[Studies on the composite joint in Cerec inlays]

In an in vitro study 32 ceramic restorations were constructed using the Cerec system and adhesively fixed in cavities prepared in extracted teeth with Dual Cement according to the supplier's instructions. The restored teeth were then histologically prepared and the joints between cement and inlay morphometrically evaluated at eight defined sites. The measurements showed average values of 118 microns with a standard deviation of 53 microns. It is particularly interesting to note the extremely great range of variation between the lowest and the highest value. The measured widths of the joints must be considered as a weakness of the system, because clinically they may result in wash-outs and material collapses in the long run. So far, no long-term studies have been conducted yet to investigate this effect.