A survey of amalgam restorations in a south-western Nigerian population.

The present survey assessed the proportion of replacement restorations in comparison with new restorations because of primary caries in a setting where the caries experience had been reported to be low but probably on the increase. Also the relative importance of the main reasons for the replacements among other things was established. A total of 488 amalgam restorations were surveyed. About 25% of all restorations were replacements of failed restorations. The main reason for the replacement was bulk amalgam fracture, which accounted for 47.1% of all restorations. These show a reversal of what had been reported in settings where the caries experience was high but now is on the decrease. The importance of bitewing radiograph of all failed restorations was emphasized in order to minimize under or over treatment. The median age of failed restorations was 5.0 years. More than half (60.3%) of replaced restorations had failed during the first 5 years of use.