What are dental implants is a common question. Dental implants are hard porcelain, custom made replacement teeth to fit with your existing teeth. They are fixed to a titanium screw which is screwed into the jaw bone. Dental implants are a permanent fixture which replace lost teeth. Dental implants prevent deformation of the jaw. In the old days false teeth were on uncomfortable mouth plates which wearers took out when food trapped between the plate and palate hurt and caused mouth ulcers.