2. MATERIALS AND METHODS
A 23-year-old male dental student was referred to the Department of Endodontics, Faculty of Dentistry, Tanta University. The patient had no significant medical history. His chief complaint was pain associated with biting in the maxillary right central incisor. There was a Class III composite restoration in the mesiolabial aspect and superficial longitudinal crack in the labial wall of the crown. Transillumination showed a labial crack line (Figure 1) and cold test caused exacerbation of severe pain that remained after the removal of the stimulus. Gingival tissues were inflamed and there was painful responsive to vertical percussion. However, radiographic examination showed radiolucency in the periapical region and the lamina dura was slightly widened.
The case was diagnosed as irreversible pulp inflammation and the treatment plan involved RCT with management of the cracked crown using simvastatin. Details of the case and the treatment plan were discussed with the patient. He signed an informing consent for using simvastatin with the acknowledge of his understanding that this material will be used as intra-canal medication and it was not previously used for this purpose. The patient agreed and permitted the publication of the case report.
After local infiltration anesthesia of 2% lidocaine and 1:100,000 epinephrine (Lidocaine, Alex Pharma, Egypt), the tooth was isolated with rubber dam and endodontic access was prepared following the conventional guidelines. A superficial crack was observed from the access preparation in labial wall that extended toward the incisal edge (Figure 2).
The working length was established with apex locator (Root ZX, J. Morita Corp., Tokyo, Japan) at 1 mm from the radiographic apex. The canal was prepared with ProTaper Universal (Dentsply-maillefer, Ballaigues, Germany) files up to F4 using 2.5% sodium hypochlorite (NaOCl) as irrigating solution during instrumentation, and 17% ethylene diamine tetra acetic acid (EDTA) (META Biomed Co, Korea) as final irrigation to remove the smear layer. Apical patency was kept with a #10 file and the canal was rinsed with normal saline and dried with paper points. Calcium hydroxide medicament (META Biomed. Co, Korea) was placed into the canal and the coronal cavity was provisionally sealed with a temporary filling material (Cavitâ„¢ G, 3M ESPE, Germany).
The patient was recalled after one week for removal of calcium hydroxide intra-canal medication. He showed pain with filing at the coronal third of the labial wall. In spite of several trials of cleaning, the labial wall of canal preparation appeared dark, sensitive and rough. After removal of calcium hydroxide, simvastatin was use as intra-canal medicament (rest-treatment). Three parts of simvastatin powder (Simvastatin_99 %, HPLC, solid, Abcam) was mixed with one part of distilled water with a sterile metal spatula on a paper pad. When the mixture exhibited a thick creamy consistency, it was immediately carried on the master cone and inserted into the canal. The coronal cavity was then filled with Cavitâ„¢ and occlusal reduction was performed for elimination of occlusal contacts to avoid any overload or possibility of splitting the cracked tooth. The patient was kept at rest-treatment for 3 months. Following that, simvastatin medication was completely removed, and the canal was freshly cleaned as previously mentioned. The canal was then filled with gutta-percha and AH-26 sealer (Dentsply, DeTrey, GmbH, Konstanz, Germany) using lateral condensation technique. A restorative glass ionomer filling (Prima Dental, GL2 2HA, UK) was immediately used to seal the coronal preparation (Figure 3).