Reliability testing of indirect composites as single implant restorations

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Prosthodontics

Background:

• Single-unit implant crowns are crucial for restoring function and aesthetics.
• Indirect composite restorations offer a viable alternative for implant-supported prosthetics.
• Understanding the mechanical reliability of these materials is essential for clinical success.

Purpose of the Study:

• To assess the fatigue reliability and failure mechanisms of two indirect composite systems.
• To compare the performance of Ceramage and Diamond Crown materials when used for implant crowns.
• To investigate the long-term durability of indirect composites on titanium alloy abutments.

Main Methods:

• Custom-milled titanium alloy abutments were prepared with two indirect composite systems.
• Step-stress and fatigue testing were performed to determine failure profiles.
• Weibull analysis was used to calculate reliability, with fracture analysis via polarized light and SEM.

Main Results:

• Weibull probability indicated fatigue as a damage factor for Ceramage (β=3.39) but not Diamond Crown (β=0.40).
• Despite differences in Weibull modulus, confidence intervals overlapped, showing no statistical difference between the groups.
• Fracture initiated below the cusp contact area and propagated towards the margins, resulting in cohesive failure.

Conclusions:

• No statistically significant differences in reliability or Weibull probability were found between Ceramage and Diamond Crown.
• Failure modes for both indirect composite systems were characterized by composite veneer chippings.
• Both materials demonstrated comparable performance when veneered onto titanium alloy abutments for implant crowns.