Download Comparison of shear bond strength of orthodontic brackets using

International Journal of Contemporary Orthodontics
doi: 10.1013/IJCO/1701-0008
Original Research
Comparison of shear bond strength of orthodontic brackets
using three different bonding techniques and two different
light cure sources.
Ishan Sojitra1, Anand Sabane2, Siddhart Shinde2, Vinit Swami2, Amol Patil2
1
Postgraduate, Department of Orthodontics, Bharati Vidyapeeth University Dental College
and Hospital, Pune, India
2
Faculty, Department of Orthodontics, Bharati Vidyapeeth University Dental College and
Hospital, Pune, India
Abstract
Aim of the study was to measure and compare shear bond strengths and evaluate the composite adhesive remnant on
the tooth surface using combination of different bonding methods as well as two different light sources.120 maxillary
premolar teeth were divided into three groups of 40 teeth and each group then subdivided in to two groups of 20 teeth
(A1,A2,B1,B2,C1,C2). An Instron universal testing machine was used to measure the shear bond strength. Following
debonding of brackets ARI was noted. ANOVA was done using Paired T-test. There were statistically significant
difference between group A1 (10.98 ± 3.47 MPa) and C1 (8.79 ± 3.23 MPa), as p value was 0.046(<0.05). Between B1
(11.37 ± 3.42 MPa) and C1 (8.79 ± 3.23 MPa), there was statistically significant difference, as p value was 0.019(<0.05).
Between A2 (9.84 ± 3.10 MPa) and C2 (7.92 ± 2.85 MPa), there was statistically significant difference, as p value was
0.049(<0.05). Between B2 (10.25 ± 4.06 MPa) and C2 (7.92 ± 2.85 MPa), there was statistically significant difference,
as p value was 0.043(<0.05). 30-35% of the samples in group A had a “0” ARI score and 30-50% of the samples in
group B had a “0” ARI score. 15% of the samples in group C had a “0” ARI score. Maximum shear bond strength and
minimum adhesive remaining on the tooth surface was seen in the group in which primer was not applied on the bracket
base. And minimum shear bond strength and minimum adhesive remaining on the tooth surface was seen in group
where primer applied on the bracket base and cured.
Keywords: Shear bond strength, LED, Halogen,
bonding material.1
Introduction
Bond strength of orthodontic brackets is an important c
onsideration in orthodontics. Shear bond strength depends on
various factors, including the adhesive properties of the bonding
materials, the attachment at the different interphases like the
tooth to composite interphase and the composite to bracket
interphase, as well as the polymerization of the composite
Correspondence: Dr Anand Sabane
Bharati Vidyapeeth University Pune
Email [email protected]
The method of attachment should allow the delivery of
orthodontic forces and should be sufficient to withstand
masticatory loads. In direct bonding of orthodontic brackets,
current bonding systems involve etching the enamel surface,
flowing an unfilled or lightly filled liquid resin into the etched
surface, and then using a filled resin on the bracket base to form
the final bond between the bracket and the tooth before selfcuring or light-curing the adhesive2. Currently clinicians use
various methods for bonding orthodontic brackets on teeth i.e.
application of primer only on the tooth surface as well as the
bracket bases. However there is variation in the bonding
methods used by clinicians.
Sabane et al.
In addition, the attachments should easily be removed at the end
of orthodontic treatment, and result in minimal enamel damage
during the procedure. While a strong and durable bond is
required, the problem of removing the bracket without
damaging the labial enamel must not be overlooked. The ideal
bonding material sandwich should fail during debonding by the
clean separation of the resin from the etched enamel.
Vol. 1 Issue 1
example, Group A1 samples numbered as A1-1 to A1-20 and in
the other groups as well, i.e. A2-1 to A2-20, B1-1 to B1-20, B21 to B2-20, C1-1 to C1-20, C2-1 to C2-20)
1.
2.
This study was designed to measure and compare shear bond
strengths and evaluate the composite adhesive remnant on the
tooth surface using combination of different bonding methods
as well as two different light sources i.e. LED and halogen light.
The outcome of this study will provide information about which
of the combinations produces a higher shear bond strength and
lower composite adhesive remnant on the tooth surface.
3.
4.
MATERIAL AND METHODS
The present study was aimed at measuring and comparing the
shear bond strength using combinations of three different
bonding methods and two different light cure sources. One
hundred and twenty (120) premolar teeth extracted for the
purpose of orthodontic therapy were used in this study. First and
second maxillary premolar teeth were used from patients who
underwent therapeutic extractions of teeth as part of orthodontic
treatment. Teeth with caries, restoration and fracture lines were
excluded from the samples. The collected extracted teeth were
washed, dried and stored in 0.9% w/v normal saline to prevent
dehydration.
Dental stone blocks (size:- 2” x 2” x 2.5”) were used to mount
the tooth for testing the shear bond strength. The dental stone
blocks were prepared such that the tooth was centred in the
block with the long axis of the teeth perpendicular to the base of
the block and embedded in the stone till cement enamel junction
and the entire crown was kept exposed for bonding the bracket.
A total of 120 dental stone blocks which were prepared by the
above mentioned method were later stored in normal saline at
room temperature before subjecting them to shear bond strength
test.
The mounted teeth were cleaned with ultrasonic scaler to
remove any left over tissue tags and calculus. The buccal
surfaces were polished with oil-free pumice slurry using rubber
cup mounted on a slow speed hand piece. They were washed by
using distilled water and then dried using oil free compressed
air. The sample of 120 teeth was divided into three groups of
forty (40) teeth each and each group then subdivided in to two
groups of twenty (20) each as shown in table below. These
samples were then numbered in a sequential manner. (For
2
5.
First, the buccal surfaces of the teeth on the stone
blocks were cleaned using pumice and with the help of
polishing cup at slow speed.
The cleaned tooth surfaces were washed with distilled
water and were dried with dry compressed air.
The area to be etched was marked on the buccal
surface by using a pencil of 0.5 mm B and a bracket
marker. The long axis of the crown was marked and
also the horizontal marking was done at 4 mm from
the incisal edges. This marking was done by leaving
approximately equal distance to the base area of the
bracket.
Application of the etchant: After the tooth marking, the
etchant was gently applied on buccal surface by using
an applicator brush. Two coats were applied, once
horizontally and once vertically.
After 15 seconds, the etchant applied on buccal surface
was washed for 10 seconds and dried with air using a
compressed air syringe.
After the brackets were bonded, the teeth with blocks were
stored again in fresh distilled water at 37 ̊ C for 40 hours (±2
hours) to simulate oral conditions prior to shear bond testing
procedure. A storage time of 40 hours was chosen so that the
bonding strength could be maximized.
An Instron universal testing machine was used to measure the
shear bond strength. The experiments were conducted at room
temperature of 25 ̊C. Each specimen (tooth mounted on plaster
block) was positioned on the Instron machine platform in such
a way that the upper jaw of instron machine was directed parallel
to the long axis of the tooth and contact was made as close as
possible to the junction of the tooth surface and the bracket base
edge. When the testing started, a progressive load was applied
at a crosshead speed of 3 mm/min. The load at which the first
sign of bracket debonding occured was recorded. This data was
subsequently added to a formula to calculate the shear bond
strength in mega Pascals.
Following the debonding of the brackets, the tooth surface
where the bracket was placed, was analysed under a optical
stereomicroscope using external illumination at 10X
magnification and given a score according to the adhesive
remnant index (ARI) given by Artun J and Berglund S3.
Analysis of Variance (ANOVA): One-way analysis of variance
was done using Paired T-test for multiple group comparison.
International Journal of Contemporary Orthodontics
Vol. 1 Issue 1
.
Sabane et al.
Table 2. The shear bond strength of maximum, minimum, mean and
standard deviation for each group.
Table 1. Group segregation of the sample and light source used

The statistically significant level was set at p < 0.05 level and p
values 0.000 and 0.001 were considered to be highly significant.
Mean values and standard deviations for each measured variable
were calculated.
RESULTS AND DISCUSSION
The mean shear bond strengths for brackets cured with LED
light source, i.e. group A1, group B1 and group C1 were 10.98
± 3.47 MPa, 11.37 ± 3.42 MPa and 8.79 ± 3.23 MPa respectively.



When mean shear bond strengths were compared between
group A1 (10.98 ± 3.47 MPa) and group B1 (11.37 ± 3.42
MPa), there was no statistically significant difference, as p
value was 0.721(>0.05).
When mean shear bond strengths were compared between
group A1 (10.98 ± 3.47 MPa) and group C1 (8.79 ± 3.23
MPa), there was statistically significant difference, as p
value was 0.046(<0.05).
When mean shear bond strengths were compared between
group B1 (11.37 ± 3.42 MPa) and group C1 (8.79 ± 3.23
MPa), there was statistically significant difference, as p
value was 0.019(<0.05).
The mean shear bond strengths for brackets cured with Halogen
light source, i.e. group A2, group B2 and group C2 were 9.84 ±
3.10 MPa, 10.25 ± 4.06 MPa and 7.92 ± 2.85 MPa respectively.


When mean shear bond strengths were compared between
group A2 (9.84 ± 3.10 MPa) and group B2 (10.25 ± 4.06
MPa), there was no statistically significant difference, as p
value was 0.725(>0.05).
When mean shear bond strengths were compared between
group A2 (9.84 ± 3.10 MPa) and group C2 (7.92 ± 2.85
MPa), there was statistically significant difference, as p
value was 0.049(<0.05).
International Journal of Contemporary Orthodontics
When mean shear bond strengths were compared
between group B2 (10.25 ± 4.06 MPa) and group C2
(7.92 ± 2.85 MPa), there was statistically significant
difference, as p value was 0.043(<0.05).
The mean shear bond strengths for brackets cured with both
light sources (LED and Halogen), i.e. group A1, group A2,
group B1, group B2, group C1 and group C2 were 10.98 ± 3.47
MPa, 9.84 ± 3.10 MPa, 11.37 ± 3.42, 10.25 ± 4.06 MPa, 8.79 ±
3.23 MPa and 7.92 ± 2.85 MPa respectively.



When mean shear bond strengths were compared
between group A1 (10.98 ± 3.47 MPa) and group A2
(9.84 ± 3.10 MPa), there was no statistically
significant difference, as p value was 0.281(>0.05).
When mean shear bond strengths were compared
between group B1 (11.37 ± 3.42 MPa) and group B2
(10.25 ± 4.06 MPa), there was no statistically
significant difference, as p value was 0.349(>0.05).
When mean shear bond strengths were compared
between group C1 (8.79 ± 3.23 MPa) and group C2
(7.92 ± 2.85 MPa), there was no statistically
significant difference, as p value was 0.371(>0.05).
The adhesive remnant index showed that group A and group B
has minimal adhesive remaining on to the tooth surface when
brackets were debonded. 30-35% of the samples in group A had
a “0” score and 30-50% of the samples in group B had a “0”
score. Group C shows maximum adhesive remaining on to the
tooth surface when brackets were debonded. 15% of the samples
in group C had a “0” score.
This study was designed to measure and compare shear bond
strengths and evaluate the composite adhesive remnant on the
tooth surface using combination of different bonding methods
as well as two different light sources i.e. LED and halogen light.
The outcome of this study will provide information about which
3
Sabane et al.
Table 3. Statistical significance values (p-values) when comparing two
groups
of the combinations produces a higher shear bond strength and
lower composite adhesive remnant on the tooth surface.
The sample size of this study was 120 extracted maxillary first
and second premolars. After extraction they all were stored in
0.9% w/v normal saline till the samples were tested. Linklater et
al4 (2001) found that premolar teeth exhibited significantly
higher shear bond strength compared to incisors and canines.
Previous investigators5,6,7 found that saline solution as a storage
medium produces comparable bond strength. Thus, saline was
chosen as a storage media in this present study.
Various authors6-21 found that etching time between 10 to 30
seconds did not affect bond strength or location of failure site
where as etching for 0 to 5 seconds reduced bond strength
significantly (<3 MPa). Hence, 15 seconds of etching time was
chosen in this present study.
According to previous researchers8-11,13,15,17-20,22-24 curing time of
40 seconds had significantly higher bond strength values. Hence,
40 seconds (10 seconds each side of the bracket) of curing time
was chosen in this present study.
It is known in the literature that shear bond strength achieved
with the light cured/dual cure resin increased with time. This
increase is either due to a dual cure system in the formulation of
the resin or due to the polymerization of the resin under the
bracket base after the diffusion of free radicals. Various studies813,15,16-20,24-35
done to evaluate shear bond strength have storage
time for 24 to 48 hours. Thus, in the present study, the storage
time chosen was 40 hours (± 2 hours).
To produce “pure shear” force vector, and eliminating other
undesirable force components, Brantley and Eliades method as
cited by Akhoundi et al36 was used where force applied to an
area near the base of the bracket or at the bracket-adhesive
4
Vol. 1 Issue 1
interface via a rod attached to the crosshead of a testing machine.
The moving crosshead of the testing machine is the component
that applies the required force to the specimens. It has been
recommended to keep the crosshead speed of the testing
machine as low as possible. Various studies9,11-13,16,20,22,26,34,36,
have recommended crosshead speed of 0.1 mm/min. The
fundamental concept may be that a lower crosshead speed
results in more accuracy. However such slow and precise force
application rarely occurs in the oral environment. This means
that using slow crosshead speeds might not be suitable for
stimulation of the forces acting in the oral cavity. Most bond
failures are caused by a much higher velocity. Versluis et al37
also have demonstrated that when higher crosshead speeds are
used, the incidence of cohesive failure in the tooth substrate
decreases significantly thus, 3 mm/min of crosshead speed was
chosen in this present study. `
After testing 120 samples the data was subjected to statistical
analysis and results have been tabulated from table-3 to table-7.
For the purpose of better understanding, the discussion is
categorized according to the various groups tested.
Groups A- primer not applied on the bracket base
In group A1, where brackets were cured with LED light, as
depicted in table-3, the mean shear bond strength is observed to
be 10.39 ± 3.47 MPa. This finding is in agreement to the shear
bond strength found by Chamada et al25 (1996) (11.46 ± 2.49
MPa), Sharma et al12 (2014) (15.49 ± 2.55 MPa), Di Nicolo et
al34 (2010) (15.88 ± 5.49 MPa) and Cerekja et al18 (2011)
(15.01 ± 3.57 MPa). Results of some investigations14,20,32 are
in disagreement with the finding of the present study.
Niepraschk et al32 (2007) found significantly higher shear bond
strength (46.16 ± 1.92 MPa) compared to findings of this present
study. The higher shear bond strength could probably be due to
variation in adhesive used by Niepraschk et al32 (2007) (Eagle
Spectrum, American Orthodontics). Bishara et al14 (2009) and
Carvalho et al20 (2013) found significantly lower shear bond
strength 6.0 ± 3.1 MPa and 5.53 ± 2.28 MPa respectively,
compared to the finding of this present study. The difference in
mean shear bond strength found by Bishara et al14 (2009) and
Carvalho et al20 (2013) probably could be due to low intensity
of curing light used in their investigation. i.e 400 mW/cm2 and
700 mW/cm2 respectively.
In Group A2, where brackets were cured with halogen light, as
depicted in table-3, the mean shear bond strength is observed to
be 9.84 ± 3.10 MPa. This finding is in agreement to the shear
bond strength found by Dunn et al13 (2002) (8.8 ± 1.0 MPa),
Banerjee et al17 (2011) (12.47 MPa) and Carvalho et al20 (2013)
(6.21 ± 1.74 MPa). Finding of the present study is not in
International Journal of Contemporary Orthodontics
Vol. 1 Issue 1
.
Sabane et al.
agreement with studied by Bishara et al14 (2003) (5.1 ± 2.5 MPa),
Niepraschk et al32 (2007) (48.35 ± 1.87 MPa) and Penido et al33
(2009) (4.21 ± 1.18 MPa). The variation could be due to low
intensity light cure used by Bishara et al14 (2003) (400 mW/cm2)
and Penido et al33 (2009) (500 mW/cm2). The higher shear bond
found by Niepraschk et al32 (2007) probably could be due to
variation in adhesive used (Eagle Spectrum, American
Orthodontics).
between the mean shear bond strengths with use of LED or
Halogen curing light as p values are greater than 0.05 (A1 vs
A2-p=0.281, B1 vs B2-p=0.349 and C1 vs C2-p=0.371). These
findings are in agreement with Di Nicolo et al34 (2008), Penido
et al33 (2009), Carvalho et al20 (2013) and Niepraschk et al32
(2007). This means that the shear bond strength may not be
significantly affected by use of either LED or Halogen light
sources.
Groups B- Primer applied on the bracket base but not
cured
Adhesive remnant index
In group B1, where brackets were cured with LED light, as
depicted in table-3, the mean shear bond strength is observed to
be 11.37 ± 3.42 MPa. In group B2, where brackets were cured
with halogen light, as depicted in table-3, the mean shear bond
strength is observed to be 10.25 ± 4.06 MPa. These results could
not be compared to other studies as a similar method of bonding
was not found in the literature.
Groups C- Primer applied on the bracket base and cured
In group C1, where brackets were cured with LED light, as
depicted in table-3, the mean shear bond strength is observed to
be 8.79 ± 3.23 MPa. Tukkarahraman et al15 (2005) found higher
shear bond strength (23.86 ± 6.20 MPa) when primer was
precured on the bracket base and brackets were cured with LED
light. These findings are in discordance with present study.
In group C2, where brackets were cured with halogen light, as
depicted in table-3, the mean shear bond strength is observed to
be 7.92 ± 2.85 MPa. Turkkahraman et al15 (2005) found higher
shear bond strength (17.38 ± 5.41 MPa) when primer was
precured on the bracket base and brackets were cured with
halogen light. This finding is in disagreement with the finding
of the present study probably due to low cross head speed of 0.5
mm/min used by Turkkahraman et al15 (2005).
Table 7 depicts that, the samples in group A and group B had
minimal adhesive remaining on to the tooth surface when
brackets were debonded by using the ARI index described by
Artun et al3 (1984). 30-35% of the samples in group A had a “0”
score and 30-50% of the samples in group B had a “0” score. “0”
score in ARI is when no residual adhesive remnant is found on
the tooth surface after the bracket is debonded. Group C showed
maximum adhesive remaining on to the tooth surface when
brackets were debonded. 15% of the samples in group c had a
“0” score.
In the present study, it was found that samples in group A, where
brackets were bonded without application of primer, showed
maximum shear bond strength and minimal adhesive remaining
on the tooth surface. It meant that bond failure occurred at
enamel adhesive interface rather than adhesive bracket interface
which was found out in the group C. These findings are in
agreement with previous investigation9,18,22,26 where they found
minimal adhesive remaining on the tooth surface when brackets
were cured without application of primer on the bracket base. In
group C, brackets were bonded with application of primer and
curing. It also showed maximum adhesive remaining on the
tooth surface after bracket debonding. This means that the bond
strength between adhesive & tooth was stronger than bracket &
adhesive.
According to findings of the present study, it can be
hypothesised that, to improve mechanical interlocking of
adhesive and bracket mesh it is necessary that the adhesive
should enter in between interlocking pattern of the bracket mesh.
When primer is cured on the bracket base, it probably blocked
the meshwork on the bracket bases, there by interfering with the
mechanical interlocking of the adhesive in the meshwork and
lowering the shear bond strength.
Currently, research is on, to develop time-conserving and step
reducing methods for bonding of orthodontic brackets. As is
observed in the present study, curing of primer on the bracket
base increases chair side time while bonding and debonding
during removal of adhesive from the tooth surface which may
possibly also damage enamel surface. This method has also
shown to produce reduced shear bond strength. So, this method
may not be as effective and efficient as the conventional bonding
method.
Comparison between the two different light
sources
CONCLUSION
Table 6 depicts the comparison of the mean shear bond strength
of groups where brackets were cured with LED and Halogen
light sources. No statistically significant difference was found
International Journal of Contemporary Orthodontics
1. The results of this study showed maximum shear bond
strength and minimum adhesive remaining on the tooth
5
Sabane et al.
surface in the group in which primer was not applied on
the bracket base.
2. Primer applied on the bracket base and cured resulted in
minimum shear bond strength and minimum adhesive
remaining on the tooth surface.
3. The mean shear bond strengths observed in samples
cured with LED are marginally higher than the mean
shear bond strengths observed in samples cured with
halogen light source. However the difference in shear
bond strengths do not show statistical significance.
Vol. 1 Issue 1
10.
11.
12.
13.
REFERENCES
1.
2.
3.
4.
5.
6.
7.
8.
9.
6
Banerjee S, Banerjee R. A comparative evaluation of
the shear bond strength of five different orthodontic
bonding agents polymerized using halogen and lightemitting diode curing lights: An in vitro investigation.
Ind J Dent Res. 2011;22(5):731-2.
Sharma S, Tandon P, Nagar A, Singh GP, Singh A,
Chugh VK. Comparison of shear bond strength of
orthodontic brackets bonded with four different
orthodontic adhesive. J Orthod Sci. 2014;3(2):29-33.
Artun J, Berglund S. Clinical trials with crystal growth
conditioning as an alternative to acid-etch enamel
pretreatment. Am J Orthod. 1984;85:333–40.
Linklater RA, Gordon PH. An ex vivo study to
investigate bond strengths of different tooth types. J
orthod. 2001;28(1):59-65.
Shahabi M, Heravi F, Mokheber N, Karamad R,
Bishara SE. Effects on shear bond strength and the
enamel surface with an enamel bonding agent. Am J
Orthod Dentofacial Orthop. 2010;137(3):375-8.
Carvalho PEG, Santos VM, Isber H, Cotrim-Ferreira
FA. Halogen light versus LED for bracket bonding:
shear bond strength. Dental Press J Orthod.
2013;18(1):31-6.
Jaffer S, Oesterle LJ, Newman SM. Storage media
effect on bond strength of orthodontic brackets. Am J
Orthod Dentofacial Orthop. 2009; 136(1):83-6.
Wang WN, Meng CL. A study of bond strength
between light and self cured orthodontic resin. Am J
Orthod Dentofacial Orthop. 1992; 101(4):350-4.
Owens SE Jr, Miller BH. A comparison of shear bond
strengths of three visible light-cured orthodontic
adhesives. Angle Orthod. 2000;70(5):352-6.
14.
15.
16.
17.
18.
19.
20.
21.
Toledano M, Osorio R, Osorio E, Romeo A. Bond
strength of orthodontic brackets using different light
and self curing cements. Angle Orthod. 2003;73(1):5663.
Summers A, Kao E, Gilmore J, Gunel E. comparison
of bond strength between a conventional resin
adhesive and a resin-modified glass ionomer adhesive:
an in vitro and in vivo study. Am J Orthod Dentofacial
Orthop. 2004;126(2):200-6.
Sharma S, Tandon P, Nagar A, Singh GP, Singh A,
Chugh VK. Comparison of shear bond strength of
orthodontic brackets bonded with four different
orthodontic adhesive. J Orthod Sci. 2014;3(2):29-33.
Dunn WJ, Taloumis LJ. Polymerization of orthodontic
resin cement with light emitting diode curing units.
Am J Orthod Dentofacial Orthop. 2002;122(3):236-41.
Bishara SE, Ajlouni R, Oonsombat C. Evaluation of a
new curing lights on the shear bond strength of
orthodontic brackets. Angle Orthod. 2003;73(4):431-5.
Turkkahraman H, Kucukesmen HC. Orthodontic
bracket shear bond strengths produced by two highpower light-emitting diode modes and halogen light.
Angle Orthod. 2005;75(5):854-7.
Signorelli MD, Kao E, Ngan PW, Gladwin MA.
Comparison of bond strength between orthodontic
brackets bonded with halogen and plasma arc curing
lights: an in-vitro and in-vivo study. Am J Orthod
Dentofacial Orthop. 2006;129(2):277-82.
Banerjee S, Banerjee R. A comparative evaluation of
the shear bond strength of five different orthodontic
bonding agents polymerized using halogen and lightemitting diode curing lights: An in vitro investigation.
Ind J Dent Res. 2011;22(5):731-2.
Cerekja E, Cakirer B. Effect of short curing times with
a high-intensity light emitting diode or high-power
halogen on shear bond strength of metal brackets
before and after thermocycling. Angle Orthod.
2011;81(3):510-6.
Retamoso LB, Onofre NM, Hann L, Marchioro EM.
Effect of light-curing units in shear bond strength of
metallic brackets: an in vitro study. J Appl Oral Sci.
2010;18(1):68-74.
Carvalho PEG, Santos VM, Isber H, Cotrim-Ferreira
FA. Halogen light versus LED for bracket bonding:
shear bond strength. Dental Press J Orthod.
2013;18(1):31-6.
Olsen ME, Bishara SE, Boyer DB, Jakobsen JR. Effect
of varying etching times on the bond strength of
ceramic brackets. Am J Orthod Dentofacial Orthop.
1996;109(4):403-9.
International Journal of Contemporary Orthodontics
Vol. 1 Issue 1
.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
Naidu E, Stawarczyk B, Tawakoli PN, Attin R, Attin T.
Shear bond strength of orthodontic resin after caries
infiltration
preconditioning.
Angle
Orthod.
2013;83(2):306-12.
Swanson T, Dunn WJ, Childers DE, Taloumis LJ.
Shear bond strength of orthodontic brackets bonded
with light-emitting diode curing units at various
polymerization times. Am J Orthod Dentofacial
Orthop. 2004;125(3):337-41.
Neugerbauer S, Jost-Brinkmann PG, Patzold B,
Cacciafesta. Plasma versus halogen light: the effect
of different light sources on the shear bond strength of
brackets. J Orofac Orthop. 2004;65(3):223-36.
Chamda RA, Stein E. Time-related bond strengths of
light cured and chemically cured bonding system: an
in vitro study. Am J Orthod Dentofacial Orthop.
1996;110(4):378-82.
Movahhed HZ, Ogaard B, Syverud M. An in vitro
comparison of the shear bond strength of a resinreinforced glass ionomer cement and a composite
adhesive for bonding orthodontic brackets. Eur J
Orthod. 2005;27(5);477-83.
Attar N, Taner TU, Tulumen E, Korkmaz Y. Shear
bond strength of orthodontic brackets bonded using
conventional vs one and two step selfetching/adhesive
systems.
Angle
Orthod.
2007;77(3):518-23.
Shahabi M, Heravi F, Mokheber N, Karamad R,
Bishara SE. Effects on shear bond strength and the
enamel surface with an enamel bonding agent. Am J
Orthod Dentofacial Orthop. 2010 ; 137 (3): 375-8.
Trakyali G, Malkondu O, Kazazoglu E, Arun T. Effects
of different silanes and acid concentration on shear
bond strength of brackets to porcelain surfaces. Eur J
Orthod. 2009;31(4):402-6.
Reicheneder CA, Gedrange T, Lange QA, Baumert U,
Proff P. Shear and tensile bond strength comparison of
various contemporary orthodontic adhesive system: an
in-vitro study. Am J Orthod Dentofacial Orthop.
2009;135(4):422-6.
Swanson T, Dunn WJ, Childers DE, Taloumis LJ.
Shear bond strength of orthodontic brackets bonded
with light-emitting diode curing units at various
polymerization times. Am J Orthod Dentofacial
Orthop. 2004;125(3):337-41.
Niepraschk M, Rahiotis C, Bradley TG, Eliades T,
Eliades G. Effect of various curing lights on the degree
of cure of orthodontic adhesives. Am J Orthod
Dentofacial Orthop. 2007;132(3):382-4.
Penido SM, Penido CV, dos Santos-Pinto A, Bagnato
VS. In vivo and in vitro study of the shear bond
strength of brackets bonded to enamel using halogen
or LED light. World J Orthod. 2009 ;10 (1) :21-8.
International Journal of Contemporary Orthodontics
Sabane et al.
34.
35.
36.
37.
Di Nicolo R, Araujo MA, Alves LA, Assuncao e Souza
RO, Rocha DM. Shear bond strength of orthodontic
brackets bonded using halogen light and light emitting
diodes at different debond times. Braz Oral Res.
2010;24(1):64-9.
Soderholm KJ. Correlation of in vivo and in vitro
performance of adhesive restorative materials: a report
of the ASC MD156 Task Group on thest methods for
the adhesion of restorative materials. Dent Mater.
1991;7(2):74-83.
Akhoundi MA, MojtahedzadehF. Problems in
standardization of orthodontic shear bond strength
tests; A brief review. 2005;2(1):36-40.
Versluis A, Tantbirojn D, Douglas WH. Why do shear
bond tests pull out dentin? J Dent Res.
1997;76(6):1298-1307.
7