Matrices including crowns for dental restoration

A dental matrix comprising:

• a body configured to correspond to the shape of a tooth including a first end oppositely disposed from a second end, the body comprising:
• an inner cavity extending from the first end to the second end, the first end being closed and the second end comprising an opening for fitting over a predefined dental area,
• an expandable portion at least proximate to the second end including an outwardly extending expandable tab including oppositely disposed flanges separated by an intermediate fold, the tab movable between a retracted position and an expanded position, such that the diameter of the second end at least proximate to the opening increases when the tab moves from the retracted position to the expanded position;
• and an aperture in the body open to the inner cavity.