What are four examples of secondary retention forms?

• A. Retention Grooves, Beveled Margins, Slots, Pins
• B. Dovetails, Slots, Pins, Bevels
• C. Retention Grooves, Beveled Margins, Slots, Pins
• D. Cement Types, Liners, Bases, Varnish

Answer: (C)

Secondary retention forms are features added to an amalgam cavity that enhance mechanical hold beyond what the basic cavity shape provides. Retention grooves are small channels cut into dentin or enamel to lock the filling in place as it is condensed, giving the material something to bite into. Beveled margins increase the marginal surface area, which helps the restoration resist displacement and improve the seal at the cavosurface margin. Slots create elongated interlocking paths along a wall, providing additional resistance to tipping or lifting. Pins are posts placed into dentin to anchor the restoration, especially in areas where walls may not converge enough on their own. Together, these features work to resist vertical and lateral dislodgement during function.

The other options include materials or margins that don’t function as secondary retention features in the same way, such as liners, bases, varnish, or cement types, which serve other purposes in preparation and restoration.