Replacement heads for hy g ionic toothbrush the hy g ionic is clinically proven by studies at universities in the usa and japan to remove plaque up to 48 more effectively than ordinary manual brushing iontophoretic action improves the effectiveness of fluoride in toothpaste helping to reduce hypersensivity in teeth plaque is difficult to remove because it has a positive polarity while teeth have a negative polarity this opposite polarity naturally attracts plaque to your teeth