Same-day CEREC crowns are an excellent option for people who are short on time. They would rather get a great crown in one visit to the dentist rather than two or more visits.  That said, there are instances when placing a permanent crown on a tooth undergoing treatment is not the best option for that patient. For example, if your tooth has extensive decay, is cracked, or is sensitive to biting, etc., getting a temporary crown placed on this tooth will allow your dentist to confirm whether you need root canal therapy before the permanent crown placement.  If you have received the permanent crown already, your dentist will need to drill through your permanent crown to do the root canal treatment. To prevent instances like this, at 905 Dental, we examine the tooth thoroughly and ensure that it is ready to take a permanent crown before we bring the patient in for a permanent crown.