RAJIV GANDHI UNIVERSITY OF HEALTH
SCIENCES,BANGALORE
KARNATAKA
ANNEXURE-II
PROFORMA FOR REGISTRATION OF SUBJECTS FOR DISSERTATION
1
2
3
4
5
NAME OF THE CANDIDATE AND
ADDRESS
Dr. GOURAV KUMAR SAHU
POST GRADUATE STUDENT,
DEPARTMENT OF CONSERVATIVE
DENTISTRY AND ENDODONTIA
RAJARAJESWARI DENTAL
COLLEGE &HOSPITAL,
BANGALORE-560074,
KARNATAKA
NAME OF THE INSTITUTION RAJARAJESWARI DENTAL
COLLEGE &
HOSPITAL,BANGALORE-560074
KARNATAKA
COURSE OF STUDY AND
MASTER OF DENTAL SURGERY IN
SUBJECT
CONSERVATIVE DENTISTRY AND
ENDODONTICS
DATE OF ADMISSION TO
31-05-2013
THE COLLEGE
TITLE OF THE TOPIC
INCIDENCE OF ROOT
MICROCRACKS AFTER ROOT
CANAL TREATMENT WITH
DIFFERENT CROSS SECTION OF
ROTARY FILES-AN INVITRO
STUDY
6. BRIEF RESUME OF THE INTENDED WORK:
6.1 NEED FOR STUDY:
The primary aim of chemo mechanical root canal preparation include the
preservation of the original course of the canal & cleaning of the entire root canal system.One
common complication associated with mechanical canal preparation is vertical root
fracture(VRF),which usually leads to tooth loss1.During The root fracture the stress generated
from inside the root canal while root canal preparation are transmitted through the root to the
surface where they might overcome the bonds holding the dentine together2.The strength of the
root filled tooth is directly related to amount of remaining sound tooth structure3. Canal
preparation which involves removal of dentine and may compromise the fracture strength of the
root, was found to have a significant effect on the incidence of incomplete apical cracks and
dentinal defects 4.
There are Several factors which may be responsible for the formation of dentin cracks.
High concentration of sodium hypochlorite could weaken the root canal wall. Compaction
technique in root canal filling, especially lateral compaction ,includes more dentin cracks than noncompaction techniques. Different root canal shaping procedures with different cutting blades, taper
and tip configuration are also responsible5.Various nickel-titanium instruments with different
designs have been introduced, but the use of probably all of them results in dental defects like
incomplete cracks or even VRF6.The dentinal cracks caused by NiTi instruments may have the
potential to develop into fractures7. Cracks after canal instrumentation were detected either in
horizontal sections cut at different levels along roots or at the apical root surface8.
Introduction of rotary system has revolutionised the field of endodontics, there are more
than 30-40 different Nickel-Titanium system available with different design, different
manufacturing process. Studies have been done to know incidence of root micro cracks using hand
and rotary files9, with single file system and multiple file system10 and with reciprocating and rotary
instruments11 but no studies have been done on different cross section of NiTi rotary files which
may induce root microcracks.
The purpose of the study is to compare the incidence of root micro cracks observed at the
apical root surface and/or in the canal wall after root canal instrumentation with 5 multiple file
system of different cross section of NiTi rotary files.
6.2 REVIEW OF LITERATURE:
 An in vitro study was done to detect the dentinal microcracks using infrared
thermography(vibrothermography-VibroIR). The study concluded that VibroIR
may be an effective method for the diagnosis of root dentinal microcracks12.
 An in vitro study was done to compare the incidence of apical root cracks and
apical dentinal detachments after canal preparation with hand(NiTi k flex) and
rotary files(k3,protaper) at different instrumentation lengths. The study
concluded that rotary instruments caused more dentinal defects than hand
instruments;instrumentation short of apical foramen reduced the risk of dentinal
defects.9
 An ex vivo study was done to observe the effect of self adjusting files, ProTaper
and Mtwo on the root canal wall after root canal preparation. The study
concluded that instrumentation of root canals with SAF,Mtwo,and ProTaper
could cause damage to root canal dentin.SAF has a tendency to cause less
dentinal cracks as compared with ProTaper or Mtwo.5
 Previous researches done an in vitro study to evaluate the incidence of dentinal
defects after root canal preparation with reciprocating instruments(reciproc and
waveone) and rotary instruments and observed after sectioned horizontally at
3,6,9 mm from the apex and evaluated under microscope. The study concluded
that reciprocating files produced significantly more incomplete dentinal cracks
than full sequence rotary systems.11
 An ex vivo study was done to evaluate the potential effects of endodontic
procedures (instrumentation & filling) on crack initiation and propagation in
apical dentine. The study concluded that root canal procedures can potentially
initiate and propagate cracks from within the root canal in the apical region. 2
 An in vitro study was done to compare the incidence of root micro cracks caused
by 3 different single-file system versus the ProTaper system,observed at the
apical root surface and/or in canal wall after canal instrumentation with 3 single
file systems viz: oneshape, reciproc, self adjusting file and the protaper system
observed under microscope. The study concluded that NiTi instruments may
cause cracks on the apical root surface or in the canal wall; the SAF and Reciproc
files causes less cracks than the ProTaper and OneShape files.10
 6.3 AIM OF THE STUDY:
1. To compare the incidence of root micro cracks observed at the apical root
surface and/or in the canal wall after canal instrumentation with 5 different
cross section of NiTi rotary files.
2. To compare the incidence of root microcracks observed at 2,4,6 mm from the
root apex.
 OBJECTIVE OF THE STUDY:
To compare the incidence of root microcracks at apical root surface caused by
5 different cross section of rotary files using stereomicroscope.
7. MATERIALS AND METHODS:
7.1 SOURCE OF DATA
Ninety extracted mandibular incisors with straight roots for the study will be
collected from patients referred to Department of Oral and MaxilloFacial
surgery,Dental campus conducted by dept of community dentistry, dental OPD
RajaRajeswari Dental college and hospital.
7.2 METHOD OF COLLECTION OF DATA:
The freshly extracted teeth will be collected and stored in 10% formalin until further
processing.
INCLUSION CITERIA:
1.
2.
3.
4.
Mandibular incisors with straight roots
Single canals
Non carious tooth
Tooth with completely formed apex.
EXCLUSION CRITERIA:
1. Mutilated teeth
2. Fractured teeth
3. Teeth with root resorption
MATERIALS:



















Endo access bur-no-1
Radiographs-IOPA
Purified filtered water
#1,#2 Gates Glidden Drills(Dentsply Maillefer)
Pro Taper(Dentsply Maillefer)
M Two(Sweden & Martin,Padova,Italy)
Pro Taper Next(Dentsply Maillefer)
K3XF(SybronEndo)
Pro File(Dentsply Maillefer)
SS Hand 10 k-file-(10-25) MANI
Aluminium foil
Acrylic resin
Hydrophilic vinyl polysiloxane impression materials
1% methylene blue solution
Stereomicroscope
Composite resin
2% Naocl solution
27-G needle
Low torque motor-XMart
METHODOLOGY:
 A total of 90 extracted mandibular cantral incisors with straight root canals
(<50) will be selected and divided into 6 groups. All the roots will be observed
with stereomicroscope under x20 magnification to exclude crack.
 Only single rooted teeth with single canal and single apical foramen (AF) will be
included. This will be verified by viewing their buccal and proximal radiographs.
Coronal access will be achieved by using diamond burs and the canals will be
controlled for apical patency with the size 15Kfile (VDW). The canal width near
the apex will be approximately compactable with size 20. This will be checked
with silver points sizes 15-25 (VDW).
 The crown will be removed 2mm above the proximal cemento enamel
junction. The distance between the coronal tip and the AF of each root will be
determined by inserting a size 10 file into the canal until the tip of the file will
be just visible at the AF.
 Each root will be wrapped with a single layer of aluminium foil and embedded
in acrylic resin set in an acrylic tube . The root will be then removed from the
tube and aluminium foil peeled off. A hydrophilic vinyl polysiloxane impression
materials that replaced the space created by the foil represented a simulated
periodontal ligaments and root will be immediately repositioned. The apical
3mm of the root will be exposed and immersed in water during
instrumentation (8-9)
 The cervical and the middle third of each canal other than the control group
will be flared with #2 and #1 GG Drills. Glide path will be created with stainless
steel K file till size 20.
 In group A 15 teeth will be enlarged with Mtwo rotary instrument till size (305%) rotating with speed 300 rpm.
 In group B 15 teeth will be enlarged with ProTaper rotary instrument till F3 size
(30-9%) rotating with speed 250-350 rpm.
 In group C 15 teeth will be enlarged with K3XF rotary instrument till size (306%) rotating with speed 450-500 rpm.
 In group D 15 teeth will be enlarged with ProTaper Next rotary instrument till
size (30-7%) rotating with speed 250-300 rpm.
 In group E 15 teeth will be enlarged with Pro File rotary instrument till size (306%) rotating with speed 200-300 rpm.
 In group F the coronal part of each 15 teeth will be flared with #2 GG drills that
no further instrumentation will be performed.
 Each of this above 5 groups, 15 canals will be enlarged. A total of 75 canals will
be prepared.
 Each Instrument will be replaced after preparing 4 canals only. Each canal will
be irrigated with 2 ml of a freshly prepared 2%NaOCl solution between the
uses of each instrument.
 The last group F (15 teeth) will be taken as a control group
After root canal preparation roots will be horizontally sectioned at 2, 4,
6 mm from the apex with low-speed saw under water cooling. All slices will be
observed under a digital stereomicroscope at x25 magnification by using light source
and photographs will be taken.
STATISTICAL ANALYSIS:
The chi-square test will be performed to compare the incidence of root micro cracks
between the experimental groups at a significance level of P< .05.
7.3 DOES THE STUDY REQUIRE ANY INVESTIGATION OR INTERVENTION TO BE
CONDUCTED ON PATIENTS OR OTHER HUMANS, ANIMALS?IF SO PLEASE DESCRIBE
BRIEFLY?
There is no need for investigation to be conducted on patients or animals.
7.4 HAS ETHICAL CLEARENCE BEEN OBTAINED FROM YOUR INSTITUTION IN CASE
OF 7.3?
Not applicable
8.LIST OF REFERENCES:
1. Tamse A,Fuss Z,lustig J.An evaluation of endodontically treated vertically
fractured teeth. J Endod 1999;25:506-8.
2. Adorno C.G, T.Yoshioka, P.Jindan, C.Kobayashi & H Suda The effect of
endodontic procedures on apical crack initiation and propagation ex vivo.
International Endodontic Journal 2013;46:763-768.
3. Zandbiglari T,Davids H,Schafer E (2006) Influence of instrument taper on the
resistance to fracture of endodontically treated roots. Oral Surgery, Oral
Medicine.Oral Pathology,Oral Radiology and Endodontics 101,126-31.
4. Adorno CG,Yoshioka T,Suda H The effect of root preparation technique
and instrumentation length on the development of apical root
cracks.Journal Of Endodontics 2009;35:389-92.
5. E.S.Hin, Min Kai Wu,P R Wesselink & H Shemesh: effects of self adjusting
files,Mtwo and ProTaper on the root canal wallJ Endod 2013;39:262-264.
6. Bier CA,Shemesh H,Tanomaru-Filoh M,et al.The ability of different nickel
titanium Rotary instruments to induce dental damage during canal
preparation. J Endod 2009;35: 236-8.
7. Tsesis I,Rosen E,Tamse A,et al. Diagnosis of vertical root fractures in
endodontically treated teeth based on clinical and radiographic indices: a
systematic review.J Endod 2010;36:1455-8.
8. Adorno CG,Yoshioka T,Suda H Crack initiation on the apical root surface
caused by three different nickel titanium rotary files at different working
lengths. J Endod 2011;37:522-5.
9. Rui Liu,A Kaiwar,H Shemesh,P R Wesselink, B Hou,Min kai Wu Incidence of
apical root cracks and apical dentinal detachments after canal preparation
with hand and rotary files with different instrumentation lengths.
J Endod 2013;39:129-132.
10.Rui Liu,Ben Xiang Hou,PR.Wesselink,MK Wu,H Shemesh: the incidence of
root microcracks caused by 3 different single file system versus the
protaper system. J Endod 2013;39:1054-56.
11.Sebastian Burklein,dr M dent,Polymnia Tsotsis,Prof Dr M Dent:incidence of
dentinal defects after root canal preparation:reciprocating versus Rotary
instruments. J Endod 2013;39:501-04.
12.M M Tokugawa,Miura,Y.Iwami,T.Sakagami,Y.Izumi,N Mori,M Hayashi,S
Imazato,F Takesige,S.Ebisu: detection of dentinal microcracks using infrared
thermography. J Endod 2013;39:88-91.
9
10
SIGNATURE OF CANDIDATE
REMARKS OF THE GUIDE
11
11.1 NAME AND DESIGNATION OF Dr. K.J.NANDA KISHORE,MDS
GUIDE
READER
DEPARTMENT OF CONSERVATIVE
DENTISTRY AND ENDODONTIA,
RAJARAJESWARI DENTAL COLLEGE AND
HOSPITAL,BANGALORE-560074
KARNATAKA.
11.2 SIGNATURE
11.3 NAME AND DESIGNATION OF Dr. MOHAMED.IDRIS,MDS
CO-GUIDE
PROFESSOR,
DEPARTMENT OF CONSERVATIVE
DENTISTRY AND ENDODONTIA,
RAJARAJESWARI DENTAL COLLEGE AND
HOSPITAL,BANGALORE-560074
KARNATAKA.
11.4 SIGNATURE
11.5 HEAD OF THE DEPARTMENT
12
11.6 SIGNATURE
12.1 REMARKS OF THE PRINCIPAL
12.2 SIGNATURE
Dr. GEETA I.B,MDS
PROFESSOR AND HEAD
DEPARTMENT OF CONSERVATIVE
DENTISTRY AND ENDODONTIA,
RAJARAJESWARI DENTAL COLLEGE AND
HOSPITAL,BANGALORE-560074
KARNATAKA.
Dr. SAVITA.S,MDS
PROFESSOR AND HEAD
DEPARTMENT OF PERIODONTICS,
RAJARAJESWARI DENTAL COLLEGE AND
HOSPITAL,BANGALORE-560074
KARNATAKA