Dental implants may suffer from bone loss around them, particularly at the upper portion where the prosthesis starts. The connection between both parts of the tooth restoration is key for avoiding micromovement during chewing, bacterial contamination and initiation of bone loss. Thus, investigating factors related to this bone loss in different types of implant-prosthetic connections is key for promoting better use of available therapeutics devices. In this study, we will study marginal bone levels over time as well as bacterial contamination and inflammatory markers in the peri-implant sulcus around implants with connical connection and compare them with those obtained when using implants with internal hexagonal connection. The hypothesis is that bone loss will be higher in implants with hexagonal connection associated with a pathological microbiome in the sulcus that induces a higher inflammatory response.

Inclusion Criteria:

• One missing tooth in the premolar or molar area with both opposing and adjacent teeth (mesial and distal).

Exclusion Criteria:

• One-stage bone augmentation.
• Uncontrolled type 1 or 2 diabetes (HgA1c>8).
• Known auto-immune or inflammatory disease.
• Severe hematologic disorders, such as hemophilia or leukemia.
• Local or systemic infection that may compromise normal healing (e.g., extensive periapical pathology).
• Liver or kidney dysfunction/failure.
• Currently receiving cancer treatment or within 18 months from completion of radio- or chemotherapy.
• Long-term history of oral bisphosphonates use (i.e., 10 years or more).
• History of intravenous bisphosphonates.
• Long-term (>3 months) history of antibiotics or drugs known to alter the inflammation and/or immunological system 3 months before inclusion.
• Severe osseous diseases (e.g., Paget disease of bone).
• Pregnant women or nursing mothers.
• Not able or not willing to follow instructions related to the study procedures.