With the advent of highly biocompatible titanium implants, implant therapy has been considered as a predictable dental treatment in recent years. However, there have been reports on poor prognosis of implant cases. Although most of these reports are related to peri-implantitis or paresthesia, there are some reports on titanium allergy cases. We have experienced one case of metal allergy ; this report presents a patient who developed oral lichen planus after implant placement.
The patient was a 56-year-old female with no significant past medical or dental history. She came to our clinic in January 2012 with a chief complaint of a mobile right mandibular molar. The second molar was extracted due to a root fracture. Her pre-operative blood tests did not show any abnormality other than a slightly elevated cholesterol level. One implant was placed at the site in June. After the surgery, she started to complain of mild spontaneous pain on the bilateral posterior buccal mucosa. We decided to watch the condition and wait. Then we observed lacy white patches on both sides of the posterior buccal mucosa at the time of re-entry in September. In October, a provisional restoration was set in her mouth. Since the symptoms did not improve, a histopathological examination was performed in February 2013 and a definitive diagnosis of oral lichen planus was made.
Even though the metal allergy was suspected as a cause of her oral lichen planus, it had been very difficult to diagnose her metal allergy before the implant surgery as there were already many metal restorations placed in her mouth. Therefore, we believe that it is necessary to consider the possibility of metal allergy before initiating implant therapy and it is advisable to add the metal allergy test to the set of pre-operative examinations such as systemic blood screening tests.