Effect of clinical finishing procedures on amalgam microstructure

Area of Science:

• Materials Science
• Dental Materials Science
• Surface Engineering

Background:

• Dental amalgams are widely used restorative materials.
• Surface finishing techniques can influence the integrity and performance of dental restorations.
• Understanding subsurface composition is crucial for predicting material behavior.

Purpose of the Study:

• To investigate the effect of different surface finishing methods on the elemental and phase distribution of spherical dental amalgams.
• To quantify variations in phase fractions at different depths from the treated surface.

Main Methods:

• Spherical amalgam specimens were subjected to four surface treatments: burnished, burnished-polished, polished (wet), and polished (dry).
• Specimens were sectioned perpendicular to the prepared surface.
• Elemental analyses were performed using an electron microprobe at incremental depths.
• Phase fractions were calculated based on elemental composition data.

Main Results:

• Significant variations in elemental and phase distributions were observed within the superficial layer (100 micrometers) of the amalgams.
• The extent and nature of these variations differed based on the surface treatment applied.
• Subsurface composition is not uniform and is influenced by surface finishing.

Conclusions:

• Surface treatments critically affect the subsurface microstructure of dental amalgams.
• These microstructural changes within the top 100 micrometers can have implications for the clinical performance and durability of amalgam restorations.
• Further research is needed to correlate these subsurface variations with specific clinical outcomes.