Optimizing adhesive protocols for CAD-CAM restorations: Is simplification a reliable alternative to conventional...

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Restorative Dentistry

Background:

• Computer-Aided Design/Computer-Aided Manufacturing (CAD-CAM) restorations require durable bonding to tooth structure.
• Optimizing silane-based surface treatments is crucial for enhancing the bond strength of various CAD-CAM materials.
• Understanding the impact of aging on bond durability is essential for clinical longevity.

Purpose of the Study:

• To compare the bond strength and surface morphology of five CAD-CAM materials.
• To evaluate the efficacy of different silane-based bonding strategies.
• To assess the influence of artificial aging on bond durability.

Main Methods:

• Five CAD-CAM materials (leucite-reinforced glass ceramic, lithium disilicate, zirconia-reinforced lithium silicate, polymer-infiltrated ceramic network, resin nanoceramic) were tested.
• Specimens were subjected to five bonding protocols: conventional silane, universal adhesive, single-step cement, ceramic primer, and no silane.
• Bond strength was measured via micro-shear testing before and after 10,000 thermal cycles; failure modes and surface morphology were analyzed.

Main Results:

• Material type, bonding strategy, and aging significantly impacted bond strength (P < .001).
• The conventional silane protocol yielded the highest bond strength across all materials.
• Simplified strategies showed intermediate, clinically acceptable bond strengths, though reduced by thermal cycling.

Conclusions:

• The conventional three-step silane protocol ensures the most reliable and durable bonding for CAD-CAM restorations.
• Simplified bonding strategies can be acceptable alternatives, contingent upon the specific CAD-CAM material used.
• Artificial aging consistently reduced bond strength, highlighting the importance of robust bonding protocols.