/home/opencode/cpanel/stomaeduj_hacked/uploads/Art-1-no4-y2020.pdf DENTAL MATERIALS www.stomaeduj.com THE MICRO-SHEAR BOND STRENGTH OF TWO Original Articles DIFFERENT REPAIR SYSTEMS TO INDIRECT RESTORATIVE MATERIALS Ayșe Atay1a* , Lamia Najafova2b , Huseyin Mehmet Kurtulmus2c , Aslihan Üşümez3d 1 Department of Prosthodontics, Faculty of Dentistry, Altinbaș University, TR-34147, Bakırkoy/Istanbul, Turkey 2 Department of Prosthodontics, Faculty of Dentistry, Istanbul Aydin University, TR-34295, Kucukcekmece/Istanbul, Turkey 3 Private Clinic, TR-34147, Bakırkoy/Istanbul, Turkey a DDS, PhD, Assistant Professor; e-mail: ayse.atay@altinbas.edu.tr; ORCIDiD: https://orcid.org/0000-0002-5358-0753 b DDS, Lecturer; e-mail: lamia.najaf@gmail.com; ORCIDiD: https://orcid.org/0000-0001-6900-8308 c DDS, PhD; e-mail: h_kurtulmus@yahoo.com; ORCIDiD: https://orcid.org/0000-0001-5013-3766 d DDS, PhD; e-mail: asli_u@hotmail.com; ORCIDiD: https://orcid.org/0000-0002-7222-7322 ABSTRACT https://doi.org/10.25241/stomaeduj.2020.7(4).art.1 Introduction The aim of this study was to evaluate the micro-shear bond strength (μSBS) of different repair systems (Clearfil Repair, iGOS Repair) to restorative materials for CAD/CAM (Cerasmart, Lava Ultimate, InCoris TZI , VITA Suprinity, VITA Mark II, IPS e.max CAD, IPS Empress CAD). Methodology The 140 1.2 mm-thick specimens were prepared from CAD/CAM blocks (n=20) and thermocycled (10,000 cycles, 5–55°C, dwell time 20s). The specimens were randomly divided into two groups according to the repair system: Clearfil Repair (40% phosphoric acid+mixture of Clearfil Porcelain Bond Activator and Clearfil SE Bond Primer+Clearfil SE Bond+CLEARFIL MAJESTY ES-2) and iGOS Repair (40% phosphoric acid+ Multi Primer LIQUID+ iGOS Bond+ iGOS Universal). The composite resins were polymerized. All specimens were stored in distilled water at 37°C for 24 hours. The μSBS test was performed with a micro-shear testing machine (at 1 mm/min). The data were analyzed using two-way ANOVA, Tukey’s multiple comparison tests at a significance level of p<0.05. Each failure modes were examined under a stereomicroscope at×16 magnification. Results The type of CAD/CAM restorative material and repair system showed a significant effect on the μSBS (p<0.05). Specimens repaired with the iGOS Repair system showed the highest μSBS values than the Clearfil Repair system among all tested materials except for the InCoris TZI group (p<0.05). Conclusion All groups, except for the InCoris TZI group, repaired with iGOS Repair system showed higher μSBS than Clearfil Repair. The type of restoration and repair material is important in the success of the fracture repair. KEYWORDS Micro-Shear Bond Strength; Repair System; CAD-CAM Materials; Adhesion; Dental Prosthesis Repair. 1. INTRODUCTION restorations which arise from traditional construction technique [1-4]. Advances in ceramic materials have enabled Nowadays, there are many types of CAD/CAM the production and application of full ceramic materials mainly metal alloys, ceramic materials, restorations without metal. Especially in the last composite resins, and PMMA’s. CAD/CAM ceramic decade, the development of CAD/CAM systems blocks could be feldspathic ceramics, lithium has provided improvement of full ceramic systems disilicate glass ceramics, yttrium tetragonal zirconia and overcoming some of disadvantages of the polycrystals or leucite-reinforced glass ceramics. OPEN ACCESS This is an Open Access article under the CC BY-NC 4.0 license. Peer-Reviewed Article Citation: Atay A, Najafova L, Kurtulmus HM, Üşümez A. The micro-shear bond strength of two different repair systems to indirect restorative materials. Stoma Edu J. 2020;7(4):233-241. Received: September 16, 2020; Revised: September 27, 2020; Accepted: October 25, 2020; Published: October 26, 2020 *Corresponding author: Assistant Professor Dr. Ayșe Atay, Department of Prosthodontics, Faculty of Dentistry, Altinbaș University, İncirli Avenue No:11/A, 34147, Bakırkoy, Istanbul, Turkey Tel.: +90-212-709 45 28, Fax: +90-212-445 81 71; e-mail: ayse.atay@altinbas.edu.tr Copyright: © 2020 the Editorial Council for the Stomatology Edu Journal. Stoma Edu J. 2020;7(4): 233-241 pISSN 2360-2406; eISSN 2502-0285 233 Atay A, et al. www.stomaeduj.com Original Articles Figure 2. Specimen testing. Figure 1. Schematic illustration of specimen preparation. Table 1. Brand names, groups, abbreviations, lot numbers, material types, compositions and manufacturers of the CAD/CAM restorative materials used in the study. Brand Name Material type Composition Manufacturer Cerasmart Hybrid ceramic Matrix: Bis-MEPP, UDMA, DMA GC Corp., Tokyo, Japan Filler: silica, barium glass nanoparticles (71 wt%) Lava Ultimate Resin nano ceramic Matrix: Bis-GMA, UDMA, Bis-EMA, TEGDMA 3M ESPE, Seefeld, Filler SiO2, ZrO2, aggregated ZrO2/ SiO2 cluster Germany (80wt%) InCoris TZI Zirconium oxide sinter ZrO2+HfO2+Y2O3 ≥99.0%, Y2O3 > 4.5 - ≤ 6.0%, Sirona Dental Systems ceramic HfO2 ≤ 5% GmbH, Bensheim, Al2O3 ≤ 0.5%, Other oxides ≤ 0.5% Germany VITA Suprinity Zirconia-reinforced 56–64% SiO2, 15–21% Li2O, 8-12% ZrO2, 3-8% P2O5, Vita Zahnfabrik H. Rauter lithium silicate ceramic 1-4% K2O, 0-4% CeO2 GmbH, Bad Säckingen, Germany VITA Mark II Feldspar ceramic 56-64% SiO2, 20-23% Al2O3, 6-9% Na2O, 6-8% K2O, VITA Zahnfabrik, Bad 0.3-0.6% CaO, 0-0.1% TiO2 Säckingen, Germany IPS e.max CAD Lithium disilicate glass- 57-80% SiO2, 11-19% Li2O, 0-13% K2O, 0-11% P2O5, Ivoclar Vivadent, Schaan, ceramic 0-8% ZrO2, 0-8% ZnO, 0-5% Al2O3, 0-5% MgO, 0-8% Liechtenstein Colouring oxides IPS Empress CAD Leucite-reinforced glass 60-65% SiO2, 16-20% Al2O3, 10-14% K2O, 3.5-6.5% Ivoclar Vivadent, Schaan, ceramic Na2O, 0.5-7% Other oxides, 0.2-1% Pigments Liechtenstein Abbreviations: Bis-MEPP: 2,2-Bis(4- methacryloxypolyethoxyphenyl) propane; UDMA: urethane dimethacrylate; DMA: dimethacrylate; Bis-GMA: bisphenol A-glycidyl methacrylate; Bis-EMA: ethoxylated bisphenol A-glycol dimethacrylate; TEGDMA: triethylene glycol dimethacrylate; SiO2: silicon dioxide; ZrO2: zirconium dioxide; HfO2: hafnium dioxide, Y2O3:yttrium Oxide; Al2O3: aluminium oxide; Li2O: lithium oxide; P2O5: phosphorus pentoxide, K2O: potassium oxide; CeO2: cerium oxide; CaO: calcium oxide; TiO2: titanium dioxide; ZnO: zinc oxide; MgO: magnesium oxide; Na2O: sodium oxide. In addition to these materials, polymer-infiltrated and cost [12,13]. However, the studies which have ceramics, nano-particulate resin composite and revealed higher survival rates when restorations zirconia-reinforced lithium silicate ceramics have repaired with repair kits compared to replacement been recently introduced for CAD/CAM use [5]. of restorations should be considered [14,15]. Today, It is stated that various factors such as failure on the the repair of ceramic restorations is divided into two bonding interface, parafunctional habits, internal as direct (oral repair) and indirect repair (extraoral stress, and inadequate occlusal adjustment can cause repair). Indirect repair is not preferred by clinicians failure in spite of improvements in CAD/CAM materials because of additional trauma to the restoration [6]. In addition to these, chipping is shown as the and soft tissue [16]. When resin-based cements most common cause of failure due to the brittleness are used for a full-ceramic cementation protocol, properties of some ceramics [7,8]. The fracture rates an intraoral repair system should be preferred on of restorations are reported approximately 2-16%, account of the difficulty of restoration removal [17]. and 75% in the maxilla [9,10]. These fractures are Repairing a ceramic fracture with composite resin is classified as cohesive (within repair system or the more conservative, less time consuming, easier and restorative material), adhesive (between the repair less costly than the complete replacement of the system and restorative material), and mixed (both restoration [18]. A number of surface conditioning cohesive and adhesive) [11]. The decision to repair methods are proposed for restorations to increase or replace the fracture restoration is based on many bond strength with resin composites. However, factors such as fracture type, material properties there is still no standard protocol for ceramic 234 Stoma Edu J. 2020;7(4): 233-241 pISSN 2360-2406; eISSN 2502-0285 The bond strength of different repair systems www.stomaeduj.com Original Articles Table 2. Brand names, chemical compositions and manufacturers of the repair systems used in the study. Brand Chemical composition Manufacturer Clearfil Repair Clearfil SE Bond Primer MDP, HEMA, dimethacrylate monomer, water, Kuraray, Okayama, Japan photoinitator Clearfil Porcelain Bond Bisphenol a polyethoxy dimethacrylate, MPS Activator Clearfil SE Bond Bond Silanated colloidal silica bisphenol A CLEARFIL MAJESTY ES-2 0.37-1.5 µm silanated barium glass filler, prepolymerized organic filler, BisGMA, hydrophobic aromatic dimethacrylate, dl-camphorquinone, accelerators, initiators, pigments, 78%wt filled iGOS Repair Multi Primer LIQUID Ethanol, thiol compound, silane coupling agent Yamakin CO., LTD., Kochi, Japan iGOS Bond ethanol, distillated water, methacrylate monomer, phosphate monomer, carboxylic monomer, photopolymerization initiator, etc. iGOS Universal Methacrylate monomer, ceramics cluster filler (1-20 µm), submicron filler (SiO2-ZrO2-Al2O3:200-600 nm ), spherical nano-filler (SiO2:20 nm), fluoride sustained release filler (glass:700 nm), inorganic filler content rate approximately 55 vol% Abbreviations: MDP: 10-Methacryloyloxydecyl dihydrogen phosphate, HEMA: 2-hydroxyethyl methacrylate, MPS: 3- metacryloxypropyl trimethoxysilane, Bis-GMA: bisphenol A-glycidyl methacrylate, SiO2: silicon dioxide, ZrO2: zirconium dioxide, Al2O3: aluminium oxide. . repair systems [19]. Micromechanical retention and and Table 2. One hundred and forty 1.2 mm-thick chemical bonding procedures are necessary to specimens were prepared from CAD/CAM blocks increase the bonding strength between the ceramic using a low‑speed diamond saw (Mecatome T180; and resin composite. Mechanical surface treatments Presi, Grenoble, France) under water cooling (n=20). provide micromechanical locking by creating micro VITA Suprinity and IPS e.max CAD discs were roughness at the ceramic surface [20]. Hydrofluoric crystallized (VITA Suprinity: 840°C for 8 minutes, VITA acid (HF) is the most commonly used chemical Vacumat 40, VITA Zahnfabrik; IPS e.max CAD: 770°C agent for roughening the porcelain surface. The for 5 min, then 850°C for 10 min, Ivoclar Vivadent AG) other micromechanical bonding procedures include following the manufacturers’ instructions. InCoris airborne particle abrasion by using aluminum TZI discs were sintered for 2 hours at a temperature oxide, tribochemical silica coating, or laser etching starting from 25°C to 1510°C according to the [21,22]. Sandblasting with Al2O3 particles increase manufacturer’s recommendations. Following the the efficiency of the porcelain surface and the thermocycling (10,000 thermal cycles between resin composite-porcelain bond strength. The 5°C-55°C with dwell and transfer times of 20 seconds, application of silane increases the wettability of the Thermocycler, Esetron Smart Robotechnologies, ceramic and support the bond between the silica Ankara, Turkey), all specimens were embedded in (inorganic phase) in the restorative materials and a self-cure acrylic resin (Vertex Self Curing; Vertex- the methacrylate groups (organic phase) in the resin Dental, Netherlands) and polished with 400, 800, with Met-methacryloxypropyl trimethoxysilane and 1200 SiC sheets respectively. The specimens of (MPS) in its content [23-25]. each CAD/CAM materials were randomly divided The aim of this study was to investigate the micro- into two subgroups to constitute the 14 test groups shear bond strength (μSBS) of two different repair for repair procedure (n=10). systems to seven different types of CAD/CAM All tested groups were etched using 40% phosphoric restorative materials and the failure types after μSBS acid (K-ETCHANT Syringe, Kuraray, Osaka, Japan) for test. The null hypotheses for this study were: a) There 5 seconds, rinsed under a water spray and dried to were no differences among the CAD/CAM restorative clean the adhesive surface except for the InCoris TZI materials and b) between two repair systems. specimens, which Isopropyl alcohol was used for the same aim. For the roughening procedure, InCoris 2. MATERIALS AND METHODS TZI, Lava Ultimate and Cerasmart specimens were sandblasted with 50 μm Al2O3 at 2.8 bar pressure The tested CAD/CAM restorative materials and (Renfert GmbH, Hilzingen, Germany) for 30 seconds two ceramic repair systems are shown in Table 1 at a distance of 10 mm according to instruments of Stoma Edu J. 2020;7(4): 233-241 pISSN 2360-2406; eISSN 2502-0285 235 Atay A, et al. www.stomaeduj.com Original Articles Table 3. Results of two-way ANOVA. Source Type III Sum of Squares df Mean Square F Sig. Ceramic type 291.424 6 48.571 38.480 .001 Repair system 187.272 1 187.272 148.367 .001 Ceramic type * Repair system 294.759 6 49.126 38.921 .001 Table 4. Mean and SD values for µSBS (MPa). Clearfil Repair iGOS Repair System µSBS values µSBS values (Mean ± SD) (Mean ± SD) Cerasmart 7.41±0.70A, abc 10.06±0.63B, a Lava Ultimate 4.66±0.90 A, d 7.16±1.05B, b InCoris TZI 8.69±1.03A, c 4.76±1.24B, c VITA Suprinity 8.17±1.34A, bc 12.80±1.73B, d VITA Mark II 7.29±1.05 A, abc 8.09±0.75A, b IPS e.max CAD 6.95±1.01A, ab 11.60±1.18B, de IPS Empress CAD 6.34±1.53 A, a 11.37±1.10B, e * Capital superscripts correspond 70the same line, lower case superscripts correspond to the same column. *Significantly different at p <0.05. Table 5. Failure mode distribution. Adhesive (%) Cohesive (%) Mixed (%) Clearfil iGOS Clearfil iGOS Clearfil iGOS p p p Repair Repair Repair Repair Repair Kit Repair Cerasmart 40 10 .303 0 0 - 60 90 .303 Lava Ultimate 50 0 .002* 0 50 .002* 50 50 - InCoris TZI 0 90 .001* 30 0 .211 70 10 .001* VITA Suprinity 20 20 - 20 20 - 60 60 - VITA Mark II 30 30 - 20 0 .114 50 70 .351 IPS e.max CAD 0 0.2 .114 80 50 .138 20 30 .603 IPS Empress CAD 10 0 .292 10 30 .248 80 70 .603 *Significantly different at p <0.001. repair kit. IPS e.max CAD and VITA Suprinity were 3M ESPE, St Paul, MN, USA) (1200mW/cm2, 430–480 etched 60 sec, VITA Mark II and IPS Empress CAD nm). The specimens treated with iGOS Repair, Multi were etched 120 sec with 10 % Hydrofluoric acid [26- Primer LIQUID was applied to the specimen surface 28] (Angelus, Londrina, PR, Brazil) and then rinsed and allowed to dry for about 60 seconds. Then iGOS thoroughly under a water spray for 10 seconds, air- Bond applied and light-cured for 10 seconds, then dried for 10 seconds according to manufacturer’s the composite resins were polymerized with the instruction of repair kits. All of the specimens were same curing unit for 20s. After polymerization, the cleaned by ultrasonic cleaner for 10 min and air‑dried transparent polyvinylchloride cylinder was carefully for 10 seconds. removed using a scalpel. During the experiment Following the surface conditioning procedures, a time, all specimens were stored in distilled water at transparent polyvinylchloride cylinder with a hole 37° C for 3 days. in the center (2 mm diameter and 2 mm deep) was The μSBS test was performed with a micro- used for the application of the repair systems to the shear testing device (MOD Dental, Esetron Smart ceramic surfaces according to the manufacturer’s Robotechnologies, Ankara, Turkey) at 1 mm/ instructions (Fig. 1). The specimens treated with the min crosshead speed using a knife edge‑shaped Clearfil Repair system, the Clearfil SE Bond Primer and indenter, which was 5 mm in diameter and 1 mm the Porcelain Bond Activator were mixed in a 1:1 ratio away from the ceramic‑composite interface, placed and applied for 5 seconds. Then, Clearfil SE Bond was between the composite resin and the CAD/CAM applied and light-cured for 10 seconds (Elipar S 10, restorative material (Fig. 2). A micro-shear load was 236 Stoma Edu J. 2020;7(4): 233-241 pISSN 2360-2406; eISSN 2502-0285 The bond strength of different repair systems www.stomaeduj.com applied until a fracture occurred, and the value was group repaired with the Clearfil Repair system. There Original Articles recorded in Newtons (N). The results were expressed were significant differences between the iGOS and in megapascal (MPa) values. Following μSBS test, the Clearfil Repair systems for adhesive and cohesive failure modes of specimens were examined under a failures in the Lava Ultimate group (p<0.001). stereomicroscope (Leica M320, Leica Microsystems (Schweiz) AG, Heerbrugg, Switzerland) at × 16 4. DISCUSSION magnifications and recorded as adhesive, cohesive or mix failure type. In the current study, the μSBS of two different repair systems to CAD/CAM restorative materials were 2.1. Statistical analysis tested. Based on the results, the null hypotheses All statistical analyses were performed using SPSS that types of CAD/CAM restorative materials and for Windows (12.0, SPSS Inc, Chicago, IL, USA). different repair systems would not affect the bond The homogeneity of variance and normality of strength were rejected. It was observed that the distribution for variables were evaluated by Levene success of the repair system depends on the CAD/ and Shapiro Wilk test, respectively. Two-way ANOVA CAM restorative materials. and Tukey-HSD multiple comparison tests were All CAD/CAM materials tested in this study are used for statistical analyses. In all tests, p<0.05 was prosthetic restoration materials. Fractures may occur considered as statistically significant. in these materials during usage. Direct application of composite resins is a good alternative to extra- 3. RESULTS oral repair techniques because composite resins are easier to apply, and they are low cost materials. 3.1. μSBS test Their usage would depend on the cause and grade The two-way ANOVA revealed that the differences of the fractures [29,30]. When repairing the fracture, among the CAD/CAM restorative material types and a conditioned surface is required to strengthen the the composite repair material types were statistically adhesion of the repair material to the restoration significant (p<0.05). There were interactions between surface. It is a challenge for the clinician to choose surface treatments and the materials (p<0.05) (Table the right option among many repair systems with 3). The mean μSBS test values and differences among different conditioning steps. Surface treatments, the groups are presented in Table 4. including acid etching, sandblasting (50 μm Specimens repaired with the iGOS Repair system Al2O3), application of a universal adhesive (silane showed the highest μSBS values as compared to the containing) and their combinations are commonly Clearfil Repair system among all tested materials used for intraoral repair or cementation of indirect except for the InCoris TZI group (p<0.05). The Lava restorations [31-33]. A low viscosity composite may Ultimate group showed the lowest μSBS values exhibit a larger volumetric shrinkage. At the same among the materials repaired with the Clearfil Repair time, they have better surface wetting properties system, while the InCoris TZI group showed the which prevent development of defects during lowest μSBS test values among the materials repaired repair. Contrarily, resin composites with higher filler with the iGOS Repair system (p<0.05). Regarding the content, would have a high modulus of elasticity VITA Mark II group, there was no significant difference which causes a lower volumetric shrinkage and in the μSBS test values between the Clearfil Repair a higher shrinkage stress at the restoration-resin system (7.29±1.05 MPa) and the iGOS Repair system interface. This stress would negatively affect the (8.09±0.75 MPa) (p >0.05). The VITA Suprinity group bond strength. Considering these contradictory showed the highest μSBS values among the other effects, it is not easy to project on the success of material groups when repaired with the iGOS Repair a chosen material [34]. In the present study, two system (p<0.05). The μSBS values were found in the different types of composites were used: 1) Clearfil InCoris TZI (8.69±1.03), VITA Suprinity (8.17±1.34), Majesty ES-2 is a nanohybrid composite and 2) iGOS Cerasmart (7.41±0.70) and VITA Mark II (7.29±1.05) Universal is a hybrid composite. The compositions groups repaired with the Clearfil Repair system, of these composite materials were quite different respectively, however, there were statistically insigni- from each other. The fact that these materials have ficant differences among them (p>0.05). different flexural strength may explain the different μSBS results of the two repair systems [35]. 3.2. Stereomicroscopic analysis In the present study, CAD/CAM materials were The failure mode distribution of different repair selected based on their conditioning concepts and systems and different CAD/CAM restorative materials compositions. Using the sandblasting method, the are presented in Table 5. According to the Chi-square surface is blasted with aluminum oxide particles to Test, significantly different failure types among the roughen and increase the bonding surface of the tested groups were observed (p<0.001). Adhesive restoration material [36]. Sandblasting reinforces fractures were mostly obtained in the InCoris TZI wetting with resin, reduces surface tension, and group repaired with iGOS Repair system while mix increases the total surface area [11]. During the use failures were mostly obtained in the InCoris TZI of the HF acid for repairing glassy-matrix ceramics, Stoma Edu J. 2020;7(4): 233-241 pISSN 2360-2406; eISSN 2502-0285 237 Atay A, et al. www.stomaeduj.com the HF acid creates microporosity on the ceramic the VITA Suprinity group repaired with two repair Original Articles surface to provide mechanical locking with the systems showed no significant difference in bond resin. Etching of the bonding surface with HF acid strength compared to the IPS e.max CAD subjected followed by the application of a silane as a coupling to HF etching. We assume that after silanization, the agent is a commonly used technique for bonding. It zirconia content of VITA Suprinity might become enhances the bond strength of silica-based ceramics more active for bonding and this may positively [37]. The HF acid acts on the silicone dioxide present affect the μSBS values of VITA Suprinity. For the iGOS in the glass phase [38]. The silane monomer has a Repair system, the μSBS values of all groups were bifunctional group called silanol which interacts with significantly higher compared to the Clearfil repair the ceramic surface together with a methacrylate system except for the InCoris TZI and the VITA Mark group that co-polymerizes with the organic matrix II materials. High filler content, homogenization of composite resins [33]. Silane also increases the technology and diversity of functional monomers wettability of the ceramic surface and allows the included in the iGOS system might contribute to the resin to penetrate deeper into its microscopic pores. adhesive strength of this system [35]. This mechanism also reinforces the ceramic-resin The tested InCoris TZI group repaired with bonding [39]. In the current study, only the specimens Clearfil showed higher bond strength values in the the InCoris TZI, Lava Ultimate and Cerasmart than the iGOS group. This should be a result of groups were sandblasted with 50 μm Al2O3 at 2.8 10-methacryloyloxydecyl dihydrogen phosphate bar pressure, while the VITA Suprinity, VITA Mark II , (MDP) content in the Clearfil SE Bond. MDP IPS e.max CAD and IPS Empress CAD groups were containing primers form a chemical bond between treated with HF according to the manufacturer’s resin cements and ceramics [45]. This chemical bond instructions. However, silane, which is available in is formed between the hydroxyl groups of zirconia the repair system, was applied to the surface of all and phosphate ester monomers of MDP [46]. Blatz et samples after surface treatment. Düzyol et al. [40]. al. [47] investigated the effect of Al2O3 sandblasting investigated the HF etching mechanism of several on bond strength between zirconia ceramics and restoration materials and they concluded that, self-adhesive resin cements. The sandblasted alumina crystals in feldspar ceramic, lithium disilicate specimens presented higher bond strength values crystals in lithium disilicate reinforced ceramic and compared to the groups without sandblasting. The zirconia fillers and resin matrix in resin nano ceramic bond strength of MDP containing resin cements was are structural parts of these materials that were also significantly higher than the other groups. not affected by the acid etching. Lithium disilicate Previous studies show that low bond strength reinforced ceramic contains a lower percentage values are associated with adhesive failures [48,49]. of glass phase compared to leucite reinforced and Stawarczyk et al. [34] investigated the tensile bond feldspar ceramic. Therefore, in our study IPS Empress strength values of resin nano ceramic (Lava Ultimate) CAD and VITA Mark II groups were etched with HF specimens which presented mostly cohesive acid for 120 seconds, while IPS e.max CAD group was failures. While Üstün et al. [44] reported that the etched for 60 seconds. Previous studies stated that Lava Ultimate and Vita Enamic specimens showed lithium disilicate reinforced glass ceramic presented only cohesive failures in their study. In the present higher microtensile bond strength (μTBS) compared study, hybrid ceramic, the Cerasmart group did not to feldspatic ceramic and leucite reinforced glass show any cohesive failures. The Lava Ultimate group ceramic [40-42]. In the current study, there was no repaired with the iGOS Repair system showed higher significant difference in bond strength values among μSBS values than the Clearfil Repair system which the VITA Mark II, IPS e.max CAD and the IPS Empress showed no adhesive failure (0%) and the fractures CAD groups repaired with the Clearfil system. were cohesive (50%) or mixed (50%). Adhesive However, the VITA Mark II group repaired with iGOS fractures were mostly obtained in the InCoris TZI showed significantly lower μSBS compared to the groups repaired with the iGOS Repair system which IPS e.max CAD and IPS Empress CAD groups. Karcı indicates that the bonding interface was weaker than et al. [43] investigated SBS of different repair systems Clearfil Repair. No adhesive failure was observed in to IPS e.max CAD and IPS Empress CAD. They found the InCoris TZI material repaired with the Clearfil that the SBS values of the IPS Empress CAD are higher Repair system. Üstün et al. [44] investigated the than those for the IPS e.max CAD. On the contrary, in SBS of different repair systems (Ceramic Repair and the present study, there was no significant difference Clearfil repair) to CAD/CAM restorative materials between the μSBS values of IPS e.max CAD and IPS (Vita Suprinity, Lava Ultimate, IPS e.max CAD, and Empress CAD groups. Üstün et al. [44] stated that the Vita Enamic) and revealed complete adhesive failure Vita Suprinity group presented lower bond strength in the Vita Suprinity and IPS e.max CAD groups values than the other groups (Vita Enamic, IPS repaired with Clearfil Repair. On the contrary, in the e.max CAD, Lava Ultimate) subjected to HF etching present study, the VITA Suprinity group repaired because the zirconia-reinforced lithium silicate with both repair sets presented mixed, adhesive ceramic group contains 8-12% ZrO2 by weight. and cohesive failures, and the IPS e.max CAD group However, in the current study, the μSBS values of repaired with the Clearfil Repair system, presented 238 Stoma Edu J. 2020;7(4): 233-241 pISSN 2360-2406; eISSN 2502-0285 The bond strength of different repair systems www.stomaeduj.com 80% cohesive failure and 20% mixed failure. 2. The Clearfil Repair system, which contains MDP Original Articles This study has several limitations. The clinical aging phosphate monomer, showed higher μSBS values of restorative materials would change their chemical than iGOS Repair for InCoris TZI. and mechanical properties. These changes would 3. The μSBS of two different repair systems applied affect their repairability as well. In the current study, to indirect restorative materials is dependent on the the specimens were subjected to thermal cycling micro-structure of both tested materials. before they were repaired, because fractures occur CONFLICT OF INTEREST during clinical use. The authors declare no conflict of interest. Future studies should be focused on the effect of thermocycling after repair process in order to AUTHOR CONTRIBUTIONS compare changes. Another limitation of this study is that in order to investigate the bond strength AA: Study and experimental design, data gathering, analysis between resin and ceramic, the repaired specimens and interpretation of the results, manuscript writing LN: Sample were only subjected to shear forces. Clinically, preparation, performed the experiment and manuscript writing repaired restorations are exposed to several intraoral HMK: Study and experimental design, manuscript proofreading stresses such as tensile, shear, compressive, and AU: Study and experimental design, analysis and interpretation of oblique forces. Additionally, the bond strength of the results, manuscript proofreading. the repaired restorations should be investigated clinically, in order to verify the outcomes of in vitro ACKNOWLEDGMENTS studies. None. 5. CONCLUSIONS Within the limitations of this study, the following conclusions could be drawn: 1. All groups, except for the InCoris TZI group, repaired with iGOS Repair system showed higher μSBS than Clearfil Repair system. REFERENCES 1. Fasbinder DJ. Computerized technology for restorative 8. Scherrer SS, Quinn GD, Quinn JB. Fractographic failure analysis dentistry. Am J Dent. 2013;26(3):115-120. of a Procera AllCeram crown using stereo and scanning electron PubMed Google Scholar Scopus WoS microscopy. Dent Mater. 2008;24(8):1107-1113. doi:10.1016/j. 2. Miyazaki T, Nakamura T, Matsumura H, et al. Current status dental.2008.01.002. of zirconia restoration. J Prosthodont Res. 2013;57(4):236-261. Full text links CrossRef PubMed Google Scholar Scopus WoS doi:10.1016/j.jpor.2013.09.001. 9. Walton JN, Gardner FM, Agar JR. A survey of crown and Full text links CrossRef PubMed Google Scholar Scopus WoS fixed partial denture failures: length of service and reasons 3. Harada A, Nakamura K, Kanno T, et al. Fracture resistance for replacement. J Prosthet Dent. 1986;56(4):416-421. of computer-aided design/computer-aided manufacturing- doi:10.1016/0022-3913(86)90379-3. generated composite resin-based molar crowns. Eur J Oral Sci. Full text links CrossRef PubMed Google Scholar Scopus WoS 2015;123(2):122-129. doi:10.1111/eos.12173. 10. Libby G, Arcuri MR, LaVelle WE, et al. Longevity of fixed partial Full text links CrossRef PubMed Google Scholar Scopus WoS dentures. J Prosthet Dent. 1997;78(2):127-131. doi:10.1016/s0022- 4. Awad D, Stawarczyk B, Liebermann A, et al. Translucency of 3913(97)70115-x. esthetic dental restorative CAD/CAM materials and composite Full text links PubMed Google Scholar Scopus WoS resins with respect to thickness and surface roughness. J Prosthet 11. Ozcan M, Niedermeier W. Clinical study on the reasons for and Dent. 2015;113(6):534-540. doi:10.1016/j.prosdent.2014.12.003. location of failures of metal-ceramic restorations and survival of Full text links CrossRef PubMed Google Scholar Scopus WoS repairs. Int J Prosthodont. 2002;15(3):299-302. 5. Lauvahutanon S, Takahashi H, Shiozawa M, et al. Mechanical CrossRef PubMed Google Scholar Scopus WoS properties of composite resin blocks for CAD/CAM. Dent Mater J. 12. Gordan VV, Garvan CW, Blaser PK, et al. A long-term 2014;33(5):705-710. doi:10.4012/dmj.2014-208. evaluation of alternative treatments to replacement of resin- Full text links CrossRef PubMed Google Scholar Scopus WoS based composite restorations: results of a seven-year study. J 6. Latta MA, Barkmeier WW. Approaches for intraoral repair of Am Dent Assoc. 2009;140(12):1476-1484. doi:10.14219/jada. ceramic restorations. Compend Contin Educ Dent. 2000;21(8):635- archive.2009.0098. 646. Full text links CrossRef PubMed Google Scholar Scopus WoS PubMed Google Scholar Scopus 13. Gordan VV, Shen C, Riley J 3rd, et al. Two-year clinical 7. Quinn GD. On edge chipping testing and some personal evaluation of repair versus replacement of composite perspectives on the state of the art of mechanical testing. Dent restorations. J Esthet Restor Dent. 2006;18(3):144-154. Mater. 2015;31(1):26-36. doi:10.1016/j.dental.2014.08.378. doi:10.1111/j.1708-8240.2006.00007.x. Full text links CrossRef PubMed Google Scholar Scopus WoS Full text links CrossRef PubMed Google Scholar Scopus Stoma Edu J. 2020;7(4): 233-241 pISSN 2360-2406; eISSN 2502-0285 239 Atay A, et al. www.stomaeduj.com 14. Hickel R, Brüshaver K, Ilie N. Repair of restorations--criteria 33. Ozcan M, Valandro LF, Amaral R, et al. Bond strength Original Articles for decision making and clinical recommendations. Dent Mater. durability of a resin composite on a reinforced ceramic using 2013;29(1):28-50. doi:10.1016/j.dental.2012.07.006. various repair systems. Dent Mater. 2009;25(12):1477-1483. Full text links CrossRef PubMed Google Scholar Scopus WoS doi:10.1016/j.dental.2009.06.020. 15. Tyas MJ, Anusavice KJ, Frencken JE, et al. Minimal intervention Full text links CrossRef PubMed Google Scholar Scopus WoS dentistry - a review - FDI Commission Project 1-97. Int Dent J. 34. Stawarczyk B, Krawczuk A, Ilie N. Tensile bond strength of 2000;50(1):1-12. doi:10.1111/j.1875-595x.2000.tb00540.x. resin composite repair in vitro using different surface preparation Full text links CrossRef PubMed Google Scholar Scopus WoS conditionings to an aged CAD/CAM resin nanoceramic. Clin Oral 16. Fan PL. Porcelain repair materials. Council on Dental Materials, Investig. 2015;19(2):299-308. doi:10.1007/s00784-014-1269-3. Instruments and Equipment. J Am Dent Assoc. 1991;122(8):124- Full text links CrossRef PubMed Google Scholar Scopus WoS 130. 35. Yamakin. Home: https://www.yamakin-global.com/igos/ Full text links CrossRef PubMed Google Scholar Scopus WoS technical_qa_pp.html#button Accessed 6/10/19 17. Denehy G, Bouschlicher M, Vargas M. Intraoral repair of 36. Kern M, Wegner SM. Bonding to zirconia ceramic: adhesion cosmetic restorations. Dent Clin North Am. 1998;42(4):719-x. methods and their durability. Dent Mater. 1998;14(1):64-71. PubMed Google Scholar Scopus doi:10.1016/s0109-5641(98)00011-6. 18. Blum IR, Jagger DC, Wilson NH. Defective dental restorations: Full text links CrossRef PubMed Google Scholar Scopus WoS to repair or not to repair? Part 2: All-ceramics and porcelain fused 37. Panah FG, Rezai SM, Ahmadian L. The influence of ceramic to metal systems. Dent Update. 2011;38(3):150-158. doi:10.12968/ surface treatments on the micro-shear bond strength of denu.2011.38.3.150. composite resin to IPS Empress 2. J Prosthodont. 2008;17(5):409- CrossRef PubMed Google Scholar 414. doi:10.1111/j.1532-849X.2007.00296.x. 19. Rathke A, Tymina Y, Haller B. Effect of different surface Full text links CrossRef PubMed Google Scholar Scopus treatments on the composite-composite repair bond strength. 38. Kupiec KA, Wuertz KM, Barkmeier WW, et al. Evaluation of Clin Oral Investig. 2009;13(3):317-323. doi:10.1007/s00784-008- porcelain surface treatments and agents for composite-to- 0228-2. porcelain repair. J Prosthet Dent. 1996;76(2):119-124. doi:10.1016/ Full text links CrossRef PubMed Google Scholar Scopus WoS s0022-3913(96)90294-2. 20. Hu M, Weiger R, Fischer J. Comparison of two test designs for Full text links CrossRef PubMed Google Scholar Scopus WoS evaluating the shear bond strength of resin composite cements. 39. Ozcan M, Vallittu PK. Effect of surface conditioning methods Dent Mater. 2016;32(2):223-232. doi:10.1016/j.dental.2015.11.023. on the bond strength of luting cement to ceramics. Dent Mater. Full text links CrossRef PubMed Google Scholar Scopus WoS 2003;19(8):725-731. doi:10.1016/s0109-5641(03)00019-8. 21. Filho AM, Vieira LC, Araújo E, et al. Effect of different Full text links CrossRef PubMed Google Scholar Scopus WoS ceramic surface treatments on resin microtensile bond 40. Duzyol M, Sagsoz O, Polat Sagsoz N, et al. The effect of surface strength. J Prosthodont. 2004;13(1):28-35. doi:10.1111/j.1532- treatments on the bond strength between CAD/CAM blocks and 849X.2004.04007.x. composite resin. J Prosthodont. 2016;25(6):466-471. doi:10.1111/ Full text links CrossRef PubMed Scopus Google Scholar jopr.12322. 22. Güngör MB, Nemli SK, Bal BT, et al. Effect of surface Full text links CrossRef PubMed Google Scholar Scopus WoS treatments on shear bond strength of resin composite bonded to CAD/CAM resin-ceramic hybrid materials. J Adv Prosthodont. 41. Neis CA, Albuquerque NL, Albuquerque Ide S, et al. Surface 2016;8(4):259-266. doi:10.4047/jap.2016.8.4.259. treatments for repair of feldspathic, leucite - and lithium Full text links CrossRef PubMed Google Scholar Scopus WoS disilicate-reinforced glass ceramics using composite resin. Braz 23. Tian T, Tsoi JK, Matinlinna JP, et al. Aspects of bonding Dent J. 2015;26(2):152-155. doi:10.1590/0103-6440201302447. between resin luting cements and glass ceramic materials. Dent Full text links CrossRef PubMed Google Scholar Scopus Mater. 2014;30(7):e147-e162. doi:10.1016/j.dental.2014.01.017. 42. Colares RC, Neri JR, Souza AM, et al. Effect of surface Full text links CrossRef PubMed Google Scholar Scopus WoS pretreatments on the microtensile bond strength of lithium- 24. Dimitriadi M, Panagiotopoulou A, Pelecanou M, et al. Stability disilicate ceramic repaired with composite resin. Braz Dent J. and reactivity of γ-ΜPTMS silane in some commercial primer 2013;24(4):349-352. doi:10.1590/0103-6440201301960. and adhesive formulations. Dent Mater. 2018;34(8):1089-1101. Full text links CrossRef PubMed Google Scholar Scopus doi:10.1016/j.dental.2018.05.006. 43. Karcı M, Demir N, Subaşı MG, et al. Shear bond strength of Full text links CrossRef PubMed Google Scholar Scopus WoS a novel porcelain repair system for different computer-aided 25. Matinlinna JP, Vallittu PK. Bonding of resin composites to design/computer-assisted manufacturing ceramic materials. etchable ceramic surfaces - an insight review of the chemical Niger J Clin Pract. 2018;21(4):507-513. doi:10.4103/njcp. aspects on surface conditioning. J Oral Rehabil. 2007;34(8):622- njcp_127_17. 630. doi:10.1111/j.1365-2842.2005.01569.x. Full text links PubMed Google Scholar Scopus WoS Full text links CrossRef PubMed Google Scholar Scopus WoS 44. Üstün Ö, Büyükhatipoğlu IK, Seçilmiş A. Shear bond strength 26. Murillo-Gómez F, Palma-Dibb RG, De Goes MF. Effect of acid of repair systems to new CAD/CAM restorative materials. J etching on tridimensional microstructure of etchable CAD/ Prosthodont. 2018;27(8):748-754. doi:10.1111/jopr.12564. CAM materials. Dent Mater. 2018;34(6):944-955. doi:10.1016/j. Full text links CrossRef PubMed Google Scholar Scopus WoS dental.2018.03.013. 45. Dias de Souza GM, Thompson VP, Braga RR. Effect of metal Full text links CrossRef PubMed Google Scholar Scopus WoS primers on microtensile bond strength between zirconia and 27. Barchetta NF, Amaral M, Prochnow C, et al. Strength of a resin cements. J Prosthet Dent. 2011;105(5):296-303. doi:10.1016/ zirconia-reinforced lithium silicate ceramic: acid-etching time S0022-3913(11)60055-3. and resin cement application effects. Int J Periodontics Restorative Full text links CrossRef PubMed Google Scholar Scopus WoS Dent. 2019;39(3):431-437. doi:10.11607/prd.411. 46. Khan AA, Al Kheraif AA, Jamaluddin S, et al. Recent trends in Full text links PubMed Google Scholar Scopus WoS surface treatment methods for bonding composite cement to 28. Güler AU, Yilmaz F, Yenisey M, et al. Effect of acid etching zirconia: a reveiw. J Adhes Dent. 2017;19(1):7-19. doi:10.3290/j.jad. time and a self-etching adhesive on the shear bond strength of a37720. composite resin to porcelain. J Adhes Dent. 2006;8(1):21-25. Full text links PubMed Google Scholar PubMed Google Scholar Scopus WoS 47. Blatz MB, Phark JH, Ozer F, et al. In vitro comparative bond 29. Elsaka SE. Repair bond strength of resin composite to a novel strength of contemporary self-adhesive resin cements to CAD/CAM hybrid ceramic using different repair systems. Dent zirconium oxide ceramic with and without air-particle abrasion. Mater J. 2015;34(2):161-167. doi:10.4012/dmj.2014-159. Clin Oral Investig. 2010;14(2):187-192. doi:10.1007/s00784-009- Full text links CrossRef PubMed Google Scholar Scopus WoS 0278-0. 30. Bona AD. Bonding to ceramics: scientific evidences for clinical Full text links CrossRef PubMed Google Scholar Scopus WoS dentistry. 1st ed. Banbury, UK: Scion Publishing Limited; 2009. 48. Elsaka SE. Effect of surface treatments on the bonding Google Scholar strength of self-adhesive resin cements to zirconia ceramics. 31. Valandro LF, Ozcan M, Bottino MC, et al. Bond strength of a Quintessence Int. 2013;44(6):407. doi:10.3290/j.qi.a29572. resin cement to high-alumina and zirconia-reinforced ceramics: Full text links PubMed Google Scholar Scopus WoS the effect of surface conditioning. J Adhes Dent. 2006;8(3):175- 49. Reich SM, Wichmann M, Frankenberger R, et al. Effect of 181. surface treatment on the shear bond strength of three resin Full text links CrossRef PubMed Google Scholar Scopus WoS cements to a machinable feldspatic ceramic. J Biomed Mater Res B 32. Blum IR, Nikolinakos N, Lynch CD, et al. An in vitro comparison Appl Biomater. 2005;74(2):740-746. doi:10.1002/jbm.b.30292. of four intra-oral ceramic repair systems. J Dent. 2012;40(11):906- Full text links CrossRef PubMed Google Scholar Scopus WoS 912. doi:10.1016/j.jdent.2012.07.008. Full text links CrossRef PubMed Google Scholar Scopus WoS 240 Stoma Edu J. 2020;7(4): 233-241 pISSN 2360-2406; eISSN 2502-0285 The bond strength of different repair systems www.stomaeduj.com Original Articles Ayșe ATAY DDS, PhD, Assistant Professor Department of Prosthodontics Faculty of Dentistry Altinbaș University TR-34147, Bakırkoy/Istanbul, Turkey CV Ayşe Atay graduated from Ege University, Faculty of Dentistry, Izmir, Turkey in 2004. She enrolled on her PhD degree in 2006 and she was awarded her PhD degree by Ege University in 2010. Since 2014, she has been working as an assistant professor at the Department of Prosthodontics within the Faculty of Dentistry of the Altınbaș University. Questions 1. Choose the appropriate surface treatment method below to repair fractured restorations below: qa. Etching with hydrofluoric acid; qb. Sandblasting with Al2O3; qc. Tribochemical silica coating; qd. All of them. 2. What is the effect of silane application in the surface treatment process? qa. Increases the wettability of the ceramic; qb. Creates micro roughness on the ceramic surface; qc. Cleans the ceramic surface; qd. Dissolves the glass matrix and the crystalline structure. 3. Which of the following is not one of the advantages of repairing a ceramic fracture with composite resin? qa. More conservative; qb. Less time consuming; qc. Less costly; qd. None. 4. According to the results of this study, which restorative material repaired with Clearfil Repair system showed favorable shear bond strength than repaired with iGOS Repair system? qa. Feldspar ceramic; qb. Lithium disilicate glass-ceramic; qc. Zirconium oxide sinter ceramic; qd. Resin nano ceramic. Stoma Edu J. 2020;7(4): 233-241 pISSN 2360-2406; eISSN 2502-0285 241