Durability of amalgam in the restoration of class II cavities in primary molars: a systematic review of the literature.

AIM: To review the available literature on the durability of amalgam when used to restore interproximal (class II) cavities in primary molars. METHODS: The literature was searched using OVID Medline and EMBASE from 1966 to 2006. The search plan of the electronic databases included: "dental amalgam or amalgam or alloy" and "deciduous or primary or milk or first or baby or natal" or "tooth or teeth or dentition" and "permanent restorations or permanent fillings". Relevant prospective clinical studies were reviewed by 2 reviewers against a set of defined criteria. Papers were graded according to the number of criteria met as A = >90%, B1 = 75%, B2 = 50% and C = <50%. RESULTS: No study achieved a Grade A; four studies rated Grade B1 and thirteen B2. Seven studies were rated Grade C. A wide range of failure rates for amalgam were reported from 0 - 58%. However, in the context of a controlled clinical environment in a developed country the failure rate varied between 0 and 22%. CONCLUSION: Amalgam remains an appropriate choice of material for the restoration of the primary dentition. However, factors other than durability are increasingly influencing its use in clinical practice.