Besides shade, the technician also needs information about the shape, size and position of teeth, particularly when aesthetic or functional demands are high.

This information lies on the impressions sent to the lab or on prints, pictures or videos received from the dental office. In complex situations, the dental technician is also involved in certain clinical stages.

When the technician begins modeling the artificial teeth, he must have precise information on their size, shape and position. How does he get these details ?

• Remaining teeth

  Generally, it is advisable that artificial teeth resemble (in shape and size) the other teeth (it is unsightly when teeth have a disproportionate size) and they must keep the normal line of the dental arch.

• Homologous teeth

  It is generally advisable that an artificial tooth should resemble its homologous tooth. Example :

  A dental crown on the second left lower premolar is designed. After preparation, the dentist makes an impression that captures the entire lower arch.

  The technician should shape the crown in a way to resemble the second right lower premolar (if this tooth is not missing and does not show advanced destructions).

  

  
  

• Preliminary or case study impressions

  These impressions show the shape and size of teeth before the preparation. They are particularly important when aesthetic demands are high and the restoration is constructed in a visible area. Example :

  A dental crown on a central incisor is designed. Before the preparation, the practitioner makes a preliminary (or case study) impression. This impression captures the normal shape and size of the incisor (assuming the incisor does not show advanced coronal destructions).

  In this situation, the technician will receive two impressions : the case study impression (made before the preparation) and the impression made after the preparation. Consequently, he will fabricate two dental casts.

  
  

  

  dental cast before teeth preparation

  

  dental cast after teeth preparation

  
  

  The technician will try to model the artificial incisor based on the shape and size of the natural incisor that was captured on the preliminary impression. This technique works only if prior to the preparation, the incisor is structurally sound, and the shape, size and position are not disturbed.

• Pictures or films

  If they exist, the dental technician can receive some pictures or videos with the patient's teeth before preparation or with the desired outcome.

The accuracy of the reproduction will be checked at the dental office during the restoration final fitting appointment. As mentioned, the dental technician can also participate at this stage when the clinical case demands it.

Temporary crowns

The session ends with the execution of the temporary restoration. In most of the cases, one or more temporary crowns are constructed.

temporary crown

The crown can be manufactured at the dental office (direct method) or at the dental laboratory after an impression made by the dentist (indirect method). Either way the temporary crowns are cemented on the abutment teeth using a soft temporary dental cement.

Precautions between appointments

• To protect as much as possible the part with the prepared teeth
• To avoid eating very cold or very hot meals
• To maintain a rigorous oral hygiene