Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Works With Oral-B "Professional Care" and "3D Action Plaque Remover" Models

My dental hygienist recommends replacing the brush heads on an electric toothbrush at least once every six months. It was getting expensive, buying brush head replacements at a local drugstore, so I checked Amazon and was happy to find these reasonably priced ones. They fit my Braun Oral-B "3D Action Plaque Remover" model, and they also fit my husband's Braun Oral-B "Professional Care" model.Over a couple of years, neither of us have had a single problem with these brush heads. We replace them when the blue indicator bristles signal that the brush head needs replacing (when the bristles have turned to half-white, half-blue). This is usually about 5-6 months after the brush head is installed.When you order these ORAL-B PROFESSIONAL PRECISION CLEAN replacement brush heads, you get a tall, slender, sealed retail package with the Oral-B brand on it. The package contains 4 replacement brush heads.