Why do you have to see a general dentist before a periodontist? general dentist said nothing wrong with gums but saw a periodontist/got deep cleaning

Because: You don't necessarily have to see a dentist before a periodontist. You can make an appointment directly with the periodontist if you like. However, general dentists are a better choice to assess overall dental health including the periodontal structures.

Always periodontist: It is very important to see a periodontist if you experience any of the symptoms of gum disease. A periodontist is a dentist specializing in the prevention, diagnosis and treatment of gum disease and alveolar bone resorption.