Bailit H L, Chiriboga D, Grasso J, Willemain T R, Damuth L
Med Care. 1979 Jul;17(7):780-6. doi: 10.1097/00005650-197907000-00008.
The length of time amalgam restorations last before replacement was investigated for use as an intermediate outcome measure in utilization review and quality assurance studies. Based on record data from 37 general dental practices, a determination was made of the average percentage of two- or three-surface amalgams receiving another service at 6, 12, and 24 months from the date of insertion. After 2 years, approximately 13 per cent of the amalgams were replaced, and the estimated median life time for amalgams was between 10 and 14 years. The variation in replacement rates among practices was substantial but was not explained by the technical quality of restorations or several practice characteristics.
