While orthodontists can do all the things dentists specialize in and sometimes do things like tooth repair, x-rays, and denture modeling, orthodontic practice focuses primarily on teeth alignment. Dentists, also known as general (or family) dentists, are concerned about overall oral health. Dentists treat decayed teeth (fillings) and remove defective teeth (extractions). They usually provide services such as crowns, veneers, or adhesives to improve the appearance and function of teeth that have extensive decay, or that are deformed or broken.
Dentists look for abnormalities in the mouth and teach patients how to prevent dental disease. Only orthodontists have two or more additional years of orthodontic education from a program accredited by the Dental Accreditation Commission, which provides them with specialized training in tooth movement. Orthodontists are specialists who focus on biting: how teeth come together and work, how they are aligned, how they are placed in the jaws, and the position and size of the upper and lower jaws. However, what the orthodontist is responsible for if you have a cavity is to remove any support or band you may have on the tooth that contains the cavity so that the dentist can fill the cavity properly.
Similarly, a dentist can provide braces or aligners to move your teeth, but that doesn't mean the dentist is an orthodontist.