A controlled clinical study of amalgam restorations: survival, failures, and causes of failure.
The survival and modes of failure of amalgam restorations were investigated retrospectively. 2660 Class I or II lesions were restored and evaluated yearly or half-yearly for failures during the 30- to 84-month follow-up. Restorations with unacceptable margins were not counted as failures if no traces of secondary caries could be seen. 8% of the restorations were lost because of patient drop-out. Of the remaining restorations, 1% was replaced due to primary caries. Of the remaining number (2431), 9% failed because of all other reasons. The leading mode of failure was bulk fracture (4.6%), followed by tooth fracture (1.9%), and marginal ridge fracture (1.3%). For all other reasons, 0.8% of the restorations failed. Only two restorations were replaced because of secondary caries. The alloy selection in both conventional and high-copper categories significantly influenced the survival of the restorations for reasons directly related to the restoration.
Letzel
H
H
van 't Hof
M A
MA
Vrijhoef
M M
MM
Marshall
G W
GW
Marshall
S J
SJ
D003723:Dental Amalgam; D003793:Dental Restoration, Permanent / Q000706:statistics & numerical data*; D005069:Evaluation Studies as Topic; D005500:Follow-Up Studies; D006801:Humans
D003723:Dental Amalgam