The purpose of this study was to evaluate the effect that microgrooved abutments may have on peri-implant tissues. After the flapless extractions of the mandibular premolars of eight dogs, four Laser-Lok implants were placed in each mandibular quadrant, and half of them received laser-microgrooved abutments. A xenograft (MinerOss X, BioHorizons) was used in the gaps. The dogs were euthanized 12 weeks after treatment, and the histomorphometric analysis was performed. Unlike the machined abutments, the microgrooved abutments influenced the orientation of connective tissue fibers, which appeared perpendicularly and adhered to the implant-abutment surfaces, preventing the apical migration of the junctional epithelium. Laser-microgrooved abutments showed superior results.