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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
DR. AMIT GOYAL
Address
PG in Dept. of Orthodontics,
J.S.S. Dental College & Hospital,
S.S. Nagar,
Mysore-570015
2.
Name of the institution
J.S.S. Dental College & Hospital,
S.S. Nagar,
Mysore – 570015.
3.
Course of the study and Master of Dental Surgery
subject
Orthodontics & Dentofacial Orthopedics.
4.
Date of admission to course
5.
Title of the topic:
11-06-2008
Effect of self-etchant pH on the shear bond strength of orthodontic brackets—an
in vitro study.
6.
Brief resume of the intended work:
6.1 Need for the study:
Over the last 50 years, the bonding of various adhesives to enamel and dentin has
developed a niche in orthodontics. The bonding of orthodontic brackets onto tooth
surfaces has greatly improved with the advent of new products with excellent
adhesive properties.1 Traditional orthodontic bracket bonding systems required the
use of a 3-step procedure involving 3 separate agents- an enamel conditioner, a
priming agent, and an adhesive resin.2 Self-etching primers were introduced in an
effort to reduce the 3-step procedure to 2 steps, effectively reducing chair time and
increasing cost effectiveness, which resulted in increased convenience and
potentially reducing costs to the patient. Self-etching primers have been used to
successfully bond orthodontic brackets with shear bond strength values similar to
those for conventional acid etch technique.3
Self-etching primers have different pH’s, penetration abilities, and shear
bond strength values. Historically, it was assumed that a deeper etching pattern
would provide a greater surface area for bonding and, thus greater bonding
strengths. However, in a test of 3 SEP’s on unground enamel, no correlation was
seen between etching aggressiveness and tensile strength.4 It was demonstrated that
the most acidic of 5 self-etchants produced the deepest hybrid layer but had the
weakest bond strengths to both enamel and dentin.5 It was suggested that the bond
strength of less aggressive SEP’s might produce lower bond strength when used on
intact enamel.6 However, there seems to be little information in the literature on
how the pH and aggressiveness of SEP’s affect the enamel surface and bracket
bonding.
Therefore, the purpose of this study was to determine how the pH
differences of 3 SEP’s affect the SBS of orthodontic brackets.
6.2 Review of Literature:
A study7 was done to see the effects of self-etchant primer/adhesive on shear bond
strength of orthodontic brackets. The in-vitro findings indicated that the use of a
self-etch primer to bond orthodontic brackets to the enamel surface resulted in a
significantly lower, but clinically acceptable shear bond force as compared with the
conventional adhesive systems.
The effect of saliva contamination on shear bond strength of orthodontic brackets
was also studied8 when using a self-etching primer. The results indicated that the
newly introduced self-etch primers have the potential to be successfully used in
bonding orthodontic brackets even after light salivary contamination.
A microscopic evaluation of dentin interface obtained with 10 contemporary selfetching systems in correlation with their pH has also been done.9 The study
concluded that the morphology of the hybrid layer depends on the composition of
the primer and that the pH is not the determining factor conditioning the action of
self-etching adhesives.
A study10 was done to see the effect of self-etchant pH on the shear bond strength of
orthodontic brackets bonded to molars. The study clearly showed that the selfetching primer with the highest pH (least acidic) bonded brackets successfully and
with the strongest shear bond strength.
6.3 Objectives of the Study:
To study the effect of self-etchant pH on shear bond strength of orthodontic
brackets.
7.
Materials and methods:
The study will be conducted at the Department of Orthodontics, JSS Dental College
& Hospital, Mysore.
7.1 Source of data (Materials) :
1. 90 freshly extracted premolars will be collected and stored in 0.2%
(weight/volume) thymol.
2. MBT stainless steel premolar brackets (slot size 0.022”X 0.028”) will be
used.
3. 3 self-etchant primers with 3 different pH will be used—
A. pH 1.0 (Transbond Plus)
B. pH 2.7 (Adper Prompt L-Pop)
C. pH 0.9 (Clearfil S3 Bond)
4. Visible light curing unit (Dentsply) will be used.
5. A light-cured composite adhesive resin (Transbond XT) will be used to bond
all groups.
6. A universal testing machine (Instron) will be used to determine the shear
bond strength of the brackets.
Inclusion criteria
Freshly extracted premolar teeth will be selected only if they—
1. have an intact buccal enamel.
Exclusion criteria:
1. Teeth having surface cracks from extraction forceps,
2. Teeth treated with chemical agents, and
3. Teeth having caries.
7.2 Method of collection of data:
Teeth randomly divided into 3 groups (30 each) with regard to the self-etchant
primer used—
1. Group I, SEP Transbond Plus, pH 1.0 will be used
2. Group II, SEP Adper Prompt L-Pop, pH 2.7 will be used
3. Group III, SEP Clearfil S3 Bond, pH 0.9 will be used
The self-etching primer will be applied to the tooth surface according to
manufacturer’s guidelines.
The metallic premolar brackets will be bonded with light cure composite adhesive
resin Transbond XT and cured with Dentsply visible light curing unit.
The shear bond strength of each group will be determined within half an hour after
bonding to simulate the clinical conditions when archwires are first tied to newly
bonded teeth and a universal testing machine will be used to determine the same.
A steel rod with a flattened end will be attached to the crosshead of the universal
testing machine to apply an occlusogingival load to the bracket-tooth interface.
The results of each test will be recorded by a computer electronically connected to
the testing machine.
Following statistical methods will be applied:
1. ANOVA
2. Duncan multiple range test
3. Chi-square test.
7.3 Does the study require any investigation or intervention on patients or
other humans or animals? If so, please describe briefly.
Yes, extracted human premolar teeth.
7.4 Has ethical clearance been obtained from your institution in case 7.3?
Yes
8.
List of references:
1. Amra I, Samsodien G, Shaikh A, Lalloo R. Xeno III self-etching adhesive in
orthodontic bonding: the next generation. Am J Orthod Dentofacial Orthop
2007;131:160-65.
2. Bishara SE, Gordan VV, Von Wald L, Olson ME. Effect of an acidic primer
on shear bond strength of orthodontic brackets. Am J Orthod Dentofacial
Orthop 1998;114:243-7.
3. Bishara SE, Oonsombat C, Ajlouni R, Laffoon JF. Comparison of the shear
bond strength of 2 self-etch primer/adhesive systems. Am J Orthod
Dentofacial Orthop 2004;125:348-50.
4. Pashley DH, Tay FR. Aggressiveness of contemporary self-etching
adhesives. Part II: etching effects on unground enamel. Dent Mater
2001;17:430-44.
5. De Munck J, Vargas M, Iracki J, Van Landuyt K, Poiterin A, Lambrechts P,
et al. One day bonding effectiveness of new self-etch adhesives to bur-cut
enamel and dentin. Oper Dent 2005;30:39-49.
6. Kanemura N, Sano H, Tagami J. Tensile bond strength to and SEM
evaluation of ground and intact enamel surfaces. J Dent 1999;27:523-30.
7. Bishara SE, Von Wald L, Laffoon JF, Warren JJ. Effect of a self-etch
primer/adhesive on the shear bond strength of orthodontic brackets. Am J
Orthod Dentofacial Orthop 2001;119:621-4.
8. Samir E Bishara, Charuphan Oonsombat, Raed Ajlouni, Gerald Denehy. The
effect of saliva contamination on shear bond strength of orthodontic brackets
when using a self-etching primer. Angle Orthod 2002;72:554-7.
9. Gregoire G, Millas A. Microscopic evaluation of dentin interface obtained
with 10 contemporary self-etching systems:correlation with their pH. Oper
Dent 2005;30:481-91.
10. Adam W Ostby, Samir E Bishara. Geralh E Denehy, John F Laffoon, John J
Warren. Effect of self-etchant pH on the shear bond strength of orthodontic
brackets. Am J Orthod Dentofacial Orthop 2008;134:203-8.
9.
Signature of the Candidate
10.
Remarks of the Guide
11.
11.1 Name and Designation of
Guide:
DR. JYOTHIKIRAN H.
DEPT. OF ORTHODONTICS
JSS DENTAL COLLEGE & HOSPITAL
MYSORE.
11.2 Signature
11.3
Co-guide
11.4 Signature
11.5 Head of Department
DR. SHIVALINGA. B.M. , MDS
PROFESSOR & INCHARGE OF PG
STUDIES.
DEPT. OF ORTHODONTICS
JSS DENTAL COLLEGE & HOSPITAL
MYSORE.
11.6 Signature
12
12.1 Remarks of the Chairman
and Principal
12.2 Signature