60 bridge frameworks are CAD/CAM manufactured from zirconia-ceramic; 30 bridges are veneered with CAD/CAM fabricated lithium disilicate ceramic, 30 bridges are manually layered. The goal is to compare clinical survival , biological or technical behaviour of the restorations.

Randomized prospective controlled clinical study with three-unit posterior bridges made of zirconia-ceramic to compare veneering with manually layering or CAD/CAM fabricated lithium disilicate ceramic veneers. The hypothesis is that there is no difference in clinical survival of the restorations and no difference in biological or technical behaviour.

Inclusion Criteria:

• single missing posterior tooth with two adjacent posterior teeth
• no acute conservative or paradontal treatment need except for the teeth to be treated in the study
• sufficient oral hygiene

Exclusion Criteria:

• known allergies to components
• bruxism
• missing antagonist tooth
• pregnancy or lactation
• missing written consent
• patients which are not expected to be compliant
• severe systemic diseases
• untreated carious lesions
• untreated parodontitis