MICROSCOPY RESEARCH AND TECHNIQUE 00:000–000 (2011)Nanoleakage Evaluation of Resin Luting Systems to DentalEnamel and Leucite-Reinforced Ceramic ´ ´ ´ ´ ´LUCIA TRAZZI PRIETO,1 EDUARDO JOSE SOUZA-JUNIOR,2 CINTIA TEREZA PIMENTA ARAUJO,1,4 ´ADRIANO FONSECA LIMA,1 CARLOS TADEU DIAS,3 AND LUIS ALEXANDRE MAFFEI SARTINI PAULILLO1*1 Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, SP-Brazil, Avenida Limeira, 901,Areiao, 13414-903, Piracicaba, SP, Brazil ˜2 Department of Restorative Dentistry, Dental Materials Division, Piracicaba Dental School, State University of Campinas, SP-BrazilAvenida Limeira, 901, Areiao, 13414-903, Piracicaba, SP, Brazil ˜3 Department of Statistical Mathematics, Luiz de Queiroz Higher School of Agriculture of the University of Sao Paulo (Esalq/USP), ˜ ´Avenida Padua Dias, 11—Piracicaba, SP, Brazi4 Department of Dentistry, Faculty of Sciences of Health, Federal University of Jequitinhonha and Mucuri Valley -UFVJM, Diamantina,Minas Gerais, Brazil KEY WORDS ceramic; adhesive system; enamel; nanoleakage; resin cement ABSTRACT Purpose: The aim of this study was to evaluate the nanoleakage patterns between dental enamel and reinforced leucite ceramic, bonded with resin luting systems and a ﬂowable composite resin. Materials and Methods: Twelve crowns of bovine incisors were randomly divided into four groups (n 5 3) according to the luting procedure: Excite/Variolink II, Clearﬁl SE Bond/ Panavia F, Scotchbond Multi-Purpose Plus/RelyX ARC, and Single Bond 2/Filtek Z350 Flow. To evaluate the nanoleakage patterns, IPS Empress Esthetic disks (5 mm Ø and 1.2-mm thick) were bonded to enamel, and, after 24 h, the specimens were immersed in a 50% (w/v) solution of silver nitrate (24 h), ﬁxed, dehydrated, and processed scanning electron microscopy (SEM). Results: None nanoleakage on interface of the groups that Single Bond 2 followed by the ﬂowable composite were used. The highest percentage of nanoleakage was shown by the Excite/Variolink II protocol. Also, in all conditions tested, none silver nitrate uptake was observed between the leucite-reinforced ce- ramic and the resin luting cement. Conclusions: The use of a two-step etch-and-rinse adhesive with ﬂowable composite was able to promote an adequate seal of the bond interface at the enamel. Moreover, the conventional dual-cured resin cements associated with simpliﬁed and dual-cured adhesives tested are also indicated to bond thin ceramics to enamel, since all presented low silver nitrate uptake. Microsc. Res. Tech. 00:000–000, 2011. V 2011 Wiley Periodicals, Inc. C INTRODUCTION 2008) Also, solvated bonding systems can compromise With the development of the adhesive dentistry, the quality of the hybrid layers, due to the inferiorresin luting strategies have been widely used to bond polymer matrix formed, decreasing the bonding per-indirect restorations to tooth structures. In this way, formance to dental substrate (Carrilho et al., 2009; Taythe dual-cured resin system aims to improve the poly- et al., 2003).merization through the indirect restorations, since the To evaluate the sealing ability of restoration by adhe-light attenuation caused by the ceramic can jeopardize sive material and the quality of the polymer formed,the degree of conversion of the luting materials. How- nanoleakage is an important indicator (Sano et al.,ever, the dual resin cements may have the original 1995). Based mainly on this technique, many studiescolor changed, due to oxidation of the amine compo- evaluating nanoleakage patterns for several bondingnent. This fact can compromise the ﬁnal esthetic systems (and their inﬂuence on bonding parameters)appearance of the restoration, especially in cases of have been performed (Makishi et al., 2010; Reis et al.,thin ceramic veneers (Karaagaclioglu and Yilmaz, 2007, 2010). Silver nitrate has been accepted as a suit-2008). To avoid this, some authors have suggested lut- able method for measuring interfacial leakage (Mala-ing thin ceramic veneers with ﬂowable resin compo- carne-Zanon et al., 2010; Reis et al., 2007; Sano et al.,sites (Moon et al., 2002). Flowable composites are light- 1995) due to the size of the silver ion dyes (0.059-nm di-cured materials, with a lower amount of amine coini- ameter) compared to the size of a typical bacteriumtiators, which may not affect the ﬁnal esthetic appear- (0.5–1.0 nm). The small size of particles and the high,ance of the ceramic restoration over time. binding tightly to any exposed collagen ﬁbrils not The resinous luting approach traditionally requiresthe use of adhesive agents, which can be either total- ´ *Correspondence to: Prof. Dr. Luıs Alexandre Maffei Sartini Paulillo, Depart-etching or self-etching systems. The bond systems pre- ment of Restorative Dentistry, Piracicaba School of Dentistry, State University ofsenting a hydrophobic resin layer, such as the three- ˜ Campinas—UNICAMP, Av: Limeira—Areiao. CEP: 13414-903, Piracicaba, SP, Brazil. E-mail: firstname.lastname@example.org etch-and-rinse and two-step self-etch, can Received 29 May 2011; accepted in revised form 26 September 2011decrease the adhesive ﬁlm permeability, favoring bond DOI 10.1002/jemt.21110stability over time (Carrilho et al., 2009; Reis et al., Published online in Wiley Online Library (wileyonlinelibrary.com).VC 2011 WILEY PERIODICALS, INC.
2 L.T. PRIETO ET AL. TABLE 1. Resin cements used in the study with composition and manufacturer’s informationResin cements Composition ManufacturerVariolink II (Batch Base: Bis-GMA, UDMA and TEGDMA, barium glass, ytterbium triﬂuoride, glass Ivoclar Vivadent, #01441) ﬂuorsilicate barium and aluminum oxides mixed spheroid. Catalyst: Bis-GMA, UDMA Schaan, and TEGDMA, ytterbium triﬂuoride, glass and aluminum ﬂuorsilicate barium and Lietchtestein spheroid mixed oxide, benzoyl peroxide, stabilizer.RelyX ARC (Batch Paste A: Silane treated ceramic, Bis-GMA, TEGDMA, photoinitiators, amine, silane 3M ESPE, St Paul, #GU9JG) treated silica, functionalized dimethacrylate polymer. Paste B: silane treated ceramic, Minesota, USA TEGDMA, Bis-GMA, silane treated silica, benzoil peroxide, functionalized dimethacrylate polymer.Filtek Z350 ﬂow Matrix: BisGMA, TEGDMA, dimethacrylate polymer. Fillers: 47% zirconia/sılica ´ 3M ESPE, St Paul, (Batch:#N124855) ﬁllers Minesota, USAPanavia F (Batch Paste A: 10-MDP, hydrophobic aromatic dimethacrylate, hydrophobic aliphatic Kuraray Medical, #00027B) ´ dimethacrylate, hydrophilic dimethacrilate, silanated sılica, photoinitiators, dl- Tokyo, Japan camphoroquinone, benzoil peroxide. Paste B: hydrophobic aromatic dimethacrylate, hydrophobic aliphatic dimethacrylate, hydrophilic dimethacrylate. Sodium aromatic sulﬁnate, accelerator, sodium ﬂuoride, silanated barium glass. TABLE 2. Adhesive systems used in the study with composition and manufacturer’s informationAdhesive systems Composition ManufacturerED Primer (Batch #01441) Primer A (Batch #00272A): 2-hydroxyethyl methacrylate (HEMA), MDP, Kuraray Medical, NM-aminosalicylic acid, diethanol-p-toluidine, water. Primer B (Batch Tokyo, Japan #00147A): NM-aminosalicylic acid, T-isopropilic benzenic sodium sulﬁnate, diethanol-p-toluidine, waterExcite (Batch #1177) Phosphonic acid acrylate, HEMA, Bis-GMA, methacrylates, silicon dioxide, Ivoclar Vivadent, ethanol, catalysts and stabilizers Schaan, LietchtesteinAdper Single Bond 2 Dimethacrylates, HEMA, Polyalkenoid acid copolymer, 5-nm silane-treated 3M ESPE, St Paul, (Batch #9XB) colloidal silica, ethanol, water, photoinitiator Minesota, USAClearﬁl SE Bond Primer (Batch #00896A): water, MDP, HEMA, camphorquinone, hydrophilic Kuraray Medical dimethacrylate. Adhesive (Batch #01320A): MDP, bis-GMA, HEMA, Inc., Tokyo, Japan camphorquinone, hydrophobic dimathacrylate, N,N-diethanol p-toluidine bond, colloidal silica.Adper Scotchbond Multi Primer:HEMA, water, copolymer of polycarboxilic acid. Adhesive: Bis-GMA, 3M ESPE, St Paul, Purpose (Batch #356B) HEMA, polyalkenoic acid copolymer, CQ, EDMAB, DHEPT. Minesota, USAenveloped by the adhesive resin, makes silver nitrate F (CSE/PN—Kuraray, Tokyo, Japan); G3—Adperthe most appropriate agent to detect the nanoporosities Scotchbond Multi-Purpose Plus/RelyX ARC (SBMP/within the hybrid layer (Carrilho et al., 2007). RX—3M/ESPE, St Paul, MN); G4—Adper Single Bond As there is no ideal material to bond indirect restora- 2/Filtek Z350 Flow (SB/FL—3M/ESPE). The composi-tions to enamel, appropriate selection of these resin tion of the resin cements and adhesive systems areluting systems, according to the different clinical situa- listed in Tables 1 and 2. The adhesive systems andtions, is required. Thus, the aim of this study was to resin cements were applied following manufacturer’sevaluate the nanoleakage patterns of resin luting sys- instructions, and are described in Table 3.tems, bonded to dental enamel and leucite-reinforced Ceramic disks (5-mm diameter, 0.6-mm-thick leu-ceramic. The hypothesis tested was that the ﬂowable cite-reinforced ceramic, and 0.6-mm-thick feldspar ce-composite would provide an effective seal for veneer ce- ramic, totaling a ceramic specimen 1.2-mm thick) wereramic cementation compared to the dual-cured resin etched for 60 s using a 10% hydroﬂuoridric acidcements. (Dentsply Caulk, Midford, DE), followed by silane (Monobond S, Ivoclar Vivadent, Schaan, Lietschestein) MATERIALS AND METHODS application for 60 s. The specimens were bonded to Specimen Preparation enamel surface, according to the manufacturer’s instructions. Twelve bovine incisors were selected, cleaned, andstored in 0.01% thymol solution at 378C for 2 weeks.The root was sectioned using a low-speed, double-faced Nanoleakage Evaluationdiamond saw (Isomet 1000, Buehler, Lake Bluff, IL). After 24 h of the luting procedure, specimens wereThe buccal surface was ground ﬂat with 400-, 600-, and longitudinally sectioned using a diamond saw. Next,1,200-grit aluminum oxide papers (Carborundum, each specimen was immersed in a 50% ammoniac sil-Saint-Gobain Abrasives, Guarulhos, SP, Brazil), under ver nitrate solution for 24 h in the dark at 378C (Tayconstant water-cooling. Next, the specimens were ran- et al., 2002). Afterward, the specimens were thor-domly distributed in experimental groups according to oughly rinsed in distilled water for 2 min andthe luting procedures (adhesive systems/resin cement): immersed in a photo-developing solution for 8 h (KodakG1—Excite /Variolink II (EX/VR—Ivoclar-Vivadent, Developer D--76-Kodak Brasileira Ind. e Com Ltda.,Schaan, Lietschestein); G2—Clearﬁl SE Bond/Panavia Sao Jose dos Campos, SP, Brazil) under ﬂuorescent Microscopy Research and Technique
BONDING AND LEAKAGE TO ENAMEL/CERAMICS INTERFACE 3 TABLE 3. Procedures for cementing systems adhesion ished sequentially with aluminum oxide papers (600-,Luting systems Procedures for cementing 1,200-, and 2,000-grit) and felt disc with diamond paste of decreasing grain (3.1 and 0.25 lm) using a metallo-Adhesive system 1) Acid etching of enamel with 35% phosphoric acid (15 s) and washing with graphic polisher (PL02, Arotec Equip, SP, Brazil). The distilled water for 15 s specimens were immersed in distilled water and placedExcite 2) Application of the adhesive system on in ultrasonic baths (Ultrasone D 1440—Odontobras ´ enamel Ind. E Com Med Odont. Ltda., Rio Preto, Brazil) for 10Resin cement 3) Mild air streamVariolink 4) Light curing for 20 s min, after each step of the polishing procedure.(Ivoclar-Vivadent) 5) Mix of resin cement pastes (base 1 Next, the specimens were dried with absorbent catalyst for 15 s) papers and immersed in a solution of 50% phosphoric 6) Light curing for 40 s. acid for 10 s, followed by rinsing in distilled water. ForAdhesive system 1) Primer application on enamel surface (Clearﬁl SE Bond) for 30 s deproteinization, a 10% solution of sodium hypochlo-Clearﬁl SE bond 2) Bond application (Clearﬁl SE Bond) and rite was used for 10 min. After this, the specimens light curing for 10 s were rinsed and dried at room temperature (2 h) andED primer 3) Application of the primer (Clearﬁl SE dehydrated with ethanol at increasing concentrations Bond) 1 Porcelain Bond Activator mix for 1 minute on ceramic surface for 1 min. of 25, 50, 75, 90, and 100%, for 10-min each. The speci-Resin cement 4) Mix of ED Primer A e B, and application mens were carbon coated (Bal-Tec SCD-050—Sputter- on the adhesive layer on enamel Coater) and analyzed in a scanning electron micro-Panavia F 5) Mix of resin cement (20 s) scope (SEM—JEOL JSM—V 5600 LV, Tokyo, Japan),(Kuraray) 6) Light curing for 40 sAdhesive system 1) Acid etching with 35% phosphoric acid at 15 kV. The images of silver-inﬁltrated specimens (15 s), and washing with distilled water were taken to calculate the marked area using com- (15 s) puter software Image Tool 3.0 (University of Texas,Scotchbond 2) Application of Activador Scotchbond and Health Science Center at San Antonio, TX). The inter- multi-uso Plus mild air stream (5 s)Resin cement 3) Application of primer agent and air spray face length between enamel/adhesive and ceramic/ (5 s) resin cement was measured, and the percentage of theRelyX ARC 4) Catalyst application in ceramic surface inﬁltrated area calculated. and enamel(3M/ESPE) 5) Mix of the resin cement (10 s) 6) Light curing for 40 s.Adhesive system 1) Acid etching with 35% phosphoric acid RESULTS (15 s), and washing with distilled water Nanoleakage Patterns for 15 sSingle bond 2) Application of two consecutives layer of Descriptive analysis of the nanoleakage patterns adhesive system was performed, as SEM evaluation showed a low per-Resin Filtek Flow 3) Light curing for 10 s centage of silver nitrate uptake; in most situations it(3M/ESPE). 4) Application of the ﬂowable resin 5) Light curing for 40 s. was 0%, excluding the statistical analysis. After analy- sis of the bonding interface between ceramic and resin cement, none nanoleakage was observed in any speci- mens. Figures 1–4 show the bonded interface with sil- ver nitrate uptake (magniﬁcation 3200 and 31,400).light, to reduce silver ions to metallic silver grains Table 4 shows the percent values of nanoleakage at thealong bonded interface, adhesive resin, and cement enamel/adhesive interface. The association of Excite/polymeric structure. Then, the stained specimens were Variolink showed higher silver nitrate uptake underembedded in a polystyrene resin, and were wet-pol- the adhesive layer (Fig. 1), followed by Clearﬁl SE Fig. 1. SEM photomicrography showing nanoleakage for the luting system Excite/Variolink II. (A) Can be noted as a silver deposition between the enamel and adhesive layer (arrows—3200). (B) Region with the silver inﬁltrated in the adhesive layer (31,400).Microscopy Research and Technique
4 L.T. PRIETO ET AL. Fig. 2. (A) Few points of silver deposition can be observed in the interface of Clearﬁl SE/Panavia (arrows—3200). (B) Region with the silver inﬁltrated points in the adhesive layer (arrows—31,400). Fig. 3. (A) Interface Scotchbond MP Plus/ RelyX ARC showing silver deposition in few regions (arrows—3200). (B) The silver inﬁltrated can be noted in increased magniﬁcation (arrows—31,400). Fig. 4. (A and B) Absence of silver deposition in the interface of ﬂowable resin even in high magniﬁ- cation (3200 and 31,400). Microscopy Research and Technique
BONDING AND LEAKAGE TO ENAMEL/CERAMICS INTERFACE 5 TABLE 4. Percentual of silver nitrate uptake at the tested groups The high concentration of hydrophobic monomersLuting system Silver nitrate uptake (BisGMA and UDMA) in EX, viscous monomers with high molecular weight (Van Landuyt et al., 2007), com-Clearﬁl SE bond/Panavia F 2.30%Excite/Variolink 15.10% bined with the low concentration of diluents (HEMA)Scotchbond multi purpose /RelyX ARC 2.20% and solvent (ethanol), increase the viscosity of this ad-Single bond 2/Filtek Z350 Flow 0 hesive, which can reduce the diffusion of the adhesive to the microretention, decreasing the quality of adhe- sive interlocking, and, consequently, compromises the sealing ability of the adhesive.Bond/Panavia F and Scotchbond Multi-Purpose Plus/ The three-step etch-and-rinse and the two-step self-RelyX ARC, which show few points of silver nitrate etch adhesives tested present a high amount of hydro-penetration in the adhesive layer (Figs. 2 and 3). The phobic monomers on the bond agent, which could com-ﬂowable composite did not present nanoleakage pat- promise sealing as with the EX. However, the primerterns on the bond interface (tooth/adhesive; Fig. 4). application improves the bond penetration into the etched surface, which might explain the results obtained for the SBMP and CSE adhesives. DISCUSSION The present study showed that the ﬂowable compos- The luting systems selected for this study are suita- ite resin associated with a simpliﬁed two-step etch-ble for ﬁxing ceramic with different compositions. How- and-rinse bond system promotes better sealing of theever, the dual-cure resin cements can cause color alter- ceramic–tooth interface, an important factor for theation, due to the oxidation of the tertiary amine, lead- longevity of tooth veneers. In light of these facts, theing to color change of the prosthetic restorations use of ﬂowable resins to bond ceramic laminates should(especially thin ceramic veneers), compromising the es- be considered, as this material can provide boththetic appearance (Ghavam et al., 2010). Moreover, adequate sealing and color stability.some manufacturers of ﬂowable composite resin recom-mend this resin for luting thin indirect restorations. In CONCLUSIONSlight of these facts, the objective of the present studywas to compare the adhesive/ﬂowable composite resin The luting agents associated with the adhesive sys-efﬁcacy, a color-stable material, with different dual- tems showed high quality of the bonding to enamel andcure luting systems, used for indirect restorations. few points of silver nitrate inﬁltration on the adhesive When the nanoleakage patterns between the leucite- interface. The ﬂowable resin is an alternative to lutingreinforced ceramic and the resinous cements were eval- thin ceramic veneers to enamel, promoting adequateuated, no silver-tracing solution was found. This might sealing between ceramic and tooth substrate.be explained by the fact that some ceramic surfacetreatments, such as ﬂuoridric acid etch, silanization, REFERENCES(Fabianelli et al., 2010) and, the application of a hydro- Carrilho MR, Carvalho RM, de Goes MF, di Hipolito V, Geraldeli S,phobic resin layer (Naves et al., 2010) after the silani- Tay FR, Pashley DH, Tjaderhane L. 2007. Chlorhexidine preserveszation approach, can guarantee adequate bonding and dentin bond in vitro. J Dent Res 86:90–94.sealing ability, preventing the inﬁltration of silver ions Carrilho MR, Tay FR, Donnelly AM, Agee KA, Carvalho RM, Hosaka K, Reis A, Loguercio AD, Pashley DH. 2009. Membrane permeabil-inside this interface. ity properties of dental adhesive ﬁlms. 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