Cost benefit analysis of direct posterior restorations

A clinical study was conducted in which three operators made 232 Class I and Class II composite and amalgam restorations in a group of 49 adult patients. The time for different parts of the operative process was measured. The time periods were analysed as to the influence of the factors operator, tooth type and number of surfaces, by an analysis of variance (ANOVA). Results show that the various factors have a significant influence on the total treatment time. The treatment time for amalgam restorations is equal to the treatment time of composite restorations. The productivity of making restorations from the 'best' available amalgams, i.e. the amalgam with an extrapolated half-life time of more than 20 yr, turns out to be more than 3-4 times better than that of the 'worst' amalgams (half-life time 4 1/2-8 yr) and more than two times better than that of making restorations of the best composite material, used in this study (extrapolated half-life time of Estic MF is 10 yr).