Inclusion Criteria:  Informed Consent signed by the subject Presence of one or more bone level titanium implant prior to insertion of the final restoration No systemic illness No heavy smoking (smoking <10 cigarettes/day) No pregnancy No active periodontitis (probing pocket depth ≤4 mm) No pharmacological treatment or antibiotic therapy during or up to three months before the study  Exclusion Criteria:  Systemic illness (e.g. Diabetes) Heavy smoking (smoking >10 cigarettes/day) Known or suspected non-compliance, drug or alcohol abuse Pregnancy Active periodontitis (probing pocket depth >4 mm) Pharmacological treatment or antibiotic therapy during or up to three months before the study