Zirconia Kinder Krowns: Wear-Kind Finish
The way a dental laboratory finishes their zirconia crowns can have a significant impact on the esthetic outcome. There are generally two ways to finish a zirconia crown: glaze and/or polishing. Kinder Krowns are polished in areas that come into contact with the opposing dentition and then completely coated with a ceramic glaze. This proprietary, two pronged approach provides unmatched esthetics and wear-kind properties.
From an esthetics standpoint, glazed zirconia crowns have a natural “orange peel” texture that is found with natural dentition. A glazed surface acts as a “visual surfactant”. The light can penetrate, instead of bouncing straight back, and it actually refracts, giving the crowns a much more vital appearance. In crown and bridge dentistry we use this to our advantage. Some call it the “chameleon effect”. The light penetrates the surface, scatters internally, including into the adjacent teeth, helping the crown to blend in with its’ neighboring teeth. There is a significant difference in the appearance, and if you hold crowns next to each other with different finishes, it’s very noticeable.
On the other hand, polished zirconia takes on a metallic, mirrored, grey and pearlescent appearance. It causes the light to reflect off the surface and the restoration will lack depth and vitality. Simply polishing a crown has inferior esthetics in our opinion.
Recent studies have shown that a polished and glazed zirconia crown is less abrasive:
“Abrasion of prefabricated molar crowns in primary dentition” M. Möhn, S. Lücker, S. Amend, R. Frankenberger, N. Krämer
Methods: 96 extracted human primary molars were prepared, and randomly assigned to six groups (n = 16): Stainless Steel Crown (SSC, 3M™), Pediatric Esthetic Crown + Ketac Cem Plus (PEC+K, 3M™), Pediatric Esthetic Crown + RelyX Unicem 2 (PEC+R, 3M™), NuSmile® Zirconia (NSZ, NuSmile®), Sprig Crown (SC, Sprig Oral Health Technologies), and KinderKrown® Zirconia (KKZ, KinderKrown®). Following 2,500 thermocycles (Syndicad; + 5 °C / + 55 °C, dwell time 15 s), mechanical loading was performed in a chewing simulator (CS 4.8, SD Mechatronik; 100,000 cycles, 50 N, 1.67 Hz). Before and after thermo-mechanical loading, replicas were produced (Alpha Die MF, Schütz Dental), and wear depth was evaluated using a 3D laser scanning microscope (VK 9700, Keyence Germany GmbH).
Results: The following means of wear depth were measured (µm, [SD], ANOVA, mod. LSD, p0.05, X shows statistically significant differences):
You have a choice of which esthetic pediatric crowns you’re using in your office – once you give Kinder Krowns® a try, we know you’ll make the switch, if you haven’t already.
Comments are closed