Final answer:
To dismiss a patient from a dental practice, a written explanation is legally necessary, providing reasons for the dismissal. While not legally required, notifying the patient's insurance company and offering a referral to another dentist is considered good practice.
Step-by-step explanation:
The legally necessary requirement to dismiss a patient from a dental practice is to provide a written explanation. This explanation should clearly outline the reasons for the dismissal, including any breaches of patient behavior or failure to comply with treatment plans. While it is not legally required to notify the patient's insurance company or offer a referral to another dentist, it is considered good practice to do so.