 |
 |
 |
    |
 |
     |
|
 |
| |
| |
 |
| |
|
|
|
|
| |
|
|
|
 |
The tooth is prepared prior to the pattern fabrication. A heated endodontic condensor is used to safely remove the gutta percha (this is best accomplished at the same time the endodontic therapy is rendered). Gates & Parapost drills are used to shape the canals to an appropriate size and depth. The most common sizes used are Brown Yellow and Red (see the table below). |
|
|
|
 |
The minimum length of the post is equal to the length of the clinical crown. The recommended length is two-thirds the length of the root in bone while maintaining 5 mm of gutta-percha at the apex. Remember chances of a perforation increase as the length of the post approaches the apex of the tooth. |
|
|
|
|
The prefabricated posts are inserted into the canals. In this case a precious metal post is being used in the lingual canal because the canal diameter is only equivalent to a brown sized Parapost (Gates #3 - see table). The precious metal posts are issued from the Dispensing Window, and require an additional fee.
Gates Drills |
Parapost Drills |
#3 |
Brown |
#4 |
Yellow |
#5 |
Red |
#6 |
Black |
(Pesso Reamers are not recommended in the preparation of teeth for post & cores). |
|
|
|
 |
An assistant holds the Duralay powder, liquid, and suction - while the core portion is made in resin. First lubricate the remaining tooth structure with a water soluble lubricant (Surgilube) then apply the resin. The assistant may move the suction near the resin, evaporating monomer from its surface, thus preventing the resin from slumping or running. |
|
|
|
 |
The completed resin core is allowed to polymerize - then it is prepared to the shape of an ideal crown preparation. |
|
|
|
 |
Using conventional diamond instruments, water and suction, the resin core is prepared in the same manner as a conventional preparation. |
|
|
|
 |
The preparation is completed to ideal form and in this case its path of insertion is aligned with the preparation of tooth #11. |
|
|
|
 |
The completed post & core pattern is submitted to the Service Laboratory for investing & casting in gold alloy. |
|
|
|
 |
The casting is cleaned and sandblasted with alumina oxide in preparation for try-in, shaping, and cementation. The canals are dried and the casting inserted using light pressure. Small shiny marks on the casting surface help indicate where adjustment should be made. |
|
|
|
 |
Once seated, the surface is "machined" or prepared with diamond instruments to finalize preparation margins and blend the post & core with the tooth surface. It is advisable an assistant hold the post with an instrument to prevent it dislodging during preparation - high speed suction may also be held near the area to evacuate debris. |
|
|
|
 |
The completed post is cemented using a Jiffy tube to inject cement into the canals which have been dried with Endodontic paper points. |
|
|
|
Back to Top
|
|
|
|
|
|
|
|
|
