A contagion effect of caries on tooth surfaces in contact with each other has previously been demonstrated; the presence of a caries lesion on an approximal tooth surface increases the risk of developing caries in a sound contact surface on the adjacent tooth. Will this increased risk for caries development be eliminated when restoring the decayed surface with a restoration? A recent publication by the NIOM scientist Dr Kopperud has elucidated the question.
Several studies have been performed in order to assess the effect of different preparation designs for all-ceramic crowns, but the results are ambiguous. Most trials have found no or little effect of different design of the cervical finish line. The new method for clinically relevant testing of all-ceramic crowns developed at NIOM and the University of Bergen in 2012, and published in Dental Materials in 2013, has now been applied to assess one essential parameter of margin design: the curvature of the cervical margin over the gingival papilla.