[An evaluation of completely ceramic crowns]

All-ceramic crowns (Cerestore by Johnson & Johnson) were made on premolars and molars following two procedures: the finishing line was a straight shoulder or a hollow chamber. In vivo replicas were made of the marginal zone on the buccal and on the lingual side. The replicas were studied with scanning electron microscopy. Results showed a relatively large variability in marginal discrepancy in the same crown margin ranging from 12.2 mm to 134.3 mm. In a second series of crowns even discrepancies up to 232.7 mm have been measured. The discrepancy slightly increased after cementation. Several crowns fractured during the try-on session. No crowns fractured after cementation in a six months' interval. The gingiva surrounding the crowns remained healthy. The esthetic results were sometimes poor due to the whitish core not covered by porcelain. This study suggests that the Cerestore crowns are acceptable as a solitary restoration in premolar and molar region but that both esthetics and marginal fit can be improved.