Horizontal bone augmentation procedures are commonly used to increase bone width to allow the placement of dental implants or to improve aesthetics in deficient areas. Smaller diameter implants could be used instead in order to avoid bone augmentation procedures.

The comparison between these two solutions will be evaluated in the trial.

Inclusion Criteria:

• Upper central incisor edentulism
• bone width between 3.5-4.5 mm
• requirement of only one implant supported crown
• patient is willing to sign an informed consent

Exclusion Criteria:

• General contraindications to implant surgery.
• Immunosuppressed or immunocompromised patients
• Patients irradiated in the head and neck area.
• Patients with poor oral hygiene and motivation.
• Uncontrolled diabetes.
• Pregnancy or lactation.
• Addiction to alcohol or drugs.
• Untreated periodontal disease.
• Treated or under treatment with intravenous amino-biphosphonates.
• Poor oral hygiene and motivation.
• Psychiatric problems and/or unrealistic expectations.
• Acute infection (abscess) or suppuration in the area intended for implant placement.
• Patients referred only for implant placement if cannot be followed at the treatment centre.
• Patient unable to attend the follow-up controls for 3 years after implant loading.
• Patient included in other studies, if this protocol cannot be properly followed.
• Immediate post-extractive sites (to be eligible at least 3 months must have passed since extraction).