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Evaluation of shear bond strength of

primer-treated ceramic bracket on

dental zirconia surface

Abstract

Evaluation of shear bond strength of

primer-treated ceramic bracket on

dental zirconia surface

Division of Dental Biomaterials Science

Department of Dental Science, Graduate School

Seoul National University

(Directed by Prof. Shin Hye Chung)

Ga Youn Ju

This study aims to evaluate the shear bond strength (SBS) of ceramic

primer-treated ceramic bracket on dental zirconia and to compare with

the SBS of ceramic bracket on conventionally treated dental zirconia.

Zirconia (LAVA Plus, 3M ESPE, St. Paul, MN, USA) samples were

sintered and polished with 500 grit diamond disc. The surface was

sandblasted with 50 μm alumina and treated as follows: no treatment of

the primer (X), treatment of the primer on the zirconia (Z), treatment of

the primer on the bracket base (B), and treatment of the primer on both

the zirconia and the bracket base (ZB). The ceramic bracket (Perfect

Clear II, Hubit, Uiwang, Korea) was bonded on the zirconia surface with

the orthodontic resin. The SBS was measured before (T0) and after the

10,000 cycles of thermocycling (T10000). After the SBS test, the bond

failure interface was explored under FE-SEM and Adhesive Remnant

Index (ARI) was evaluated. Statistical significance of the data of SBS

was analyzed using the program (α = 0.05).

In T0 and T10000, significantly high SBS was obtained in ZB (primer

on both the zirconia and the bracket base) (p < 0.05). There was no

significant difference in SBS between Z (primer on the zirconia) and B

(primer on the bracket base). The adhesive failure occurred at zirconia-

resin interface in B while Z showed adhesive failure at resin-bracket

interface. In ZB, mixed failure was shown at the zirconia-resin-bracket

bonding interfaces.

The highest SBS was obtained when the ceramic primer was treated to

both the zirconia and the bracket base. The application of the ceramic

primer on the bracket base increased bonding strength to the level of the

ceramic primer treated zirconia.

Keywords: dental zirconia, ceramic primer, ceramic bracket, shear bond

strength, surface treatment

Student Number: 2015-30620

Contents

1. Introduction .................................................................................... 1

2. Materials and Methods .................................................................. 4

2.1. Specimen Preparation ...................................................................... 4

2.2. Surface Treatment and Bracket Bonding .......................................... 4

2.3. Microstructure Observations ............................................................ 5

2.4. Shear Bond Testing and Failure Mode Observations ........................ 8

3. Results .......................................................................................... 10

3.1. Microstructure Observations .......................................................... 10

3.2. Shear Bond Testing and Failure Mode Analysis ............................. 10

4. Discussion ..................................................................................... 20

5. Conclusion .................................................................................... 25

References ........................................................................................ 26

Abstract in Korean........................................................................... 30

1. Introduction

Increasing interest in aesthetics and the need to overcome the

disadvantages of traditional porcelain fused metal crown, such as low

strength of porcelain and greyish shade of gingiva from metal

substructures, have led to the development of a wide range of ceramic

systems (1-3). Amongst them, the use of dental zirconia has increased

recently. Polycrystalline zirconia is a frequently used ceramic system in

load bearing area with aesthetic demands, primarily consists of yttria

stabilized tetragonal zirconia polycrystal (Y-TZP) (4-6). The phase

transformation of Y-TZP from tetragonal to monoclinic under stress

conditions increases the particle volume, which inhibits crack

propagation, resulting in high flexural strength (4, 5, 7). Due to high

mechanical properties, it has been used in inlays, onlays, crowns, post

and core systems, and as frameworks for porcelain fused zirconia (PFZ)

restorations (5, 6, 8, 9). Although PFZs provide enhanced aesthetics,

chipping and delamination of the veneered porcelain limit their use in

dental restoration (5, 6, 10). Together with the development of zirconia

with increased translucency, the use of full-contoured zirconia (FCZ) is

increasing for both anterior and posterior restorations (6).

The zirconia is acid-resistant because it does not contain silica

particles while most dental ceramics contain that. This makes it less

responsive to hydrofluoric acid etching, which is an effective surface

treatment method for other glass ceramic systems (3, 6, 11-16). To

enhance the resin bond strength on zirconia, air particle abrasion or

tribochemical silica coating were suggested (11-13, 15). However, in the

latter case, the attachment of silica on the zirconia surface was not

predictable after the artificial aging processes (11). In case of the zirconia

restorations, application of primers or bonding systems with functional

monomers (eg, 10-methacryloyloxydecyl dihydrogen phosphate; 10-

MDP) on the roughened surface showed increased bonding strength (11,

15).

As the number of adult patients performing orthodontic treatment

is growing, the cases of bracket bonding on zirconia restorations are

increasing. A bracket bonding failure on posterior teeth can be solved by

using orthodontic metal bands, while in anteriors, bonding is more

challenging because of aesthetic considerations. Studies have conducted

on the bonding between feldspathic porcelain and brackets (17-19).

However, there are not many studies about FCZ and ceramic bracket

although it requires a different bonding protocol. A study reported that

silane treatment on glazed FCZ was sufficient to achieve adequate bond

strength (20). Yet another study reported that sandblasting and 10-MDP

containing primer application on glazed zirconia surface was effective

(21). Still, bonding ceramic bracket on FCZ is controversial. It is

believed that there is a need for more studies about a protocol for

obtaining bonds that are time/cost-effective and have long-term stability.

This study aims to evaluate the shear bond strength of primer-

treated ceramic bracket on dental zirconia and to compare with

conventional zirconia surface treatment. The null hypotheses were; 1)

The primer application on zirconia does not enhance the bond strength;

2) The primer treatment on bracket base does not enhance the bond

strength.

2. Materials and Methods

2.1. Specimen Preparation

Eighty zirconia (LAVA Plus, 3M ESPE, St. Paul, MN, USA)

specimens in 15 (width) × 15 (height) × 3 (thickness) mm were prepared

from a green stage zirconia block and the specimens were sintered by

following manufacturer’s instructions. Each specimen was embedded in

a polyester resin (EC-304, Aekyung, Seoul, Korea) and polished with a

diamond disc (MD-Piano, Struers, Ballerup, Denmark) up to 500 grit

under water irrigation. The surfaces of the all samples were sandblasted

with 50 �m alumina (SandStorm Expert, Vaniman, Fallbrook, CA, USA)

from a distance of 20 mm for 20 sec in a circular motion under a pressure

of 400 kPa. The samples were cleaned in an ultrasonic bath with distilled

water for 2 min and dried.

2.2. Surface treatment and Bracket Bonding

All the zirconia samples were randomly divided into 4 groups (n

= 20). All the zirconia surfaces were roughened by alumina sandblasting.

In X, no surface treatment was done on the alumina blasted zirconia

surface. In Z, a ceramic primer (CP; Clearfil ceramic primer, Kuraray,

Tokyo, Japan) was applied on the zirconia surface. In B, CP was applied

on the bracket base. In ZB, CP was applied on both the zirconia surface

and the base of the bracket. After the surface primer treatment, the

adhesive primer (Transbond XT adhesive primer, 3M Unitek, Monrovia,

CA, USA) was applied on the zirconia surface and the bracket (Perfect

Clear II, Hubit, Uiwang, Korea) was bonded using the adhesive paste

(Transbond XT adhesive paste, 3M Unitek) under gentle pressure.

Excess resin was removed and light cured (Elipar Free Light 2, 3M ESPE,

St. Paul, MN, USA) for 10 sec on each side of the bracket for a total of

40 sec. A flow chart of experiment is shown in Figure 1. The composition

of the materials used in this study is shown in Table 1.

2.3. Microstructure Observations

The surface of the intact bracket base was observed under field

emission scanning electron microscopy (FE-SEM; S-4700, Hitachi,

Tokyo, Japan). The retentive structures of the intact bracket base were

analysed with an energy dispersive x-ray spectrometer (EDS; EMAX

7200H, HORIBA, England). Surface roughness (Ra) of the polished and

sandblasted zirconia surfaces was determined by using a confocal laser

scanning microscope (CLSM; LSM 800-MAT, Carl Zeiss MicroImaging

GmbH, Jena, Germany).

Figure 1. Flowchart of the experiment. Ceramic primer (CP), control

group (X), group treated with CP on zirconia (Z), group treated with CP

on bracket (B), and group treated with CP on both the zirconia and the

bracket (ZB).

Table 1. Materials used in this study

Materials Brand name LOT No. Composition Manufacturer

Zirconia LAVA Plus

515920

Tetragonal polycrystalline

zirconia, 3mol-% Yttria,

Alumina

3M ESPE,

USA

Primer

Clearfil

ceramic

primer

240010

3-Methacryloxypropyl

triethoxy silane, *10-MDP,

Ethanol

Kuraray,

Japan

Adhesive

Transbond

XT

adhesive

primer

ER7BS

Triethylene glycol

dimethacrylate,

Bisphenol A diglycidyl

ether dimethacrylate,

Triphenylantimony,

4-(Dimethylamino)-

Benzeneethanol,

dl-Camphorquinone,

Hydroquinone

3M Unitek,

USA

Composite

Resin

Transbond

XT

adhesive

paste

ER7BS

Silane treated quartz,

Bisphenol A diglycidyl

ether dimethacrylate,

Bisphenol A Bis(2-

hydroxyethyl ether)

dimethacrylate, Silane

treated silica

3M Unitek,

USA

*10-MDP (10-methacryloyloxydecyl dihydrogen phosphate)

2.4. Shear Bond Testing and Failure Mode Observations

After the bracket bonding, the samples were stored in 100%

relative humidity at 37°C for 24 hour. The half of randomly distributed

samples were tested after 24 hour of storage. The other half underwent

aging process by a thermal circulator (DTRC-640, Jeiotech, Daejeon,

Korea) for 10,000 cycles at 5 ��and 55 ���The dwelling time was 30

sec and the transfer time was 20 sec. SBS was measured by using a

universal testing machine (Instron 8848, Instron, Norfolk County, MA,

USA) at a crosshead speed of 0.5 mm/min. The maximum load at failure

was calculated in MPa by dividing the maximum load (N) by the area of

the bracket base (12.24 mm2). The bond failure interface was evaluated

under FE-SEM and both failure mode and ARI was evaluated using

modified ARI scores (Table 2). Statistical analysis was performed by

Kruskal-Wallis test using the Statistical Package for the Social Sciences

(version 22.0; IBM Corp., Armonk, NY, USA) �������.

Table 2. Criteria of modified adhesive remnant index (ARI) scores

1 Entire composite remained on the zirconia 2 More than 90% of the composite remained on the zirconia

3 More than 10% but less than 90% of the composite

remained on the zirconia

4 Less than 10% of the composite remained on the zirconia

5 No composite remained on the zirconia

Criteria Score

3. Results

3.1. Microstructure Observations

The surface polished to with a diamond disc showed shallow

scratch lines without directionalities and average surface roughness (Ra)

of 0.10 �m. Sandblasted surfaces showed multiple short but deeper

scratches that were uniformly distributed and increased surface

roughness (Ra) to �����m (Figure 2). The bracket base showed multiple

spherical-shaped retentive beads (diameter of approximately 80 to 100

�m) attached to the surface except for the outer margin (approximately

� �m in width). The spherical shaped retentive beads showed

characteristic micro-rough surfaces and the EDS evaluation revealed that

they were mainly composed of aluminium (Figure 3).

3.2. Shear Bond Testing and Failure Mode Analysis

Before the thermocycling (T0), a significantly higher bonding

strength was obtained in ZB. Z and B had no significant difference. After

the thermocycling (T10000), reduced SBS was obtained when compared

with T0. The SBS was significantly decreased in X, B, and ZB in T10000

and was not significantly decreased in Z. Still, ZB, in which both the

zirconia and the bracket base were treated with ceramic primer, showed

highest SBS than the other groups in T10000 (Table 3, 4, 5, Figure 4).

Figure 2. CLSM images of the zirconia surface before (A, C) (Ra: 0.10

�m) and after the sandblasting (B, D) (Ra�������m). Sandblasted surface

(B, D) showed evenly distributed micro-roughness.

Figure 3. SEM images of the bracket base at ×30 (A) and ×300 (B). EDS

analysis of the spherical retentive microstructures (white diamond in B)

(C).

Table 3. Comparison of SBSs (MPa) of the experimental groups

Group SBS (MPa, mean ± SD)

P value T0 (n = 10) T10000 (n = 10)

X 5.71 ± 0.48 Aa 2.03 ± 0.78 Db p = 0.000

Z 9.79 ± 1.94 Bc 8.16 ± 1.78 Ec p > 0.05

B 11.76 ± 2.55 Bd 8.49 ± 2.29 Ee p = 0.007

ZB 15.96 ± 2.49 Cf 11.65 ± 3.95 Fg p = 0.001

Same uppercase letters indicate no significant difference in each column and same

lowercase letters indicate no significant difference in each row.

Table 4. P value between experimental group in T0 (p < 0.05)

T0 X Z B ZB

X - 0.000 0.000 0.000

Z - 0.249 0.000

B - 0.008

ZB -

Table 5. P value between experimental group in T10000 (p < 0.05)

T10000 X Z B ZB

X - 0.000 0.000 0.000

Z - 0.978 0.001

B - 0.003

ZB -

Figure 4. Comparison of SBSs before (T0) and after (T10000) the

thermocycing (n = 10). Same uppercase letters indicate no significant

difference in T0 and T10000. Same lowercase letters indicate no

significant difference between T0 and T10000.

A modified ARI score was used in the bonding failure measurements (22).

The criteria for modified ARI is shown in Table 2. Small amounts of

tagged resin left between the retention beads of the bracket were not

considered while scoring. In T0, all of the samples of X showed adhesive

failure at the zirconia and resin interface in which no resin was left on

the zirconia surface (ARI score 5). All of the samples of Z showed

adhesive failure at the resin and bracket interface in which all resin was

left on the zirconia surface (ARI score 1). Almost all the samples in B

showed adhesive failure at the zirconia and resin interface in which no

resin was left on the zirconia surface (ARI score 5). All the samples in

ZB showed mixed failure in which some resin was left on the zirconia

surface as well as on the bracket base (ARI score 3). In T10000, 90% of

the samples of X showed adhesive failure at the zirconia and resin

interface (ARI score 5). In Z, all showed adhesive failure at the resin and

bracket interface in which remnants of resin were left on all zirconia

surfaces regardless of thermocycling (ARI score 1). In B, adhesive

failures with no resin remained on the zirconia surface were mainly

occurred (ARI score 5). Almost all the samples in ZB showed mixed

failure in which some resin was left on the zirconia surface as well as on

the bracket base (ARI score 3) (Figures 5, 6, 7).

Figure 5. Comparison of modified adhesive remnant index (ARI) scores

before (T0) and after (T10000) the thermocycling (n = 10).

Figure 6. Representative SEM images of bonding failure observation of

T0 (×30). A and E showed adhesive failure at the zirconia-resin interface;

C showed adhesive failure at the resin-bracket interface; G showed

mixed failure at the zirconia-resin-bracket interface. Triangle (resin);

Square (captured resin between the retention beads).

Figure 7. Representative SEM images of bonding failure observation of

T10000 (×30). A and E showed adhesive failure at the zirconia-resin

interface; C showed adhesive failure at the resin-bracket interface; G

showed mixed failure at the zirconia-resin-bracket interface. Triangle

(resin); Square (captured resin between the retention beads).

4. Discussion

This study evaluated the effect of the MDP-containing ceramic

primer on the SBS of zirconia and the bracket. All the zirconia surfaces

were first uniformly grinded by 500-grit diamond disc to reproduce the

surface roughness of full-contoured zirconia crown made from a

diamond cutting bur. Then, the surfaces were sandblasted to increase the

surface area as used in bonding zirconia restorations. There is a concern

that the mechanical properties of zirconia are weakened by air-abrasion.

Still, micro-mechanical retention formed by sandblasting is preferred

since the bonding strength decreases dramatically when air-abrasion is

not performed (23, 24). The sandblasting conditions such as time,

particle size, pressure, and distance were set in this study to attain the

maximum bonding strength within a range in which the physical

properties of zirconia are not diminished (25).

The undercut and roughness of zirconia surfaces were increased

by sandblasting, but the results were limited due to hardness of zirconia.

Furthermore, decreased bonding strength was reported after the thermal

aging process (26). In control group X, which used Transbond XT

adhesion system after sandblasting without the primer treatment had the

lowest SBS (5.71 MPa) compared with other groups in T0 and SBS

significantly decreased in T10000 (2.03 MPa). Without the primer

treatment, the bonding strength of 6–8 MPa required by natural teeth was

not achieved, and it can be assumed that it will have insufficient bonding

strength in clinical situations (27, 28).

It is known that chemical bonds in the zirconia and the primer are

achieved between the functional monomers of the primer and the metal

ions of the ceramic surface (29, 30). Treating the zirconia surface with a

functional monomer such as 10-MDP (10-methacryloyloxydecyl

dihydrogen phosphate) is recommended for improving the bonding

strength with resin (29-31). More specifically, direct bonding occurs

between the dihydrogen phosphate group of 10-MDP and the zirconium

ion of the zirconia surface; secondary van der Waals bonding or

hydrogen bonding also occurs. In addition, the bonding strength is

improved by enhancing the surface wettability of the zirconia ceramic

(32, 33).

A commercial MDP-containing primer was used to condition the

zirconia and bracket surfaces. In the previous studies, to obtain a long-

term bonding strength between zirconia and resin, 10-MDP primer in

combination with sandblasting of the zirconia surface was effective (33,

34). The results of this experiment agree with this. When 10-MDP primer

was applied to zirconia (Z) or the base of the bracket (B), the SBS was

significantly higher. In case of T0, primer-treated group (Z, B and ZB)

had higher SBS than the control (X). A significantly higher SBS value

was observed when 10-MDP primer was applied to both the zirconia and

bracket surfaces (ZB). In case of T10000, the SBS in ZB was

significantly higher than in other experimental groups. It seemed that the

10-MDP containing primer clearly plays a role in increasing the bonding

strength between zirconia and resin and between the bracket and resin,

and the bonding strength differs according to the treated surface. Based

on the results, hypotheses 1 and 2 of this experiment were dismissed.

From the EDS analysis, a major component of the spherical

retentive bead on the surface of the bracket base was aluminium and

oxygen. Alumina also forms a chemical bond with the 10-MDP primer

because it is a metal oxide like zirconia (29). In B, on the primer-treated

bracket base, the possibility of chemical bond occurred between the

bracket and the primer is assumed to be contributed to the increased SBS.

Thermocycling is an artificial aging method to simulate the long-

term use of the brackets within the oral condition (35, 36). It can also

evaluate the hydrolysis resistance of the bonding interface (37).

Performing 10,000 cycles of thermocycling has a similar effect as

approximately 12 months of their use in the mouth (38). Therefore,

considering the period of orthodontic treatment, this experiment

performed 10,000 cycles of thermocycling. Many previous studies have

reported that the SBS was greatly reduced after the thermocycling (39,

40). In the results of this study as well, the average SBS was reduced

after the thermocycling. However, Z, B, and ZB, which had primer-

treated surface, showed higher bonding strength than 6-8 MPa required

by natural teeth and brackets, even after the thermocycling. Therefore,

regardless of which surface is treated, the clinically required level of

bracket bonding strength is available on the zirconia through surface

treatment using ceramic primer.

In case of T0 and T10000, about ARI, results that the resin had

continuity with the zirconia surface was shown in 100% of the samples

in Z. In 80-90% of the samples in B, there was no resin left on the

zirconia surface, and there was no significant difference between the

SBSs of group Z and group B. When the bracket is bonded to the zirconia

surface in dental clinics, the SBS can be raised if the primer is applied to

only the bracket base. The advantage of the ceramic bracket priming is

the preservation of the surface of restorations. When dealing with

orthodontic brackets, removing should be concerned after the certain

period. If the surface treatment is only limited on the restoration, the

higher the bond strength, the higher the possibility of the surface fracture.

The increased bond strength in the primer treated bracket, supported by

the results from ARI, it also gives the benefit of obtaining a better

zirconia surface integrity when the bracket is removed.

When the primer was applied to the adhesion surface of the

ceramic bracket (B), without surface treatment of the zirconia surface,

the bonding strength was increased to the level of zirconia surface

treatment (Z). In SBS testing, the bonding failure occurs at the point

where the load is concentrated. After the primer application on the

bracket surface, it is considered that the stress distribution becomes

uniform by acting as a single unit composed of ceramic and resin

resulting in the increased SBS. Further study, using techniques such as

finite element analysis to examine the reason is needed to explain the

increase in the SBS despite the occurrence of adhesive failure between

the zirconia and the resin when the primer is applied to the bracket base.

5. Conclusion

The following conclusions were obtained by this study; The primer

application on bracket base enhanced bonding strength as well as the

ceramic primer on zirconia; Applying the ceramic primer to both the

zirconia and the bracket base showed highest bonding strength. In

clinical practice, when sufficient bonding strength is required between

ceramic bracket and zirconia, ceramic primer application on both surface

is recommended.

References

1. Mclaren EA. All-ceramic alternatives to conventional metal-ceramic

restorations. Compendium, 1998;19:307–325.

2. Blatz MB. Long-term clinical success of all-ceramic posterior

restorations. Quintessence Int. 1985;33:415–426.

3. Özcan M, Vallittu PK. Effect of surface conditioning methods on the

bond strength of luting cement to ceramics. Dent Mater. 2003;19:725–

731.

4. Christel P, Meunier A, Heller M, Torre J, Peille C. Mechanical

properties and short�term in vivo evaluation of yttrium�oxide�partially�

stabilized zirconia. J Biomed Mater Res. 1989;23:45–61.

5. Al�Amleh B, Lyons K, Swain M. Clinical trials in zirconia: a

systematic review. J Oral Rehabil. 2010;8:641–652.

6. Bavbek NC, Roulet JF, Ozcan M. Evaluation of microshear bond

strength of orthodontic resin cement to monolithic zirconium oxide as

a function of surface conditioning method. J Adhes Dent. 2014;16:473–

480.

7. Piconi C, Maccauro G. Zirconia as a ceramic biomaterial. Biomaterials.

1999;20:1–25.

8. Meyenberg KH, Lüthy H, Schärer P. Zirconia Posts: A new all�ceramic

concept for nonvital abutment teeth. J Esthet Restor Dent. 1995;7:73–

80.

9. Lopes GC, Baratieri LN, De Andrada MAC, Maia HP. All-ceramic post,

core, and crown: technique and case report. J Esthet Restor Dent.

2001;13: 285–295.

10. Heintze SD, Rousson V. Survival of zirconia- and metal-supported

fixed dental prostheses: a systematic review. Int J Prosthodont.

2010;23:493–502.

11. Yi YA, Ahn JS, Park YJ, Jun SH, Lee IB, Cho BH, Son HH. The effect

of sandblasting and different primers on shear bond strength between

yttria-tetragonal zirconia polycrystal ceramic and a self-adhesive resin

cement. Oper Dent. 2015;40:63–71.

12. Tanaka R, Fujishima A, Shibata Y, Manabe A, Miyazaki T.

Cooperation of phosphate monomer and silica modification on

zirconia. J Dent Res 2008;87:666–670.

13. Özcan M, Nijhuis H, Valandro LF. Effect of various surface

conditioning methods on the adhesion of dual-cure resin cement with

MDP functional monomer to zirconia after thermal aging. Dent Mater.

2008;27: 99–104.

14. Rüttermann S, Fries L, Raab WHM, Janda R. The effect of different

bonding techniques on ceramic/ resin shear bond strength. J Adhes

Dent. 2008;10:197–203.

15. Maeda FA, Bello-Silva MS, De Paula Eduardo C, Miranda Junior WG.

Association of different primers and resin cements for adhesive

bonding to zirconia ceramics. J Adhes Dent. 2014;16: 261–265.

16. Magne P, Paranhos MP, Burnett LH. New zirconia primer improves

bond strength of resin-based cements. Dent Mater. 2010;26:345–352.

17. Abdelnaby YL. Effects of cyclic loading on the bond strength of metal

orthodontic brackets bonded to a porcelain surface using different

conditioning protocols. Angle Orthod. 2011;81:1064–1069.

18. Sarac YS, Kulunk T, Elekdag-Turk S, Sarac D, Turk T. Effects of

surface-conditioning methods on shear bond strength of brackets

bonded to different all-ceramic materials. Eur J Orthodont.

2011;33:667–672.

19. Falkensammer F, Freudenthaler J, Pseiner B, Bantleon HP. Influence

of surface conditioning on ceramic microstructure and bracket

adhesion. Eur J Orthodont. 2012;34:498–504.

20. Kwak JY, Jung HK, Choi IK, Kwon TY. Orthodontic bracket bonding

to glazed full-contour zirconia. Restor Dent Endod. 2016;41:106–113.

21. Amer JY, Rayyan MM. Effect of different surface treatments and

bonding modalities on the shear bond strength between metallic

orthodontic brackets and glazed monolithic zirconia crowns. J Orthod

Sci. 2018;7:23.

22. Damon PL, Bishara SE. Bond strength following the application of

chlorhexidine on etched enamel. Angle Orthod. 1997; 67:169–172.

23. Yang B, Barloi A. Influence of air-abrasion on zirconia ceramic

bonding using an adhesive composite resin. Dent Mater. 2010;26:44–

50.

24. Zhang Y, Lawn BR, Rekow ED, Thompson VP. Effect of sandblasting

on the long-term performance of dental ceramics. J Biomed Mater Res

B. 2004;71:381–386.

25. Kim SH, Lee JB, Han JS, Yeo IS. Effects of airborne-particle abrasion

protocol choice on the surface characteristics of monolithic zirconia

materials and the shear bond strength of resin cement. Ceram Int.

2016;42:1552–1562.

26. Kern M, Wegner SM. Bonding to zirconia ceramic: adhesion methods

and their durability. Dent Mater. 1998;14:64–71.

27. Reynolds IR. A review of direct orthodontic bonding. British Journal

of Orthodontics 1975;2:171–178.

28. Whitlock BO, Eick JD, Ackerman RJ, Glaros AG, Chappell RP. Shear

strength of ceramic brackets bonded to porcelain. Am J Orthod

Dentofac. 1994;106:358–364.

29. Blatz MB, Sadan A, Kern M. Resin-ceramic bonding: a review of the

literature. J Prosthet Dent. 2003;89:268–274.

30. Uo M, Sjøgren G, Sundh A, Goto M. Effect of surface condition of

dental zirconia ceramic on bonding. Dent Mater J. 2006;25:626–631.

31. Atsu SS, Kilicarslan MA, Kucukesmen HC, Aka PS. Effect of

zirconium-oxide ceramic surface treatments on the bond strength to

adhesive resin. J Prosthet Dent. 2006;95:430–436.

32. Kern M, Barloi A, Yang B. Surface conditioning influences zirconia

ceramic bonding. J Dent Res. 2009;88:817–822.

33. Byeon SM, Lee MH, Bae TS. Shear bond strength of Al2O3

sandblasted Y-TZP ceramic to the orthodontic metal bracket. Materials.

2017;10:148.

34. Tsuo Y, Yoshida K, Atsuta M. Effects of alumina-blasting and adhesive

primers on bonding between resin luting agent and zirconia ceramics.

Dent Mater J. 2006;25:669–674.

35. Yang B, Wolfart S, Scharnberg M. Influence of contamination on

zirconia ceramic bonding. J Dent Res. 2007;86:749–753.

36. Roulet JF, Söderholm KJM, Longmate J. Effects of treatment and

storage conditions on ceramic/composite bond strength. J Dent Res.

1995;74:381–387.

37. Da Silva EM, Miragaya L, Sabrosa CE, Maia LC. Stability of the bond

between two resin cements and an yttria-stabilized zirconia ceramic

after six months of aging in water. J Prosthet Dent. 2014;112:568–575.

38. Gale MS, Darvell BW. Thermal cycling procedures for laboratory

testing of dental restorations. J Dent.1999;27:89–99.

39. Valandro LF, Ozcan M, Amaral R, Pereira Leite FP, Bottino MA.

Microtensile bond strength of a resin cement to silica-coated and

silanized in-ceram zirconia before and after aging. Int J Prosthodont.

2007;20:70–72.

40. Blatz MB, Sadan A, Martin J, Lang B. In vitro evaluation of shear bond

strengths of resin to densely-sintered high-purity zirconium-oxide

ceramic after long-term storage and thermal cycling. J Prosthet Dent.

2004;91:356–362.

1. Introduction2. Materials and Methods2.1. Specimen Preparation2.2. Surface Treatment and Bracket Bonding2.3. Microstructure Observations2.4. Shear Bond Testing and Failure Mode Observations

3. Results3.1. Microstructure Observations3.2. Shear Bond Testing and Failure Mode Analysis

4. Discussion5. ConclusionReferencesAbstract in Korean

81. Introduction 12. Materials and Methods 4 2.1. Specimen Preparation 4 2.2. Surface Treatment and Bracket Bonding 4 2.3. Microstructure Observations 5 2.4. Shear Bond Testing and Failure Mode Observations 83. Results 10 3.1. Microstructure Observations 10 3.2. Shear Bond Testing and Failure Mode Analysis 104. Discussion 205. Conclusion 25References 26Abstract in Korean 30