Background: Amalgam is a common filling material for posterior teeth, as with any restoration amalgams have a finite life-span. Traditionally replacement was the ideal approach to treat defective amalgam restorations, however, repair offers an alternative more conservative approach where restorations are only partially defective. Repairing a restoration has the potential of taking less time and may sometimes be performed without the use of local anaesthesia hence it may be less distressing for a patient when compared with replacement. Repair of amalgam restorations is often more conservative of the tooth structure than replacement.
Objectives: To evaluate the effects of replacing (with amalgam) versus repair (with amalgam) in the management of defective amalgam dental restorations in permanent molar and premolar teeth.
Search methods: For the identification of studies relevant to this review we searched the Cochrane Oral Health Group's Trials Register (to 5 August 2013); the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2013, Issue 7); MEDLINE via OVID (1946 to 5 August 2013); EMBASE via OVID (1980 to 5 August 2013); BIOSIS via Web of Knowledge (1969 to 5 August 2013); Web of Science (1945 to 5 August 2013) and OpenGrey (to 5 August 2013). Researchers, experts and organisations known to be involved in this field were contacted in order to trace unpublished or ongoing studies. No restrictions were placed on the language or date of publication when searching the electronic databases.
Selection criteria: Trials were selected if they met the following criteria: randomised controlled trial (including split-mouth studies), involving replacement and repair of amalgam restorations in adults with a defective restoration in a molar or premolar tooth/teeth.
Data collection and analysis: Two review authors independently assessed titles and abstracts for each article identified by the searches in order to decide whether the article was likely to be relevant. Full papers were obtained for relevant articles and both review authors studied these. The Cochrane Collaboration statistical guidelines were to be followed for data synthesis.
Main results: The search strategy retrieved 201 potentially eligible studies after de-duplication. After examination of the titles and abstracts, full texts of the relevant studies were retrieved but none of these met the inclusion criteria of the review.
Authors' conclusions: There are no published randomised controlled trials relevant to this review question. There is therefore a need for methodologically sound randomised controlled trials that are reported according to the Consolidated Standards of Reporting Trials (CONSORT) statement (www.consort-statement.org/). Further research also needs to explore qualitatively the views of patients on repairing versus replacement and investigate themes around pain, distress and anxiety, time and costs.