Braces for fillings are usually recommended after root canal treatment. After root canal treatment, the tooth will become more brittle without nerve and blood nourishment, and will not be able to withstand excessive biting pressure, which will easily cause the crown or even the root to fracture when biting on hard objects. Therefore, after root canal treatment, the dead pulp tooth needs to be protected by a porcelain crown or all-porcelain crown on the upper part of the tooth to enable the tooth to withstand greater occlusal stress and to enable the tooth to last longer in the mouth. All-porcelain crowns are usually recommended because they do not contain metal and will not interfere with cranial MRI examinations, nor will they produce the precipitation and release of metal ions that can have adverse effects on the body.