Cemented Single Crown Retention on Dental Implants: An In Vitro Study

Area of Science:

• Dental Materials Science
• Biomaterials Engineering

Background:

• Zirconia restorations are widely used in dentistry due to their biocompatibility and mechanical properties.
• Ensuring long-term retention of zirconia crowns on zirconia abutments is crucial for clinical success.

Purpose of the Study:

• To investigate the impact of different cements, abutment heights, and aging on the retention of zirconia crowns.
• To determine the optimal conditions for durable cementation of zirconia restorations.

Main Methods:

• Zirconia crowns and abutments of varying heights (4.0 or 5.5 mm) were prepared.
• Crowns were cemented using five distinct luting agents and subjected to axial pull-off testing.
• Specimens underwent either thermocycling or 3 days of water storage to simulate aging.

Main Results:

• Increased abutment height correlated with higher decementation forces for permanently cemented crowns.
• Temporary cementation resulted in a significant decrease in crown retention after aging.
• Permanent cements demonstrated a moderate increase in retention following aging protocols.

Conclusions:

• Permanent cements are essential for achieving clinically acceptable decementation forces.
• The choice of cement significantly influences the long-term stability of zirconia crowns on zirconia abutments.
• Abutment height plays a role in retention, but cement type is the primary determinant of adequate retention.