Regenerative Endodontics Using Different Intracanal Medicaments on Radiographic Outcomes and Periapical MMP-8 Levels

Calcium hydroxide (Merck, Darmstadt, Germany): prepared by mixing with sterile distilled water and then placed in the coronal 1/3 of the root canals.

Double antibiotic paste (DAP): metronidazole (Flagyl, Sanofi-Aventis, Turkey) and ciprofloxacin (Cipro, Biofarma, Turkey) powdered antibiotics were stored and sealed in airtight containers. The same amount of each drug powder (1:1) was mixed and the mixed samples were combined with sterile distilled water to form an ointment. DAP was introduced in roots canals using a lentulo to fill the entire root canal space.

Post-operative periapical radiographs were obtained with Digora Optime SPP system (Soredex Corp., Tuusula, Finland) using intraoral film holders to keep the plates parallel to the long axis of the teeth. A size #2 SPP was used for all exposures. SPPs were exposed with a Gendex Oralix DC dental x-ray unit (Gendex Dental Systems, Milan, Italy) operating at 60 kVp, 7 mA, 0.25 sec. and the plates were scanned immediately after exposure. The clinical and radiographical follow up was performed on 12th months. Image-J program (version 1.47, National Institutes of Health, Bethesda, MD) with TurboReg plug-in (Biomedical Imaging Group, Swiss Federal Institute of Technology, Lausanne, Switzerland) was used to determine the increase in root length, root width, and radiographic root area at 12th month follow up.

Periapical exudate samples were collected at the beginning of the RET and at 14th day. MMP-8 levels were measured by immunofluorometric assay (IFMA). Briefly, two monoclonal MMP-8-specific antibodies, 8708 and 8706 (Oy Medix Biochemica Ab, Espoo, Finland) were used as catching antibody and tracer antibody, respectively. Samples were diluted in enzyme buffer (50 mM Tris-HCl, pH 7.5; 0.2 mM NaCl, 1 mM CaCl2). Twenty microlitres of samples and 80 μl of assay buffer (20 mM Tris-HCl, pH 7.5, 0.5 M NaCl, 5 mM CaCl2, 0.5% BSA, 0.05% sodium azide and 20 mg/l diethylenetriaminepentaacetic acid with 2 μg/ml normal mouse serum) were pipetted into the wells. The tracer antibody was labelled using europium chelate. After adding the enhancement solution, fluorescence was measured using a 1234 Delfia Research Fluorometer (Wallac, Turku, Finland).