Twelve participants with edentulous alveolar crests in the distal portion of the arches will be included in the study. At least two implant sites will be identified in each patient and will be sub-prepared with drills or sonic instruments. One site will be used as a test and one as a control where experimental mini-implants will be installed. Reconstructive surgical procedures will be applied at the biopsy sites.

Objective: - To evaluate histologically the influence of the functional load on implants, both immediate and delayed.

Material and methods: 12 participants with edentulous alveolar crests in the distal portion of the arches will be included in the study. At least two implant sites will be identified in each patient and will be sub-prepared with drills or sonic instruments to obtain a high degree of torque to ensure optimum primary stability. At least one site will be used as a test and one as a control where experimental mini-implants will be installed. Test sites will be loaded immediately. The control sites will remain unloaded. After 2 months, mini-implants will be recovered as planned for each group. Reconstructive surgical procedures will be applied at the biopsy sites, if necessary, using autologous bone or bone substitutes and membranes. Standard implants will be installed during the same surgical session and, after 2 months, the planned prosthesis will be performed. Patients will be followed for at least 2 years for evaluation and intervention, if necessary.

Biopsies will be included in resin to obtain wear cuts for histomorphometric analysis. The bone histomorphometry will be evaluated and statistical analysis will be carried out.

Inclusion Criteria:

• Adult participants (≥25 years of age) with the need of at least two implants to replace teeth of the jaw will be included.
• Natural antagonist teeth have to be present both at test and control sites to guarantee occlusal contacts

Exclusion Criteria:

• untreated rampant caries or uncontrolled periodontal disease of the remaining teeth
• diabetes not controlled diabetes or any other systemic or local disease that could compromise postoperative healing and / or osseointegration
• need for systemic corticosteroids or any other medication that could compromise postoperative healing and / or osseointegration
• inability or unwillingness to return to follow-up not likely to be able to comply with the study procedures according to the judgment of the investigators
• pregnancy

patients with edentulous spaces

there is a plan to save all the data to do the follow up

One of the researchers , neither involved in the selection of the patients nor in the surgical and prosthetic treatment, will carry out electronically the randomization (randomization.com). Will be prepared sealed opaque envelopes and opened at the time of surgery.