REPLACEMENT RISK OF AMALGAM TREATMENT MODALITIES - 15-YEAR RESULTS

Objectives: This paper reports on the replacement risk of different tr eatment modalities for Class II amalgam restorations in a clinical tri al of 15 years' duration, Methods: The performance of 1117 conventiona l Class II amalgam restorations in a controlled, longitudinal study we re analysed using logistic regression with a random component. Primary variables regarding replacement risk were the treatment modality (cav ity wall treatments) and alloy (conventional versus high copper). Seco ndly, the operator, type of tooth and type of restoration (MO/DO vs MO D) were considered. Results: Over 15 years, 17% of the restorations we re replaced (true failures). The application of copalite varnish or si lver suspension and the type of alloy did not reduce the replacement r isk. Reduced risks were observed by providing a 90 degrees cavosurface angle combined with a cavity wail finish, The operator and the type o f restoration determine replacement risk to a significant extent. Conc lusions: Additional treatment modalities do not necessarily reduce rep lacement risks of Class II amalgam restorations within 15 years, while clinical variables affect the risk of replacement to a certain degree . (C) 1998 Elsevier Science Ltd. All rights reserved.