Surfaces of ceramic crowns are modified several times Background: before being exposed to wear in the oral cavity. Grinding and different finishing procedures may be associated with teeth wear due to increased surface roughness. Limited data is available with regard to the effect of polishing procedures on the surface roughness and wear behavior of ceramic crowns. This study was conducted to assess the influence of polished and polished-ground-repolished surface finish on the roughness and wear performance of three ceramic crowns.36 natural 1st molar teeth were prepared using a CNC milling Methods: machine and classified into three groups (n=12/group): zirconia,

Objective: to assess the amount of vertical and lateral gingival tissue displacement and recovery obtained by a retraction cord and Magic Foam ® paste. Material and Methods: twenty-two participants, requiring full coverage prosthesis in the anterior area, were prepared using a deep subgingival chamfer finish line, then randomly allocated to the retraction cord group (Group RC, n = 11 teeth) or the Magic Foam ® Paste group (Group FP, n = 11 teeth). The amount of lateral and vertical tissue displacement was measured by comparing the pre-and post-displacement casts at three fixed points (midbuccal, mesial and distal) using a stereomicroscope. After two weeks, tissue recovery was assessed by taking an impression using a double mix. The amount of tissue recovery was measured vertically from the gingival margin to the bottom of the sulcus and by comparing the results to the pre-displacement records. Results: there was no significant difference in the vertical gingival displacement (P > 0.05). However, there was significantly less lateral gingival displacement of the Magic Foam ® Paste in the mesial and mid-buccal surfaces only (P < 0.05). The Magic Foam ® Paste showed significantly more tissue recovery than the retraction cord (P< 0.05). Conclusion: both the retraction cord and the Magic Foam ® Paste are considered effective means of retraction as they give the least amount of retraction needed both laterally and vertically.