There are two different methods for external bleaching, the first is to have the dentist take impressions of the patients teeth so that custom trays (specifically for bleaching) can be made. When the trays are completed, you give the trays and a bleaching kit to the patient to take home so that they can bleach their teeth at home. The second is performed entirely in the dental office. This process takes about an hour from start to finish. While the patient is seated in an operatory chair the bleaching compound is placed directly on their teeth after some preparation to protect their lips and gum tissue. A high intensity light is directed at their teeth for approximately 30 minutes. The code for either of these types of bleaching is D9972 per arch or D9973 per tooth.

Internal tooth bleaching is a completely different process that requires access inside the tooth. A cotton pellet is soaked in the bleaching compound and placed in the center of the tooth and covered with a temporary filling material to seal the opening.
The patient keeps this material inside the tooth for approximately one week and then returns to the dental office to assess the results of the bleaching. This is coded using D9974 and it is billed out per tooth unlike external bleaching where it can be either per tooth or per arch.

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