Zirconia ceramics are popular in dentistry for their strength, biocompatibility, and esthetics, with yttria content critically influencing their properties. Low-yttria zirconia (3Y-PSZ) offers high strength through transformation toughening, while high-yttria types (5Y-PSZ) provide better translucency but reduced bond strength. This study examines how yttria content affects adhesion performance and surface treatment effectiveness. Air-particle abrasion combined with 10-MDP primers remains the most reliable bonding method across zirconia types, though high-yttria zirconia requires gentler protocols to avoid damage. Bond strength tests and aging simulations reveal that higher yttria content often leads to weaker and less durable bonds. Tailoring adhesion strategies to yttria composition is essential for the long-term success of zirconia restorations.