Effects of some chemical surface modifications on resin zirconia adhesion. Adhesion mechanisms at the interface between Y-TZP and veneering ceramic with and without modifier. Surface Characterization and Short-term Adhesion to Zirconia after Ultra-short Pulsed Laser Irradiation. Evaluation of four surface coating treatments for resin to zirconia bonding. Effect of surface pre-treatments on the zirconia ceramic-resin cement microtensile bond strength. Effect of an experimental zirconia-silica coating technique on micro tensile bond strength of zirconia in different priming conditions. The Effect of Laser Treatment on Bonding Between Zirconia Ceramic Surface and Resin Cement Association of different primers and resin cements for adhesive bonding to zirconia ceramics. Effect of various surface conditioning methods on the adhesion of dual-cure resin cement with MDP functional monomer to zirconia after thermal aging. Improved bonding of zirconia substructures to resin using a "glaze-on" technique. Effects of multipurpose, universal adhesives on resin bonding to zirconia ceramic. Evaluation of self-adhesive resin cement bond strength to yttria-stabilized zirconia ceramic (Y-TZP) using four surface treatments. Effect of Resin Luting Systems and Alumina Particle Air Abrasion on Bond Strength to Zirconia. Silica-based nano-coating on zirconia surfaces using reactive magnetron sputtering: effect on chemical adhesion of resin cements. Comparison of resin cement adhesion to Y-TZP ceramic following manufacturers’ instructions of the cements only Zirconium dioxide based dental restorations. Studies on clinical performance and fracture behaviour. Bond strength of resin cement to zirconia ceramic with different surface treatments
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 OBJECTIVE This study investigated the mechanism of action at the interface between a commercially available Y-TZP  and its veneering ceramic after final firing . Particular attention was paid , from a microstructural point of view , to evaluating the effects of different surface treatments carried out on the zirconia . METHODS In total , 32 specimens of presintered zirconia Y-TZP ( LavaFrame , 3 M ESPE , Germany ) were cut with a low-speed diamond blade . The specimens were divided in two major groups , for testing after fracture or after mirror finishing , and were sintered following the manufacturer 's instructions . Each major group was then r and omly divided into four subgroups , according to using or not using the dedicated framework modifier , with or without a preliminary silica coating ( CoJet , 3 M ESPE ) . A suitable veneering ceramic was used for each group ( Lava Ceram Overlay Porcelain , 3 M ESPE ) . A detailed microstructural study of the interfaces of the zirconia-veneering ceramic was performed using a scanning electron microscope equipped with an energy-dispersive X-ray spectrometer to evaluate chemical variation at the interfaces . RESULTS When the framework modifier was not applied on the Y-TZP surface , microdetachments , porosities , and openings in the ceramic layer were observed at the interlayers . A degree of diffusion of different elements through the interfaces from both the zirconia and veneering layers was detected . CONCLUSIONS Application of the framework modifier can increase the wettability of the zirconia surfaces , allowing a continuous contact with the veneering layer . The micro- analysis performed showed the presence of a reaction area at the interface between the different material s. CLINICAL SIGNIFICANCE the increase of the wettability of the zirconia surface could improve the adhesion at interface with the veneering ceramic and reduce the clinical failure as chipping or delamination 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 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 To evaluate the influence of different surface treatments on the microtensile bond strength of resin cement to zirconia ceramic . MATERIAL S AND METHODS Twelve cylinder-shaped ( ∅ 12 × 5.25 mm high ) blocks of a commercial zirconium-oxide ceramic ( Cercon ® Zirconia , DENTSPLY ) were r and omly divided into 4 groups ( n=3 ) , based on the surface treatment to be performed : ( 1 ) airborne particle abrasion with 125 μm Al₂O₃ particles ( S ) ; ( 2 ) selective infiltration etching ( SIE ) ; ( 3 ) experimental hot etching solution applied for 30 min ( ST ) and ( 4 ) no treatment ( C ) . Paradigm MZ100 blocks ( 3 M ESPE ) were cut into twelve cylinders of 4 mm in thickness . Composite cylinders were bonded to conditioned ceramics using a resin cement ( Calibra ® , DENTSPLY ) , in combination with the proprietary adhesive system . After 24h bonded specimens were cut into microtensile sticks and loaded in tension until failure . Bond strength data were analyzed with Kruskall-Wallis and Dunn 's Multiple Range test for multiple comparisons ( p < 0.05 ) . Failure mode distribution was recorded and the interfacial morphology of debonded specimens was analyzed using a scanning electron microscope ( SEM ) . RESULTS Bond strength values achieved after SIE and ST treatment were significantly higher than after S treatment and without any treatment ( p < 0.05 ) . Premature failures were mostly recorded in the S group . SIGNIFICANCE Conditioning the high-strength ceramic surface with SIE and ST treatments yielded higher bond strengths of the resin cement than when zirconia ceramic was treated with airborne particle abrasion or left untreated OBJECTIVES This study aim ed to evaluate the adhesive properties of a MDP-containing resin cement to a colored zirconia ceramic , using an experimental zirconia-silica coating technique with different priming conditions . METHODS 18 zirconia ceramic discs ( Cercon base colored ) were divided into two groups : the control group and the experimental zirconia-silica coating group . Specimens in each group were further divided into 3 subgroups ( n = 3 ) according to the priming conditions : no primer , a MDP-containing primer ( ED Primer II ) or a silane coupling primer ( RelyX ™ Ceramic Primer ) . Then resin-composite discs ( Filtek ™ Z250 ) were bonded to the treated surface using a MDP-containing resin cement ( Panavia F 2.0 ) . The bi-layered specimens were cut into microbars and 20 microbars were r and omly selected from each specimen , half of which were stored in 37 ° C water bath for 24h , and the other half were stored for 30 days . After water storage , the sample s were exposed to a micro tensile bond strength test ( MTBS ) . The results were analyzed by ANOVA , while the fracture surfaces were examined by SEM . RESULTS After 24h water storage , zirconia-silica coating followed by silanization showed a significantly ( P<0.001 ) higher MTBS value 45.0 (10.9)MPa . Water storage affected ( P<0.05 ) MTBS in the control group ( 24.1 - 30.3 MPa to 2.8 - 3.1 MPa ) , but only partially in the zirconia-silica coating group ( 20.0 - 45.1 MPa to 17.4 - 25.9 MPa ) . SEM analysis revealed a failure mode change after water storage . SIGNIFICANCE The combination of zirconia-silica coating with silane coupling can improve the bonding of resin cement to this colored zirconia Abstract Objective . The purpose of this in-vitro study was to evaluate and compare the effects of different surface treatments and laser irradiation on the shear bond strength of resin cement to zirconia-based ceramic . Material and methods . Forty zirconia core specimens ( 10-mm diameter , 2-mm thickness ) were produced and embedded in the centers of autopolymerizing acrylic resin blocks . Subsequently , specimens were r and omly divided into four groups , each containing 10 specimens , for different surface treatment methods . The details of the groups are as follows : Group C , no treatment applied ( control ) ; Group SB , bonding surfaces of ceramic disks were airborne particle-abraded with 110-μm alumina oxide particles ; Group HF , bonding surfaces of ceramic disks were etched with 9.6 % hydrofluoric acid ; and Group L , bonding surfaces of ceramic disks were irradiated by a CO2 laser . A total of 40 composite resin disks were fabricated and cemented with an adhesive resin cement to the specimen surfaces . A universal test machine was used for the shear bond strength test at a crosshead speed of 1 mm/min . Results . The highest shear bond strength values were obtained with Group L ( 20.99 ± 3.77 MPa ) and the lowest values with Group C ( 13.39 ± 3.10 MPa ) . Although there was no significant difference between Groups C , HF and SB ( P > 0.05 ) , Group L showed a significant difference from all other groups ( p < 0.05 ) . Conclusion . All surface treatment methods improved the bond strength between resin cement and the zirconium oxide ceramic surface . CO2 laser etching may represent an effective method for conditioning zirconia surfaces , enhancing micromechanical retention and improving the bond strength of resin cement on zirconia ceramic PURPOSE To evaluate the shear bond strength ( SBS ) to zirconia ceramics using different associations of primers and resin cements . MATERIAL S AND METHODS Two blocks of LAVA zirconia ( 3Y-TZP ) were r and omly su bmi tted to an application of three different commercially available primers : Alloy Primer ( AP ) , Z-Prime Plus ( ZP ) , and Signum Zirconia Bond ( SZB ) . Nonprimed specimens were considered controls . After treatment , the 80 specimens ( 5 mm × 5 mm × 2 mm ) were r and omly cemented with one of the resin cements : Panavia F , Multilink , seT , and NX3 . For cementation , cylinders of resin cement were built on the ceramic surfaces using the SDI SBS apparatus . The specimens were su bmi tted to the SBS test . Fractured surfaces were observed under stereomicroscopy to determine the failure mode , and mean bond strength values were analyzed using the Kruskal-Wallis and Mann-Whitney tests ( α = 0.05 ) . RESULTS Signum Zirconia Bond had the highest SBS compared to all other primers and the control group , regardless of the resin cement used . The highest values were obtained when associating Panavia F with Signum Zirconia Bond . Alloy Primer increased bonding values when associated with seT cement only . When no primer was used , no statistical difference was observed among resin cements . All specimens fractured due to adhesive failure . CONCLUSION Signum Zirconia Bond is capable of increasing bonding values of resin cements to zirconia ceramics . Its association with Panavia F shows enhanced results when considering short-term adhesion to zirconia This study evaluated the effect of chairside and laboratory types of surface conditioning methods on the adhesion of dual-cure resin cement with MDP functional monomer to zirconia ceramic after thermocycling . Disk-shaped ( diameter : 10 mm , thickness : 2 mm ) Y-TZP ceramics ( Lava , 3 M ESPE ) were used ( N=40 ) and finished with wet 1200-grit silicon carbide abrasive paper . Specimens were r and omly divided into four experimental groups according to the following surface conditioning methods ( n=10 per group ) : Group 1 - -Chairside airborne particle abrasion with 50-microm Al2O2 + Alloy Primer ( Kuraray ) ; Group 2 - -Airborne particle abrasion with 50-microm Al2O3 + Cesead II Opaque Primer ( Kuraray ) ; Group 3 - -Airborne particle abrasion with 50-microm A12O3 + Silano-Pen + silane coupling agent ( Bredent ) ; Group 4 - -Laboratory tribochemical silica coating ( 110-microm Al2O3 + 110-microm SiOx ) ( Rocatec ) + silane coupling agent ( ESPE-Sil ) . Adhesive cement , Panavia F 2.0 ( Kuraray ) , was bonded incrementally to the ceramic surfaces using polyethylene molds ( diameter : 3.6 mm , height : 5 mm ) . All specimens were thermocycled ( 5 and 55 degrees C , 6,000 cycles ) and subjected to shear bond strength test ( 1 mm/min ) . Data were statistically analyzed ( one-way ANOVA , alpha=0.05 ) , whereby no significant differences were found among the four groups ( 8.43+/-1.3 , 8.98+/-3.6 , 12.02+/-6.7 , and 8.23+/-3.8 MPa ) ( p=0.1357 ) . Therefore , the performance of chairside conditioning methods used for zirconia was on par with the laboratory alternative tested OBJECTIVE To investigate the influence of applying thin intermediary coatings of acid-etchable glasses on the shear bond strength between a methacrylate resin based cement and an yttria-stabilized zirconia dental ceramic substrate . METHODS The upper and lower surfaces of 110 sintered yttria-stabilised tetragonal zirconia polycrystalline disc-shaped specimens were polished using sequential grade s of Silicon Carbide , then air-abraded with 25 μm diameter alumina particles . Specimens were r and omly allocated to 11 groups ( A-K ) ( n=10 ) , group A acting as control . The upper surface of Group A specimens was subjected to a tribochemical coating regime ( CoJet , 3 M ESPE ) . Five glazing ceramics were applied and fired according to the manufacturer 's recommended firing regime . The glaze was etched with 10 % HF acid and all specimens coated with a silane primer . Two differing storage regimes were employed ( wet storage vs thermocycling ) . Shear bond strength testing specimens were created by cementing resin-based composite cylinders to the centre of the prepared ceramic surface using Rely-X Unicem ( 3 M ESPE ) resin based cement . Shear bond strength testing was performed and load at failure recorded . RESULTS A factorial analysis of variance at a 95 % significance level demonstrated that all glazing techniques result ed in a significant increase in the shear bond strength compared with using the resin based cement alone ( P<0.01 ) , with the different glazing ceramics result ing in significant differences in mean shear bond strength ( P=0.008 ) . The differences were a function of the storage state ( wet storage vs thermocycling ( P=0.013 ) ) . CONCLUSION The glazing techniques used in the current investigation result ed in a significantly enhanced shear bond stress to the resin based cement when compared with the current ' gold st and ard ' - tribochemical coating 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 evaluate the influence of four surface treatments on the bond strength of a self-adhesive resin cement to an yttria-stabilized zirconia ( Y-TZP ) ceramic material ( Lava Frame zirconia ) . MATERIAL S AND METHODS Forty plates ( 8 x 6 x 1 mm ) of a Y-TZP ceramic restorative material were r and omly assigned to four groups ( n = 10 ) according to the surface treatments : control , no treatment ; airborne-particle abrasion with 50-μm Al2O3 ; coating with an MDP-based primer ; conditioning with Rocatec System . The ceramic plates treated with each of the four methods were further divided into 2 subgroups according to the resin cement tested : RelyXTM ARC ( ARC , conventional ) and RelyXTM Unicem ( Ucem , self-adhesive ) . The resin cements were put into PVC tubes ( diameter 0.75 mm , 0.5 mm height ) placed on the ceramic plate surfaces . After water storage at 37 ° C for 24 h , the specimens were su bmi tted to a microshear bond strength ( μSBS ) test at a crosshead speed of 1.0 mm/min . RESULTS The surface treatments significantly influenced the μSBS ( p < 0.05 ) . For the four surface treatments , UCem presented significantly higher μSBS than ARC ( p < 0.05 ) . For both resin cements , the best result was produced by the MDP-based primer : ARC 15.9 ± 5.0 MPa and UCem 36.2 ± 2.1 MPa . The highest μSBS values were presented by UCem on ceramic plates treated with the MDP-based primer ( 36.2 ± 2.1 MPa ) and Rocatec system ( 37.4 ± 2.3 MPa ) . CONCLUSION Irrespective of the surface treatment , the self-adhesive resin cement performed better in terms of bond strength to yttria-stabilized zirconia ceramic than did conventional resin cement 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 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 The objectives of this study were ( 1 ) to evaluate the bond strength of four resin material s with various chemical compositions following the manufacturers ’ instructions only and ( 2 ) to test their durability in dry and thermal aged conditions when they were bonded to zirconia ceramic . Four types of resin material s namely , Panavia F 2.0 , Multilink , SuperBond and Quadrant Posterior Dense , were attached to the disc-shaped zirconia ceramics ( LAVA , 3 M ESPE ) using polyethylene molds and polymerized accordingly after the ceramics were wet ground finished and ultrasonically cleaned . The specimens were r and omly divided into two groups for ageing conditions . While the dry groups were tested immediately after attachment of the resin cement , the other specimens were subjected to thermocycling ( ×6,000 , 5–55 ° C ) . Bond strength results were significantly affected by the storage condition ( p < 0.001 ) and type of resin ( p < 0.001 ; analysis of variance ) . Panavia F 2.0 showed the highest bond strength results under dry conditions ( 9.6 ± 4.1 MPa ) . When manufacturers ’ instructions of the resin cements were followed , no adhesion ( 0 MPa ) was achieved on the zirconia after 6,000 thermal cyclings including Panavia F 2.0 Loss of teeth can affect a person 's appearance and functions such as eating and speaking . There is thus a need for prosthetic rehabilitation to improve quality of life . For many patients , a fixed dental restoration is preferred , and a common restoration is a porcelain-fused-to-metal bridge retained by teeth or implants . Metal-based restorations can potentially cause adverse reactions though , and this is cause for the search for alternative material s. All-ceramic material s are characterized by strong atomic bonds that make them reluctant to react with the environment , and thus unlikely to cause adverse reactions . All-ceramic material s have other attractive material properties and excellent aesthetic properties and have been successfully used in dentistry , mostly for smaller anterior restorations . Ceramics , however , do not withst and tensile forces as well as metals , and are susceptible to brittle fractures with the connector area being especially prone to fracture . More recently , a new type of ceramic material , based on zirconium dioxide , has been developed . Yttria-stabilized tetragonal zirconia polycrystal , Y-TZP , has a unique ability to resist crack propagation by being able to transform from one crystalline phase to another , and the result ant volume increase stops the crack and prevents it from propagating . This material has the potential to be used for larger restorations and in the molar area . Not enough information , however , is available on clinical follow-up of zirconia-based restorations , especially long-term , and information about all-ceramic restorations supported by implants is lacking . The aim of this thesis was to evaluate design s of zirconia-based restorations in relation to achieving increased fracture resistance and evaluate the clinical performance of implant-supported zirconia-based restorations . In paper I implant-supported all-ceramic fixed partial dentures of two different ceramic material s were compared ; a zirconia-toughened alumina material ( group 1 ) and a fully-sintered Y-TZP material ( group 2 ) . Eighteen patients were r and omly divided between the two groups . At the one-year follow-up , all restorations were in function and no complete fractures were noted . However , fractures of the veneering material were noted . There was a significant difference between the two material s : 54 % of the restorations in group 2 showed veneer fractures compared to 8 % of the restorations in group 1 . Paper IV is a five-year follow-up of the same patient groups . All restorations were still in function without complete fractures , but an increase in veneer fractures was noted : 69 % of the restorations in group 2 showed veneer fractures compared to 17 % in group 1 . In paper II the fracture strength was evaluated for 4-unit Y-TZP fixed dental prosthesis frameworks with different connector dimensions : 2.0 , 2.5 , 3.0 , 3.5 and 4.0 mm . The results showed a significant increase in load at fracture for each increase in connector diameter and recommendations for clinical ly relevant connector dimensions were suggested . In paper III implant-supported Y-TZP fixed full-arch m and ibular dentures were evaluated . At the three-year follow-up all restorations were in function and no complete fractures were noted . However , fractures of the veneering material were noted in nine of the ten patients , affecting 34 % of the units . In paper V the fracture strength of  crowns  with different types of Y-TZP core material s and different core design and different veneering material s was evaluated . The crowns were cemented onto tooth-like abutments , except for one group cemented onto implant-like titanium abutments . The results showed significantly higher loads at fracture and less severe veneer fractures for crowns with anatomically shaped cores compared to simple cores of even thickness . Crowns supported by implant-like titanium abutments showed significantly higher loads at fracture than did those supported by tooth-like abutments . The type of core- material and veneering material did not influence the results Zirconia-based ceramics offer strong restorations in dentistry , but the adhesive bond strength of resin cements to such ceramics is not optimal . This study evaluated the influence of surface treatments on the bond strength of resin cement to yttrium-stabilized tetragonal zirconia ( Y-TZP ) ceramic . Seventy-five plates of Y-TZP ceramic were r and omly assigned to five groups ( n = 15 ) according to the surface treatments [ airborne particle abrasion , neodymium-doped yttrium aluminum garnet ( Nd : YAG ) laser irradiation ( Fidelis Plus 3 , Fotona ; 2 W , 200 mJ , 10 Hz , with two different pulse duration s 180 or 320 μs ) , glaze applied , and then 9.5 % hydrofluoric acid gel conditioned , control ] . One specimen from each group was r and omly selected , and specimens were evaluated with x-ray diffraction and SEM analysis . The resin cement ( Clearfil Esthetic Cement , Kuraray ) was adhered onto the zirconia surfaces with its corresponding adhesive components . Shear bond strength of each sample was measured using a universal testing machine at a crosshead speed of 1 mm/min . Bond strengths were analyzed through one-way ANOVA/Tukey tests . Surface treatments significantly modified the topography of the Y-TZP ceramic . The Nd : YAG laser-irradiated specimens result ed in both increased surface roughness and bond strength of the resin cement . The highest surface roughness and bond strength values were achieved with short pulse duration . Nd : YAG laser irradiation increased both surface roughness of Y-TZP surfaces and bond strength of resin cement to the zirconia surface
Airborne-particle abrasion and tribochemical silica coating are reference pretreatment methods .
STATEMENT OF PROBLEM With a number of  zirconia ceramic material s currently available for clinical use , an overview of the scientific literature on the adhesion methods and their potential influence is indicated .
PURPOSE The purpose of this systematic review was to classify and analyze the existing methods and material s proposed to improve adhesion to zirconia surfaces .
Adhesive monomers are necessary for chemical bonding .
Surface contamination and aging have negative effects on adhesion to zirconia .