Review on 🦷 10-Pack Jiuzhoudeal Replacement Toothbrush Heads for Philips Sonicare C2 Plaque Control ProtectiveClean 4100 5100 6100 Electric Toothbrush HX9023 by James Beird

Despite the product description, the bristles are NOT rounded. I changed the toothbrush head to Jiuzhoudeal and found my gums were sore the next day. When I pulled out the microscope to check the bristles, they were indeed square and sharp. See photo. In the first picture of the Jiuzhoudeal fiber, notice the square ends. In the second picture, the real Sonicare head: see how gently the tips are rounded? This is what a toothbrush should look like. If you have bulletproof gums these toothbrush heads will likely work for you, but for most people there are better alternatives that are less harmful to your gums. At least for me the difference is significant.