Background Nowadays, peri-implantitis, a destructive inflammatory process around implants contributing to bone loss, has become the main reason for implant failure. Bacterial colonization and subsequent plaque formation on the implant surface is one of the main factors causing peri-implantitis. Totarol is a kind of natural biocompatible antibacterial agent, with bactericidal effect towards a wide range of gram-positive, even antibiotic-resistant bacteria, including the methicillin-resistant S. aureus. Aim/Hypothesis This in vitro study aims at applying totarol coatings on experimental dental implant and abutment surfaces and investigating the antibacterial capability of totarol coatings in a simulated oral environment. Material and Methods After ultrasonic cleaning with 70% ethanol, highly polished Ti disks (D = 10 mm) are coated with totarol by spin coating. Column chromatography-purified totarol dissolved in ethyl acetate solutions (20 mg/ml) is coated on Ti disks. Ti disks (n = 6 group) with and without totarol coating are incubated in an S. gordonii-suspension in Schaedler medium or in a mixed oral bacteria suspension in Schaedler medium (start OD λ=620 nm = 0.54) in a stirring system (each cycle including pause for 60 min and stirring for 15 min in, 37°C incubator) simulating the eating and resting period in human oral environment. The incubated Ti disks were harvested after 4 h, 8 h, 24 h, 48 h of incubation, respectively, then went through Live Dead staining for testing the vitality and through crystal violet staining for quantifying the amount of surface-bound bacteria. One-way ANOVA was used to analyze differences of the quantity of surface-bound bacteria between totarol coatings and control group. Results Approximately all S. gordonii and all mixed oral bacteria bound onto the totarol surface are red stained compared with the green stained live bacteria in the Ti control group after 4 h, 8 h, 24 h incubation (Fig. 1). This implied a contact killing effect towards S. gordonii and the mixed oral bacteria at a different stage of biofilm formation. Furthermore, crystal violet staining shows a significantly lower density of bacteria (P < 0.05) on totarol compared with the control, indicating an inhibition effect of totarol coatings towards the S. gordonii and multi-species oral biofilm growth (Fig. 2). Conclusion and Clinical Implications The natural antibacterial totarol coating showed promising bactericidal effects towards the early oral colonizer S. gordonii and the multispecies oral bacterial culture, and simultaneously significantly inhibits their biofilm growth. This might favor the undisturbed formation of a tight epithelial seal and prevent bacterial infiltration. Therefore, totarol coatings on dental implant and abutment surfaces showed great potential for the reduction or prevention of bacterial caused peri-implantitis.