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RAJIV GANDHI UNIVERSITY OF HEALTH SCIENCES
BANGALORE, KARNATAKA.
ANNEXURE II
PROFORMA FOR REGISTRATION OF SUBJECTS FOR DISSERTATION
1.
NAME OF THE CANDIDATE
AND
ADDRESS
(IN
Dr. KANAV JAIN
BLOCK POSTGRADUATE STUDENT,
DEPARTMENT
LETTERS)
OF
CONSERVATIVE
DENTISTRY AND ENDODONTICS,
COLLEGE OF DENTAL SCIENCES,
DAVANGERE – 577 004.
KARNATAKA.
2.
NAME OF THE INSTITUTION
COLLEGE OF DENTAL SCIENCES,
DAVANGERE – 577 004.
KARNATAKA.
3.
COURSE OF STUDY
MASTER
OF
DENTAL
AND SUBJECT
CONSERVATIVE DENTISTRY
SURGERY
IN
AND ENDODONTICS.
4.
DATE
OF
ADMISSION
TO 30/05/2012
COURSE
5.
TITLE OF THE DISSERTATION
“EVALUATION
FORMATION
OF
BY
PRECIPITATE
THE
CHEMICAL
INTERACTION OF SODIUM HYPOCHLORITE
WITH CHLORHEXIDINE AND ALEXIDINE AN IN VITRO STUDY.”
1
6.
BRIEF RESUME OF INTENDED WORK
6.1 Need for the study:
The ability to effectively clean the endodontic space is dependent on both
instrumentation and irrigation via chemo mechanical means.1 Commonly used irrigants are
sodium hypochlorite (NaOCl), chlorhexidine (CHX) and ethylenediamine tetraacetic acid
(EDTA). The irrigation regimen proposed is the use of 2.5% NaOCl during
instrumentation, and a final flush of canals is performed in the sequence of 17% EDTA,
2.5% NaOCl, and 2% CHX. However, the presence of NaOCl in the canals during
irrigation with CHX produces an orange-brown precipitate known as para-chloroaniline
(PCA). The precipitate occludes the dentinal tubules and may compromise the seal of the
obturated root canal.2 Further, PCA is possibly carcinogenic to humans (IARC Group 2B).3
Similar to CHX, Alexidine (ALX) is a bisbiguanide disinfectant that has been
previously used as a mouthwash solution and contact lens solution.4 To date, however, very
few studies have been conducted on the antimicrobial effects of ALX or its chemical
interaction with NaOCl as an endodontic irrigant.
Therefore the aim of the study was to determine, by assessment of color changes and
scanning electron microscopy, whether the chemical interaction of NaOCl with different
concentrations of CHX and ALX results in precipitate formation.
6.2 Review of literature:
An in vitro study was done to evaluate the effect of irrigating root canals with a
combination of NaOCl and CHX on root dentin and dentinal tubules by using the
environmental scanning electron microscope (ESEM) and a computer program (Photoshop
CS2). Forty-four extracted single-rooted human teeth were instrumented and irrigated with
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both NaOCl and CHX to produce a precipitate. Root canal surfaces were analyzed with
ESEM. The study concluded that the NaOCl/CHX precipitate tends to occlude the dentinal
tubules. Until this precipitate is studied further, caution should be exercised when irrigating
with NaOCl and CHX.5
An in vitro study was done to compare the combined use of NaOCl and CHX with
citric acid and CHX on dentinal permeability and precipitate formation. Thirty-four upper
anterior teeth were prepared and randomly divided into three equal groups as follows:
positive control group (PC), no irrigation; 15% citric acid + 2% CHX group (CA + CHX);
and 1% NaOCl + 2% CHX group (NaOCl + CHX). They were then scanned and analyzed
for the assessment of leakage in percentage. For scanning electron microscopy (SEM)
analysis, four teeth were taken. The study concluded that the combination of 1% NaOCl
and 2% CHX solutions results in the formation of a flocculate precipitate that acts as a
chemical smear layer reducing the dentinal permeability in the apical third.1
An in vitro study was done to evaluate the maximum thickness and chemical
composition of the precipitate formed between NaOCl and CHX and to evaluate
effectiveness of absolute alcohol to remove residual NaOCl and thereby prevent
the formation of the precipitate. Forty extracted single-rooted human teeth were prepared.
In the test group (Ts group), canals were irrigated with 17% EDTA and 2.5% NaOCl
followed by 2% CHX. In the absolute alcohol (Aba), saline (Sa), and distilled water (Dw)
groups, intermediate flushes of the same were used between the last two irrigants. Teeth
were sectioned longitudinally and subjected to stereomicroscopic examination. The study
concluded that the interaction between NaOCl and CHX resulted in an insoluble neutral
salt as a precipitate that can be prevented using absolute alcohol and minimized using
saline and distilled water as intermediate flushes.2
An in vitro study was done to determine by electrospray ionization mass
3
spectrometry (ESI-MS) and SEM whether the chemical interaction between ALX and
NaOCl results in PCA or precipitates. As control groups, 1% ALX, 0.5% PCA, and a
mixture of 2% CHX and 4% NaOCl were analyzed and ESI-MS was performed on 4
different concentrations of ALX (1%, 0.5%, 0.25%, and 0.125%) with 4% NaOCl to detect
the presence of PCA. This was observed by SEM and the color change in the reaction
solutions was also analyzed. The study concluded that the interaction of ALX and NaOCl
did not produce PCA or precipitates and the color of the reacted solution changed
transparent with decreasing ALX concentration.4
An in vitro study was done to determine if the formation of PCA can be avoided by
using an alternative irrigant following NaOCl but before CHX. Fifty-five single-rooted
teeth were prepared and randomly divided into three experimental and two control groups.
Group 1 was irrigated with saline followed by 2% CHX. Group 2 was irrigated with 50%
citric acid (CA) followed by 2% CHX. Group 3 was irrigated with 14% EDTA followed by
2% CHX. The chemical identity and quantification of the PCA in the formed precipitate
was determined using gas chromatography/mass spectrometry (GC/MS). The study
concluded that citric acid used as the intermittent irrigant had the least amount of PCA
formation in the canal system. Until the threshold required to cause biological damage in
humans is determined, the combination of NaOCl and CHX in root canal treatment should
be avoided.6
6.3 Aims and Objectives of the study:
To evaluate the formation of precipitate by the chemical interaction of sodium
hypochlorite with different concentrations of chlorhexidine and alexidine.
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7.
MATERIALS AND METHODS:
7.1 Source of Data :
An in vitro study will be conducted in 35 test tubes and 12 extracted single rooted
human mandibular premolar teeth collected from Department of Oral and Maxillofacial
Surgery, College of Dental Sciences, Davangere.
Inclusion criteria:
1. Teeth extracted due to periodontal or orthodontic reasons.
2. Teeth devoid of any developmental defects.
Exclusion criteria:
1. Carious teeth.
2. Teeth that have undergone restorative or endodontic treatment.
3. Fractured teeth.
4. Teeth with attrition, abrasion or erosion.
Materials and equipment :
1. Extracted human lower premolar teeth.
2. Test tubes.
3. Incubator.
4. Centrifugator (R8C lab centrifuge).
5. K files (Mani).
6. K 3 NiTi Rotary instruments (Sybron Endo).
7. Micro motor (NSK).
8. 25mm 30-guage needle.
9. Distilled water.
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10. Sodium Hypochlorite (Neelkanth Health Care ltd.).
11. Ethylene Diamine Tetra Acetic acid.
12. Chlorhexidine (Neelkanth Health Care ltd.).
13. Alexidine (Sigma Aldrich).
14. Glass rod.
15. Cutting disk.
16. Chisel.
17. Scanning electron microscope (Cambridge S360 SEM).
7.2 Method of Collecting Data (including sampling procedure if any):
Solutions of 4% NaOCl, 2% CHX, and 1% ALX will be prepared with distilled water.
NaOCl will be refrigerated to maintain the chloride ion activity. Seven test tubes will be
prepared random sampling method.
TUBE 1 - 2 ml of 2% CHX
TUBE 2 - 1ml of 0.2% CHX + 1ml of 4% NaOCl
TUBE 3 - 1 ml of 2% CHX + 1 ml of 4% NaOCl
TUBE 4 - 1 ml of 1% ALX + 1 ml of 4% NaOCl
TUBE 5 - 1 ml of 0.5% ALX + 1 ml of 4% NaOCl
TUBE 6 - 1 ml of 0.25% ALX + 1 ml of 4% NaOCl
TUBE 7 - 1 ml of 0.125% ALX + 1 ml of 4% NaOCl
All 7 solutions will be stirred with a glass rod and kept at 36.5 C with 95% humidity
for 2 weeks. Samples will be observed and recorded for the formation of precipitates or
colour changes in the reaction solutions every 15 minutes for the first 2 hours and until 2
6
weeks. This process will be repeated 5 times. To check for any precipitate, all 7 tested
solutions will be centrifuged at 1000 rpm for 10 minutes.
For additional conformation
The working length will be determined by using a #10 K-file, and the samples will be
prepared to 40/.06 size by using K3 nickel titanium rotary instruments with a crowndown
technique. Irrigation will be performed by using 5 mL of 4% NaOCl solution and 25-mm
30-gauge needle between each instrument. The root canal surfaces will be conditioned for
smear layer removal by using a 17% EDTA solution for 2 minutes, followed by a final
flush with distilled water to remove any trace of the demineralizing solution. All teeth will
be dried and irrigated alternatively with the following solutions for 3 minutes:
Group 1 - 6 teeth will be irrigated with 10 ml of 4% NaOCl and 10 ml of 2% CHX.
Group 2 - 6 teeth will be irrigated with 10 ml of 4% NaOCl and 10 ml of 1% ALX.
The root surfaces will be grooved with a disk, split by using a chisel, and observed for
the presence of any precipitates on the dentinal surfaces by SEM. The central beam of the
scanning electron microscope will be directed to the surface area of each tooth under x500
magnification.
Statistical Analysis :
The results will be subjected for appropriate statistical analysis. Categorical data will
be analyzed by chi square test for any difference between the groups. Fisher exact test will
be used to compare the outcome between the two groups. A p value of ≤ 0.05 will be
considered statistically significant.
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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 required.
7.4 Has ethical clearance been obtained from your institution in case of 7.3.?
Not required.
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8.
LIST OF REFERENCES:
1. Akisue E, Tomita VS, Gavini G, Poli de Figueiredo JA. Effect of the
combination of sodium hypochlorite and chlorhexidine on dentinal permeability
and scanning electron microscopy precipitate observation. J Endod 2010;36:847–
50.
2. Krishnamurthy S, Sudhakaran S. Evaluation and prevention of the precipitate
formed on interaction between sodium hypochlorite and chlorhexidine. J Endod
2010;36:1154-7.
3. Barbin LE, Saquy PC, Guedes DF, Sousa-Neto MD, Estrela C, Pécora JD.
Determination of para-chloroaniline and reactive oxygen species in chlorhexidine
and
chlorhexidine
associated
with
calcium
hydroxide.
J
Endod
2008
Dec;34(12):1508-14.
4. Kim HS, Zhu Q, Baek SH, Jung IY, Son WJ, Chang SW et al. Chemical
interaction of alexidine and sodium hypochlorite. J Endod 2012 Jan;38(1):112-6.
5. Bui T, Baumgartner C, Mitchell J. Evaluation of the interaction between sodium
hypochlorite and chlorhexidine gluconate and its effect on root dentin. J Endod
2008;34:181–5.
6. Mortenson D, Sadilek M, Flake NM, Paranjpe A, Heling I, Johnson JD et al.
The effect of using an alternative irrigant between sodium hypochlorite and
chlorhexidine to prevent the formation of para-chloroaniline within the root canal
system. Int Endod J. 2012 Sep;45(9):878-82.
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9.
SIGNATURE OF CANDIDATE
10.
REMARKS OF THE GUIDE
11.
NAME & DESIGNATION OF (IN Dr. G.B. SHIVAMURTHY, M.D.S.
PROFESSOR
BLOCK LETTERS)
DEPARTMENT
OF
CONSERVATIVE
11.1 GUIDE
DENTISTRY AND ENDODONTICS,
COLLEGE OF DENTAL SCIENCES.
DAVANGERE – 577004.
KARNATAKA.
11.2 SIGNATURE
11.3 CO-GUIDE
(IF ANY)
11.4 SIGNATURE
11.5 HEAD OF
DEPARTMENT
Dr. DHANYAKUMAR N.M., M.D.S.
PROFESSOR AND HEAD
DEPARTMENT
OF
CONSERVATIVE
DENTISTRY AND ENDODONTICS,
COLLEGE OF DENTAL SCIENCES.
DAVANGERE – 577004.
KARNATAKA.
11.6 SIGNATURE
12.
12.1 REMARKS OF THE
CHAIRMAN & PRINCIPAL
12.2. SIGNATURE
10