O comportamento clínico dos implantes extra-estreito de diâmetro de 2,9 mm: um estudo prospectivo

Abstract

Smaller diameter implants were designed to rehabilitate small mesio-distal spaces and for cases of bone atrophy. Commercially, implants of 3.25 to 3.5 mm in diameter are found. It happens, however, that in some clinical situations, given the specific characteristics of patients whose teeth are genetically very narrow, or due to severe buccal resorption of the ridge, these 3.25 to 3.5 mm diameter implants become clinically unfeasible, invariably leading to the indication of grafts and/or complex orthodontics. These borderline cases led some manufacturers to develop even narrower systems, and it was then that implants considered to be extra-narrow (≤3.0 mm) appeared, such as the Direct from NobelBiocare or the Titanium zirconium alloy narrow-diameter implants from Straumann. In Brazil, with the same purpose, Neodent developed Facility, commercially launched in 2013. It is indicated to replace single elements in regions with little masticatory effort or under overdentures. The differential used by this company to preserve its mechanical strength and not be produced in a single piece (as is the case of Direct by NobelBiocare), was to remove the internal threads and use a ”Morse” type joint without an internal screw. However, it is necessary to understand the biomechanical behavior of these implants to ensure their good clinical indication. Thus, the aim of this study was to evaluate the clinical behavior of implants with a diameter of 2.9 mm (Facility, Neodent, Paraná, Brazil), through a prospective randomized clinical study. Clinical behavior was evaluated after installation of overdenture-type prostheses under 2 implants in atrophic maxillae and single implants in reduced three-dimensional space (upper lateral incisors and lower incisors) with a 2-year follow-up. In the proposed overdenture treatment with two extra-narrow implants, the results show that the installation of two extra-narrow implants improved masticatory performance, bite force and quality of life for patients. In the group that received implants in single spaces, the results showed that these can be indicated for places with little masticatory effort and that the 2.9 mm diameter implants (Facility, Neodent, Paraná, Brazil), had behavior similar to those larger diameter implants.