An Appropriate Post
A 79-year-old lady chips her front tooth a week before hip surgery (Fig.1*). She wants to fix it immediately, because she cannot smile. The chip is severe. Most of the tooth is gone (Fig.2 arrowheads). To fix the chip, a post and crown are needed. First, a space is created (Fig.3 S) after removal of part of root canal filling (compare to R in Fig.2). The size and length of the space for the post are critical. If the space is too short or small, the post may easily come out. The other way (too long or too big) is also bad. The top portion of root canal filling should be untouched to prevent re-infection. This decides the length of the space. If the space is made too big (Fig.4 black lines), it weakens the root and increases the chance of root fracture during chewing (Fig.5 red lines, as compared to Fig.2 red arrowheads: crown fracture).
With the appropriate post space created, the post (Fig.6 P) is cemented (C, white material). Composite (resin, white filling material) is built up around the sticking-out portion of the post as a core (Fig.7 C) so that a temporary crown (Fig.8 T) can attach to the core and tightly stays in the mouth after cementation. A few days later before hip surgery, a permanent crown is seated. She smiles like a Hollywood movie star. We wish her having a successful hip surgery. If she can return for further dental care after hip surgery, we will take photos to show her big smile.
This procedure takes two appointments to finish. The post used is called preformed. If the fractured tooth is wider and chip is larger than this case, a cast post may be required. It will take three appointments to finish (including cementation of the permanent crown).
Xin Wei, DDS, PhD, MS 1st edition 05/16/2012, last revision 05/23/2012