Marginal Integrity of Different CAD/CAM Monolithic Ceramic Crowns with Vertical and Horizontal Finish Line Preparations

Purpose: Evaluate the marginal fit of different monolithic ceramic crowns for prepared teeth with vertical and horizontal finish lines. Materials & Methods: Sixty monolithic ceramic crowns were fabricated, divided equally into two groups: vertical finish line preparation design (VFL) and horizontal finish line preparation design (HFL). Each group was divided according to the utilized ceramic material into three subgroups (n=10). Subgroup {CZI}: Zirconia (Ceramill Zolid), subgroup {VE}: Hybrid ceramic (Vita Enamic) and subgroup {CD}: Zirconia reinforced Lithium Silicate (Celtra Duo). Vertical gaps of all ceramic crowns were measured at 20 predetermined points without cementation. Results: All marginal gap results lied within the clinically acceptable range. {VFL} Group: {VE}subgroup showed the lowest mean marginal gap followed by {CZI} then {CD}subgroups with statistically significant difference between {VE}&{CD}subgroups. {CZI} showed a non-significant difference with and {VE} and {CD} subgroups. {HFL} Group: {VE}subgroup showed the lowest mean marginal gap value followed by {CD} then {CZI}with a statistically significant difference between the three subgroups. All {VFL}, subgroups showed significantly higher marginal gaps compared to their corresponding subgroups in the {HFL} group.Conclusions: Both finish line preparations offered clinically acceptable marginal gaps for the 3 ceramic materials used, although each material presented significantly different marginal gaps with both preparations.