METHODS OF COLLECTING THE DATA :
60 single rooted permanent human maxillary pre-molars will be used in this study. The teeth collected will be stored in 2.5%sodium hypochlorite for 6hrs and then stored in 0.9% saline until used.
The crown will be sectioned with diamond to allow access to root canal and establish a surface to serve as a stable reference for all measurements. Gates Glidden burs #5 & #6 will be used to flare the coronal one-third of each canal and irrigated with sterile saline and the patency of the apical foramen will be verified using #20 Flexofile.
The teeth will be divided in 4 groups, each containing 10 teeth.
Group Ι – Working length measured using Propex-2
Group ΙΙ – Working length measured using Sybron mini apex locator
Group ΙΙΙ – Working length measured using I-Pex apex locator.
Group ΙV – Working length measured using conventional radiography.
Electronic measurement will be achieved by using propex-2, Sybron mini apex locator and I-Pex.The teeth will be placed in contact with a conducting gel that consists of alginate to simulate the periodontium.The teeth will be kept in position until the alginate sets completely. All measurements will be made in an interval of 2hrs with the gel kept sufficiently humid.
Measurements will be taken after 2ml irrigation with 2.5% sodium hypochlorite into the root canals and dried with cotton tips to eliminate the excess irrigating solution. When the signal reaches 0.0mark (apical foramen) the measurement will be noted. The Flexofile will be placed in the canal while attached to the electrode of the apex locator and the other electrode will be attached to conductive gel and will be operated according to manufacturers instructions.
The electronic length will be measured by adjusting the silicone stop and the file will be measured with a caliper.The actual root length will be measured by inserting #20file into the root canal until the file tip is visible at the level of apical foramen and will be magnified under a magnification of 5x.
The silicone rubber stop will be adjusted at the coronal reference and then the file will be removed from the canal. The difference between file tip and the stopper representing the actual root canal length will be measured to the nearest tenth of a millimetre.
The results obtained will be recorded in independent tables. In each case we will subtract the corresponding reference measurement from the electronically determined distance, recording the result in tabular form as positive (measurement exceeding the foramen), negative (measurement short of apical foramen) &correct (measurement coinciding with actual length) witha 0.5mm acceptable range.
Values will be recorded and subsequently examined with paired t’ test to analyse the significance of mean difference between electronic length and actual length.
7.3 Does the study require any investigations or interventions to be conducted on patients or other humans or animals? If so, please describe briefly.
Not applicable.
7.4 Has ethical clearance been obtained from your institution in case of 7.3?
Not applicable.
8. / LIST OF REFERENCES:
1. Fabio luiz cunha d’ assuncao, Diana Santana de Albuquerque, Linalda correia de queiroz Ferreir-The ability of two apex locators to locate the apical foramen: an in vitro study. Journal of Endodontics2006;32:560-62
2. Tinaz.A.C, Alacam.T, Topuz.O-A simple model to demonstrate the electronic apex locator.
International Endodontic journal 2002 ; 35:940-945
3.Kaufman.A.Y, Keila.S, Yoshpe.M-Accuracy of a new apex locator: an invitro study.
International endodontic Journal2002; 35:186-192
4. Abdeen, Dilshan; MacFarlane, Tatiana V. – Effect of an apex locator on exposure to radiation during endodontic therapy.
Journal of Endodontics 2002; 28(7):524-26
  1. Kumar.S.S,Chacko.Y,Lakshminarayanan.L – A simple model to demonstrate the working of electronic apex locators
Journal of endodontology;2004;16;50-53
9. / SIGNATURE OF THE CANDIDATE / (Dr. Akshata Kulkarni)
10. / REMARKS OF THE GUIDE / This is a genuine study to be done under my supervision.
11. / NAME AND DESIGNATION OF(IN BLOCK LETTERS)
11.1 GUIDE / Dr. RAMYA RAGHU, MDS
PROFESSOR AND H.O.D
DEPARTMENT OF CONSERVATIVE DENTISTRY AND ENDODONTICS,
BANGALORE INSTIUTE OF DENTAL SCIENCES & HOSPITAL,
BANGALORE-29
11.2SIGNATURE
11.3 HEAD OF THE
DEPARTMENT
11.4 SIGNATURE / Dr. RAMYA RAGHU, MDS
PROFESSOR AND H.O.D
DEPARTMENT OF CONSERVATIVE DENTISTRY AND ENDODONTICS,
BANGALORE INSTIUTE OF DENTAL SCIENCES & HOSPITAL,
BANGALORE-29
12. / 12.1 REMARKS OF CHAIRMAN AND PRINCIPAL
12.2 SIGNATURE