An analysis of durability data on post and core restorations.

An attempt was made to review the dental literature since 1970, presenting clinical data of posts and core restorations, by the use of a meta-analytic procedure. Fourteen publications were found that contained durability data on post and core systems. According to the exclusion criteria 11 studies were excluded for further analysis of the data. The survivals of these studies varied from 98.6% survival after a follow-up period of more than 10 years (F.S. Weine et al. 1991, J. Endodont. 17, 293-297) to 77.6% survival after a mean follow-up period of 5.2 years (D.H. Roberts, 1970, Br. Dent. J. 128, 117-124). The data of the three selected studies were reconstructed according to the method of Kaplan-Meier but could not be combined for an overall survival assessment because the study characteristics were too heterogeneous. Therefore the survivals were presented separately. The reconstructed survivals of the studies after 6 years were 81% survival (standard error 6%) for resin composite build-ups in combination with screw posts and 91% survival for two studies including cast posts and cores (standard errors respectively 3% and 2%). Although it was not meaningful to combine the data for an overall survival, the meta-analytic method of this study revealed homogenic survival data and as such the followed procedure is considered to be an appropriate method to obtain insights in clinical durability data.