title: Effects of some chemical surface modifications on resin zirconia adhesion. Air-particle abrasion on zirconia ceramic using different protocols: effects on biaxial flexural strength after cyclic loading, phase transformation and surface topography. Effect of different surface treatments on adhesion of In-Ceram Zirconia to enamel and dentin substrates. Effect of Adhesive Cementation Strategies on the Bonding of Y-TZP to Human Dentin. Effect of Resin Luting Systems and Alumina Particle Air Abrasion on Bond Strength to Zirconia. Effects of different surface treatments on bond strength between resin cements and zirconia ceramics. Thermocycling effect on microshear bond strength to zirconia ceramic using Er:YAG and tribochemical silica coating as surface conditioning Fatigue behavior of the resinous cement to zirconia bond. Silica-based nano-coating on zirconia surfaces using reactive magnetron sputtering: effect on chemical adhesion of resin cements. Different Strategies to Bond Bis-GMA-based Resin Cement to Zirconia. Effect of chemical etching solutions versus air abrasion on the adhesion of self-adhesive resin cement  to IPS e.max ZirCAD with and  without aging. Effects of multipurpose, universal adhesives on resin bonding to zirconia ceramic. Can application of universal primers alone be a substitute for airborne-particle abrasion to improve adhesion of resin cement to zirconia? Evaluation of four surface coating treatments for resin to zirconia bonding. Effect of Er:YAG laser irradiation on bonding property of zirconia ceramics to resin cement. Evaluation of a commercial primer for bonding of zirconia to two different resin composite cements. Surface Characterization and Short-term Adhesion to Zirconia after Ultra-short Pulsed Laser Irradiation. Can the Application of Multi-Mode Adhesive be a Substitute to Silicatized/Silanized Y-TZP Ceramics?
abstract: OBJECTIVES To evaluate the effects of various chemical surface modifications on adhesion between zirconia and resin adhesive . MATERIAL AND METHODS Pre-sintered zirconia discs were sectioned from commercial cylindrical blocks and polished with abrasive papers under running tap water . All the discs were r and omly divided into five study groups according to the methods of surface treatment , including : the  control group ( fully sintered , without any modification ) , group S ( fully sintered and s and blasted with silica coated alumina particles ) , group HN ( fully sintered and etched with a blend of mineral acid solution at 100 ° C for 25 min ) , group HF ( fully sintered and etched with 48 % hydrofluoric acid solution at 100 ° C for 25 min )  , and group Si ( coated with silica particles and then fully sintered ) .  The mean value of surface roughness was evaluated before further treatment . Resin stubs ( 3.6 mm in diameter and 3 mm in height ) were adhered and light cured on each zirconia disc after the application of a silane coupling agent . In each group , all the sample s were further divided into three subgroups with each n=12 , one for the measurement of initial adhesion strength ( shear bond ) value and the other two were tested after thermal cycling for 10,000 and 20,000 cycles , respectively . The results were analyzed with two-way ANOVA and Turkey HSD ( p<0.05 ) . XRD technique was utilized in the examination of zirconia surface crystallinity . The morphological appearance of zirconia surface after surface treatment was observed with SEM . RESULTS The control group showed the lowest initial shear bond strength ( SBS ) value ( 16.8 ± 2.4 MPa ) and did not survive the aging treatments . All the investigated surface treatments improved resin zirconia bond strength significantly , the group S displaying the highest initial value of 25.1 ± 2.7 MPa . However , the highest resistance to the aging effects of thermal cycling was found in group Si . It was further shown in the XRD examination that only the grit-blasting caused the crystalline transformation from tetragonal phase to monoclinic phase ( T → M ) . On the other h and , such a phase transformation could not be detected in all the other four groups . SIGNIFICANCE Resin zirconia adhesion could be effectively improved by both HF etching and silica coating on zirconia surface , without leading to a T → M crystalline phase transformation This study evaluated the effect of different air-particle abrasion protocol s on the biaxial flexural strength and structural stability of zirconia ceramics . Zirconia ceramic specimens ( ISO 6872 ) ( Lava , 3 M ESPE ) were obtained ( N=336 ) . The specimens ( N=118 , n=20 per group ) were r and omly assigned to one of the air-abrasion protocol s : Gr1 : Control ( as-sintered ) ; Gr2 : 50 µm Al2O3 ( 2.5 bar ) ; Gr3 : 50 µm Al2O3 ( 3.5 bar ) ; Gr4 : 110 µm Al2O3(2.5 bar ) ; Gr5 : 110 µm Al2O3 ( 3.5 bar ) ; Gr6 : 30 µm SiO2 ( 2.5 bar ) ( CoJet ) ; Gr7 : 30 µm SiO2(3.5 bar ) ; Gr8 : 110 µm SiO2 ( 2.5 bar ) ( Rocatec Plus ) ; and Gr9 : 110 µm SiO2 ( 3.5 bar ) ( duration : 20 s , distance : 10 mm ) . While half of the specimens were tested immediately , the other half was subjected to cyclic loading in water ( 100,000 cycles ; 50 N , 4 Hz , 37 ° ° C ) prior to biaxial flexural strength test ( ISO 6872 ) . Phase transformation ( t→m ) , relative amount of transformed monoclinic zirconia ( FM ) , transformed zone depth ( TZD ) and surface roughness were measured . Particle type ( p=0.2746 ) , pressure ( p=0.5084 ) and cyclic loading ( p=0.1610 ) did not influence the flexural strength . Except for the air-abraded group with 110 µm Al2O3 at 3.5 bar , all air-abrasion protocol s increased the biaxial flexural strength ( MPa ) ( Controlnon-aged : 1,030 ± 153 , Controlaged : 1,138 ± 138 ; Experimentalnon-aged : 1,307 ± 184 - 1,554 ± 124 ; Experimentalaged : 1,308 ± 118 - 1,451 ± 135 ) in both non-aged and aged conditions , respectively . Surface roughness ( Ra ) was the highest with 110 µm Al2O3(0.84 µm . FM values ranged from 0 % to 27.21 % , higher value for the Rocatec Plus ( 110 µm SiO2 ) and 110 µm Al2O3 groups at 3.5 bar pressure . TZD ranged between 0 and 1.43 µm , with the highest values for Rocatec Plus and 110 µm Al2O3 groups at 3.5 bar pressure PURPOSE Resin bonding of In-Ceram Zirconia ( ICZ ) ceramics is still a challenge , especially for minimally invasive applications . This study evaluated the adhesion of ICZ to enamel and dentin after different surface treatments of the ceramic . MATERIAL S AND METHODS ICZ ceramic specimens ( diameter : 6 mm ; thickness : 2 mm ) ( N = 100 ) were fabricated following the manufacturer 's instructions and r and omly assigned to 5 groups ( n = 20 ) , according to the surface treatment methods applied . The groups were as follows : group C : no treatment ; group SB : s and blasting ; group SCS-S : CoJet+silane ; group SCS-P : CoJet+Alloy Primer ; group GE-S : glaze+ hydrofluoric acid etching ( 9.6 % ) for 60 s+silane . Each group was r and omly divided into two subgroups to be bonded to either enamel or dentin ( n = 10 per group ) using MDP-based resin cement ( Panavia F2.0 ) . All the specimens were subjected to thermocycling ( 5000x , 5 ° C-55 ° C ) . The specimens were mounted in a universal testing machine and tensile force was applied to the ceramic/cement interface until failure occurred ( 1 mm/min ) . After evaluating all the debonded specimens under SEM , the failure types were defined as either " adhesive " with no cement left on the ceramic surface ( score 0 ) or " mixed " with less than 1/2 of the cement left adhered to the surface with no cohesive failure of the substrate ( score 1 ) . The data were statistically evaluated using 2-way ANOVA and Tukey 's tests ( α = 0.05 ) . RESULTS The highest tensile bond strength for the enamel surfaces was obtained in group GE-S ( 18.1 ± 2 MPa ) and the lowest in group SB ( 7.1 ± 1.4 MPa ) . Regarding dentin , group CSC-P showed the highest ( 12 ± 1.3 MPa ) and SB the lowest tensile bond strength ( 5.7 ± 0.4 MPa ) . Groups SB , CSC-S , CSC-P , and GE-S did not show significant differences between the different surface treatments on either enamel or dentin surfaces ( p < 0.05 , p < 0.001 , respectively ) . Groups CSC-P and GE-S presented similar bond strength for both the enamel and dentin substrates ( p < 0.8 and p < 0.9 ) , respectively . While on enamel substrates , exclusively adhesive failures from ICZ ( score 0 ) were found , on dentin exclusively mixed failures were observed ( score 1 ) . CONCLUSION Adhesion of ICZ to both enamel and dentin can be improved when ceramics are glazed , etched , and silanized , or s and blasted , primed , and cemented with an MDP-based cement This study evaluated the effects of different adhesive strategies on the adhesion of zirconia to dentin using conventional and self-adhesive cements and their corresponding adhesive resins . The occlusal parts of human molars ( N=80 ) were sectioned , exposing the dentin . The teeth and zirconia cylinders ( N=80 ) ( diameter=3.4 mm ; height=4 mm ) were r and omly divided into eight groups according to the factors " surface conditioning " and " cement type " ( n=10 per group ) . One conventional cement ( CC : RelyX ARC , 3 M ESPE ) and one self-adhesive cement ( SA : RelyX U200 , 3 M ESPE ) and their corresponding adhesive resin ( for CC , Adper Single Bond Plus ; for SA , Scotchbond Universal Adhesive-SU ) were applied on dentin . Zirconia specimens were conditioned either using chairside ( CJ : CoJet , 30 μm , 2.5 bar , four seconds ) , laboratory silica coating ( RC : Rocatec , 110 μm , 2.5 bar , four seconds ) , or universal primer ( Single Bond Universal-UP ) . Nonconditioned groups for both cements acted as the control ( C ) . Specimens were stored in water ( 37 ° C , 30 days ) and subjected to shear bond strength ( SBS ) testing ( 1 mm/min ) . Data ( MPa ) were analyzed using two-way analysis of variance and a Tukey test ( α=0.05 ) . While surface conditioning significantly affected the SBS values ( p=0.0001 ) ( C < RC = CJ = UP ) , cement type did not ( p=0.148 ) ( CC = SA ) . The interaction terms were significant ( p=0.014 ) . Failure types were predominantly adhesive . Air-abrasion and the use of the universal primer improved the bond strength of zirconia to dentin compared to the control group , regardless of the type of resin cement used This study aim ed to evaluate the effect of different primer/resin luting agent combinations and alumina air abrasion on the adhesion to zirconia . Eighty blocks ( 4 × 4 × 3 mm ) of Lava Frame Zirconia ( 3 M ESPE ) were produced and r and omly assigned into eight groups ( n=10 ) according to two zirconia surface treatments  ( untreated or air abrasion with 50-μm alumina particles ) and four luting systems ( SU : Scotchbond Universal/RelyX Unicem 2 ; ZP : Z-Prime Plus/Duo-link Universal ; MB : Monobond Plus/Variolink II ; and AP : Alloy Primer/ED Primer II/Panavia F 2.0 ) . After the conditioning and primer applications , resin luting agents were manipulated and applied on the zirconia , using a matrix , to form a cylinder ( 2 mm in diameter × 2 mm high ) , followed by photoactivation for 40 seconds . After that , the specimens were stored in distilled water ( 37 ° C ) for 120 days and then su bmi tted to shear bond strength testing , followed by failure mode evaluation under an optical microscope ( 30 × ) . A two-way analysis of variance and Tukey test ( α=0.05 ) were used for data analysis . Alumina air abrasion ( Al ) promoted higher bond values for the three luting systems , except for SU , which showed the best results without air abrasion , while with air abrasion , Al-SU , Al-ZP , and Al-MB presented higher values compared to Al-AP . We concluded that the alumina air abrasion of zirconia surfaces seemed to be dispensable for the SU group , while air abrasion ( topographical alterations ) enhanced the adhesion of the ZP , MB , and AP groups This study compares the bond strength of resin cement and yttrium-stabilized tetragonal zirconia polycrystalline ( Y-TZP ) ceramic with different surface conditioning methods . Two hundred presintered Y-TZP ceramic specimens were prepared , sintered ( 4 × 4 × 4 mm ) , and r and omly assigned to four equal groups as control ( C , no conditioning ) ; airborne particle abraded ( APA , air abrasion with 11 μm Al2O3 ) ; tribochemical silica coating/silane coupling system ( TSC , Rocatec , air abrasion with 110 μm Al2O3 , 30 μm silica-coated Al2O3 and silane ) ; and laser ( L , Er : YAG laser irradiation treated at a power setting of 200 mJ ) . After specimen preparation , composite resin cylinders were prepared and cemented with resin cements ( Clearfil Esthetic , Panavia F 2.0 , Rely X-U100 , Super Bond C&B , and Multilink Automix ) on the ceramic surfaces and kept in an incubator at 37 ° C for 60 days . All specimens were tested for shear bond strength with a universal testing machine , and fractured surfaces were evaluated by environmental scanning electron microscopy . Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U-tests ( α=0.05 ) . The bond strengths for C and L groups were not significantly different according to adhesive resin cement . APA and TSC result ed in increased bond strength for Panavia F 2.0 and Rely X-U100 resin cements . Additionally , TSC presented higher bond strength with Multilink Automix . Adhesive fracture between the ceramic and resin cement was the most common failure . Complete cohesive fracture at the ceramic or composite cylinders was not observed . Regardless of the adhesive resin cement used , laser treatment did not improve resin bond strength The purpose of this study is to evaluate the thermocycling effect on the microshear bond strength ( μSBS ) of different self-adhesive resin cements to zirconia using tribochemical silica coating Rocatec ™ ( ROC ) and Er : YAG as surface conditioners . Two hundred forty square-like zirconia sample s were polished and r and omly assigned in four groups according surface treatment applied as follows : ( 1 ) no treatment ( NT ) , ( 2 ) silica coating with ROC , 3 ) Er : YAG laser irradiation ( LAS : 2.940 nm , 200 mJ ; 10 Hz ) , and ( 4 ) laser followed by Rocatec ™ ( LAROC ) . Each group was divided into two subgroups according the resin tested as follows : ( A ) BiFix SE ( BIF ) and ( B ) Clearfil SA ( CLE ) . After 24 h , half of the specimens from each subgroup were tested . The other half was stored and thermocycled ( 5–55 ° C/5,000 cycles ) . A μSBS test was performed using a universal testing machine ( cross head speed = 0.5 mm/min ) . Failure modes were recorded and observed by scanning electronic microscopy . Data was analyzed with ANOVA , Student ’s t test , and chi-square tests , and linear regression was performed ( p < 0.05 ) . Before thermocycling , both cements showed higher μSBS results with ROC and LAROC . After aging , ( 1 ) all BIF specimens evidence d severely decreased adhesion with mostly adhesive failures and ( 2 ) CLE maintained the initial results in ROC and LAROC groups , performing better with ROC . Thermocycling did not negatively influence the resin – zirconia μSBS results in the self-adhesive resin cement containing 10-MDP when used on zirconia surface coated with silica , independently of previous Er : YAG surface treatment PURPOSE Resinous cements are widely used for luting zirconia restorations . Adhesive failures have occurred at the cement/zirconia interface , rather than at the cement/dentin interface , suggesting that the cement/zirconia bond may lack durability ; however , few comprehensive , comparative evaluations of fatigue effects have been reported . The rate of fatigue-induced loss of bond strength may be a more important predictor of long-term success than a single snapshot of bond strength after an arbitrary number of thermocycles . Previous studies have failed to identify trends by investigating bond strengths at several different numbers of cycles . This may result in invalid conclusions about which cements have superior bond strengths . The purpose of this study was to investigate the effects of artificial aging by thermocycling and resinous cement type on bond strengths to zirconia . MATERIAL S AND METHODS The effect of the number of thermocycles ( 0 , 1 , 10 , 100 , 1000 , and 10,000 ) on the bond strengths of  five resinous cements  , two of which were used with and without a primer , and an oxygen-inhibiting gel , was studied . Specimens were r and omly assigned to thermocycle number/cement-type test groups . Because zirconia has a very low thermal diffusivity , exceptionally long thermocycle dwell times were used . Cylinders of zirconia were bonded end-to-end . One end of each bonded specimen was insulated , specimens were thermocycled and tested in shear , and bond strengths were calculated and analyzed . RESULTS Two-way ANOVA revealed that the effects of cement type , the number of thermocycles , and their interaction all significantly affected bond strength ( p < 0.0001 ) . By 10,000 cycles , most cements had lost at least half of their initial bond strengths , and two cements effectively recorded zero bond strengths . Failure modes were cement specific , but adhesive modes predominated . Fatigue resistance of two cements was greatly improved by use of a primer and an oxygen-inhibiting gel , as recommended by their respective manufacturers . CONCLUSIONS Both the type of resin cement and the number of thermocycles influenced bond strength . Fatigue through thermocycling affected different cement types in different ways . Some material s displayed more rapid loss of bond strength than others . Cements differed in their failure modes PURPOSE To compare the effect of silica (Si)-based nano-coating deposited by reactive magnetron sputtering ( RMP ) with that of conventional surface conditioning using metal/zirconia primer alone or after air-particle abrasion on the adhesion of resin cements to zirconia ceramic . MATERIAL S AND METHODS Two hundred forty zirconia ceramic blocks ( Cercon ) were sintered , finished with 1200- grit SiC paper under water cooling , and cleaned ultrasonically in distilled water for 10 min . The blocks ( 4.5 mm x 3.5 mm x 4.5 mm ) were r and omly divided into 24 groups ( n = 10 ) according to 3 testing parameters : a ) resin cements ( Multilink , Panavia F , RelyX U100 ) , b ) surface conditioning ( no conditioning as control group ; Metal/Zirconia Primer ; air abrasion + Metal/Zirconia Primer ; Si-based nanofilm + Monobond s ) ; c ) aging ( no aging vs thermocycling at 5 ° C to 55 ° C , 6000 cycles ) . The nanofilm was deposited by direct current using argon/oxygen plasma ( 8:1 in flux ) on the zirconia surface . Resin cements were bonded to zirconia surfaces using polyethylene molds . The shear bond strength ( SBS ) test was performed using a universal testing machine ( 1 mm/min ) , and after debonding , the substrate and adherent surfaces were analyzed using optical and scanning electron microscopes to categorize the failure types . The data were statistically evaluated using 3-way ANOVA and Tukey 's test ( 5 % ) . RESULTS Resin cement type ( p < 0.05 ) , surface conditioning method ( p < 0.05 ) , and aging condition ( p < 0.05 ) had a significant effect on the bond strength results . Interactions were also significant ( p < 0.05 ) . In the nonaged condition , while control groups presented the lowest results with all cements ( 0 to 5.2 MPa ) , the airabraded group in combination with RelyX U100 result ed in the highest SBS ( 21.8 ± 6.7 MPa ) . After aging , the SBS results decreased in the air-abraded groups for all cements ( 4.54 to 9.44 MPa ) and showed no statistical significance compared to the Si-based nanocoated groups ( 4.24 to 6.44 MPa ) . After air-abrasion and primer application , only Panavia F and RelyX U100 cements showed exclusively mixed failures , but after nanofilm coating and silanization , all cements showed exclusively mixed failures with and without aging . CONCLUSION Chemical adhesion of the resin cements tested to zirconia was similar after silica-based nanofilm deposition and air abrasion followed by primer application PURPOSE To evaluate the effect of different bonding strategies on short- and long-term bis-GMA-based resin cement bond strengths to zirconia . MATERIAL S AND METHODS One hundred twenty sample s of fully-sintered zirconia ( Prettau Zirconia ) were s and blasted and r and omly distributed into 5 groups ( n = 24 ) : UA : Scotchbond Universal Adhesive ; SZP : Signum Zirconia Bond I + II ; ZPP : Z-Prime Plus ; EXP : MZ experimental primer ; CO : no primer application ( control ) . After performing these surface treatments , translucent tubes ( 0.8 mm diameter and 1.0 mm height ) were placed on the zirconia specimens , and bis-GMA-based cement ( Duo-Link ) was injected into them and light cured . Specimens were tested for microshear bond strength either 24 h or 6 months ( m ) after water storage ( 37 ° C ) and surfaces were characterized by SEM and EDX . Two-way ANOVA and Tukey 's post-hoc test ( p < 0.05 ) were used to evaluate bond strength results . RESULTS The mean bond strengths ( MPa ± SD ) were : UA=14.6 ± 4.7a ( 24 h ) ; 16.0 ± 4.8a ( 6 m ) ; SZP = 14.0 ± 5.4ab ( 24 h ) ; 11.9 ± 2.6ab ( 6 m ) ; ZPP=8.0 ± 1.8b ( 24 h ) ; 8.6 ± 3.3b ( 6 m ) ; EXP = 1.2 ± 0.5c ( 24 h ) ; 0.6 ± 0.7c ( 6 m ) ; CO=1.0 ± 1.2c ( 24 h ) ; 1.3 ± 1.2c ( 6 m ) . Bonding strategy significantly influenced bond strength ( p = 0.0001 ) , but storage time did not ( p = 0.841 ) . Groups UA and SZP showed a homogeneous layer covering the zirconia surface . In these groups , EDX demonstrated the presence of phosphorus . Group ZPP result ed in a nonhomogeneous layer , exposing the zirconia substrate underneath . EXP application result ed in an undetectable layer . CONCLUSION Water storage did not affect resin cement bond strengths to zirconia irrespective of the surface treatment . Bis-GMA-based resin cement bond strengths to zirconia are affected by specific bonding strategies OBJECTIVES This study evaluated the adhesion of self-adhesive resin cement to zirconia after various surface conditioning methods in non-aged and aged conditions . METHODS Zirconia ( IPS e.max ZirCAD , Ivoclar Vivadent ) and resin composite blocks were obtained and r and omly divided into four groups according to one of the following surface conditioning methods : C : No surface treatment ( Control ) ; AS : Air abrasion ( 50 µm Al2O3 ) at low pressure ( 0.2 MPa ) plus silane ( Monobond Plus , Ivoclar Vivadent ) ; MC : Methylene chloride for 60 min ; CE : Chemical etching solution at 100 ° C for 60  min . Surface roughness ( Ra ) measurements were performed on the control and conditioned zirconia specimens using a profilometer . Each conditioned zirconia block was bonded to its corresponding resin composite block using self-adhesive resin cement ( RelyX Unicem Aplicap , 3 M ESPE ) under a load of 300 g. Half of the groups were tested without aging ; the other half were tested after x6000 thermocycling . Sticks were obtained from bonded specimens and subjected to microtensile bond strength ( MTBS ) testing in a universal testing machine ( 0.5 mm/min ) . Failure types were classified after debonding . Data ( MPa ) were analyzed using two-way ANOVA and Tukey 's tests ( α = 0.05 ) . RESULTS The highest mean Ra value was obtained in Group CE ( 0.52 µm ) , and the lowest in Group C ( 0.25 µm ) . Significantly lower MTBS test results were obtained in Group C , both in non-aged ( 17.4 ± 1.1 MPa ) and aged ( 5.11 ± 0.5 MPa ) conditions than in the other groups ( 34.6 ± 1.5 to 51.2 ± 1.1 MPa ; 28.0 ± 0.9 to 49.5 ± 1.0 MPa in non-aged and aged conditions , respectively ) ( P < 0.05 ) . Group CE presented the highest MTBS test results in both non-aged and aged conditions ( 51.2 ± 1.1 MPa and 49.5 ± 1 MPa , respectively ) ( P < 0.05 ) . Failure types were predominantly adhesive in all groups before and after aging . After aging , less adhesive and more mixed and cohesive failures in cement were observed in Groups AS and CE than in the other groups . CONCLUSION Chemical etching of zirconia may have potential use as a substitute for air abrasion as a surface conditioning method for zirconia This study evaluated the effects of single-bottle , multi purpose , universal adhesives on the bond strength of resin cement to zirconia ceramic . Polished zirconia ceramic ( Cercon base ) discs were r and omly divided into four groups ( n=40 ) according to the applied surface-conditioning agent : Single Bond 2 , Single Bond Universal , All-Bond Universal , and Alloy Primer . Cured composite cylinders ( Ø 0.8 mm × 1 mm ) were cemented to the conditioned zirconia specimens with resin cement ( RelyX ARC ) . The bonded specimens were subjected to a microshear bond-strength test after 24 hours of water storage and after 10,000 cycles of thermocycling . The surface-conditioning agent significantly influenced the bond strength ( p<0.05 ) . Single Bond Universal showed the highest initial bond strength ( 37.7 ± 5.1 MPa ) , followed by All-Bond Universal ( 31.3 ± 5.6 MPa ) , Alloy Primer ( 26.9 ± 5.1 MPa ) , and Single Bond 2 ( 8.5 ± 4.6 MPa ) . Artificial aging significantly reduced the bond strengths of all the test groups ( p<0.05 ) . After 10,000 cycles of thermocycling , All-Bond Universal showed the highest bond-strength value ( 26.9 ± 6.4 MPa ) . Regardless of artificial aging , Single Bond Universal and All-Bond Universal showed significantly higher bond strengths than Alloy Primer , a conventional metal primer PURPOSE To determine whether universal primers alone can deliver similar levels of adhesion of resin cement to zirconia ceramic when compared to their application in conjunction with airborne-particle abrasion . MATERIAL S AND METHODS Sintered zirconia blocks ( N = 160 ) ( Lava , 3 M ESPE ) , ( 5.25 × 5.25 × 3 mm3 ) were embedded in acrylic resin , polished , and r and omly distributed into 16 groups ( n = 10 per group ) , according to the factors " universal primer " ( 8 levels ) and " air-particle abrasion " ( 2 levels ) : 1 . ctr : control , without application of a universal primer ; 2 . AP : Alloy Primer ; 3 . MP : Monobond Plus ; 4 . MZP : Metal Zirconia Primer ; 5 . MZ : MZ Primer ; 6 . Sg : Signum Zirconia Bond ; 7 . SbU : Singlebond Universal ; 8 . ZP : Z Prime Plus . The universal primers were also used after air abrasion ( A ) of zirconia to form the following 8 groups : Ctr-A , AP-A , MP-A , MZP-A , MZ-A , Sg-A , SbU-A , and ZP-A. After ultrasonic cleaning , air abrasion was performed using Al2O3 particles ( 110 μm , 2.5 bar , 20 s at 10 mm ) in a chairside air-abrasion device . After ultrasonic cleaning again , universal primers were applied according to each manufacturer 's recommendation . The resin cement ( RelyX ARC , 3 M ESPE ) was built up incrementally and photopolymerized on the zirconia surface using a silicone mold ( Ø = 3.5 , height = 3 mm ) . All specimens were stored in distilled water ( 60 days at 37 ° C ) and then subjected to shear bond strength testing ( SBS ) in a universal testing machine ( 1 mm/min ) . On a separate set of zirconia specimens , contact angle measurements were made using the sessile drop technique with a goniometer after the application of universal primers on control and air-abraded zirconia surfaces . Data ( MPa ) were analyzed using one-way ANOVA , Tukey 's test , and Student 's t-test ( α = 0.05 ) . RESULTS When universal primers were used alone , SbU presented significantly higher mean SBS ( 19.5 ± 5.8 ) that did the other primers ( 0 to 9.9 ± 6.6 ) ( p = 0.001 ) . When air abraded , the groups AP-A ( 14.1 ± 6.1 ) , MP-A ( 15.9 ± 5.4 ) , ZP-A ( 16.9 ± 7.3 ) , SG-A ( 19.1 ± 2.1 ) , SbU-A ( 12 ± 1.5 ) showed significant differences ( p = 0.03 ) . Adhesive performance of all universal primers was enhanced after air abrasion , with the exception of the SbU and MZ primers . After air abrasion , contact angle measurements were lower for the each primer ( without air abrasion : 28.9 to 83.9 ; with air abrasion : 27.1 to 63.0 ) , except for MZP . CONCLUSION Air abrasion with 110 μm Al2O3 followed by universal primer application increased the  bond strength of tested resin cement to zirconia , with the exception of SbU and MZ OBJECTIVES To compare the effects of four surface coating methods on resin to zirconia  shear bond strength . MATERIAL AND METHODS Eighty pre-sintered zirconia discs were prepared and r and omly divided into five study groups according to the corresponding methods of surface treatments as follows : group C ( control group , fully sintered without any surface treatment ) , group S ( fully sintered and then s and blasted with silica coated alumina powder ) , group G ( fully sintered and then coated with glazing porcelain followed by acid etching ) , group Si ( pre-coated with silica slurry then fully sintered ) , and group Z ( coated with zirconia particles and then fully sintered ) . The observation of surface morphology and elemental composition analysis were conducted by SEM and EDX . Self-adhesive resin cement stubs ( diameter 3.6 mm and height 3 mm ) were then bonded on the zirconia discs with a cylindrical shape . Both initial and artificial aged ( including 30-day water storage , thermal cycling for 3000 and 6000 cycles ) shear bond strengths were then evaluated . RESULTS All the tested coating methods showed significantly higher shear bond strengths than the control group , in both dry and aged conditions . Group S produced the strongest initial zirconia/resin bonding ( 19.7MPa ) and the control group had the lowest value ( 8.8MPa ) . However , after thermal cycling , group Z exhibited the highest mean value . All the sample s in the control group failed in the thermal cycling . Both different coating methods ( p<0.001 ) and various aging treatments ( p<0.001 ) produced significant influence on resin-zirconia shear bond strength . CONCLUSIONS A reliable and durable resin zirconia bonding is vital for the longevity of dental restorations . Silica coating might be a reliable way in enhancing adhesion between resin and zirconia OBJECTIVE This study aim ed to investigate whether or not an erbium : yttrium-aluminum-garnet ( Er : YAG ) laser could improve the bonding property of zirconia ceramics to resin cement . BACKGROUND DATA Surface treatments can improve the bonding properties of dental ceramics . However , little is known about the effect of Er : YAG laser irradiated on zirconia ceramics . MATERIAL S AND METHODS Specimens of zirconia ceramic pieces were made , and r and omly divided into 11 groups according to surface treatments , including one  control group ( no treatment )  ,  one air abrasion group  , and  nine Er : YAG laser groups .  The laser groups were subdivided by applying different energy intensities ( 100 , 200 , or 300 mJ ) and irradiation times ( 5 , 10 , or 15 sec ) . After surface treatments , ceramic pieces had their surface morphology observed , and their surface roughness was measured . All specimens were bonded to resin cement . Shear bond strength was measured after the bonded specimens were stored in water for 24 h , and additionally aged by thermocycling . Statistical analyses were performed using one way analysis of variance ( ANOVA ) and Tukey 's test for shear bond strength , and Dunnett 's t test for surface roughness , with α=0.05 . RESULTS Er : YAG laser irradiation changed the morphological characteristics of zirconia ceramics . Higher energy intensities ( 200 , 300 mJ ) could roughen the ceramics , but also caused surface cracks . There were no significant differences in the bond strength between the control group and the laser groups treated with different energy intensities or irradiation times . Air abrasion with alumina particles induced highest surface roughness and shear bond strength .  CONCLUSIONS Er : YAG laser irradiation can not improve the bonding property of zirconia ceramics to resin cement . Enhancing irradiation intensities and extending irradiation time have no benefit on the bond of the ceramics , and might cause material defect PURPOSE To evaluate the effects of a commercial zirconia primer ( Choice or RelyX Unicem ) on shear bond strength ( SBS ) of two different resin composite cements - Choice ( a conventional bis-GMA-based resin cement ) and RelyX Unicem ( self-adhesive resin cement ) - to zirconia . MATERIAL S AND METHODS Zirconia blocks were manufactured and r and omly divided into 5 main groups ( n = 20 ) that received surface treatments and cements as follows : no surface treatment , Choice and RelyX Unicem ( groups C and U , resp . ) ; tribochemical silica coating followed by silanization , Choice ( group SSC ) ; application of a zirconia primer , Choice and RelyX Unicem ( groups ZC and ZU , resp . ) . Light-curing composite resin cylinders were prepared and bonded on the prepared zirconia blocks using the two different resin cements . Half of the specimens in each group were stored in water for 24 h , and half were aged by 50 days of water storage followed by thermocycling ( 12,000 cycles between 5 ° C and 55 ° C ) . Thereafter , all of them were su bmi tted to the SBS test . Fourier transmission infrared ( FT-IR ) spectrum analysis and gas mass spectrometry ( MS ) analysis were adopted for characterization of the zirconia primer . RESULTS Statistical analysis of the SBS test showed that group C presented the lowest SBS values and group SSC the highest ( p < 0.01 ) . Artificial aging exerted no influence on the SBS of groups U , SSC , ZC , or ZU . FT-IR analysis suggested that benzene rings and carboxylic groups exist in the zirconia primer . MS analysis detected that 2-hydroxyethyl methacrylate , triethylamine , ethyl-4-dimethylaminobenzoate , ethanol , and water are contained in the primer . CONCLUSION The zirconia primer and self-adhesive resin cement increased the SBS of zirconia PURPOSE To evaluate the suitability of an ultra-short pulsed laser ( USPL ) to treat zirconia ceramic surfaces and increase their adhesion to dual-curing resin cement . MATERIAL S AND METHODS Twenty 10 × 10 × 5 mm³ blocks were prepared from a zirconia ceramic ( Y-TZP ) . The specimens were polished and r and omly assigned to four groups ( n = 5 ) which received the following surface treatments : s and blasting ( SB ) with Al₂O₃ particles and silica coating ( SC ) with SiO₂ particles as positive controls ; two groups received USPL irradiation , one with 10 scan repetitions ( L10 ) and the other with 20 ( L20 ) . Laser irradiation was performed at 1030 nm , 2.3 J/cm² , 6 ps pulse duration . The ceramic blocks were duplicated in composite resin and cemented with a dual-curing resin cement . Half of the blocks were then stored in water ( 37 ° C ) for 24 h and the other half for 1 month . At each time , 40 to 60 sticks per group were subjected to microtensile bond strength testing . Data were analyzed statistically using the Kruskal-Wallis test ( α = 0.05 ) . RESULTS Laser-treated zirconia presented statistically significantly higher roughness than did SB and SC . After 24 h , the highest bond strength means ( MPa ) were achieved by L10 ( 42.3 ± 10.8 ) and L20 ( 37.9 ± 14.4 ) , and both of them were statistically significantly higher than SB ( 22.0 ± 5.3 ) and SC ( 20.8 ± 7.1 ) ( p < 0.05 ) . After 1 month of storage , L10- and L20-treated zirconia still showed significantly higher bond strengths than did SB- and SC-treated zirconia ( p < 0.05 ) . CONCLUSION USPL irradiation significantly increases bond strength of zirconia ceramic to dual-curing resin cement and might be an alternative for improving adhesion to this material This study evaluated the effectiveness of a multi-mode adhesive ( SBU-Scotch Bond Universal/3 M ) as a substitute for silica coating and silane application on the bonding of zirconia ceramics to resin cement . One-hundred and twenty sintered zirconia ceramic blocks ( 5 x 5 x 5 mm ) were obtained , finished by grounding with silicon carbide paper ( # 600 , # 800 , # 1000 and # 1200 ) and r and omly divided into 12 groups ( n=10 ) in accordance with the factors " surface treatment " ( ScSi - silicatization + silanization ; ScSBU - silicatization + SBU ; SBU - SBU without photoactivation and SBUp - SBU photoactivated ) and " ceramic " ( Lava / 3 M ESPE , Ceramill Zirconia / Amann Girrbach and Zirkonzahn / Zirkonzahn ) . Dual resin cement cylinders ( RelyX Ultimate/3 M ESPE ) were subsequently produced in the center of each block using a silicon matrix ( Ø=2 mm , h=5 mm ) and photoactivated for 40 s ( 1200 mW/cm2 ) . The sample s were stored for 30 days in distilled water ( 37ºC ) and su bmi tted to shear bond strength test ( 1 mm/min , 100 KgF ) . Data ( MPa ) were analyzed under ANOVA ( 2 levels ) and Tukey test ( 5 % ) . Complementary analyzes were also performed . ANOVA revealed that only the factor " surface treatment " was significant ( p=0.0001 ) . The ScSi treatment ( 14.28A ) promoted statistically higher bond strength values than the other ScSBU ( 9.03B ) , SBU ( 8.47B ) and SBUp ( 7.82B ) , which were similar to each other ( Tukey ) . Failure analysis revealed that 100 % of the failures were mixed . The silica coating followed by the silanization promoted higher bond strength values of resin cement and ceramic , regardless of the zirconia ceramic or SBU
target: Conclusions .
  Airborne-particle abrasion and tribo-chemical silica coating are the pre-treatment methods with more evidence in the literature .
  Increased adhesion could be expected after physico-chemical conditioning of zirconia .
  Surface contamination has a negative effect on adhesion .
  There is no evidence to support a universal adhesion protocol
background: Background .
  Reliable bonding between resin composite cements and high strength ceramics is difficult to achieve because of their chemical inertness and lack of silica content that makes etching impossible .
  The purpose of this review is to classify and analyze the existing methods and material s suggested to improve the adhesion of zirconia to dental substrate by using composite resins , in order to explore current trends in surface conditioning methods with predictable results .
  Methods .