Teeth cleaning, which is called dental scaling in medical science, means to use the cleaning instrument to remove supragingival calculus, plaque and stain, polish the tooth surface, so as to delay the re-deposition of plaque and tartar. People who have bad oral hygiene, calculus in the oral cavity, halitosis and suffer from gingivitis and periodontitis need teeth cleaning. It is the main treatment method for gingivitis, and also the first step in the treatment of periodontal disease.