Retention of pins in amalgam

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Restorative Dentistry

Background:

• Retention pins are crucial for reinforcing dental amalgam restorations.
• Titanium alloy pins offer biocompatibility and strength for dental applications.
• Evaluating pin retention is essential for long-term restoration success.

Purpose of the Study:

• To compare the retention strength of the Max 021 titanium alloy self-threading pin against the Link Plus titanium alloy self-threading pin in amalgam.
• To determine the failure modes of each pin type under tensile load.

Main Methods:

• Fifteen amalgam specimens were prepared with either Max 021 or Link Plus pins.
• Specimens were subjected to a continuous tensile force using an Instron Testing Machine at a rate of 1 mm/min until failure.
• Failure forces and modes were recorded and analyzed.

Main Results:

• The Max 021 pin required a mean force of 87.6 N for failure, primarily due to amalgam fracture with intact pin retrieval.
• The Link Plus pin required a significantly higher mean force of 180.4 N for failure, with the pin itself fracturing.
• A statistically significant difference in retention strength was observed between the two pin types.

Conclusions:

• The Link Plus titanium alloy self-threading pin exhibits significantly greater retention in amalgam compared to the Max 021 pin.
• The failure mechanism differs, with Max 021 pins failing due to amalgam integrity and Link Plus pins failing due to pin fracture.
• These findings have implications for selecting appropriate retention pins in clinical restorative dentistry.