Longevity of cusp-covered amalgams: survivals after 15 years

The longevity of 124 cusp-covered class 2 amalgam restorations and 644 restorations placed without cusp coverage was assessed over periods of up to 15 years. The survivals of both groups of restorations were approximately 72% after 15 years. The longevity of the cusp-covered restorations was not affected significantly by the use of pins for retention, or by patient age. The survivals were much better than the estimates of longevity generally ascribed by dentists to cusp-covered or complex amalgam restorations.