Cementation Protocol for Bonding Zirconia Crowns to Titanium Base CAD/CAM Abutments

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Prosthodontics

Background:

• Zirconia-based CAD/CAM restorations are widely used in prosthodontics due to their excellent mechanical properties and aesthetics.
• Ensuring durable cementation of zirconia crowns to Ti-Base abutments is crucial for long-term clinical success.
• Various factors, including abutment height, cement type, and surface treatment, can influence the bond strength.

Purpose of the Study:

• To determine the optimal cementation protocol for bonding zirconia crowns to Ti-Base CAD/CAM abutments.
• To evaluate the impact of abutment height, cement type, and surface pretreatment on the retention strength.
• To identify the most effective combination of factors for maximizing bond durability.

Main Methods:

• Zirconia crowns were fabricated for short (2.5 mm) and tall (4.0 mm) Ti-Base abutments.
• Conventional resin cement (RelyX Ultimate) and self-adhesive resin cement (RelyX U200) were tested.
• Surface pretreatments included no treatment, sandblasting (SB), tribochemical blasting (TBS), and combined SB + TBS.

Main Results:

• Taller Ti-Base abutments demonstrated significantly higher retention strength compared to shorter ones.
• Conventional resin cement (RelyX Ultimate) showed superior retention compared to self-adhesive resin cement (RelyX U200).
• Combined surface pretreatment (SB + TBS) yielded the highest retention, followed by SB and TBS, with no treatment being the least effective.

Conclusions:

• Ti-Base abutment height, surface pretreatment, and cement type are critical factors influencing zirconia crown retention.
• Taller abutments and conventional resin cement with universal adhesive, combined with effective surface pretreatment, provide the most robust cementation.
• These findings offer valuable guidance for optimizing clinical protocols for zirconia crown cementation.