Peri-implant Tissues on the Galimplant Anti-rotational Slim Abutment.

A dental implant is an alloplastic material surgically inserted in a residual bone ridge, mainly with a prosthetic foundation. Nowadays the most widely used implants and with a higher degree of scientific evidence are the titanium root-form endosseous implants. In addition to the root component, the prosthodontic systems that allow the crown to be connected to the implant are very important. The aim of this project is to compare a classic anti-rotational straight esthetic multi-position attachment with the new anti-rotational straight esthetic slim multi-position abutment, both placed at the time of implant surgery. A multicenter randomized single-blind (for the patient) split-mouth randomized clinical trial will be performed to compare the composition, distribution and structure of the peri-implant tissues around the classic straight (control) and Slim (test) intermediate prosthetic abutments of the manufacturer Galimplant (Sarria; Lugo, Spain). The objective is to study which abutment design obtains a better biological seal from the clinical and histomorphometric point of view. For this purpose, 60 dental implants will be placed for the replacement of bilateral posterior absences in 30 patients attending the Master of Oral Medicine, Oral Surgery and Implantology of the University of Santiago de Compostela, Spain.

Throughout implantological history there have been many proposals and modifications in terms of anchorage system, shape, materials, etc. In this project we intend to compare a classic anti-rotational straight esthetic multi-position attachment with the new anti-rotational straight esthetic slim multi-position abutment.

This will hypothetically allow to increase the contact surface of the peri-implant connective tissue, increase the adhesion and sealing power, improve the biological width and consequently minimize the risk of peri-implant diseases such as mucositis and peri-implantitis.

In this regard, we must analyze the healing process of the peri-implant soft tissue after surgery, which will result in a stable peri-implant mucosa. After surgery, soft tissue healing around the transmucosal portion of an implant begins with the formation of a blood clot and the induction of an inflammatory process aimed at tissue formation and remodeling. If that soft tissue formation and remodeling is adequate, the healing process will result in an effective attachment mucosa around the transmucosal portion of the implant.

To obtain this adequate peri-implant mucosa, it is very important that a proper healing process takes place. This process includes the recruitment of inflammatory cells and a process of angiogenesis; and if both processes are correctly developed, all the phases of mucosal healing (hemostasis, inflammation, proliferation, and remodeling of the collagen matrix) will occur successfully.

Eligibility Criteria:
Inclusion Criteria:

* Patients who meet all the inclusion criteria and none of the exclusion criteria will be informed verbally and in writing about the study and will sign the informed consent form provided for their participation.
* Systemic conditions favorable for the performance of oral surgical procedures (ASA I/II).
* Not to be completely edentulous
* Bilateral absence of at least two teeth (one per hemimaxillary) in the posterior area (from the first premolar to the second molar) with or without free distal ends.
* That do not require regenerative techniques
* That allow the placement of Galimplant implants of 4.5 or 5 mm in diameter in edentulous areas with mature bone of at least 3 months healing time
* With a prosthetic space of at least 8 mm.
* In case of odd absences, a slim abutment will be placed, being the group to be tested always in the majority.

Exclusion Criteria:

* Presence of any disease, condition or medication that may compromise the healing and/or osseointegration of dental implants (uncontrolled diabetes mellitus, immunosuppression, administration of bone modifying agents (BMA). Presence of any severe mental disorder, and patients who have received head and neck radiotherapy during the previous 18 months.
* Patients who do not have sufficient peri-implant keratinized gingiva to allow at least 1 mm of residual gingiva after excision of the tissue under study.
* Esthetic edentulous areas of 13-23, Implants with primary stability with ISQ \< 50 or \<40N, or with abutments that cannot receive torque at 30N are excluded.