Longevity of restorations: survey results of dentists' estimates and attitudes.

A cross-sectional survey of 571 clinicians was conducted to obtain information about expected and observed restoration longevity. Clinicians believed that average large amalgam, small amalgam, and cast restorations lasted 6, 11, and 13 years, respectively. Patients were thought to be responsible for 47%, dentists for 30%, and materials used for 23% of restoration failures. The clinicians perceived the restorations that they placed to be more long-lasting than those placed by other clinicians. Clinical measurements of restoration longevity were shown to be influenced by the judgment criteria used by clinicians.