The purpose of treatment for peri-implantitis is to achieve structural and functional restoration of the lost supporting tissues around implants, including re-osseointegration. Both surgical and non-surgical approaches in combination with a variety of anti-microbial treatment regimens have been applied depending on the size and shape of the bone defect. Tetracycline-HCl (Tc) treatment has been considered as a effective chemical modality for decontamination and detoxification of contaminated implant surfaces. The aim of this study was to examine if Tc conditioning changes the microstructures of the modified surface of dental implants. Dental implants with (1) hydroxyapatite-coated surface (HAS) (Replace® select HA, Nobel Biocare AB, Göthenburg, Sweden), (2) TiO2-blasted surface (TBS) (Astra TiOblast®, ASTRA Tech AB, Mölndal, Sweden) were used in this study. Tc treatment noticeably altered the surface of HAS and TBS. HAS and TBS were partially removed from the implant surface as early as 90 and 60 sec, respectively.