Fat Transfer would be a permanent type of implant and filler that could be your option. They are natural, from your own body, take on the characteristics of the tissue that you inject them near, have less chance of reactions, and are not foreign. Depending on what you need exactly, other fillers can also help, including silicone implants that are placed around your mouth.
Silicone injections, however, are something that I would stay away from as they are hard to remove and once they’re in, they are permanent. I don’t do silicone injections and don’t plan on ever doing them. Other dermal fillers can improve your lips appearance but again, as you probably know, they are not permanent and last 6 months to a year.