Background and aim.  This paper reviews three published papers and adds results from a fourth study which aimed to determine which restorative material would be the best alternative(s) to amalgam (AM) in primary teeth.

Design.  All studies had a practice-based design and were part of the routine treatment of children and adolescents. The clinicians were assigned which materials to use in a randomised matter in the first three studies which lasted for 7–8 years. In the fourth study conducted 4 years after the initial studies, the clinicians were free to select the restorative materials.

Results and conclusions.  Resin modified glass ionomer (RMGI) and compomer (COM) restorations showed similar longevity compared with AM, whereas conventional GI restorations showed significantly shorter longevity. The studies indicated that the ‘new and improved’ materials based on in vitro tests did not always show enhanced clinical properties. In the last study, where clinicians freely selected the restorative materials they used in their practices, seven used COM, one used conventional GI materials and one used a combination of the two types of material.