Results: SDF/KI exhibited a potent antibacterial effect, as represented by a significantly higher percentage of dead bacteria, in comparison with Carisolv and Papacarie (p < 0.05). The application of SDF/KI following Carisolv and Papacarie chemomechanical caries removel gels significantly reduced the viability of intra-tubular bacteria in these groups. Conclusions: The use of the silver diamine fluoride/potassium iodide product is effective in reducing the numbers of S. mutans in dentinal tubules infected with this organism.