The effectiveness of amoxicillin in treating periodontitis is very limited. It is true that periodontitis is a periodontal lesion caused by bacterial invasion, but the best treatment for this lesion is not the application of medication, but the removal of the causative factors of periodontal disease. Generally, periodontal disease is a chronic and destructive disease of the periodontium caused by poor oral hygiene and the presence of large amounts of plaque and calculus. The basic periodontal treatment, which generally includes supragingival scaling, subgingival scraping, root planing, etc., allows us to achieve a healthier periodontium, so that we can try to control and keep periodontitis from developing. After cleaning the periodontium, you can consider applying some anti-inflammatory drugs for the periodontium, generally minocycline hydrochloride ointment is appropriate, and for oral drugs amoxicillin is not a better oral drug, generally for periodontitis, you can consider applying metronidazole for anti-inflammatory treatment, but the premise must first control the plaque and calculus of the periodontium.