When the ceramic crowns of patients fracture and debond, this is often because they were subject to endodontic treatment, and the tooth was overprepped, especially the distal. If existing prep has insufficient resistance or retention form, it might be necessary for the dentist to recreate a portion of the tooth’s structure which has been lost.
How To Deal With Overprepped Teeth
The dentist will first want to “dust” the axial walls through the usage of a diamond bur. This will allow some of the core occlusal buildup to be removed, perhaps a millimeter or so. It can be tough to create engagement between the Tofflemire band and tooth, since there may be nothing to grab onto, particularly if previous dentists transformed the tooth into a teepee. The band will tend to slip off as it tightens.
However, by using older crown forms, you can etch and bond using a Scotchbond universal, warm up a bit of bulk composite in heated water and then fill the endo access portion of the tooth as well as the crown. Afterwards, the dentist can “smash” the former which is filled with composite on the tooth and then utilize the explorer for the removal of excess material. Then a curing light can be used to cure each side.
Working With The Tooth’s Core Form
Once the core former is removed, the dentist will be left with a core that is overbuilt. But the good news is that now you can do what is needed in regards to prep recreation through the usage of a superior axial parallelism. The tooth must now be re-prepped so a fresh crown (gold or ceramic), can be installed. Gold crowns have the advantage of being more conservative when it comes to prep, and once the prepping is completed the buildup must once again be cured using the curing light.
After prepping is complete the dentist should be able to see the location where composite buildup has occurred, especially in the axial region. Because of tooth angulation, it can be challenging to visualize whether you have sufficient occlusal reduction, so one solution is to create bite registration using Blue-Mousse along with a caliper so that indirect measurements can be taken and the dentist can verify sufficient clearance. Once the dentist is satisfied, he can utilize a diamond to square up and smooth the tooth’s marginal and distal proximal ridge.
One last Impregum impression should be taken, along with an alginate so that the dentist can produce a temporary impression (unless an original crown is available). Once the alginate impression is complete, the dentist can use a number eight round bur that is slow speed and carve the alginate out so that a negative can be made of the temporary crown. Then Luxatemp can be used to seat it inside the patient’s mouth. A small amount of flowable may be necessary to fill up some of the blanks, and then a flame diamond (high speed) can be used for hand carving so that it resembles a tooth.