Printer Friendly

ADHESIVE SYSTEM AFFECTS REPAIR BOND STRENGTH OF RESIN COMPOSITE/Adeziv Sistem Kompozit Rezinin Tamir Baglanma Dayanimini Etkiler.


Resin composite restorations are widely used by many dentists mostly with respect to their esthetic properties. Besides, developments in adhesive systems help clinicians to restore teeth by using the minimally invasive approach and prolong the lifespan of both tooth and restoration. Due to their increased service life, resin composite restorations may eventually suffer from degradations, fractures, discolorations, marginal gaps and secondary caries. In these circumstances, clinician is faced with a choice of either replacement or repair of the defective composite restoration. Replacement of a defective restoration would lead to larger restorations, which would eventually fail and consequently would lead to more complex restorations, root canal therapy and even tooth loss. This restorative cycle of death of the tooth (1, 2) could be prevented by the repair of the composite restorations, since repair requires little intervention to the restoration and the tooth. Although some restorations would need replacement; in the case of repair, treatment times and costs are reduced and tooth tissue is conserved (3). Clinical studies showed that, repair of the composite restorations may be a feasible and an alternative treatment to replacement (4, 5). However, replacement or repair of the restoration often depends on the decision of the dentist. Eventually, the choice of repair versus replacement of defective restorations are based on patient-centered or tooth-specific criteria (3). Tooth-specific criteria include but not limited to, localized marginal defects and stains, small fractures of the restoration, discolorations, localized degradations and fractures of surrounding tooth. Difficulties in patient cooperation, patients with compromised medical conditions are suitable for restoration repairs. Several methods, alone or in combination, are suggested to provide a sufficient bond between the old and the repair composite as follows; roughening with coarse diamond burs (6-9), phosphoric acid etching (6, 8, 10-14), sandblasting with aluminum oxide powder (6, 8, 15, 16) and application of silane coupling agent (17, 18). The use of an intermediate adhesive agent has also an impact on the bond strength of the repair restorations (9, 19). The purpose of this study was to evaluate the effects of different adhesive systems on the repair bond strength of aged resin composite. The null hypothesis tested was the type of the adhesive system would not have any effect on repair bond strength of the aged resin composite.

Materials and Methods

Experimental groups

This study was carried out in three main groups according to the adhesive system used. Each main group was further divided into two subgroups as aging and control (Table 1). In all groups the same resin composite resin material was applied (Table 2).

Specimen preparation

Ninety resin composite discs (8 mm diameter, 5 mm height) were incrementally prepared in a teflon mold using a resin composite (Clearfil Majesty Esthetic, Kuraray, Osaka, Japan). Each 2 mm-increment was light-cured for 20 s with a LED curing unit (Demetron II, Kerr, Orange, CA, USA) with an output intensity of 750 mW/[cm.sup.2]. After polymerization, discs were removed from mold and the bottom surfaces of the discs were additionally cured for 60 s. To create a uniform smear layer, topmost surfaces of the specimens were abraded with 600 grit silicon carbide paper under running water for 30 s. All discs were cleaned in distilled water using an ultrasonic cleaner. Cleaned specimens were kept in distilled water at 37[degrees]C for 24 h.

All composite discs were roughened by a diamond bur (150[micro]m grit size). A new diamond bur was used for each specimen. Each bur was used with five back and forth strokes for a total of 10 s using a high-speed hand-piece under air and water cooling. Specimens were thoroughly cleaned with water and air dried.

Testing procedures

Specimens were equally divided into 3 main groups according to the adhesive system used; two-step self-etch adhesive (2SE) (Clearfil SE Bond, Kuraray, Osaka, Japan), two-step total-etch adhesive (2TE) (XP Bond, Dentsply Caulk, Milford, CT, USA) and one-step self-etch adhesive (1SE) (I-Bond, Heraeus Kulzer, Hanau, Germany). Half of the specimens in each main group were subjected to thermal aging (TA) in distilled water for 50000 cycles (5-55[degrees]C, 60 s immersion time, 10 s transfer time) to simulate the aged, old composite. Other halves in each main group did not receive any aging protocol (Control) (n=15). Before the application of the adhesive systems, all specimens were rinsed with water and thoroughly air-dried. In each main group, adhesive systems were applied according to manufacturer's instructions (Table 3).

After applying the adhesives, specimens were placed on a test jig (Bonding Assembly, Ultradent, South Jordan, UT, USA) for placement of the repair restoration. A tube with an inner diameter of 2.39 mm and 3 mm in height were used for composite placement.

Specimens were repaired with the same resin composite material with two increments. Each layer was polymerized for 20 s from the top surface. After removal from the sample holder, specimens were circumferentially polymerized for a total of 40 s. After polymerization, all specimens were stored in distilled water at 37[degrees]C for 24 h before bond strength test. Shear bond strength (SBS) values of each specimen after repair was measured by a testing device (Shear Bond Tester, Bisco, Schaumburg, USA) equipped with a non-bevelled chisel-shaped metallic tip with a crosshead speed of 1.0 mm/min (Figure 1).

GraphPad Prism 6 statistical analysis software (Prism 6, GraphPad Software, CA, USA) was used in this study. As the data was completely numerical, distribution characteristics and equality of variances were checked with Kruskal-Wallis and Levene's tests. respectively. Since the normality assumptions have been met, two-way analysis of variance (ANOVA) test was selected for comparing multiple groups. Tukey's honestly significant difference (HSD) post-hoc test was usedfor subsequent pairwise comparisons. Confidence interval was set to 95% and probability (p) values less than 0.05 were considered as statistically significant.


Two-way ANOVA results revealed no interaction between the adhesive type and thermal aging. However, adhesive type and thermal aging significantly affected SBS values (p<0.001). The obtained SBS values and their respective standard deviations are shown in Table 4. No statistically significant difference was found between 2TE-TA and 2SE-TA. Bond strengths of 2TE-TA and 2SE-TA were significantly lower than their corresponding control groups (2TE-control, 2SE-control) (p<0.0001 and p=0.005 respectively). Bond strength values of 1SE-TA were not statistically different than 1SE-control.


This study evaluated the initial (24 h) repair bond strengths of thermally aged resin composite in vitro repaired with three different adhesive systems; two-step total-etch, two-step self-etch and one-step self-etch systems. Type of the adhesive significantly affected repair bond strength of the aged resin composite (p<0.05). Therefore, the null hypothesis postulating that the type of adhesive would not have any effect on repair bond strength of the resin composite was rejected. The two-step self-etch and two-step total-etch adhesives performed better when compared with the one-step self-etch adhesive in both aged and non-aged groups (p<0.05). When there is a need for repair on the composite restoration, macro-mechanical, micro-mechanical retention and chemical adhesion are equally important aspects to consider. It is possible to obtain a chemical bond between the old and fresh composite (20), since within two weeks free radicals inside the old resin composite may still be available for a chemical reaction (21). In this study, aging period was roughly equivalent to 5 years of clinical service (22), which was much higher than 2 weeks; thus, the possibility of the chemical bond between the composites was eliminated. Macro-mechanical retention can be obtained by creating retention holes and undercuts. Roughening the surface of the old composite with a coarse diamond bur, may provide better macro-mechanical retention (7-9, 14, 23). Most significant mechanism acting on the bond between the old and the fresh composite is micro-mechanical interlocking (24, 25). Use of a readily available diamond bur is a simple method to apply. However, the use of diamond burs with varying grit sizes does not yield different bond strength values (6, 8, 12, 26). Therefore, in the present study, a coarse diamond bur (150 [micro]m grit size) was used to aid in micro-mechanical interlocking, as suggested by other studies (4, 5, 7, 9).

Use of an intermediate adhesive agent also plays a significant role in the repair process of resin composite restorations (9, 19). Bond strength of the repair restoration is significantly improved when the adhesives are applied after surface pretreatments (9, 19, 27). In this study, three different adhesive systems were evaluated, a two-step total-etch adhesive, a two-step self-etch adhesive and a one-step self-etch adhesive. Two-step total-etch adhesive, XP Bond, showed similar repair bond strength values in both aged and non-aged composite groups when compared with the two-step self-etch adhesive, the Clearfil SE Bond. Similar results have been previously reported (28). The one-step self-etch adhesive, I-Bond, showed significantly lower repair bond strength values in both aged and non-aged composite groups when compared to other adhesive systems which is in agreement with the findings reported by Teixeria et al. (29).

Resin composite restorations are constantly exposed to oral fluids and may eventually absorb water and swell. This may lead to degradation of the resin and leaching of the filler particles (30). Since self-etch adhesives are hydrophilic, self-etching primers may therefore effectively bind to the surface of the old composite through interaction of the phosphate groups of the adhesive systems (9). Similar to Cavalcanti et al. (8); in the present study, repair of the aged composite with Clearfil SE Bond, which contains a functional monomer, 10-methacryloyloxydecyl dihydrogenphosphate (10-MDP), showed higher bond strength values than those of other bonding agents. This may be attributed to the wetting ability of 10-MDP applied on composites. However, further research is still needed to test this hypothesis.

The use of total-etch systems requires etching with a phosphoric acid. Acid etching helps removal of the debris on the surface of the restoration to be repaired and could expose the underlying surface and filler (31). This would increase the surface area (23) and wettability (32) of the resin composite to be repaired. For the self-etch adhesives similar effect can be achieved by the acidic primer of the system (8). Although composites are mostly hydrophobic, they absorb some water during service (29). The ability of the adhesive systems to penetrate into the aged composite surface depends on their chemical affinity and the degree of hydration of the composites (29, 33). Application procedure of two-step self-etch adhesives involves etching of the surface with a hydrophilic self-etching primer followed by covering with a rather hydrophobic adhesive layer. One-step adhesives are generally more hydrophilic than their two-step counterparts and contain highly acidic monomers (34). Absence of the additional adhesive layer may therefore negatively influence their bonding ability to composite. Repair bond strengths of the aged composites were significantly lower than those of non-aged composites for the two-step self-etch and two-step total-etch adhesives. For the one-step self-etch adhesive, bond strength was not statistically different regardless of aging. However, bond strength values of the one-step self-etch adhesive (control, 8.93 [+ or -] 1.90; thermal aging, 5.63 [+ or -] 1.56) were significantly lower when compared to other adhesive systems and was below the clinically acceptable level which was reported to be a minimum of 18 MPa or between 20-25 MPa (19, 27, 35). All of the failure modes observed in this study was of adhesive type and this may indicate that the bond strength may be weaker than the cohesive strength of the resin composite used, regardless of aging, although cohesive strength of the resin composite was not measured. It was reported that the repair bond strength of the resin composites vary between 20% and 96% of the cohesive strength of the intact composite (9, 28, 36, 37). It is still not possible to offer a universal repair protocol for all composites, since many of the studies have found different results (6, 19, 29, 38, 39). However, one should choose a protocol which is safer to use intraorally. Surface modification techniques such as sandblasting and application of hydrofluoric acid may have side effects (11). Therefore, the use of an intermediate adhesive system after pretreating the composite surface with a coarse diamond bur could be a method which is safer and easier to perform.


Within the limitations of this experimental study, repair of aged composites using a two-step self-etch or a two-step total-etch adhesive demonstrated higher bond strength values than repair with a one-step self-etch adhesive. Further studies are needed to assess the performance of these adhesive with different resin composites and in longer periods of aging.

Source of funding

None declared.

Conflict of interest

None declared.


(1.) Elderton RJ. Restorations without conventional cavity preparations. Int Dent J 1988;38(2):112-118.

(2.) Simonsen RJ. New materials on the horizon. J Am Dent Assoc 1991;122(7):24-31.

(3.) Blum IR, Jagger DC, Wilson HH. Defective dental restorations: To repair or not to repair? Part 1: Direct composite restorations. SADJ 2011;66(3):114-118.

(4.) Gordan VV, Garvan CW, Blaser PK, Mondragon E, Mjor IA. A long-term evaluation of alternative treatments to replacement of resin-based composite restorations: Results of a seven-year study. J Am Dent Assoc 2009;140(12):1476-1484.

(5.) Moncada G, Fernandez E, Martin J, Arancibia C, Mjor IA, Gordan VV. Increasing the longevity of restorations by minimal intervention: A two-year clinical trial. Oper Dent 2008;33(3):258-264.

(6.) Bonstein T, Garlapo D, Donarummo J, Jr., Bush PJ. Evaluation of varied repair protocols applied to aged composite resin. J Adhes Dent 2005;7(1):41-49.

(7.) Bouschlicher MR, Reinhardt JW, Vargas MA. Surface treatment techniques for resin composite repair. Am J Dent 1997;10(6):279-283.

(8.) Cavalcanti AN, De Lima AF, Peris AR, Mitsui FH, Marchi GM. Effect of surface treatments and bonding agents on the bond strength of repaired composites. J Esthet Restor Dent 2007; 19(2):90-98; discussion 99.

(9.) Shahdad SA, Kennedy JG. Bond strength of repaired anterior composite resins: An in vitro study. J Dent 1998;26(8):685-694.

(10.) Loomans BA, Cardoso MV, Opdam NJ, Roeters FJ, De Munck J, Huysmans MC, Van Meerbeek B. Surface roughness of etched composite resin in light of composite repair. J Dent 2011 ;39(7):499-505.

(11.) Loomans BA, Cardoso MV, Roeters FJ, Opdam NJ, De Munck J, Huysmans MC, Van Meerbeek B. Is there one optimal repair technique for all composites? Dent Mater 2011;27(7):701-709.

(12.) Papacchini F, Toledano M, Monticelli F, Osorio R, Radovic I, Polimeni A, Garcia-Godoy F, Ferrari M. Hydrolytic stability of composite repair bond. Eur J Oral Sci 2007;115(5):417-424.

(13.) Rathke A, Tymina Y, Haller B. Effect of different surface treatments on the composite-composite repair bond strength. Clin Oral Investig 2009;13(3):317-323.

(14.) Yesilyurt C, Kusgoz A, Bayram M, Ulker M. Initial repair bond strength of a nano-filled hybrid resin: Effect of surface treatments and bonding agents. J Esthet Restor Dent 2009;21 (4): 251 -260.

(15.) Hannig C, Laubach S, Hahn P, Attin T Shear bond strength of repaired adhesive filling materials using different repair procedures. J Adhes Dent 2006;8(1):35-40.

(16.) Rinastiti M, Ozcan M, Siswomihardjo W, Busscher HJ. Immediate repair bond strengths of microhybrid, nanohybrid and nanofilled composites after different surface treatments. J Dent 2010;38(1):29-38.

(17.) Hisamatsu N, Atsuta M, Matsumura H. Effect of silane primers and unfilled resin bonding agents on repair bond strength of a prosthodontic microfilled composite. J Oral Rehabil 2002;29(7):644-648.

(18.) Soderholm KJ, Roberts MJ. Variables influencing the repair strength of dental composites. Scand J Dent Res 1991;99(2):173-180.

(19.) Turner CW, Meiers JC. Repair of an aged, contaminated indirect composite resin with a direct, visible-light-cured composite resin. Oper Dent 1993;18(5):187-194.

(20.) Dall'Oca S, Papacchini F, Goracci C, Cury AH, Sun BI, Tay FR, Polimeni A, Ferrari M. Effect of oxygen inhibition on composite repair strength over time. J Biomed Mater Res B Appl Biomater 2007;81(2):493-498.

(21.) Burtscher P. Stability of radicals in cured composite materials. Dent Mater 1993;9(4):218-221.

(22.) Gale MS, Darvell BW. Thermal cycling procedures for laboratory testing of dental restorations. J Dent 1999;27(2):89-99.

(23.) Fawzy AS, El-Askary FS, Amer MA. Effect of surface treatments on the tensile bond strength of repaired water-aged anterior restorative micro-fine hybrid resin composite. J Dent 2008;36(12):969-976.

(24.) Blum IR, Jagger DC, Newton JT, Wilson NH. The opinions of manufacturers of resin-based composite materials towards the repair of failing composite restorations. Prim Dent Care 2009;16(4):149-153.

(25.) Soderholm KJ. Flexure strength of repaired dental composites. Scand J Dent Res 1986;94(4):364-369.

(26.) Dall'oca S, Papacchini F, Radovic I, Polimeni A, Ferrari M. Repair potential of a laboratory-processed nano-hybrid resin composite. J Oral Sci 2008;50(4):403-412.

(27.) Kupiec KA, Barkmeier WW. Laboratory evaluation of surface treatments for composite repair. Oper Dent 1996;21(2):59-62.

(28.) Celik EU, Ergucu Z, Turkun LS, Ercan UK. Tensile bond strength of an aged resin composite repaired with different protocols. J Adhes Dent 2011;13(4):359-366.

(29.) Teixeira EC, Bayne SC, Thompson JY, Ritter AV, Swift EJ. Shear bond strength of self-etching bonding systems in combination with various composites used for repairing aged composites. J Adhes Dent 2005;7(2): 159-164.

(30.) Ferracane JL, Marker VA. Solvent degradation and reduced fracture toughness in aged composites. J Dent Res 1992;71(1): 13-19.

(31.) Ahmadizenouz G, Esmaeili B, Taghvaei A, Jamali Z, Jafari T, Amiri Daneshvar F, Khafri S. Effect of different surface treatments on the shear bond strength of nanofilled composite repairs. J Dent Res Dent Clin Dent Prospects 2016;10(1):9-16.

(32.) El-Askary FS, Fawzy AS, Abd Elmohsen HM. Tensile bond strength of immediately repaired anterior microfine hybrid restorative composite using nontrimmed hourglass specimens. J Adhes Dent 2009;11(1):41-47.

(33.) Lastumaki TM, Kallio TT, Vallittu PK. The bond strength of light-curing composite resin to finally polymerized and aged glass fiber-reinforced composite substrate. Biomaterials 2002;23(23):4533-4539.

(34.) Van Landuyt KL, Snauwaert J, De Munck J, Peumans M, Yoshida Y, Poitevin A, Coutinho E, Suzuki K, Lambrechts P, Van Meerbeek B. Systematic review of the chemical composition of contemporary dental adhesives. Biomaterials 2007;28(26):3757-3785.

(35.) Puckett AD, Holder R, O'Hara JW. Strength of posterior composite repairs using different composite/bonding agent combinations. Oper Dent 1991;16(4):136-140.

(36.) Kim JS, Choi YH, Cho BH, Son HH, Lee IB, Um CM, Kim CK. Effect of light-cure time of adhesive resin on the thickness of the oxygen-inhibited layer and the microtensile bond strength to dentin. J Biomed Mater Res B Appl Biomater 2006;78(1):115-123.

(37.) Oztas N, Alacam A, Bardakcy Y The effect of air abrasion with two new bonding agents on composite repair. Oper Dent 2003;28(2): 149-154.

(38.) Gregory WA, Pounder B, Bakus E. Bond strengths of chemically dissimilar repaired composite resins. J Prosthet Dent 1990;64(6):664-668.

(39.) Pounder B, Gregory WA, Powers JM. Bond strengths of repaired composite resins. Oper Dent 1987;12(3):127-131.


Department of Restorative Dentistry Faculty of Dentistry Eskisehir Osmangazi University

Corresponding Author: Ozgur IRMAK

Department of Restorative Dentistry

Faculty of Dentistry Eskisehir Osmangazi University

26480 Odunpazari-Eskisehir / Turkey

Phone: +90 222 239 37 50


Received: 28/10/2016

Accepted: 01/02/2017
Table 1. Experimental groups (2SE, two-step self-etch adhesive; 2TE,
two-step total-etch adhesive; 1SE, one-step self-etch adhesive; TA,
thermal aging).

Groups       Composite                  Thermal Aging  Adhesive System

2SE-control  Clearfil Majesty Esthetic  -              Clearfil SE Bond
2SE-TA       Clearfil Majesty Esthetic  +              Clearfil SE Bond
2TE-control  Clearfil Majesty Esthetic  -              XP Bond
2TE-TA       Clearfil Majesty Esthetic  +              XP Bond
1SE-control  Clearfil Majesty Esthetic  -              I Bond
1SE-TA       Clearfil Majesty Esthetic  +              I Bond

Groups       Repair Composite

2SE-control  Clearfil Majesty Esthetic
2SE-TA       Clearfil Majesty Esthetic
2TE-control  Clearfil Majesty Esthetic
2TE-TA       Clearfil Majesty Esthetic
1SE-control  Clearfil Majesty Esthetic
1SE-TA       Clearfil Majesty Esthetic

Table 2. Materials used in the study (4-META, 4-methacryloyloxyethyl
trimellitate anhydride; 10-MDP, 10-methacryloyloxydecyl
dihydrogenphosphate; Bis-GMA, bisphenolA diglycidylmethacrylate; HEMA,
2-hydroxyethyl methacrylate; PENTA, dipentaerythritolpentaacrylate
monophosphate; TCB, butan- 1, 2, 3, 4-tetracarboxylic acid
di-2-hydroxyethylmethacrylate ester; TEGDMA, triethylene glycol
dimethacrylate; UDMA, urethane dimethacrylate.

Brand             Type

Clearfil Majesty  Resin composite
Clearfil SE Bond  2-step self-etch adhesive
XP Bond           2-step total-etch
I Bond            1-step self-etch adhesive

Brand             Ingredients

Clearfil Majesty  Silanated barium glass filler (40%vol, 0.37-1.5
Esthetic          [micro]m particle size), pre-polymerized organic
                  filler, Bis-GMA, hydrophobic aromatic
                  dimethacrylate, dl-camphorquinone
Clearfil SE Bond  Primer: MDP, HEMA, hydrophilic dimethacrylate,
                  photo-initiator, water
                  Bond: MDP, HEMA, Bis-GMA, hydrophobic
                  dimethacrylate, photo-initiator, silanated colloidal
XP Bond           PENTA, TCB resin, UDMA, TEGDMA, HEMA, nanofiller,
                  camphorquinone, butilated benzenediol, tertiary
I Bond            UDMA, 4-META, glutaraldehyde, acetone, water,
                  photo-initiator, stabilizer

Brand             Manufacturer

Clearfil Majesty  Kuraray Co., Ltd,
Esthetic          Osaka, Japan
Clearfil SE Bond  Kuraray Co., Ltd,
                  Osaka, Japan
XP Bond           Dentsply Caulk,
                  Milford, CT, USA
I Bond            Heraeus Kulzer
                  GmbH, Hanau,

Table 3. Application protocols of the adhesive systems.

Adhesive      Application Protocol

Clearfil SE   Apply the primer to the surface with a brush, wait for
Bond          20s, air dry. Apply the bond to the surface with a brush,
              air dry. Light cure for 10s.
XP Bond       Apply the phosphoric acid gel for 15s, rinse with water
              for 15s, air dry lightly.
              Apply the adhesive to the surface, wait for 20s, air dry.
              Light cure for 20s.
I Bond Self-  Apply with a brush by light rubbing for 20s. Air dry
Etch          for 5s. Light cure for 20s.

Table 4. Shear bond strengths (MPa) and their standard deviations
(Means sharing a letter are not significantly different, uppercase
letters compare means in the same row, Lowercase letters compare means
in the same column).

                    2SE (SE Bond)           2TE (XP Bond)

Control             18.19 [+ or -] 3.20 Aa  19.15 [+ or -] 5.10 Aa
Thermal Aging (TA)  13.66 [+ or -] 3.55 Ab  12.78 [+ or -] 3.46 Ab

                    1SE (I Bond)

Control             8.93 [+ or -] 1.90 Ba
Thermal Aging (TA)  5.63 [+ or -] 1.56 Ba
No portion of this article can be reproduced without the express written permission from the copyright holder.
Copyright 2017 Gale, Cengage Learning. All rights reserved.

Article Details
Printer friendly Cite/link Email Feedback
Author:Irmak, Ozgur; CelIksoz, Ozge; Yilmaz, Begum; Yaman, Batu Can
Publication:Journal of Istanbul University Faculty of Dentistry
Article Type:Report
Date:Oct 1, 2017

Terms of use | Privacy policy | Copyright © 2022 Farlex, Inc. | Feedback | For webmasters |