One Year Evaluation of Lava DVS and Lava Zirconia Crowns 

Method: Two clinicians placed 100 crowns (50 of each type) in 66 molars and 34 bicuspids for 77 patients.  The crown preparation was consistent with the principles for an all ceramic crown.  A Lava COS digital impression unit (3M ESPE) was used to record the preparation quadrant, opposing quadrant, and facial bite registration.  After necessary chairside adjustments the internal surface of the crown was lightly air abraded with 30 micron silica at 40 psi and cemented with a self-etching, self-adhesive resin cement (RelyXUnicem 2). Recall evaluations were at baseline, 6 months and 1 year.

Result: Tooth sensitivity was evaluated by report to cold stimulus. Three crowns of each DVS and Zirconia had mild to moderate sensitivity at one week with no sensitivity reported in either group after 2 weeks through 12 months.  The crowns were evaluated by two independent examiners using a modified USPHS rating. Both DVS and Zirconia groups had 100% alpha scores for margin adaptation, surface finish and absence of caries at baseline, 6 and 12 months. One DVS crown presented with localized margin discoloration at 6 and 12 months. One crown of each group presented with a polishable chip at 6 months; the chip on the DVS crown progressed to exposure of the coping, while the Zirconia crown remained the same at 12 months. Color match was >96% for both materials at all recall intervals. 

Conclusion: The Lava DVS and Lava Zirconia Crowns have performed similarly well with a self-etching, self-adhesive cement at one year. This study was supported by a grant from 3M ESPE.