Yes, I'm a big fan of them. Not many problems. They do have gaskets that fit over the retaining teeth. These gaskets can stain and dry out over time and need replacement every one to two years. When the time comes, you just remove the remains of the existing gasket and take an impression inside the existing denture around the abutment teeth. I really like to do them as immediates for lower arches where the patient has the remaining canines, but they aren't so strong that I feel comfortable doing a cast partial, but the patient could get some use out of them for a little longer. Most patients are happy to keep a couple of their own teeth and have the retention that it affords their denture. For some, it gives them time to save up for implants in the future. You adjust the underside of a cusil like any denture when sore spots develop under the hard acrylic. Cusils are not particularly aesthetic since the gasket is quite large and covers up a good portion of the abutment teeth. For lower canines it's not much of a problem. Good luck with them!