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).