Ghada Mohamed Mahmoud Aly, Dawlat Moustafa Ahmed, Nancy Mamdouh Saad
Aims: the objective of the study was to assess the wear of primary teeth against three types of crown coverage, both quantitavely and qualitatively. Methods: specimens of 30 extracted primary molars, were mounted against 10 specimens of zirconia crowns (group A), 10 specimens of preveneered stainless steel crowns (group B), and 10 extracted primary molars and 10 specimens of stainless steel crowns (group C) and were undergone in vitro wear testing using an abrasive machine. Measurement of the amount of weight loss was performed, in addition to a scanning electron microscopic examination of the worn enamel surfaces. Results: the greatest wear was recorded in zirconium specimens, and the lowest was in preveneered stainless steel crowns with a significant difference noted between the three groups (p<0.001).The micro-morphological wear characteristics revealed the most aggressive wear with complete loss of enamel structure in zirconium specimens. Conclusions: the zirconium crowns induced the most severe wear in primary molars, followed by stainless steel crowns, and the least wear was induced by preveneered stainless steel crowns.