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 .
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 .
Effect of Resin Luting Systems and Alumina Particle Air Abrasion on Bond Strength to Zirconia.
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
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 .
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 .