Placement of Dental crown is usually a two appointment procedure. There is gap of two weeks between the two dental appointments. In the first appointment, tooth which is to be covered by dental crown is anaesthetized and tooth is reduced to accurate dimensions. After selective grinding of tooth, impression is taken and then temporary dental crown is placed over it. It takes 25-30 minutes to complete tooth preparation. Impression is sent to the dental laboratory technician for fabrication of permanent dental crown. In the second visit, dentist will cement the finished dental crown in place. If dentist is having ceramic milling machine, then placement of dental crown can be done in single appointment procedure.
First dental appointment
Need of local anesthesia:
If RCT is not done in the tooth to be covered by crown, patient may experience pain due to sensitivity of dentin during tooth cutting. Also, when cutting is done around the tooth, pain is experienced in the adjacent gingiva. So, to allay this pain, tooth and its surrounding tissues are anesthetized before tooth reduction.
If root canal treatment is done in the tooth then there is no need to anesthetize the tooth because root canal treated tooth is not painful during tooth cutting. Although mild gingival pain may occur if tooth has to be reduced below the gingiva and if this pain is not bearable by the patient then topical local anesthesia has to be applied and preferably local anesthesia is injected in the surrounding tissues.
Need for Tooth Reduction
To create a space for the placement of dental crown, tooth has to be reduced.
Material used for crown fabrication should have certain minimum thickness for adequate strength and to bear the chewing forces.
Tooth to be covered by dental crown should retain its original dimensions and it should not be bulky otherwise supporting tissues of tooth may get inflamed.
After the tooth is reduced to its proper shape and dimensions, an impression of tooth is taken using a suitable impression material. It takes 5-10 minutes to take impression of tooth. Tooth preparation is done in such a way to ensure stability and retention of dental crown.
If there is loss of much of tooth structure, then dentist will firstly build up the tooth structure with a filling material before giving dental crown. Post and core procedure followed by dental crown may also be required in case of excessive loss of tooth structure.
Tooth Reduction before Giving Dental Crown
Impression taken after Tooth Preparation
After tooth preparation, dental impression is taken. Impression can be taken using impression material that is paste and putty like compound.
The impression is then sent to special laboratory where dental crown is fabricated by a dental technician.
Dental Crown fabrication in lab is completed in 7-14 days.
Placing Temporary Crown
Permanent dental crown is given after around 2 weeks of tooth preparation. By that time, temporary dental crown can be given to the patient. Temporary dental crown prevents sensitivity to hot and cold food stuffs to prepared tooth, prevent deposits and food accumulates around the prepared tooth and prevent the prepared tooth and teeth adjacent t prepared tooth from shifting. If it is front tooth, then it will provide esthetics.
Choosing shade of dental crown
If porcelain or porcelain fused to metal dental crown is to be given to the patient, then shade of porcelain is selected which closely resembles neighboring teeth color shade. Shade guide is used by the dentist to select the shade. Shade of the tooth is selected by the dentist with the patient’s consent.
Second Dental Appointment
In the 2nd appointment, temporary dental crown is removed, try in of permanent dental crown is done and it is then cemented over tooth. So, 2nd appointment is short and dental crown is cemented in 15-20 minutes.
Temporary Dental Crown Removed
Dentist will remove the temporary dental crown and will clean the remnants which may remain on the tooth after removal of temporary dental crown.
Try in of Permanent Dental Crown
Before cementation of permanent dental crown, dentist will do try in of permanent dental crown. Fit and appearance of dental crown is evaluated. Dentist will check whether the dental crown is seating properly or not.
Cementation of Permanent Dental Crown
If dental crown is seating properly, then cementation of dental crown is done. Luting cement is used for cementation of permanent dental crown. Excess of dental cement is scrapped off by the dentist.
Use of Ceramic Milling Machine (CAD-CAM Technique)
After tooth reduction, an optical impression of the tooth is taken which is displayed on computer screen. Dentist designs the crown using computer aided designing (CAD) and it is then transferred to ceramic milling machine and this machine prepares the crown from a ceramic block using computer aided machining (CAM). So, there is no need of any lab procedure and crown is fabricated and cemented in a single appointment. But crowns prepared by this technique are much expensive.
After getting permanent dental crown, patient has to take care of crown. Certain precautions need to be followed after getting permanent dental crown.