When missing tooth structure or teeth are replaced, minimal biologic risk should be involved to re-establish function and esthetics. The increased use of the adhesive technique and preservation of dental tissues have greatly impacted conservative tooth preparation design. The development use of zirconia technology and all-ceramic systems has opened the potential for fabrication inlays zirconia bridges with durability and good aesthetics.

The purpose of this study is to clinically evaluate the placement of inlay bridge made of a Y-TZP framework veneered with a pressed ceramic and bonded with a completely adhesive approach in the replacement of a single missing tooth.

This study evaluates the use of inlay bridge made of Zirconia and all ceramic systems with three designs in the replacement process of one single tooth (i.e. a missing premolar or molar.) The first design is going to be fabricated with CAD/CAM Zirconia and the occlusal surface from e-max press.

The second design is going to be fabricated with CAD/CAM Zirconia and the occlusal surface from e-max press and the internal surface coated with glaze layer to improve the adhesion.

The third design is going to be fabricated with CAD/CAM Zirconia and the occlusal surface from e-max press and the internal surface coated with a layer of e-max ceramic press to improve the adhesion.

Inclusion Criteria:

1. Good oral hygiene
2. Low susceptibility to caries
3. Parallel alignment of abutment teeth
4. Immobility of the abutment teeth
5. Minimum height of abutment teeth ≥ 5 mm (connector thickness)
6. Maximum mesio-distal extension of the inter-dental gap of 9 mm (width of premolar) or 12 mm (width of molar)

Exclusion Criteria:

• Severe para-functional habits.
• Short clinical crowns (<5 mm)
• Extensive defects of the clinical crown,
• Loosening of teeth because of factors related to the periodontal tissues.