CAM polymers and resin composite cements.

JJOD 2255 1–10 journal of dentistry xxx (2014) xxx–xxx

Available online at www.sciencedirect.com

ScienceDirect journal homepage: www.intl.elsevierhealth.com/journals/jden 1 2 3

Impact of different adhesives on work of adhesion between CAD/CAM polymers and resin composite cements

4 5

6 7 8 9

Q1

Christine Keul a, Manuel Mu¨ller-Hahl a, Marlis Eichberger a, Anja Liebermann a, Malgorzata Roos b, Daniel Edelhoff a, Bogna Stawarczyk a,* a b

Department of Prosthodontics, Munich Dental School, Munich, Germany Division of Biostatistics, Institute of Social and Preventive Medicine, University of Zurich, Switzerland

article info

abstract

Article history:

Objective: To determine the impact of pre-treatment of adhesive systems on the work of

Received 18 November 2013

adhesion (WA) between CAD/CAM polymers and resin composite cements and compare

Received in revised form

with conventional tests method of previous studies.

19 February 2014

Methods: Surface parameters were measured by contact angle measurement (2700 mea-

Accepted 24 February 2014

surements) and WA was calculated. Five CAD/CAM polymers were used for fabrication of

Available online xxx

specimens (n = 75/subgroup): artBloc Temp (A), Telio CAD (B), Nano Composite CFI-C (C),

Keywords:

mens were pre-treated (n = 15 per group): Ambarino P60 (I), Monobond Plus/Heliobond (II),

exp. CAD/CAM nanohybrid composite (D), and LAVA Ultimate (E). Then, air-abraded speciWork of adhesion

visio.link (III), VP connect (IV), and no pre-treatment (V). Resin composite cement specimens

Polymeric CAD/CAM materials

(n = 75) were smoothed out homogeneously on a glass plate (n = 15/group): RelyX ARC (RXA),

Resin composite cements

Variolink II (VAR), Panavia F2.0 (PAN), RelyX Unicem (RXU), and Clearfil SA Cement (CSA).

Adhesive

Contact angles were determined with 3 drops of distilled water and diiodomethane each.

Contact angle

Data were analyzed using Kruskal–Wallis-H test and Spearman-Rho correlation (p < 0.05). Results: CAD/CAM materials (B), (A), and (C) showed higher WA compared to (D) and (E). (II) and (IV) resulted in higher WA than (I), (III) and (V). VAR had the significantly lowest WA, followed by RXU, RXA, CSA and PAN. No correlation occurred between WA and TBS/SBS whereas polar SFE-component of CAD/CAM resin and SC showed significant positive correlation with TBS/SBS. Conclusions: Determination of WA is not a proper method to draw conclusions about the bond between resin materials. Destructive test methods are not dispensable. Clinical significance: The successful outcome of fixed dental restorations depends, among others, on the quality of bonding between the tooth and the restoration. Additional pretreatment of the dental CAD/CAM resin restoration by bonding systems can be recommended for clinical use. Pre-treatment showed a significant impact on the surface properties. # 2014 Elsevier Ltd. All rights reserved.

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15 Q2 * Corresponding author at: Goethestrasse 70, 80336 Munich, Germany. Tel.: +49 89 5160 9573; fax: +49 89 5160 9503.

E-mail addresses: [email protected], [email protected] (B. Stawarczyk). http://dx.doi.org/10.1016/j.jdent.2014.02.020 0300-5712/# 2014 Elsevier Ltd. All rights reserved.

Please cite this article in press as: Keul C, et al. Impact of different adhesives on work of adhesion between CAD/CAM polymers and resin composite cements. Journal of Dentistry (2014), http://dx.doi.org/10.1016/j.jdent.2014.02.020

JJOD 2255 1–10

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journal of dentistry xxx (2014) xxx–xxx

1.

Introduction

Industrially prefabricated computer aided design/computer aided manufacturing (CAD/CAM) polymers can be used as an alternative to glass-ceramics especially for thin restorations, what is primarily caused by their higher mean fracture load, the better stress distribution [1–5] and less wear in the antagonists enamel [6,7]. Different material classes of CAD/ CAM polymers, such as PMMA- or composite-based are available for dental restorations. In general, by the industrial polymerization of CAD/CAM polymers under standardized high pressure and temperature, a higher degree of conversion with less residual monomer can be achieved. This is considered advantageous with regard to material-biocompatibility [8,9], but can lead to difficulties in bonding to resin composite cement [10–12]. The specific selection of the material contents of the dental restoration as well as the bonding and cement system affects the adhesion properties, which are an important parameter for the preparation design, namely; retentive or non-retentive. Bonding can emerge by chemical reaction, mechanical retention or the combination of both and is strongly related to the composition of the resin composite cement system and the pre-treatment of the restoration as well as the dental hard tissue [13]. Shear bond strength (SBS) and tensile bond strength (TBS) tests are commonly used as laboratory test methods to determine the stress necessary to dissolve the bond between two materials [14]. Previous studies investigated the bond strength of CAD/CAM polymers to resin composite cements after use of bonding systems [10,11]. For both studies highest TBS and SBS was observed for composite-based CAD/ CAM resin to Variolink II after use of visio.link. In general, the bond strength depends, among others, on the ability of the adhesive to wet the surface of the substrate [15] and its surface free energy (SFE) [16]. The SFE includes two components: (1) the polar interactions and (2) the dispersive forces [17,18]. Wettability can be determined by contact angle measurement with liquid droplets. Surface modifications such as acid-etching or air abrasion impact the wettability of the substrate [19] and therefore also the SFE [20]. When liquids with different polarities are used, the theoretical work of adhesion (WA), the interfacial tension (IFT) and the spreading coefficient (SC) of materials can be calculated. The WA provides important information about the surface and material characteristics. It plays an important role in biocompatibility and adhesion performance, and therefore the clinical longevity of reconstruction materials [21,22]. For industrially fabricated CAD/CAM polymers, there is only very limited information available about the theoretical adhesion to resin composite cements after pre-treatment with bonding systems. The objective of this laboratory study was to determine the SFE with polar and disperse parts of CAD/CAM polymers after pre-treatment with bonding systems and resin composite cements. Also WA, IFT and SC between the CAD/CAM polymers after pre-treatment with bonding systems and resin composite cements were analyzed. The null-hypothesis was that by additional use of bonding systems the surface parameters with respect to WA are similar than without

regardless of CAD/CAM polymer. The second aim was to compare the calculated parameters; SFE with polar and disperse parts of CAD/CAM polymer after pre-treatment and resin composite cement as well as the WA, IFT and SC between the CAD/CAM polymers after pre-treatment with bonding systems and resin composite cements with measured TBS and SBS values of previous studies [10,11]. Therefore, the second hypothesis stated that the calculated surface parameters show a correlation to TBS or SBS values.

2.

Materials and methods

2.1.

Specimen preparation

73 74 75 76 77 78 79 80 81 82 83

CAD/CAM polymers (n = 375) were manually sectioned under water-cooling using a turbine (KaVo, Leutkirch, Germany) with a diamond cutting disc (Komet Dental, Gebr. Brasseler GmbH & Co. KG, Lemgo, Germany) with 6000–8000 rpm (approx. 2 mm 10 mm 10 mm):

84 85 86 87 88 89

artBloc Temp (Lot-No: 44308) Telio CAD (Lot-No: N73354) Nano Composite CFI-C (Lot-No: 2007000908) exp. CAD/CAM nanohybrid composite (Lot-No: 28923) LAVA Ultimate (Lot-No: N370932)

90 91 91 93 92 92 95 94 93 97 96 94 99 98 95 100 96 101 97 102 98 103 99 104 105 106 107 108 109 110 111 112

(A) (B) (C) (D) (E)

Subsequently specimens were mechanically polished on one side under water-cooling up to SiC P2400 (Siliciumcarbidepaper, Abramin, Struers, Ballerup, Denmark) and air-abraded for 20 s (Al2O3 (50 mm, basis Quattro IS, Renfert, Hilzinger, Germany), 458 angle, distance 10 mm, pressure 0.2 MPa). Thereafter specimens were cleaned with distilled water for 5 min using an ultrasonic bath (L&R Keary, New Jersey, USA) and dried with oil-free air. Each CAD/CAM polymer was further divided according to the intended pre-treatment (n = 15). Bonding systems were used according to manufacturer’s recommendation: (I) Ambarino P60 (Lot-No: 2011004057) was applied using a microbrush applicator and air-dried for 2 min. (II) Monobond Plus (Lot-No: R26662) was applied using microbrush applicator, after 60 s Heliobond (Lot-No: R22281) was applied and light cured for 10 s (Elipar S10, 3M ESPE). (III) visio.link (Lot-No: 114784) was applied using microbrush applicator and light polymerized for 90 s using bre.LuxPowerUnit (Bredent). (IV) VP connect (Lot-No: VP22912) was applied using microbrush applicator and air-dried for 3 min. (V) Without pre-treatment acted as control group. Specimens of five resin composite cements (n = 75) were manufactured by smoothing them out in a homogenous plane layer of 0.5 mm on a glass slide (Menzel, Braunschweig, Germany) using a spatula: (RXA) RelyX ARC (Lot-No: N199496) (VAR) Variolink II (Lot-No: Base: R46653, Catalyst: R42290) (PAN) Panavia F2.0 (Lot-No: A-Paste: 00518B, B-Paste: 00263B)


113 114 114 115 115 117 116 116 118 117 119 118 120 119 122 121 120 123 121 124 122 126 125 123 127 124 129 128 125 130 126 131 127 132 128 133 134 135 136 137 138


(RXU) RelyX Unicem Automix (Lot-No: 475760) (CSA) Clearfil SA Cement (Lot-No: 058AAA)

142 143 145 144 146 147 148

Table 1 includes all tested products, their chemical composition and the manufacturers.

149

2.2.

150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185

The contact angle measurements of CAD/CAM polymers were conducted directly after the application of the adhesives. For the composite resin cements the contact angle measurements were carried out in non-polymerized state in dark. To achieve approximately complete darkness during the measurement, the device was covered with a light-tight box with a small textile-covered recess that allows manual adjustment of the specimen. In total 2700 measurements of contact angles were performed. Fig. 1 depicts the study design. For the determination of the contact angles a contact angle metre (EasyDrop, Kru¨ss, Hamburg, Germany) was used. Measurements were performed via the sessile drop technique with a defined liquid volume of distilled water and diiodomethane 99% (CAS: 15.842-9 Sigma-Aldrich, Steinheim, Germany, Lot.No: S65447-448). Each specimen was measured six times, 3 using distilled water (defined drop volume: 10 ml) and 3 using diiodomethane (defined drop volume: 5 ml) in an air-conditioned room at 23 8C. Depending on the emerging angle between fluid and solid, two different computation methods were chose, depending on the resulting drop contour, to determine the contact angle. The Circle Method was applied for diiodomethane (evaluation of the droplet contour by a circle fitting, due to the emerging flat angles of the droplet: The drop shape is mathematically adjusted to a circular segment shape. In this way, the entire drop shap can be evaluated.), while the Tangent 1 Method was used for distilled water (evaluation of the droplet contour by fitting a tangent, due to the larger angle: a polynomial function of the drop profile is fitted the base line near the base line. From the adjusted parameters, firstly the gradient of the three-phase-contact point on the base line and thereof the contact angle can be determined). Based on the contact angles the surface free energy (SFE), the polar and disperse parts (DropShape Analysis 4, Kru¨ss) were calculated according to OWENS, WENDT, RABEL and KAELBLE method [23,24]:

186

Determination of surface properties

qffiffiffiffiffiffiffiffiffiffiffi ð1 þ cos uÞ SFEL qffiffiffiffiffiffiffiffiffiffiffiffi ¼ SFEPS ð2 SFED L

sffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi qffiffiffiffiffiffiffiffiffiffiffiffi SFEPL þ SFED S D SFEL

applicated on CAD/CAM polymer (BS) as well as the resin composite cements (RC) according to the following equation: qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi D WA ¼ 2 SFED SFEPBS SFEPRC BS SFERC þ 2

200 201

The following formulas were used to calculate the interfacial tension (IFT) and the spreading coefficient (SC). qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi qffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffiffi D SFEs PBS SFEPRC IFT ¼ SFEBS þ SFERC 2 SFED BS SFEs RC 2

203 204 205 206 207

SC ¼ WA 2 SFES

202

208 209 210 211 212 213

SFEBS: Surface free energy of the bonding system, SFEBSP: polar component SFERC: Surface free energy of the resin composite cement, SFERCP: polar component SFEBS: Surface free energy of the bonding system, SFEBSD: dispersive component SFERC: Surface free energy of the resin composite cement, SFERCD: dispersive component

The values calculated for the SFE with polar and disperse parts, WA, IFT and spreading coefficient of present study were put in correlation with the measured TBS and SBS values of two prior published studies, also performed in our laboratory [10,11]. Both studies were performed with the same batches of CAD/CAM polymers, adhesive systems for pre-treatment and resin composite cements.

214 215 216 215 218 217 216 219 217 221 220 218 222 219 224 223 220 225 221 222 226 223 227 224 225 228 229 230 231 232 233 234

2.4.

235

2.3.

Comparison to measured TBS and SBS of prior studies

Statistical analysis

Descriptive statistics were calculated. The Kruskal–Wallis-H test was used to determine the significant differences between groups with respect of CAD/CAM polymer, pre-treatment method and resin composite cement. Spearman-Rho correlation coefficient was calculated to determine the association between single parts of the surface properties and TBS, as well as SBS. The data were analyzed using SPSS Version 20 (SPSS INC, Chicago, IL, USA). p-Values smaller than 0.05 were assumed to be statistically significant.

3.

Results

3.1.

Surface properties

3.1.1.

SFE with polar and disperse parts

236 237 238 239 240 241 242 243 244 245 246 247

188 187 189 190 191 192 193 194 195 196 197 198 199

3

SFELP: Surface free energy of the liquid, polar component SFESP: Surface free energy of the solid, polar component SFELD: Surface free energy of the liquid, dispersive component SFESD: Surface free energy of the solid, dispersive component u: contact angle WA was determined by the sum of the polar and disperse parts of the surface energies of the bonding systems

Table 2 presents the descriptive statistics of the SFE with the respective dispersive and polar components. Additionally the percentage stage of the polar components was calculated. According to three-way ANOVA the CAD/CAM polymer and the pre-treatment showed a significant impact on all parameters (p < 0.001). In view of SFE TelioCAD and Nano Composite CFI-C showed the lowest values, followed by artBloc Temp and exp. CAD/ CAM nanohybrid composite and highest LAVA Ultimate. In view of the pre-treatment methods, differences were found for each material, listed in ascending order: visio.link, without


248 249 250 251 252 253 254 255 256 257 258

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259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302


Table 1 – Materials, group coding and composition as used in the study. Code CAD/CAM polymers

Pre-treatment method

Resin composite cement

Material

A

artBloc Temp

PMMA unfilled

B

Telio CAD

PMMA unfilled

C

Nano-composite with additives

D

exp. CAD/CAM nanohybrid composite Nano Composite CFI-C

E

LAVA Ultimate

I

Ambarino P 60

II

Monobond Plus Heliobond

III

visio.link

IV

VP connect

RXA

RelyX ARC

VAR

Variolink II

PAN

Panavia F 2.0

RXU

RelyX Unicem Automix

CSA

Clearfil SA Cement

303 304 305 306 307 308 309 310 311 312

Compositions

Strontium aluminium borosilicate glass, nanofillers, BODMA, Bis-GMA, UDMA Composite

Dimethacrylate based on phosphor acidesters and phosphon acidesters Ethanol, 3-trimethoxysilylpropyl methacrylate, methacrylated phosphoric acid ester Bis-GMA, TEGDMA, initiators, stabilizers MMA, PETIA, dimethacrylates, diphenyl(2,4,6,-trimethylbenzoyl)phosphinoxide MMA

PASTE A: silane treated ceramic, TEGDMA, BisGMA, silane treated silica, functionalized dimethacrylate polymer, triphenylantimony PASTE B: silane treated ceramic, TEGDMA, BisGMA, silane treated silica, functionalized dimethacrylate polymer, 2-benzotriazolyl-4-methylphenol, benzoyl peroxide BASE: Bis-GMA, UDMA TEGDMA CATALYST: Bis-GMA, UDMA, TEGDMA dibenzoylperoxide, INORGANIC FILLERS: ytterbium trifluoride, BaAl fluorosilicate glass, spheroid mixed oxide ADDITIONAL: stabilizers, pigments PASTE A: MDP, dihydrogen phosphate, Hydrophobic aromatic dimethacrylate, Hydrophobic aliphatic methacrylate, Hydrophilic aliphatic dimethacrylate, Silanated silica filler, Silanated colloidal silica, dl-Camphorquinone, Catalysts, Initiators, Others PASTE B: Hydrophobic aromatic dimethacrylate, Hydrophobic aliphatic methacrylate, Hydrophilic aliphatic dimethacrylate, Silanated barium glass filler, Catalysts, Accelerators, Pigments, Others CATALYST: silane treated glass powder, substituted dimethacrylate, 1-benzyl-5-phenyl-barbic-acid, calcium salt, silane treated silica sodium p-toluenesulfinate, 1,12-dodecane dimethycrylate, calcium hydroxide, methacrylated aliphatic amine, methacrylated aliphatic amine, titanium dioxide, BASE: silane treated glass powder, 2-propenoic acid, 2-methyl-, 1,10 -[1-(hydroxymethyl)-1,2- ethanediyl] ester, reaction products with 2-hydroxy-1,3-propanediyl, dimethacrylate and phosphorus oxide, TEGDMA, silane treated silica, sodium persulfate, glass powder, tert-butyl peroxy-3,5,5- trimethylhexanoate, cooper (II) acetate monohydrate MDP, Bis-GMA, sodium fluoride, TEGDMA, hydrophobic aromatic dimethacrylate, hydrophobic aliphatic dimethacrylate, silanated barium glass filler, silanated colloidal silica, dl-camphorquinone, initiators, accelerators, catalysts, pigments

312 Manufactures Merz Dental, Lu¨tjenburg, Germany Ivoclar-Vivadent, Schaan, Liechtenstein Ivoclar-Vivadent, Schaan, Liechtenstein Creamed, Marburg, Germany 3M ESPE, Seefeld, Germany Creamed, Marburg, Germany Ivoclar-Vivadent, Schaan, Liechtenstein Bredent, Senden, Germany Merz Dental, Lu¨tjenburg, Germany 3M ESPE, Seefeld, Germany

Ivoclar-Vivadent, Schaan, Liechtenstein

Kuraray Med., Sakazu, Okayama, Japan

3M ESPE, Seefeld, Germany

Kuraray Med., Sakazu, Okayama, Japan

TEGDMA, triethylenglycol-dimethacrylate; MMA, Methyl-methacrylate; Bis-GMA, Bisphenol A diglycidylmethacrylate; UDMA, Urethane-dimethacrylate; MDP, 10-methacryloyloxydecyl-dihydrogenphosphat; PETIA, pentaerythritoltriacrylate; BODMA, benzyl-octadecyl-dimethacrylate.


313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369

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pre-treatment, Ambarino P60, Monobond Plus/Heliobond and highest values for VP connect. Regarding the dispersive components, Nano Composite CFI-C showed the lowest values, followed by exp. CAD/CAM nanohybride composite, followed by LAVA Ultimate, highest artBloc Temp. TelioCAD was in the same value range together with exp. nanohybrid CAD/CAM composite and LAVA Ultimate. For pre-treatment, visio.link showed the lowest values followed without pre-treatment, followed by Ambarino P60 and highest VP connect and Monobond Plus/Heliobond. Concerning the polar components, artBloc Temp and TelioCAD showed the lowest values, followed by Nano Composite CFI-C, highest LAVA Ultimate. Exp. CAD/CAM nanohybrid composite was in the same value range together with Nano Composite CFI-C and LAVA Ultimate.

259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278

Fig. 1 – Study design for determination of the work of adhesion between groups.

3.1.2.

WA, IFT and spreading coefficient

Descriptive statistics (mean, SD) for WA, IFT and SC of all groups are presented in Table 3. Concerning the CAD/CAM polymer, the pre-treatment method and the resin composite

Table 2 – Mean values with standard deviation (SD) of SFE, disperse and polar parts values for CAD/CAM polymers with pre-treatment and resin composite cements separately. Pre-treatment CAD/CAM polymer artBloc Temp

SFE (mJ/m2)

Disperse (mJ/m2)

Polar (mJ/m2)

Surface polarity (%)

Mean (SD)

Mean (SD)

Mean (SD)

Mean

Ambarino P60 Monobond Plus/Heliobond visio.link VP connect Without

49.5 63.8 45.1 64.1 50.6

(1.2)a (0.5)a (0.6)a (0.6)a (2.2)a

49.1 49.7 42.5 50.1 48.9

(1.1)a (0.2)a (0.5)a (0.3)a (1.0)a

0.4 14.1 2.6 14.0 1.7

(0.4)a (0.5)a (0.2)a (0.6)a (1.4)a

0.8 22.1 5.8 21.8 3.4

Telio CAD


48.2 64.2 44.2 64.0 49.5

(1.5)a (0.5)a (0.5)a (0.9)a (3.0)a

47.9 49.9 41.8 50.1 47.5

(1.3)a (0.3)a (0.3)a (0.1)a (1.9)a

0.3 14.3 2.4 13.9 1.9

(0.3)a (0.6)a (0.3)a (0.9)a (1.5)a

0.6 22.3 5.4 21.7 3.8

Nano Composite CFI-C


53.3 64.1 44.7 64.8 43.7

(2.9)a (0.8)a (0.8)a (0.6)a (3.4)a

49.7 50.0 42.4 49.5 42.8

(0.3)a (0.2)a (0.6)a (0.3)a (3.1)a

3.6 14.1 2.3 15.4 0.9

(2.6)a (0.7)a (0.4)a (0.8)a (2.0)a

6.8 22.0 5.1 23.8 2.1

exp. CAD/CAM nanohybrid composite


56.0 63.1 44.7 63.5 46.7

(1.9)a (2.4)a (1.0)a (1.1)a (2.4)a

49.7 49.2 42.3 49.3 46.1

(0.3)a (1.5)a (0.5)a (0.3)a (2.2)a

6.3 13.9 2.4 14.2 0.6

(2.0)a (1.0)a (0.6)a (1.1)a (0.4)a

11.3 22.0 5.4 22.4 1.3

LAVA Ultimate


56.8 63.2 44.5 63.9 47.8

(2.4)a (0.8)a (0.9)a (1.1)a (2.0)a

49.9 49.7 42.1 49.5 46.7

(0.3)a (0.1)a (0.5)a (0.2)a (1.8)a

6.9 13.5 2.4 14.4 1.0

(2.3)a (0.8)a (0.4)a (1.0)a (0.9)a

12.1 21.4 5.4 22.5 2.1

48.4 48.6 49.1 41.3 48.3

(0.5)a (0.5)a (0.3)a (1.5)a (0.5)a

10.3 1.1 23.1 11.1 18.7

(1.6)a (0.4)a (2.5)a (1.2)a (0.6)a

17.5 2.2 32.0 21.2 28.0

Cement RelyX ARC Variolink II Panavia F 2.0 RelyX Unicem Clearfil SA Cement a

58.7 49.7 72.2 52.4 66.7

(1.3)a (0.6)a (2.2) (1.3) (2.5)a

Not normally distributed.


278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 Pre-treatment

ArtBloc Temp

TelioCAD

Nano Composite CFI-C

WA IFT SC WA IFT SC (mN/m) (mN/m) (mN/m) (mN/m) (mN/m) (mN/m) RelyX ARC 101.1 Variolink II 98.8 Panavia F 2.0 103.5 RelyX Unicem 93.8 Clearfil SA 102.3 Cement

(2.5) 7.1 (2.1) 16.3 (1.3) 0.4 (0.6)a 0.7 (3.5) 18.2 (3.7) 40.9 (3.0) 8.2 (2.5) 11.2 (3.2) 13.7 (4.4) 30.7

(3.1) 99.4 (1.7) 97.5 (5.7) 101.7 (3.5) 92.2 (7.1)a 100.5

(2.9) 7.6 (2.5) 18.1 (1.8) 0.4 (0.3)a 1.9 (4.0) 18.7 (3.0)a 42.7 (3.6) 8.5 (2.3) 12.8 (3.6) 14.2 (2.6) 32.5

Monobond Plus/ Heliobond

RelyX ARC 122.2 Variolink II 106.1 Panavia F 2.0 134.9 RelyX Unicem 115.7 Clearfil SA 130.6 Cement

(1.8)a 0.4 (1.4) 7.4 (1.9) 1.2 (1.6) 0.6 (0.6) 0.3

(0.3)a 4.7 (1.0) 6.7 (0.5) 9.5 (0.2) 10.7 (2.5)a 2.4

(0.9) 122.5 (0.7) 106.4 (2.7) 135.3 (1.1) 116.0 (5.1)a 131.0

(1.6) 0.4 (1.4) 7.6 (1.5) 1.2 (1.4) 0.7 (0.9) 0.3

visio.link


(0.9) 2.8 (0.7) 16.4 (0.7) 0.6 (0.3) 5.2 (1.3) 10.6 (1.5)a 37.7 (1.6) 3.1 (0.6) 10.4 (1.0) 7.0 (2.5)a 28.4

(2.1) 99.8 (0.7) 93.3 (3.6)a 105.4 (1.7) 93.4 (5.2)a 103.3

(0.7) 3.1 (0.8) 17.6 (0.8) 0.5 (0.2) 6.1 (1.4) 11.0 (1.5) 39.0 (1.6) 3.3 (0.9) 11.6 (1.0) 7.4 (2.6)a 29.7

VP connect


(1.4)a 0.4 (1.4) 7.4 (1.9) 1.2 (1.7) 0.7 (0.9) 0.3

without pretreatment


(4.4) 4.6 (2.8) 12.8 (2.1) 0.4 (0.4) 0.4 (6.5) 13.6 (4.8) 35.2 (5.3) 5.5 (3.0) 7.4 (5.8) 9.7 (4.1) 25.6

a

(0.4) 5.0 (1.2) 122.3 (1.0) 7.0 (0.7) 106.4 (0.5) 9.3 (2.9) 134.9 (0.2) 11.0 (1.1) 115.8 (2.6)a 2.1 (5.5)a 130.7

(5.4) 104.1 (1.9)a 98.7 (7.5) 108.7 (5.1) 97.0 (6.5) 106.9

Not normally distributed.

(1.7) 0.4 (1.3) 7.3 (2.4) 1.3 (1.7) 0.6 (1.1) 0.2

(4.4) (1.6) (5.3) (3.0) (5.2)

108.7 101.6 114.3 101.4 112.1

(0.4)a 5.1 (0.9) 122.4 (1.1) 6.9 (0.7) 106.4 (0.6) 9.1 (3.1) 135.1 (0.2) 11.1 (1.3) 115.9 (2.6)a 2.0 (5.1)a 130.9

(2.3) 100.2 (0.5) 93.9 (3.7) 105.6 (1.8) 93.7 (5.2)a 103.6

(0.3)a 4.9 (1.2) 122.9 (1.2) 7.0 (0.7) 103.2 (0.4) 9.5 (2.5) 136.2 (0.2) 10.9 (1.3)a 116.6 (2.5)a 2.3 (5.1)a 131.8

(5.2) 4.1 (2.3) 13.7 (2.9) 0.5 (0.4) 0.8 (7.2) 13.0 (5.0)a 35.7 (4.6) 4.9 (2.5) 8.0 (6.6) 9.1 (5.0) 26.1

(5.2) (3.0) (9.2) (6.2) (8.9)

94.8 92.5 97.5 94.3 96.2

SC (mN/m)

(6.7) 3.3 (3.5)a 8.7 (2.1) 1.4 (1.2)a 2.2 (9.6) 11.2 (7.3)a 30.1 (6.7) 4.3 (4.0) 3.5 (8.9) 7.6 (5.3)a 20.9

(1.6) 0.4 (1.5) 7.4 (2.1) 1.1 (1.7) 0.6 (1.2) 0.3

(5.7) 113.9 (2.1) 103.4 (10.8) 122.6 (6.9) 107.2 (7.8) 119.6

(0.4)a 5.0 (1.2) 121.5 (1.0) 6.9 (0.8) 105.5 (0.5) 9.3 (2.8) 134.1 (0.1) 11.0 (1.2) 115.0 (2.5)a 2.1 (5.1)a 129.9

(1.3) 3.2 (0.8) 17.2 (0.9) 0.5 (0.3)a 5.5 (1.6) 11.3 (2.1) 38.8 (1.4) 3.4 (0.7) 11.2 (1.6) 7.6 (2.8)a 29.4

(1.6) 0.6 (1.5) 8.4 (1.9) 0.9 (1.5) 0.8 (1.0) 0.5

WA IFT SC (mN/m) (mN/m) (mN/m)

(2.2) (0.9) (4.7) (2.1) (5.6)a

100.4 93.9 106.0 93.9 103.8

(0.4)a 5.5 (1.0) 121.8 (1.3) 6.8 (0.8) 105.7 (0.5) 8.2 (2.8) 134.6 (0.2) 11.6 (1.2) 115.4 (2.5)a 1.2 (4.9)a 130.3

(5.3) 7.6 (3.2) 22.6 (3.5) 1.0 (0.9)a 7.0 (7.8)a 18.4 (5.8) 46.9 (4.0)a 8.2 (3.4) 16.9 (6.9)a 14.0 (5.6)a 36.8

(5.5)a (3.3) (7.5) (5.1) (8.0)

99.0 96.1 101.9 92.0 100.6

0.8 2.3 5.6 1.3 2.9

(1.0)a 3.5 (1.2) 4.0 (2.5) 21.8 (0.9) 2.3 (2.8)a 13.4

(3.6) (1.0) (5.1) (2.3) (5.6)

(3.3) 0.4 (1.7)a 7.3 (2.9) 1.3 (2.1) 0.6 (2.7)a 0.3

(0.3)a 4.0 (1.3) 6.1 (0.6) 10.3 (0.2)a 10.1 (2.6)a 3.1

(1.7) 3.0 (0.9)a 17.1 (1.0) 0.5 (0.3) 5.6 (2.6) 10.9 (1.5) 38.4 (1.9) 3.3 (0.9) 11.1 (1.8) 7.4 (2.7)a 29.2

(2.7) (1.5) (4.6) (3.7) (3.8)

(2.1)a 0.4 (1.3) 7.6 (2.3) 1.2 (1.5) 0.6 (1.3) 0.3

LAVA Ultimate WA IFT SC (mN/m) (mN/m) (mN/m) 114.9 103.9 123.8 108.1 120.7

0.6 2.7 5.2 1.2 2.6

(0.8) 2.5 (1.5) 4.4 (2.6) 20.6 3.1 (0.9)a (2.2) 12.3

(3.1) (1.1) (6.1) (3.5) (4.8)

(2.1) 121.6 (1.8) 105.9 (4.2) 134.0 (3.0)a 115.1 (6.2)a 129.9

(1.8)a 0.3 (1.3) 7.0 (2.1) 1.3 (1.5) 0.5 (1.0) 0.2

(0.3) 4.2 (1.2) 6.5 (0.5) 10.4 (0.1) 10.2 (2.6)a 3.1

(1.0) (0.7) (2.8) (1.4) (5.4)a

(2.2) 100.2 (0.9) 93.7 (3.3) 105.8 (2.2) 93.8 (5.4)a 103.7

(1.3) 3.0 (0.9) 17.2 (0.9) 0.5 (0.2) 5.7 (2.0) 10.9 (1.7) 38.6 (2.2) 3.2 (0.8) 11.2 (1.6) 7.3 (3.0)a 29.3

(2.6) (1.0) (3.8) (1.8) (6.1)a

(0.9)a 4.4 (1.0)a 122.2 (1.5) 6.3 (0.7) 106.1 (0.5) 9.8 (2.9) 135.0 (0.2) 10.5 (1.7) 115.8 (2.6)a 2.7 (5.3)a 130.8

(4.1) 3.5 (3.6) 18.4 (4.0) 101.1 (2.8) 0.3 (0.3) 3.3 (2.5) 97.2 (5.0) 17.1 (4.1) 42.5 (6.9) 104.5 (4.4) 7.2 (2.1) 12.9 (4.0) 94.1 (4.7) 12.7 (3.1) 32.4 (5.3) 103.1

(3.5) (1.5) (4.6) (3.3) (4.3)

(1.8) 0.5 (1.5) 7.6 (1.7) 1.1 (1.6) 0.6 (1.5) 0.4

(0.4)a 4.8 (1.3) (1.0) 6.6 (0.9) (0.7) 9.4 (3.6) (0.2) 10.8 (1.6) (2.5)a 2.2 (5.5)a

(3.0) 5.4 (1.8) 16.4 (2.0) 0.3 (0.4)a 2.2 (4.1) 15.5 (4.6) 39.9 (3.3) 6.2 (1.8) 10.9 (3.8) 11.2 (4.1) 29.9

(3.5) (2.0)a (6.2) (3.3) (6.3)


Ambarino P60

WA IFT (mN/m) (mN/m)


JJOD 2255 1–10

6


Table 3 – Mean values with standard deviation (SD) of WA, IFT and SC values according pre-treatment and resin composite cement.

297 298 299 300 301 302

303

304 305 306 307 308 309 310 311

312

371 370 369 368 367 366 365 364 363 362 361 360 359 358 357 356 355 354

JJOD 2255 1–10

7

2.8 (4.1) 8.9 (5.5) 14.3 (3.5) 10.8 (4.0) 0 (0) (6.7) (6.3) (3.8) (5.3) (5.6) 13.1 25.3 31.5 31.2 23.9 (5.6) (6.2) (5.4) (5.3) (5.3) 13.4 3.1 29.2 2.7 32.4 (3.8) (2.7) (1.8) (1.3) (4.7) 119.6 129.9 103.8 130.3 100.6 0 (0) 12.2 (4.0) 19.6 (6.5) 12.8 (5.6) 0 (0) (13.3) (12.1) (7.0) (10.5) (8.4) 19.5 32.0 38.0 24.9 16.8 (1.0) (2.1) (2.2) (0.7) (2.5) 4.0 4.0 17.1 6.3 3.3 (1.5) (1.7) (1.0) (1.3) (2.8) 103.4 105.5 93.9 105.7 96.1 (2.0) (1.0) (0.6) (1.1) (0.4) Ambarino P60 Monobond Plus/Heliobond visio.link VP connect Without pre-treatment

6.3 13.9 2.4 14.2 0.6

0 (0) 14.1 (4.4) 15.8 (4.2) 11.1 (5.1) 0 (0)


TBS Lit. [21]

0 (0) 25.9 (7.3) 23.7 (6.4) 18.7 (6.3) 5.3 (6.2) (7.1) (5.1) (5.2) (5.5) (6.5)

SC

30.7 2.4 28.4 2.1 25.6 (3.2) (0.6) (1.0) (0.9) (5.8) 102.3 130.6 104.6 130.9 107.4

WA SBS Lit. [20]

0 (0) 14.2 (4.8) 17.0 (4.6) 18.1 (3.8) 0 (0) (6.7) (8.3) (7.5) (9.7) (6.8)

TBS Lit. [21]

8.2 28.1 25.6 36.0 7.7 (1.7) (0.7) (0.7) (0.7) (1.9)

SC

0.7 6.7 5.2 7.0 0.4 (1.3) (1.4) (0.7) (1.4) (2.1)

WA

98.8 106.1 94.2 106.5 99.9 (0.4) (0.5) (0.2) (0.6) (1.4)

The adherence between the cement and the dental restoration is a critical factor for successful outcome of a fixed dental restoration [11,21,25] and depends on many different factors [26]. The properties of a dental restoration and the resin composite cement systems are significant factors for the bond performance between the restoration and cement [21,27]. Therefore, the present study investigated the impact of pretreatment with varying adhesive systems on surface parameters between the CAD/CAM polymers and resin composite cements. The null-hypothesis – that by additional use of bonding systems WA is similar than without, regardless of CAD/CAM polymer – has to be rejected. The pre-treatment method of choice had a significant impact on WA. Monobond Plus/Heliobond and VP connect resulted in the significantly highest WA compared to all other tested adhesive systems. Only the use of visio.link showed no significant increase of WA compared to the control group without pre-treatment. In terms of the secondary investigation of this study – that the calculated surface properties show a positive correlation to the measured TBS or SBS of prior studies [10,11] – the

0.4 14.1 2.6 14.0 1.7

313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332

Discussion

Ambarino P60 Monobond Plus/Heliobond visio.link VP connect Without pre-treatment

4.

ArtBloc Temp

312

Clearfil SA Cement

Table 4 lists the calculated values for the WA together with the TBS and SBS values obtained in two earlier studies [10,11]. WA resulted in no correlation to TBS or SBS whereas polar components of SFE of pre-treated CAD/CAM polymer showed a significant positive correlation with TBS (r2 = 0.406, p < 0.001) and SBS (r2 = 0.406, p < 0.001). Also the SC showed a positive correlation to TBS (r2 = 0.205, p < 0.001) and SBS (r2 = 0.201, p = 0.001).

Variolink II

304 305 306 307 308 309 310 311

Comparison to measured TBS and SBS of prior studies

Polar Component of SFE of pretreated CAD/CAM polymer

3.2.

Pre-treatment

303

CAD/CAM polymer

cement a significant impact on the WA, IFT and SC was found (p < 0.001). Both PMMA-based materials Telio CAD and artBloc Temp as well as Nano Composite CFI-C showed significantly higher WA compared to exp. CAD/CAM nanohybrid composite and LAVA Ultimate. Monobond Plus/Heliobond and VP connect resulted in significantly higher WA than Ambarino P60, whereas visio.link and un-treated groups resulted in significantly lower WA than Ambarino P60. The use of VAR resulted in the significantly lowest WA, followed by RXU, RXA and CSA in ascending order. For PAN the significant highest WA was determined. LAVA Ultimate and exp. CAD/CAM nanohybrid composite showed lower IFT values than Nano composite CFI-C, artBloc Temp and Telio CAD. Monobond Plus/Heliobond and VP connect resulted in lower IFT than visio.link, followed by Ambarino P60 and highest values for groups without pretreatment. RXU and PAN resulted in lower IFT than CSA, RXA and VAR. TelioCAD, Nano composite CFI-C and artBloc Temp resulted in lower SC than exp. CAD/CAM nanohybrid composite and LAVA Ultimate. Visio.link and no pre-treatment resulted in lower SC than Ambarino P60. Monobond Plus/Heliobond and VP connect resulted in highest values. VAR, CSA and RXA resulted in lower SC than PAN and RXU.

Table 4 – Mean and standard deviation of work of adhesion [N/m] together with TBS [MPa] and SBS [MPa] results of prior studies [20,21].

278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302

SBS Lit. [20]



333 334 333 335 334 333 336 335 334 333 337 336 335 334 333 338 337 336 335 334 333 339 338 337 336 335 334 333 340 339 338 337 336 335 334 333 341 340 339 338 337 336 335 334 333 342 341 340 339 338 337 336 335 334 333 343 342 341 340 339 338 337 336 335 334 333 344 343 342 341 340 339 338 337 336 335 334 333 345 344 343 342 341 340 339 338 337 336 335 334 333 346 345 344 343 342 341 340 339 338 337 336 335 334 333 347 346 345 344 343 342 341 340 339 338 337 336 335 334 333 348 347 346 345 344 343 342 341 340 339 338 337 336 335 334 333 349 348 347 346 345 344 343 342 341 340 339 338 337 336 335 334 333 350 349 348 347 346 345 344 343 342 341 340 339 338 337 336 335 334 333 351 350 349 348 347 346 345 344 343 342 341 340 339 338 337 336 335 334 351 350 349 348 347 346 345 344 343 342 341 340 339 338 337 336 335 334 352 351 350 349 348 347 346 345 344 343 342 341 340 339 338 337 336 335 352 351 350 349 348 347 346 345 344 343 342 341 340 339 338 337 336 335 353 352 351 350 349 348 347 346 345 344 343 342 341 340 339 338 337 336 353 352 351 350 349 348 347 346 345 344 343 342 341 340 339 338 337 336 354 353 352 351 350 349 348 347 346 345 344 343 342 341 340 339 338 337 354 353 352 351 350 349 348 347 346 345 344 343 342 341 340 339 338 337 355 354 353 352 351 350 349 348 347 346 345 344 343 342 341 340 339 338 355 354 353 352 351 350 349 348 347 346 345 344 343 342 341 340 339 338 356 355 354 353 352 351 350 349 348 347 346 345 344 343 342 341 340 339 356 355 354 353 352 351 350 349 348 347 346 345 344 343 342 341 340 339 357 356 355 354 353 352 351 350 349 348 347 346 345 344 343 342 341 340 357 356 355 354 353 352 351 350 349 348 347 346 345 344 343 342 341 340 358 357 356 355 354 353 352 351 350 349 348 347 346 345 344 343 342 341 358 357 356 355 354 353 352 351 350 349 348 347 346 345 344 343 342 341 359 358 357 356 355 354 353 352 351 350 349 348 347 346 345 344 343 342 359 358 357 356 355 354 353 352 351 350 349 348 347 346 345 344 343 342 360 359 358 357 356 355 354 353 352 351 350 349 348 347 346 345 344 343 360 359 358 357 356 355 354 353 352 351 350 349 348 347 346 345 344 343 361 360 359 358 357 356 355 354 353 352 351 350 349 348 347 346 345 344 361 360 359 358 357 356 355 354 353 352 351 350 349 348 347 346 345 344 362 361 360 359 358 357 356 355 354 353 352 351 350 349 348 347 346 345 362 361 360 359 358 357 356 355 354 353 352 351 350 349 348 347 346 345 347 346 363 362 361 360 359 358 357 356 355 354 353 352 351 350 349 348 363 362 361 360 359 358 357 356 355 354 353 352 351 350 349 348 347 346 364 363 362 361 360 359 358 357 356 355 354 353 352 351 350 349 348 347 364 363 362 361 360 359 358 357 356 355 354 353 352 351 350 349 348 347 365 364 363 362 361 360 359 358 357 356 355 354 353 352 351 350 349 348 365 364 363 362 361 360 359 358 357 356 355 354 353 352 351 350 349 348 366 365 364 363 362 361 360 359 358 357 356 355 354 353 352 351 350 349 366 365 364 363 362 361 360 359 358 357 356 355 354 353 352 351 350 349 367 366 365 364 363 362 361 360 359 358 357 356 355 354 353 352 351 350 367 366 365 364 363 362 361 360 359 358 357 356 355 354 353 352 351 350 368 367 366 365 364 363 362 361 360 359 358 357 356 355 354 353 352 351 368 367 366 365 364 363 362 361 360 359 358 357 356 355 354 353 352 351 369 368 367 366 365 364 363 362 361 360 359 358 357 356 355 354 353 352 369 368 367 366 365 364 363 362 361 360 359 358 357 356 355 354 353 352 370 369 368 367 366 365 364 363 362 361 360 359 358 357 356 355 354 353 370 369 368 367 366 365 364 363 362 361 360 359 358 357 356 355 354 353 371 370 369 368 367 366 365 364 363 362 361 360 359 358 357 356 355 354 371 370 369 368 367 366 365 364 363 362 361 360 359 358 357 356 355 354

JJOD 2255 1–10

8 462 372 371 370 369 368 367 366 365 364 363 362 361 360 359 358 357 356 355 432 463 433 373 464 434 374 465 435 375 466 436 376 467 437 377 468 469 438 378 470 439 379 471 440 380 472 441 381 473 442 382 474 443 383 475 444 384 476 477 445 385 478 446 386 479 447 387 480 448 388 481 449 389 482 450 390 483 484 451 391 485 452 392 486 453 393 487 454 394 488 455 395 489 456 396 490 457 397 491 492 458 398 493 459 399 494 460 400 495 461 401 496 462 402 497 463 403 498 464 404 499 500 465 405 501 466 406 502 467 407 503 468 408 504 469 409 505 470 410 506 507 471 411 508 472 412 509 473 413 510 474 414 511 475 415 512 476 416 513 417 477 514 515 478 418 516 479 419 517 480 420 518 481 421 519 482 422 520 483 423 521 484 424 522 523 485 425 524 426 485 525 427 486 526 428 527 486 429 528 487 430 529 530 488 431


hypothesis also has to be rejected. Solely the polar component of the SFE of pre-treated CAD/CAM polymers showed a significant positive correlation with measured TBS and SBS. This indicates that simply taking single surface parameters into consideration, may lead to false assumptions. Currently, literature focusing on WA in the dental field is lacking. One prior study investigated the bond strength and WA between posts after different pre-treatments and resin cements and concluded that the bond strength values correlated to the disperse parts of WA [15]. It was stated that differences exist between the surface energy characteristics of the polymerized surface of the adhesive and the polymer forming the interface between the adherent and the polymerized adhesive. The authors used four different liquids to determine the contact angles and a different mode of calculating the WA, integrating the dispersive, acid and base components of the SFE, while the present study only distinguished between dispersive and polar components on basis of two different liquids. Measurement of contact angles with different liquid droplets is a common method to determine the wettability and therefore the SFE of a material [17,28]. In the present study liquids with different polarities were used. This is necessary for the calculation of the WA between two surfaces. Diiodomethane shows lower surface tension and higher viscosity than water. In general, lower surface tension leads to a lower contact angle [16]. Contrary to the inner body of a material, the atomic surface characteristics are not in equilibrium, as there are different interatomic interactions on the outer atomic layer [28]. The difference between the atoms of the deeper layer and the superficial layer is represented by the SFE [29], based on which the WA was calculated. To determine the contact angle, the present study worked on the sessile drop technique with static drops. Hereby, a constant drop volume was applied before measurement. However, the contact angle can be influenced by several factors [30] and does not remain constant over a long time period, as interactions at the boundary surface result in continuous increase or decrease with time. Possible interactions could be chemical reaction between the specimen’s surface and the liquid [31], swelling or dissolving of the specimen by the liquid [32] or for example evaporation of the liquid. Therefore, all measurements were performed after standardized time subsequent to application of the liquid drop. The present study determined the contact angles of the CAD/ CAM polymer after pre-treatment with bonding systems according to the manufacturer’s recommendations. Usually, the chemical, physical, and/or mechanical processes between CAD/CAM polymer and bonding system are completed before testing takes place. Contrary to this, contact angles of resin composite cements were measured in an unpolymerized state in approximately complete darkness to prevent or retard the polymerization process as much as possible. Therefore the measuring device was covered with a light-tight box. However, despite utmost care, a minimal incidence of light and therefore a beginning of polymerization cannot be avoided. In this sense, the oxygen inhibition layer of the resin composite cement must be considered, as it may influence the surface parameters. Prior studies investigated the influence of the oxygen inhibition layer

of light polymerized self-adhesives bonding systems applied to enamel and dentine [33,34]. The authors determined the bond strength and SFE with its components. Both studies reported that the oxygen-inhibited layer of adhesive liquids appeared to promote higher bond strength. Opposed to this, the total SFE values were significantly higher after removing the oxygeninhibited layer. In this context it should be mentioned, that the experimental in vitro study design could not be transferred to the clinical daily routine, which makes it nearly impossible to work in absolute darkness. In this context, a beginning of polymerization after mixing of the cement takes presumably place during the cementation of a dental restoration. For screening of the bond strength by means of destructive stress tests like TBS and SBS the plastic and elastic properties of the substrate, the bonding system and the resin composite cement as well as the stress during the test have an unknown influence on the test results [15]. Furthermore these investigation methods show differences in test design, such as specimen dimension, type of testing jig, and adjustment of the testing machines. In general, the surface microstructure, hence the roughness parameters after various pretreatment of the substrate and therefore the mechanical interlocking of the resin composite cement seem to influence the bond strength [12,35]. Therefore it needs to be questioned if there is a lack of standardization and, in consequence, difficultly while comparing the results [36]. Nevertheless, these methods are simple laboratory testing methods to evaluate the effectiveness of bonding [28]. Determination of the surface properties focused only on the short term binding characteristics, whereas the measurement of bond strength was performed for specimens after completed reaction between pre-treated CAD/CAM polymer and resin composite cement. In addition to the mechanical bonding processes, two different reaction types can be distinguished [28]: the chemical reaction (chemisorption) which results in new chemical bonds between the substrate surface (CAD/CAM polymers after pre-treatment) and the resin composite cement. Opposed to this is physical adsorption (physisorption); a process which leaves the chemical species of the substrate and resin composite cement intact and is barely perturbed upon adsorption. Physisorption is present in general, although the energy values are in a low range [28]. The binding energy of physisorption lies within a range of 4–40 kJ/mol, while chemisorption reaches values about ten times as high. Unfortunately it is difficult to reconstruct all reaction mechanisms between the investigated materials as, so far, no precise manufacturer’s data in view of the exact molecular content is available. Analyzing molecular content of substrates can be performed using energy dispersive X-ray spectroscopy (EDX) [37–39]. Nevertheless, to the author’s best knowledge no information is available about the CAD/CAM polymers, investigated in present study. This should be topic of a further investigation.

5.

Conclusion

The sole determination of WA is not a sufficient method to draw conclusions about the bond between different materials. The present study shows, that further factors, like polar and


530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598


489 490 491 492 493 494

disperse components of the SFE, SC and IFT need to be considered. Furthermore, destructive testing methods are required to test the real bond strength, as approximate intraoral conditions’ simulation via artificial ageing procedures is allowed.

495

Acknowledgements

496 497 498

The authors like to express their gratefulness to Ivoclar Vivadent, 3M ESPE, Creamed, Merz Dental, Kuraray and Bredent for supporting this study with materials.

499

references

500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548

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9

Q3

549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617

JJOD 2255 1–10

10 617 618 619 620 621 622 623 624 625 626 627 628 629


bond strength of self-etch adhesives. Dental Materials Journal 2012;31:26–31. [34]. Koga K, Tsujimoto A, Ishii R, Iino M, Kotaku M, Takamizawa T, Tsubota K, Miyazaki M. Influence of oxygen inhibition on the surface free-energy and dentin bond strength of self-etch adhesives. European Journal of Oral Science 2011;119:395–400. [35]. Chen JH, Matsumura H, Atsuta M. Effect of different etching periods on the bond strength of a composite resin to a machinable porcelain. Journal of Dentistry 1998;26:53–8. [36]. Kelly JR, Benetti P, Rungruanganunt P, Bona AD. The slippery slope: critical perspectives on in vitro research methodologies. Dental Materials 2012;28:41–51.

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CAM resin and resin composite cements dependent on bonding agents: three different in vitro test methods.

CAM applications.

CAM composite materials and the bond strength of resin cements.

Microhardness of dual-polymerizing resin cements and foundation composite resins for luting fiber-reinforced posts.

A systematic approach to standardize artificial aging of resin composite cements.

Effect of indirect composite treatment microtensile bond strength of self-adhesive resin cements.

Assessing degradation of composite resin cements during artificial aging by Martens hardness.

Evaluation of a commercial primer for bonding of zirconia to two different resin composite cements.

Bond strength of self-adhesive resin cements to composite submitted to different surface pretreatments.

CAM resin-ceramic hybrid materials.

Synthesis of radiopaque cyclophosphazene monomers, properties of bulk polymers and their application to composite resin.

Self-adhesive resin cements: a clinical review.

Composite cements benefit from light-curing.

Effect of configuration factor on gap formation in hybrid composite resin, low-shrinkage composite resin and resin-modified glass ionomer.

Adhesion between the resin shell and composite resin.

Silver nanoparticles in resin luting cements: Antibacterial and physiochemical properties.

Class I composite resin restoration.

Comparison of the shear bond strength of a titanium composite resin material with dentinal bonding agents versus glass ionomer cements.

Do conventional glass ionomer cements release more fluoride than resin-modified glass ionomer cements?

CAM hybrid ceramic using different repair systems.

The composite resin dowel and core.

Effects of 'resin-compatible' cavity varnishes on composite resin microhardness.

CAM ceramic material.

CAM resin nanoceramic.