Hello, you have reached the dental office of Dr. X. We are busy assisting a patient now, but will call you back as soon as possible. Please leave your name, reason for calling, and your number. If this is an urgent enquiry, please call 911. In this case, the dentist is giving a reason for not being available and they’re providing a way to prioritize the patients who need the most help. They’re also leaving an emergency number for the most severe of situations.
Using concise and simple words in your scripting helps ensure callers can comprehend what is being said. Although a complete on-hold message can be quite lengthy, it should include concise and to the point single messages. Aim to get each message across in around 35 to 40 words. Remember, what may read great in written word doesn't necessary sound great said out aloud.

Whether you’re out for the day or are off for the week, the first rule of an out of office voicemail greeting is: let callers know when you’ll be back! You’ll save them the frustration of continuing to call and yourself the hassle of listening to redundant voicemails. It’s also a good idea to set the expectation of whether you are answering messages while you’re away, and who they can reach for assistance in your absence.
13. “Hi, you’ve reached [company]. We’re available by phone from [hour] to [hour] [time zone] Monday through Friday [optional: and from hour to hour on the weekends]. You can also contact us by going to our website, [URL], and live-chatting or emailing us. If you’d like us to call you back, please leave your name and number after the beep.”