Marginal deterioration of amalgam restoration should be due to.. Improper manipulation of amalgam

Marginal deterioration of amalgam restoration should be due to:

• A. No enough bulk of dentine.
• B. Corrosion.
• C. Over carving.
• D. Improper manipulation of amalgam.
• E. A and b.
• F. C and d.
• G. All the above.
• H. B, c and d.

Amalgams that are corroded or have inadequate bulk to distribute stresses may fracture. At margins, where amalgams are thinner, extrusion may have occurred, and corrosion may have compromised the integrity of the amalgam, fracture is even more likely.

The most likely cause of marginal deterioration of an amalgam restoration is: H. B, c and d. (Corrosion, Over carving, and Improper manipulation of amalgam)

Here's why:

- Corrosion:

Over time, amalgam restorations can undergo corrosion, leading to a breakdown of the material and potential weakening at the margins.

- Over carving:

Excessive removal of tooth structure during cavity preparation can leave the remaining dentin insufficient to support the amalgam, increasing stress on the restoration, particularly at the thinner margins, making them more susceptible to deterioration.

- Improper manipulation of amalgam:

This can include issues like improper mixing, condensation, or finishing, which can lead to weaker margins and increased risk of deterioration.

While insufficient dentin bulk (A) can contribute to stress on the restoration, it's not the only factor, and the other options (C and D) are more directly related to the integrity of the amalgam material itself at the margins.

Therefore, H. B, c and d is the most comprehensive and accurate explanation for marginal deterioration of amalgam restorations.