Clearfil Ceramic Primer Research Articles

Shear bond strengths of an indirect composite layering material to a tribochemically silica-coated zirconia framework material.

This study evaluated shear bond strengths of a layering indirect composite material to a zirconia framework material treated with tribochemical silica coating. Zirconia disks were divided into two groups: ZR-PRE (airborne-particle abrasion) and ZR-PLU (tribochemical silica coating). Indirect composite was bonded to zirconia treated with one of the following primers: Clearfil Ceramic Primer (CCP), Clearfil Mega Bond Primer with Clearfil Porcelain Bond Activator (MGP+Act), ESPE-Sil (SIL), Estenia Opaque Primer, MR. Bond, Super-Bond PZ Primer Liquid A with Liquid B (PZA+PZB), and Super-Bond PZ Primer Liquid B (PZB), or no treatment. Shear bond testing was performed at 0 and 20,000 thermocycles. Post-thermocycling shear bond strengths of ZR-PLU were higher than those of ZR-PRE in CCP, MGP+Act, SIL, PZA+PZB, and PZB groups. Application of silane yielded better durable bond strengths of a layering indirect composite material to a tribochemically silica-coated zirconia framework material.

Durability of Resin-Zirconia Bonds Produced Using Methods Available in Dental Practice.

To evaluate the strength, after artificial aging, of resin-zirconia bonds yielded by methods available in dental practice. Standardized test specimens consisting of composite resin cylinders cemented to Y-TZP disks were assigned to 24 groups (n=20 per group) on the basis of the surface conditioning of the disks and the adhesive used (cement+manufacturer-specific primer). Conditioning methods were: none (control), airborne particle abrasion (50-μm Al2O3 at 0.05, 0.10, or 0.25 MPa), or tribochemical silica coating (Rocatec or CoJet). Panavia 21+Clearfil Ceramic Primer, Multilink Automix+Monobond Plus, BiFix QM+Ceramic bond, or RelyX Ultimate+Scotchbond Universal were used for cementation. Specimens were stored in water at 37°C either for 3 days or for 150 days in conjunction with 37,500 thermocycles before being submitted to a tensile test (crosshead speed: 1 mm/min). Nonparametric ANOVA and post-hoc tests within the same model were applied to the results (α=0.05). Conditioning, cement, aging, and all their interactions significantly affected bond strength (p<0.0001). After storage in water for 3 days, bond strengths ranged between 4 and 45 MPa (values were lowest in the BiFix QM groups). After long-term aging, the best results were obtained for silica-coated (Rocatec) zirconia samples cemented with Panavia 21/Clearfil Ceramic Primer; this was the only group for which bond strengths were >10 MPa. Premature failure of the resin-ceramic bond was usually observed during long-term aging, the only exception being the non-control groups cemented with Panavia. Most bonding strategies failed to create bonds to zirconia with acceptable strength after long-term aging. It might therefore be unwise to rely solely on adhesion for retention of load-bearing Y-TZP restorations.

Effect of Different Silane-Containing Solutions on Glass-Ceramic/ Cement Bonding Interacting with Dual-Cure Resin Cements

&lt;p&gt;&lt;span&gt;The aim of this study is to determine the effect of different silane-containing solutions on ceramic-cement bonding and their interaction with different dual-cure resin cements. Forty five glass- ceramic plaques (IPS e.max CAD®) were sandblasted with aluminum oxide for 5s, etched with 10% hydrofluoric acid gel (HF) for 20s and then divided in three groups of 15 each to be treated with different silane-containing solutions: RelyX Ceramic Primer® (AS), Scotchbond Universal® (SU), Clearfil Ceramic Primer® (CP). Then each group was divided in five groups of three plaques to receive the following dual-cure resin cements: Conventional: RelyX Ultimate (RU), RelyX ARC (AR), VarioLink II (VL); and two self-adhesive: RelyX UNICEM 2 (U2), and BiFix (BF). Eight cement cylinders of each cement were distributed on each plaque and polymerized, summarizing 24 cylinders per group. After 24 h storage in relative humidity at 37°C, each cylinder was subjected to a microshear testing. Failure mode was analyzed using scanning electron microscopy (SEM). Data were statistically analyzed with two-way ANOVA (resin cement and silane ) and Tukey test (p≤0.05). Both factors significantly influenced the results and also interaction between them was detected (p=0.0001). μSBS was significantly higher when ceramic was treated with AS for all cements. Most of cements showed no statistically different means when treated with SU and CP, except BF-SU and AR-CP that showed significantly lower means within their treatment groups. Some incomplete polymerization areas were observed in SEM images for those cases. Cohesive failure in resin cement type was predominant with higher results while adhesive with lower results. The sole silane solution improved better bonding than the universal adhesive and the ceramic primer. In general, universal adhesive and ceramic primer produced acceptable mean values and they were statistically comparable. Compatibility between silane solutions and dual-cure resin cements may be material dependent. &lt;/span&gt;&lt;/p&gt;

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

The aim of this study was to assess the bonding properties between CAD/CAM resin and three resin composite cements combined with different bonding agents using three test methods. Four hundred twenty CAD/CAM resin substrates were fabricated and divided into three test methods (shear bond strength (SBS, n = 180), tensile bond strength (TBS, n = 180) and work of adhesion (WA, n = 60)), further into four pretreatment methods (VP connect (VP), visio.link (VL), Clearfil Ceramic Primer (CP) and no pretreatment (CG)) and three cements (RelyX ARC, Variolink II and Clearfil SA Cement). Each subgroup contained 15 specimens. SBS and TBS were measured after 24h H2O/37°C + 5000 thermal-cycles (5/55°C) and failure types were assessed. WA was determined for pretreated CAD/CAM resin and non-polymerized resin composite cements. Data were analysed with Mann-Whitney U, Kruskal-Wallis H, Chi(2) and Spearman's Rho tests. Within SBS and TBS tests, CGs and groups pretreated with CP (regardless of resin composite cements), and VP pretreated with Clearfil SA Cement showed no bond. However, CG combined with RelyX ARC showed a TBS of 5.6 ± 1.3MPa. In general, highest bond strength was observed for groups treated with VL. CG and groups pretreated using VL showed lower WA than the groups treated with VP or CP. Measured TBS values were higher than SBS ones. In general, SBS and TBS showed similar trends for the ranges of the values for the groups. WA results were not comparable with SBS/TBS results and admitted, therefore, no conclusions on it. For a clinical use of XHIP-CAD/CAM resin, the bond surface should be additionally pretreated with visio.link as bonding agent.

Retention Forces between Titanium and Zirconia Components of Two-Part Implant Abutments with Different Techniques of Surface Modification.

The adhesive connection between titanium base and zirconia coping of two-part abutments may be responsible for the failure rate. A high mechanical stability between both components is essential for the long-term success. The aim of the present in-vitro study was to evaluate the influence of different surface modification techniques and resin-based luting agents on the retention forces between titanium and zirconia components in two-part implant abutments. A total of 120 abutments with a titanium base bonded to a zirconia coping were investigated. Two different resin-based luting agents (Panavia F 2.0 and RelyX Unicem) and six different surface modifications were used to fix these components, resulting in 12 test groups (n = 10). The surface of the test specimens was mechanically pretreated with aluminium oxide blasting in combination with application of two surface activating primers (Alloy Primer, Clearfil Ceramic Primer) or a tribological conditioning (Rocatec), respectively. All specimens underwent 10,000 thermal cycles between 5°C and 55°C in a moist environment. A pull-off test was then conducted to determine retention forces between the titanium and zirconia components, and statistical analysis was performed (two-way anova). Finally, fracture surfaces were analyzed by light and scanning electron microscopy. No significant differences were found between Panavia F 2.0 and RelyX Unicem. However, the retention forces were significantly influenced by the surface modification technique used (p < 0.001). For both luting agents, the highest retention forces were found when adhesion surfaces of both the titanium bases and the zirconia copings were pretreated with aluminium oxide blasting, and with the application of Clearfil Ceramic Primer. Surface modification techniques crucially influence the retention forces between titanium and zirconia components in two-part implant abutments. All adhesion surfaces should be pretreated by sandblasting. Moreover, a phosphate-based primer serves to enhance long-term retention of the components.

Effect of Surface Treatments on the Bond Strength of Veneering Ceramic to Zirconia

The purpose of this study was to evaluate the effect of different surface treatments on the bond strength of veneering ceramic to zirconia. Square (15 mm x 10 mm x 2 mm) zirconia specimens (n=18) received one of the following surface treatments: Group 1, sandblasting; Group 2, Clearfil ceramic primer application; Group 3, grinding; Group 4, alloy primer application; and Group 5, RelyX ceramic primer application. The zirconia core specimens were layered with a veneering porcelain (5 mm x 3 mm x 3 mm). Mean shear bond strength values (MPa) were calculated. Data were analyzed with one-way ANOVA and Tukey's post hoc pairwise comparisons (α=0.05). Fractured surfaces of the specimens were examined with scanning electron microscope (SEM). This study showed that bond strengths of the metal primer-treated zirconia specimens (Group 4) were significantly higher than those of the other paired groups. The application of metal primer affected the specimens' failure mode. SEM analysis demonstrated that Group 4 had mainly cohesive fractures, while the other groups showed approximately equal levels of adhesive and mixed fracture types. The mean and SD values for shear bond strengths ranged from 8.90 ± 3.42 MPa (Group 2) to 19.74 ± 4.96 MPa (Group 4). In conclusion, the application of a metal primer to a zirconia core increased the bond strength of veneering ceramics. The use of chemical agents to improve the strength of the zirconia core's bond to veneering ceramic may have more benefits than the use of mechanical pretreatments.

Efficiency of different repair kits on bonding to aged dental resin composite substrates

ObjectiveTo assess the efficiency of intraoral repair kits on the tensile bond strength (TBS) of resin composites (RCs) to aged RC substrates. Methods840 aged (six months, 37°C, distilled water) RC substrates (Tetric EvoCeram) were air-abraded (CoJet) with and without following phosphoric acid contamination or treated with silicon carbide (SiC) grinding paper. Seven repair kits were used as intermediate agents (Embrace First-Coat, CLEARFIL CERAMIC PRIMER, Tokuso Ceramic Primer, Monobond Plus+Heliobond; Scotchbond Universal, One Coat Bond and visio.link) for conditioning. Specimens were repaired using two direct RCs (Clearfil Majesty ES2 and Clearfil Majesty Posterior), stored in distilled water (37°C, 24h) and thermal aged (5°C/55°C, 10,000 cycles). The cohesive strength of the repair RCs (N=40) served as control and was determined by applying the RCs on the fresh polymerized substrates, followed by thermal-aging procedure. TBS and failure types were determined and evaluated with three-/one-way ANOVA, and chi-square test (p<0.05). ResultsThe highest influence on the TBS was exerted by the intermediate agent (repair kit) (partial eta squared ηP²=0.320, p<0.001), while the impacts of the repair RC (ηP²=0.017, p<0.001) and surface pre-treatment (ηP²=0.015, p=0.003) were significant but low. Except for Embrace First Coat and Tokuso Ceramic Primer, phosphoric acid contamination after air-abrasion maintains the TBS. ConclusionsAir-abrasion induced superior TBS compared with grinding the surface with SiC paper prior to repair. Tested universal adhesives as well as the combination between a universal primer and an adhesive were in-vitro efficient intermediate agents for repairing aged RCs.

Contemporary Ceramics and Cements

Contemporary Ceramics and Cements

Influence of PEEK surface modification on surface properties and bond strength to veneering resin composites.

To test the impact of mechanical and chemical treatments of PEEK on surface roughness (SR), surface free energy (SFE), and tensile bond strength (TBS) to veneering resin composites. PEEK specimens (N = 680) were fabricated and divided into treatment groups (n = 170/group): 1. air abrasion (AIA); 2. etching with piranha solution (PIS); 3. air abrasion + piranha acid etching (AIP); and 4. no treatment (NO). Ten specimens of each treatment group were assessed with a contact angle measuring device and profilometer to determine SFE and SR, respectively. The remaining 160 specimens of each group were divided into subgroups according to coupling method (n = 32/subgroup): 1. Monobond Plus/ Heliobond (MH); 2. Visio.link (VL); 3. Clearfil Ceramic Primer (CCP); 4. Signum PEEK Bond (SPB); and 5. control, no coupling (CG). Specimens were veneered using Signum Composite/SiCo or Signum Ceramis/SiCe (both: n = 16), incubated in water (60 days at 37°C) and thermocycled (5000 cycles of 5°C/55°C). TBS was measured and data analyzed by three- and one-way ANOVA, Kruskal-Wallis and Mann-Whitney tests (p < 0.05). A significant effect of surface treatment (p < 0.001) and coupling agent application (p < 0.001) on TBS was observed. AIA specimens with/without PIS showed the highest SFE, SR, and TBS. No differences were measured between PIS and NO, and between AIA and AIP. When no coupling agent was used, no adhesion was obtained. CCP resulted in low adhesion values, whereas MH, SPB, and VL exhibited increased TBS. No significant impact of the veneering resin composite on TBS was found (p = 0.424). AIA and AIP combined with VL, SPB, and MH can be recommended for clinical use.

Effects of surface treatments and cement types on the bond strength of porcelain-to-porcelain repair.

The purpose of this in vitro study was to evaluate the effects of four surface treatments and two resin cements on the repair bond strength of a ceramic primer. Eighty-eight pairs of disks (10 and 5 mm in diameter, 3 mm thickness) were prepared from heat-pressed feldspar ceramics (GC Initial IQ). After being stored in mucin-artificial saliva for 2 weeks, the 10-mm disks were divided into four surface treatment groups (n = 22) and then treated as follows: (1) no treatment (control); (2) 40% phosphoric acid; (3) 5% hydrofluoric acid + acid neutralizer + 40% phosphoric acid; (4) silica coating (CoJet-sand) + 40% phosphoric acid. The 5-mm disks were treated with 5% hydrofluoric acid + 40% phosphoric acid. The two sizes of porcelain disks, excluding the control group, were primed with Clearfil Ceramic Primer. The specimens in each group were further divided into two subgroups of 11 each, and bonded with Clearfil Esthetic Cement (CEC) or Panavia F 2.0 Cement (PFC). The specimens were stored in distilled water at 37°C for 24 hours, thermocycled for 3000 cycles at 5 to 55°C, and stored at 37°C for an additional 7 days. Shear bond strength (SBS) was measured with a universal testing machine at a 0.5 mm/min crosshead speed until fracture. Statistical analysis of the results was carried out with a two-way ANOVA and Tukey HSD test (α = 0.05). Debonded specimen surfaces were examined under an optical microscope to determine the mode of failure. The statistical analysis showed that the SBS was significantly affected by surface treatment and resin cement (p < 0.05). For treatment groups bonded with CEC, the SBS (MPa) values were (1) 2.64 ± 1.1, (2) 13.31 ± 3.6, (3) 18.88 ± 2.6, (4) 14.27 ± 2.7, while for treatment groups cemented with PFC, the SBS (MPa) values were (1) 3.04 ± 1.1, (2) 16.44 ± 3.3, (3) 20.52 ± 2.2, and (4) 16.24 ± 2.9. All control specimens exhibited adhesive failures, while mixed types of failures were observed in phosphoric acid-treated groups. The other groups revealed mainly cohesive and mixed failures. Combined surface treatment of etching with hydrofluoric acid and phosphoric acid provides the highest bond strengths to porcelain. Also, PFC exhibited higher SBS than CEC did.

Bonding of resin cement to zirconia with high pressure primer coating.

ObjectivesTo investigate the effect of air-drying pressure during ceramic primer coating on zirconia/resin bonding and the surface characteristics of the primed zirconia.MethodsTwo ceramic primers (Clearfil Ceramic Primer, CCP, Kuraray Medical Inc. and Z-Prime Plus, ZPP, Bisco Inc.) were applied on the surface of air-abraded zirconia (Katana zirconia, Noritake) and dried at 4 different air pressures (0.1–0.4 MPa). The primed zirconia ceramic specimens were bonded with a resin-based luting agent (SA Luting Cement, Kuraray). Micro-shear bond strengths of the bonded specimens were tested after 3 days of water storage or 5,000× thermocycling (n = 12). Failure modes of the fractured specimens were examined with scanning electron miscopy. The effects of air pressure on the thickness of the primer layers and the surface roughness (Sa) of primed zirconia were evaluated using spectroscopic ellipsometry (n = 6), optical profilometry and environmental scanning electron microscopy (ESEM) (n = 6), respectively.ResultsClearfil Ceramic Primer air-dried at 0.3 and 0.4 MPa, yielding significantly higher µSBS than gentle air-drying subgroups (p<0.05). Compared to vigorous drying conditions, Z-Prime Plus air-dried at 0.2 MPa exhibited significantly higher µSBS (p<0.05). Increasing air-drying pressure reduced the film thickness for both primers. Profilometry measurements and ESEM showed rougher surfaces in the high pressure subgroups of CCP and intermediate pressure subgroup of ZPP.ConclusionAir-drying pressure influences resin/zirconia bond strength and durability significantly. Higher air-drying pressure (0.3-0.4 MPa) for CCP and intermediate pressure (0.2 MPa) for ZPP are recommended to produce strong, durable bonds between resin cement and zirconia ceramics.

Dentin bond strength of two recent CAD/CAM-materials after storage

Purpose: To investigate the bond strength to dentin of two recent resin-ceramic materials for computer-aided design/computer-aided manufacturing (CAD/CAM) after 24 hours and after six months storage. Methods and Materials: Ninety cylinders were milled out of Lava Ultimate (3M ESPE) and 90 cylinders out of VITA ENAMIC (VITA Zahnfabrik) (dimension of cylinders: ∅=3.6 mm, h=2 mm). All Lava Ultimate cylinders were sandblasted (aluminium oxide, grain size: 27 μm) and cleaned with ethanol, whereas all VITA ENAMIC cylinders were acid-etched (5% hydrofluoric acid) and cleaned with water-spray. According to the three groups of cements used, the cylinders (n=30/resin-ceramic material) were further pretreated with 1) Scotchbond Universal for RelyX Ultimate (3M ESPE), 2) CLEARFIL Ceramic Primer for PANAVIA F2.0 (Kuraray), or 3) no further pretreatment for Ketac Cem Plus (3M ESPE). The cylinders were then bonded to ground human dentin specimens with 1) Scotchbond Universal and RelyX Ultimate (light-cured), 2) ED PRIMER II and PANAVIA F2.0 (light-cured), or 3) no adhesive system; Ketac Cem Plus (self-cured). Shear bond strength (SBS) was measured after 24 hours for 15 specimens/group and after six months (37°C, 100% humidity) for the other 15 specimens/group. SBS-values were statistically analysed with nonparametric ANOVA followed by exact Wilcoxon rank sum tests (α=0.05). Results: SBS of the two resin-ceramic materials and the three cements after 24 hours and after six months storage are shown in Figure 1. The statistical analysis showed that the duration of storage had a significant effect on SBS of Lava Ultimate for all three cements but had no significant effect on SBS of VITA ENAMIC. For Lava Ultimate SBS-values were (MPa; medians after 24 hours/six months): 13.5/22.5 (p=0.04) for RelyX Ultimate, 11.4/5.8 (p=0.0006) for PANAVIA F2.0, and 0.34/0.09 (p=0.04) for Ketac Cem Plus (Fig. 1). For VITA ENAMIC SBS-values were (MPa; medians after 24 hours/six months): 16.0/21.2 (p=0.10) for RelyX Ultimate, 11.4/14.4 (p=0.06) for PANAVIA F2.0, and 0.43/0.41 (p=0.32) for Ketac Cem Plus (Fig. 1). After 24 hours, there was no significant difference in SBS between Lava Ultimate and VITA ENAMIC for all three cements (p≥0.37). After six months, there was no significant difference in SBS between Lava Ultimate and VITA ENAMIC for RelyX Ultimate and Ketac Cem Plus (p≥0.07) whereas for PANAVIA F2.0, SBS was significantly lower for Lava Ultimate than for VITA ENAMIC (p<0.0001). Conclusion: SBS of Lava Ultimate was more affected by six months storage and by the cement used than was VITA ENAMIC.

Bonding effectiveness to different chemically pre-treated dental zirconia

The objective of this study was to evaluate the effect of different chemical pre-treatments on the bond durability to dental zirconia. Fully sintered IPS e.max ZirCAD (Ivoclar Vivadent) blocks were subjected to tribochemical silica sandblasting (CoJet, 3M ESPE). The zirconia samples were additionally pre-treated using one of four zirconia primers/adhesives (Clearfil Ceramic Primer, Kuraray Noritake; Monobond Plus, Ivoclar Vivadent; Scotchbond Universal, 3M ESPE; Z-PRIME Plus, Bisco). Finally, two identically pre-treated zirconia blocks were bonded together using composite cement (RelyX Ultimate, 3M ESPE). The specimens were trimmed at the interface to a cylindrical hourglass and stored in distilled water (7 days, 37 °C), after which they were randomly tested as is or subjected to mechanical ageing involving cyclic tensile stress (10 N, 10 Hz, 10,000 cycles). Subsequently, the micro-tensile bond strength was determined, and SEM fractographic analysis performed. Weibull analysis revealed the highest Weibull scale and shape parameters for the 'Clearfil Ceramic Primer/mechanical ageing' combination. Chemical pre-treatment of CoJet (3M ESPE) sandblasted zirconia using Clearfil Ceramic Primer (Kuraray Noritake) and Monobond Plus (Ivoclar Vivadent) revealed a significantly higher bond strength than when Scotchbond Universal (3M ESPE) and Z-PRIME Plus (Bisco) were used. After ageing, Clearfil Ceramic Primer (Kuraray Noritake) revealed the most stable bond durability. Combined mechanical/chemical pre-treatment, the latter with either Clearfil Ceramic Primer (Kuraray Noritake) or Monobond Plus (Ivoclar Vivadent), resulted in the most durable bond to zirconia. As a standard procedure to durably bond zirconia to tooth tissue, the application of a combined 10-methacryloyloxydecyl dihydrogen phosphate/silane ceramic primer to zirconia is clinically highly recommended.

Durable bonding to mechanically and/or chemically pre-treated dental zirconia

ObjectivesTo evaluate the effect of mechanical and chemical surface pre-treatment on the bond durability of two composite cements to dental zirconia. MethodsFully sintered IPS e.max ZirCAD (Ivoclar-Vivadent) blocks were either subjected to tribochemical silica sandblasting (CoJet, 3M ESPE) or not mechanically pre-treated. Next, the zirconia samples were either additionally pre-treated using one of two silane/MDP-combined ceramic primers (Clearfil Ceramic Primer, Kuraray; Monobond Plus, Ivoclar-Vivadent), or not further chemically pre-treated. Finally, two identically pre-treated zirconia blocks were bonded together using either a conventional BisGMA-based (Clearfil Esthetic Cement, Kuraray) or an MDP-based (Panavia F2.0, Kuraray) ‘self-etch’ dual-cure composite cement. The specimens were trimmed at the interface to a cylindrical hour-glass shape and stored for 7 days in distilled water (37°C), after which they were randomly exposed to one of three ageing protocols: (1) immersed in 37°C water for 10 days (10d); (2) subjected to 10,000 thermo-cycles (TC); or (3) immersed in 37°C water for 6 months (6m). After storage, the micro-tensile bond strength (μTBS) was determined in MPa (n=15–21/group). Fractographic analysis was performed using SEM. ResultsWeibull analysis revealed the highest Weibull scale and shape parameters for the ‘CoJet/Clearfil Ceramic Primer/Panavia F2.0/10d’ combination. While the BisGMA-based composite cement Clearfil Esthetic Cement (Kuraray) bonded equally well to zirconia using either tribochemical silica sandblasting (CoJet, 3M ESPE) or not, sandblasting appeared indispensable for the MDP-based and more hydrophilic composite cement Panavia F2.0 (Kuraray). ConclusionsCombined mechanical and chemical pre-treatment can best be recommended to durably bond to zirconia. Clinical significanceAs a standard procedure to durable bond zirconia to tooth tissue, both mechanical (tribochemical silica coating) and chemical (silane/MDP-combined ceramic primers) is clinically highly recommended.

Two-Year Interfacial Bond Durability and Nanoleakage of Repaired Silorane-Based Resin Composite

To investigate the effect of silane primer application, intermediate adhesive agent/repair composite, and storage period on the interfacial microtensile bond strength (μTBS) of repaired silorane-based resin composite compared with unrepaired composites and on the nanoleakage. Forty-eight 1-month-old substrate specimens from Filtek P90 were roughened, etched, and distributed over two groups (n=24) based on receiving silane (Clearfil Ceramic Primer) or not. Then, half of the specimens (n=12) were repaired with P90 System Adhesive/Filtek P90 and the other half with Adper Scotchbond Multipurpose adhesive/Filtek Z250 resin composite. Within each repair category, repaired specimens were stored in artificial saliva at 37°C for either 24 hours (n=6) or two years before being serially sectioned into sticks (0.6 ± 0.01 mm(2)). From each specimen, two sticks were prepared for nanoleakage determination and four sticks were used for μTBS testing. Additional unrepaired specimens from each composite (n=12) were made to determine the cohesive strength at 24 hours and two years. Mean μTBS were calculated and statistically analyzed. Modes of failure were also determined. General linear model analysis revealed no significant effect for the silane priming, intermediate adhesive agent/repair composite, and storage period or for their interactions on the μTBS values of the repaired specimens. There was no significant difference between the cohesive strength of Filtek P90 and Filtek Z250; both were significantly higher than all repaired categories. At 24 hours, nanoleakage was not detected when silorane-based composite was repaired with the same material. However, after two years, all repair categories showed nanoleakage. Silane application has no effect on μTBS and nanoleakage. Durability of the interfacial bond of repaired silorane-based resin composite appeared successful regardless of the chemistry of the intermediate adhesive agent/composite used for repair. However, nanoleakage was detected early when a different repair intermediate adhesive agent/composite was used.

Surface characterisation and bonding of Y-TZP following non-thermal plasma treatment

Objectives(1) To chemically characterise Y-TZP surface via X-ray photoelectron spectroscopy (XPS) and evaluate the surface energy levels (SE) after non-thermal plasma (NTP). (2) To test the microtensile bond strength (MTBS) of Y-TZP bonded to cured composite disks, after a combination of different surface conditioning methods. MethodsTwenty-four Y-TZP discs (13.5mm×4mm) were obtained from the manufacturer and composite resin (Z-100) discs with similar dimensions were prepared. All discs were polished to 600 grit and divided into 8 groups (n=3 disks each), four control (non-NTP treated) and four experimental (NTP treated for 10s) groups. All groups received one of the four following treatments prior to cementation with Rely×Unicem cement: sand-blasting (SB), a Clearfil ceramic primer (MDP), sand-blasting+MDP (SBMDP), or baseline (B), no treatment. SE readings and surface roughness parameters were statistically analysed (ANOVA, Tukey's, p<0.05). Mixed model and paired samples t-tests were used to compare groups on MTBS. ResultsXPS showed increase in O and decrease in C elements after NTP. The polar component increased for BP (42.20mN/m) and SBP (43.77mN/m). MTBS values for groups BP (21.3MPa), SBP (31MPa), MDPP (30.1MPa) and SBMDPP (32.3MPa) were significantly higher in specimens treated with NTP than their untreated counterparts B (9.1MPa), SB (14.4MPa), MDP (17.8MPa) and SBMDP (24.1MPa). Conclusions(1) Increase of O and decrease of C led to higher surface energy levels dictated by the polar component after NTP; (2) NTP application increased MTBS values of Y-TZP surfaces.

Influence of surface conditioning on bonding to polyetheretherketon (PEEK)

ObjectiveThe purpose of the study was the evaluation of the bond strength of a provisional resin to a polyetheretherketon (PEEK) using different surface treatments and conditioning methods. MethodsPEEK disks were polished with 600grit rotating silicon carbide papers. Plexiglas tubes were filled and bonded with a provisional resin (Luxatemp Fluorescence) to the PEEK disks which were air-abraded either with 110μm alumina particles (Rocatec Pre) and conditioned with the primers Ecusit Composite Repair, Luxatemp Glaze & Bond or Clearfil Ceramic Primer or they were tribochemically silica-coated (Rocatec Plus) and silanated with Espe Sil or Clearfil Ceramic Primer. Air-abraded PEEK disks without priming served as control. Subgroups of 8 specimens each were stored in distilled water at 37°C either for 3 days without thermal cycling (TC) or for 150 days with additional 37,500 thermal cycles between 5 and 55°C (dwell time 30s). Following storage tensile bond strength (TBS) was tested at a crosshead speed of 2mm/min in a universal testing machine. Statistical analysis was conducted with Kruskal–Wallis test followed by Wilcoxon rank sum test adjusted by Bonferroni–Holm. ResultsAfter 3 days TBS ranged from 0 to 15.0MPa. After artificial aging over 150 days TBS ranged from 0 to 12.9MPa. Using air-abrasion and priming with Luxatemp Glaze & Bond resulted in significantly higher TBS than all other methods, which was also durable over time. ConclusionThe use of the methylmethacrylate containing primer Luxatemp Glaze & Bond after air-abrasion of PEEK surfaces can be recommended clinically as promising bonding method to PEEK.

Influence of sandblasting granulometry and resin cement composition on microtensile bond strength to zirconia ceramic for dental prosthetic frameworks

ObjectivesTo evaluate the effect of the particle size of sandblasting and the composition of the resin cement on the microtensile bond strength (MTBS) to zirconia. MethodsForty zirconia blocks (Cercon, Dentsply) were polished and randomly treated as follows: Group 1 (NT): no treatment; Group 2 (APA-I): airborne particle abrasion (Cobra, Renfert) using 25-μm aluminium-oxide (Al2O3)-particles; Group 3 (APA-II): APA with 50-μm Al2O3-particles; and Group 4 (APA-III): APA using 110-μm Al2O3-particles. Ceramic blocks were duplicated in composite resin. Samples of each pretreatment group were randomly divided into two subgroups depending on the resin cement used for bonding the composite disks to the treated zirconia surfaces. Subgroup 1 (PAN), which was a 10-MDP-containing luting system, used Clearfil Ceramic Primer plus Panavia F 2.0 (Kuraray) and Subgroup 2 (BIF) used Bifix SE (VOCO) self-adhesive cement. After 24h, bonded specimens were cut into 1±0.1mm2 sticks. MTBS values were obtained using a universal testing machine (cross-head speed=0.5mm/min). Failure modes were recorded and the interfacial morphology of the debonded microbars was SEM-assessed. Two-way ANOVA, Student–Newman–Keuls tests, and the step-wise linear regression analysis were performed with the MTBS being the dependent variable (p<0.05). ResultsDespite the sandblasting granulometry, PAN bonded to air-abraded surfaces attained the highest MTBS and frequently showed mixed fractures. BIF recorded no significant differences in MTBS depending on the conditioning method, and registered the highest rates of premature and adhesive failures. ConclusionsThe 10-MDP-containing luting system seems to be the most suitable to bond zirconium-oxide ceramic, mainly after sandblasting.

Bond strength of selected composite resin-cements to zirconium-oxide ceramic

Objectives: The aim of this study was to evaluate bond strengths of zirconium-oxide (zirconia) ceramic and a selection of different composite resin cements. Study Design: 130 Lava TM cylinders were fabricated. The cylinders were sandblasted with 80 µm aluminium oxide or silica coated with CoJet Sand. Silane, and bonding agent and/or Clearfil Ceramic Primer were applied. One hundred thirty composite cement cylinders, comprising two dual-polymerizing (Variolink II and Panavia F) and two autopolymerizing (Rely X and Multilink) resins were bonded to the ceramic samples. A shear test was conducted, followed by an optical microscopy study to identify the location and type of failure, an electron microscopy study (SEM and TEM) and statistical analysis using the Kruskal-Wallis test for more than two independent samples and Mann-Whitney for two independent samples. Given the large number of combinations, Bonferroni correction was applied (α=0.001). Results: Dual-polymerizing cements provided better adhesion values (11.7 MPa) than the autopolymerizing (7.47 MPa) (p-value M-W<0.001). The worst techniques were Lava TM + sandblasting + Silane + Rely X; Lava TM + sandblasting + Silane + Multilink and Lava TM + CoJet + silane + Multilink. Adhesive failure (separation of cement and ceramic) was produced at a lesser force than cohesive failure (fracture of cement) (p-value M-W<0.001). Electron microscopy confirmed that the surface treatments modified the zirconium-oxide ceramic, creating a more rough and retentive surface, thus providing an improved micromechanical interlocking between the cement and the ceramic. Key words:Shear bond strength, silica coating, surface treatment, zirconia ceramics, phosphate monomer.

Bonding of resin-based luting cements to zirconia with and without the use of ceramic priming agents.

This study evaluated and compared bonding characteristics of resin-based luting agents and special ceramic primers to zirconia. Disk specimens (n = 242) were fabricated from zirconium dioxide ceramics (Katana) and bonded with four resin-based luting agents without priming. In addition, zirconia was bonded with 7 bondingsystem combinations of three priming agents and three resin-based luting agents. Two of the resin-based luting agents and two ceramic priming agents contain an identical adhesive monomer, 10-methacryloyloxydecyl dihydrogen phosphate (MDP), either in the material itself or in the priming agent. Shear bond strength was determined after 20,000 cycles of thermocycling. The Kruskal-Wallis test was performed for both pre- and post-thermocycling groups to evaluate the difference among primer and luting agent variations. On the basis of the Kruskal-Wallis test, Steel-Dwass multiple comparisons were further performed to compare the difference among four luting agents and seven conbinations of three primers and three luting agents for both pre- and post-thermocycling conditions. Within the four unprimed groups, Clearfil SA Cement (5.8 MPa) and Panavia F 2.0 (6.7 MPa) showed statistically higher post-thermocycling bond strength than the other materials (0.1 MPa) (p < 0.05). Among the seven primer/cement combinations, Clearfil Ceramic Primer combined with Clearfil Esthetic Cement exhibited the highest post-thermocycling bond strength (7.5 MPa), followed by two groups primed with Monobond Plus (4.0-4.6 MPa) (p < 0.05). Application of resin-based luting and priming agents containing the adhesive monomer MDP provide better bond strength to zirconia than do other systems.