The distribution of marginal excess cement of implant-supported vented and non-vented zirconia crowns with and without cleaning procedures.

Abstract

To investigate the distribution of marginal excess cement in vented and non-vented crowns and evaluate the effect of clinical cleaning procedures on the reduction of excess cement. Forty models with implant analogs in the position of the right maxillary first molar were divided into four groups (n=10/group, vented/non-vented crowns with or without cleaning procedures). The abutment finish lines were placed 1mm below the artificial gingiva buccally, mesially, and distally and at the gingival level palatally. A standardized amount (20mg) of resin cement was applied in a thin layer to the intaglio surface of zirconia vented and non-vented crowns. The excess cement was removed by a dental explorer in groups with cleaning procedures. The distribution (area and depth) of the marginal excess cement was measured at each quadrant (buccal, mesial, palatal, and distal) for all study samples. The data were analyzed using descriptive and analytical statistics (ɑ=0.05). The area and depth values of the excess cement in each quadrant in the vented group were significantly smaller than that in the non-vented group, both with and without cleaning (p<0.001). Cleaning procedures significantly reduced the area of excess cement in both vented and non-vented groups (all, p<0.001 except for p<0.05 at the buccal aspect of the vented group). The depth of excess cement in the vented group was significantly decreased with cleaning in the buccal quadrant compared with that without cleaning (p<0.01). However, the depth of excess cement of the non-vented group was significantly increased with cleaning in all quadrants compared with that without cleaning (all, p<0.001 except for p<0.05 at the distal aspect). Crown venting significantly reduced the area and depth of the marginal excess cement in vitro. Cleaning procedure with a dental explorer significantly reduced the area of marginal excess cement in vitro; however, the excess cement can be pushed deeper in the non-vented group.