Together with materials and type of retention, the stability of the implant abutment connection represents one of the key factor for the success rate of an implant supported restoration. The recent diffusion of high quality and easy to use CAD/CAM systems has contributed to market launch of a number of competing companies that offer the so called "clonical" or "compatible" restorative components. Although they are claimed to be identical, the original abutments are supposed to present maximum accuracy and consequently lower microleakage.

The aim of the present randomized controlled trial will be to analyze the implant abutment junction stability comparing implant-supported crowns restored with original components and compatible non-original abutments.

The hypothesis is that original components will present significantly better stability than non-original abutments.

Inclusion Criteria:

• Any healthy patient scheduled for an implant-supported restoration will be considered for inclusion in this study, independently of the implant and prosthetic protocols used.

Exclusion Criteria:

• general medical contraindications to oral surgery (American Society of Anesthesiologist, ASA, class III or IV),
• patients <18 years of age,
• smoking habit (>10 cigarettes/day),
• sites with acute infection or requiring regenerative procedures,
• Full Mouth Plaque Score
• Full Mouth Bleeding Score >25 %,
• pregnant and lactating.

The devices will have the same shape and will be delivered to the surgeon unlabeled in an identical sterile envelope.