The influence of the mucosal sealing around Laser-Lok abutments in the onset and progress of induced peri-implantitis in mini-pigs

Abstract

Background: Since the first description of osseointegration in 1977, oral rehabilitation with dental implants has become a successful possibility. Changes on the surface of implants have shown promising results in their ability to promote biological effects that influence cell adhesion and growth. In addition, alterations on the surface of the abutments, appears to bring the additional benefits. the Laser-Lok® abutments for example, contributes with a shorter junctional epithelium plus oblique and/or parallel orientated supracrestal connective tissue fibers in the direction of the implants, thus it could be suggested that this could influence the onset and progression of peri-implantitis. Objective: The present study will investigate if the shorter and oblique and parallel disposition of the subcrestal connective tissue fibers seen in the presence of the Laser-Lok® microchannels, can influence the onset and/or progression of ligature induced periimplantits in comparison to longer junctional epithelium and parallel fibers associated to smooth abutments. Materials and Methods: Two mandibular premolars and the first molar of 9 mini pigs will be extracted during flapless surgeries and 3 immediate implants will be installed in each hemi-arch with immediate provisionalization. In addition to the platform-switching design, implants will be modified using either only RBT or RBT and Laser-Lok® surface applications. One hemi-mandible will randomly receive Laser-Lok® implant and Laser-Lok® abutments and the opposite hemi-mandible will receive RBT implants and smooth surface abutments. Finally, eight weeks later ligatures will be placed to induce peri-implantitis. Eight weeks after inducing, the minipigs will be euthanized and specimens of interest will be separated and properly prepared for the analysis by histomorphometry using light microscopy and polarized light microscopy and highresolution Xray phasecontrast microtomography. For the latter, the blocks containing the implants will be sectioned longitudinally (MESIO-DISTALLY) and transversally. Results: Bone remodeling and inflammatory response will be evaluated through radiographic and histomorphometry analysis. (AU)