A healing abutment is a small metal cap placed on the dental implant. In dental implant treatment, a healing abutment is first placed on the implant. The top of the healing abutment is exposed in the oral cavity, while its body penetrates the soft mucosal tissue. During the implant treatment, the healing abutment is temporarily removed and replaced into several times until the prosthesis is delivered. During these procedures, the clinician can always observe the contaminated surface of the healing abutment.

Although the clinician cleaned the contaminated healing abutment with conventional cleaning methods such as mechanical wiping with disinfecting clothes or ultrasonic bath for 10–60 min in alcohol or water before replacing it again, the surface remains dirty after cleaning. Thus, new cleaning method using a detergent and a strong solvent was developed to clean the contaminated surface [1]. Although this new method can effectively clean the surface, the perfect cleaning was not achieved. In addition, the procedure of this cleaning method is neither simple nor safe.

Peri-implantitis, an inflammatory destruction of the tissues around the implant, is a big clinical problem in dentistry. Colonization of bacterial biofilm on dental implant surface is scientifically accepted as the main reason for peri-implantitis [2, 3]. Hence, most of the treatments for peri-implantitis are based on the treatment of periodontitis [4]. However, the form and surface structure of the dental implant and the tooth differ greatly. Current implant surface is not smooth because of being modified to enhance osseointegration. Biofilm tightly adheres to the implant’s rough surface. Furthermore, the implant has threads and grooves. These features make the mechanical cleaning imperfect [5].

Most of the current decontamination methods have been focused on the elimination of the bacteria without any physiochemical alteration of the implant surface or removal of the organic contaminants that tightly adhered to titanium surfaces [6]. Interestingly, an innovative approach to disinfect the implants by electrolysis has been recently reported [7]. This alternative minimally invasive approach effectively reduced the number of viable microorganisms on the dental implants. Pure water can be decomposed into hydrogen and oxygen. At the cathode, water is decomposed into hydrogen and hydroxide ions, which creates an alkaline environment of high pH. At the anode, oxygen and protons are generated producing low pH condition. In addition, oxidative substances are formed depending on the material of the electrode [8] and current/voltage.

Recently, disinfection of biofilm-contaminated implant surfaces with low direct currents has been reported [9, 10]. In these previous studies, electrolysis was applied to kill or remove the bacteria forming the oral biofilm. Charging the implant afflicted by bacteria with current or voltage is extremely effective in particular concerning the removal of organic residues still adhering on the material after the bacteria have been killed. The purpose of the present study was to examine the effects of electrolysis on cleaning the contaminated healing abutment surface and to detect the optimal condition for cleaning the contaminated surface.