Effect of Different Finish Line Designs on Vertical Marginal Gap Distance of Two Types of Zirconia Ceramic Restorations (In-Vitro Study)

Background: Recently, ceramic restorations have gained popularity in dentistry due to their superior optical, mechanical, and aesthetic properties. They are known for their biocompatibility, low thermal conductivity, higher abrasion resistance, and shade stability. Aim of the study: To evaluate the vertical marginal gap distance of two types of ceramic materials KATANA Zirconia “Yttria-stabilized tetragonal” and IPS e.max ZirCAD Prime “Gradient zirconia’ using three different finish lines designs chamfer, shoulder and featheredge. Materials and methods: A total of 30 crowns will be constructed. The number of samples will be divided into two groups according to materials (tetragonal and gradient zirconia) (n=15), Each group will be further sub divided into three subgroups (n=5) according to type of finish line (chamfer, shoulder, featheredge). Vertical marginal gap distance will be examined under digital microscope using equidistant points standardized for all samples. Results: Tetragonal zirconia group “KATANA Zirconia” (10.06±1.87) and Gradient zirconia group “IPS e.max ZirCAD Prime” crowns had no statistical difference and were within the clinically acceptable level for vertical marginal gap distance which was (12.15±3.15) with chamfer. While in shoulder Katana was (13.92±1.48) and IPS e.max ZirCAD Prime was (16.61±2.03) and featheredge finish line for Katana zirconia (62.75±9.12) and IPS e.max ZirCAD Prime was (30.88±5.55). Conclusion: Tetragonal and Gradient zirconia crowns showed a clinically acceptable level of VMG. While finish line designs chamfer and shoulder showed VMG readings with least measurements while featheredge finish line showed higher VMG measurements.