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Creep as a mechanism for sealing amalgams
1School of Dentistry, University of Colorado Health Sciences Center, Denver, CO, USA. john.osborne@UCHSC.edu
Operative Dentistry
|July 11, 2006
Summary
Dental amalgam restorations seal microleakage over time, not just through corrosion, but potentially via a creep mechanism. This expansion fills gaps between the amalgam and tooth structure, improving the seal.
Area of Science:
- Dental Materials Science
- Restorative Dentistry
- Biomaterials Engineering
Background:
- Dental amalgam restorations are known to reduce microleakage over time.
- This sealing effect is commonly attributed to corrosion products filling the interface gap.
- However, empirical evidence supporting the corrosion theory is limited.
Purpose of the Study:
- To propose and explore the creep mechanism as an alternative explanation for the reduction of microleakage in dental amalgam restorations.
- To investigate the role of amalgam's physical properties in sealing the tooth-restoration interface.
Main Methods:
- Review of existing literature on dental amalgam behavior and metallurgical principles.
- Analysis of clinical observations and research data related to amalgam restoration sealing.
- Theoretical modeling of amalgam expansion within confined cavity preparations.
Main Results:
- The creep mechanism, involving amalgam expansion due to internal phase changes, offers a plausible explanation for sealing microleakage.
- Confined expansion of amalgam can fill the tooth/amalgam interface gap.
- Amalgam sliding along the preparation plane, a consequence of creep, aligns with metallurgical studies and clinical observations like extrusion.
Conclusions:
- The creep mechanism provides a compelling alternative to corrosion for explaining the self-sealing property of dental amalgam restorations.
- Amalgam's inherent material properties and behavior under confinement play a crucial role in long-term restoration integrity.
- Further research is warranted to fully elucidate the contribution of creep to amalgam sealing and its clinical implications.
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